Add m-esr52 at 52.6.0

7 files changed, 3671 insertions, 0 deletions

diff --git a/nsprpub/pr/src/threads/combined/Makefile.in b/nsprpub/pr/src/threads/combined/Makefile.in
new file mode 100644
index 000000000..14b9eac00
--- /dev/null
+++ b/nsprpub/pr/src/threads/combined/Makefile.in
@@ -0,0 +1,40 @@
+# 
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+#! gmake
+
+MOD_DEPTH	= ../../../..
+topsrcdir	= @top_srcdir@
+srcdir		= @srcdir@
+VPATH		= @srcdir@
+
+include $(MOD_DEPTH)/config/autoconf.mk
+
+include $(topsrcdir)/config/config.mk
+
+ifdef USE_PTHREADS
+CSRCS =         \
+	$(NULL)
+else
+CSRCS =         \
+    prucpu.c      \
+	prucv.c      \
+	prulock.c    \
+	pruthr.c     \
+    prustack.c    \
+	$(NULL)
+endif
+
+TARGETS	= $(OBJS)
+
+INCLUDES = -I$(dist_includedir) -I$(topsrcdir)/pr/include -I$(topsrcdir)/pr/include/private
+
+DEFINES	+= -D_NSPR_BUILD_
+
+include $(topsrcdir)/config/rules.mk
+
+export:: $(TARGETS)
+
diff --git a/nsprpub/pr/src/threads/combined/README b/nsprpub/pr/src/threads/combined/README
new file mode 100644
index 000000000..aa2666528
--- /dev/null
+++ b/nsprpub/pr/src/threads/combined/README
@@ -0,0 +1,62 @@
+NSPR 2.0 evolution
+------------------
+
+
+Phase 1- today
+
+Currently (Oct 10, 1996) NSPR 2.0 has two modes.  Either _PR_NTHREAD 
+is defined, in which case the PR_CreateThread() call always creates a 
+native kernel thread, or _PR_NTHREAD is not defined and PR_CreateThread() 
+always creates user level threads within the single, original process.  This 
+source code is reflected in two directories, nspr20/pr/src/threads/native, and 
+nspr20/pr/src/threads/user.  Although the PR_CreateThread() function has
+a paramter to specify the "scope" of a thread, this parameter is not yet 
+used- except on solaris where it uses it to specify bound vs unbound threads.
+
+Phase 2 - next week
+
+The next step is to provide a combination of user and native threads.  The
+idea, of course, is to have some small number of native threads and each of 
+those threads be able to run user level threads.  The number of native
+threads created will most likely be proportional to the number of CPUs in
+the system.  For this reason, the specific set of native threads which are
+used to run the user-level threads will be called "CPU" threads.  
+
+The user level threads which will be run on the CPU threads are able to
+run on any of the CPU threads available, and over the course of a user-level
+thread's lifetime, it may drift from one CPU thread to another.  All 
+user-level threads will compete for processing time via a single run queue.
+
+Creation of a CPU thread will be primarily controlled by NSPR itself or by
+the user running a function PR_Concurrency().  The details of PR_Concurrency()
+have not yet been worked out; but the idea is that the user can specify to 
+NSPR how many CPU threads are desired.
+
+In this system, user-level threads are created by using PR_CreateThread() and
+specifying the PR_LOCAL_SCOPE option.  LOCAL_SCOPE indicates that the thread
+will be under the control of the "local" scheduler.  Creating threads with
+GLOBAL_SCOPE, on the other hand will create a thread which is under the 
+control of the system's scheduler.  In otherwords, this creates a native thread
+which is not a CPU thread; it runs a single thread task and never has more 
+than one task to run.  LOCAL_SCOPE is much like creating a Solaris unbound 
+thread, while GLOBAL_SCOPE is similar to creating a Solaris bound thread.
+
+To implement this architecture, the source code will still maintain the "user"
+and "native" directories which is has today.  However a third directory 
+"combined" will also exist.  To compile a version of NSPR which only creates
+native threads, the user can define _PR_NTHREAD.  For exclusive user-level
+threads, do not define _PR_NTHREAD.  To get the combined threads, define
+_PR_NTHREAD and _PR_USE_CPUS.
+
+
+Phase 3 - later than next week
+
+The goal is to eliminate the 3 directories.  Once these three models are in
+place, the remaining work will be to eliminate the native and user thread
+directories for all platforms, so that the entire thread model is contained
+within what is today called the "combined" model.  This new and glorious
+source code will attempt to make the "combined" model on any platforms which
+provide the necessary underlying native threading, but will also be 
+capable of using exclusive user-level threads on systems which don't have
+native threads.
+
diff --git a/nsprpub/pr/src/threads/combined/prucpu.c b/nsprpub/pr/src/threads/combined/prucpu.c
new file mode 100644
index 000000000..3913dc8de
--- /dev/null
+++ b/nsprpub/pr/src/threads/combined/prucpu.c
@@ -0,0 +1,405 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "primpl.h"
+
+_PRCPU *_pr_primordialCPU = NULL;
+
+PRInt32 _pr_md_idle_cpus;       /* number of idle cpus */
+/*
+ * The idle threads in MxN models increment/decrement _pr_md_idle_cpus.
+ * If _PR_HAVE_ATOMIC_OPS is not defined, they can't use the atomic
+ * increment/decrement routines (which are based on PR_Lock/PR_Unlock),
+ * because PR_Lock asserts that the calling thread is not an idle thread.
+ * So we use a _MDLock to protect _pr_md_idle_cpus.
+ */
+#if !defined(_PR_LOCAL_THREADS_ONLY) && !defined(_PR_GLOBAL_THREADS_ONLY)
+#ifndef _PR_HAVE_ATOMIC_OPS
+static _MDLock _pr_md_idle_cpus_lock;
+#endif
+#endif
+PRUintn _pr_numCPU;
+PRInt32 _pr_cpus_exit;
+PRUint32 _pr_cpu_affinity_mask = 0;
+
+#if !defined (_PR_GLOBAL_THREADS_ONLY)
+
+static PRUintn _pr_cpuID;
+
+static void PR_CALLBACK _PR_CPU_Idle(void *);
+
+static _PRCPU *_PR_CreateCPU(void);
+static PRStatus _PR_StartCPU(_PRCPU *cpu, PRThread *thread);
+
+#if !defined(_PR_LOCAL_THREADS_ONLY)
+static void _PR_RunCPU(void *arg);
+#endif
+
+void  _PR_InitCPUs()
+{
+    PRThread *me = _PR_MD_CURRENT_THREAD();
+
+    if (_native_threads_only)
+        return;
+
+    _pr_cpuID = 0;
+    _MD_NEW_LOCK( &_pr_cpuLock);
+#if !defined(_PR_LOCAL_THREADS_ONLY) && !defined(_PR_GLOBAL_THREADS_ONLY)
+#ifndef _PR_HAVE_ATOMIC_OPS
+    _MD_NEW_LOCK(&_pr_md_idle_cpus_lock);
+#endif
+#endif
+
+#ifdef _PR_LOCAL_THREADS_ONLY
+
+#ifdef HAVE_CUSTOM_USER_THREADS
+    _PR_MD_CREATE_PRIMORDIAL_USER_THREAD(me);
+#endif
+
+    /* Now start the first CPU. */
+    _pr_primordialCPU = _PR_CreateCPU();
+    _pr_numCPU = 1;
+    _PR_StartCPU(_pr_primordialCPU, me);
+
+    _PR_MD_SET_CURRENT_CPU(_pr_primordialCPU);
+
+    /* Initialize cpu for current thread (could be different from me) */
+    _PR_MD_CURRENT_THREAD()->cpu = _pr_primordialCPU;
+
+    _PR_MD_SET_LAST_THREAD(me);
+
+#else /* Combined MxN model */
+
+    _pr_primordialCPU = _PR_CreateCPU();
+    _pr_numCPU = 1;
+    _PR_CreateThread(PR_SYSTEM_THREAD,
+                     _PR_RunCPU,
+                     _pr_primordialCPU,
+                     PR_PRIORITY_NORMAL,
+                     PR_GLOBAL_THREAD,
+                     PR_UNJOINABLE_THREAD,
+                     0,
+                     _PR_IDLE_THREAD);
+
+#endif /* _PR_LOCAL_THREADS_ONLY */
+
+    _PR_MD_INIT_CPUS();
+}
+
+#ifdef WINNT
+/*
+ * Right now this function merely stops the CPUs and does
+ * not do any other cleanup.
+ *
+ * It is only implemented for WINNT because bug 161998 only
+ * affects the WINNT version of NSPR, but it would be nice
+ * to implement this function for other platforms too.
+ */
+void _PR_CleanupCPUs(void)
+{
+    PRUintn i;
+    PRCList *qp;
+    _PRCPU *cpu;
+
+    _pr_cpus_exit = 1;
+    for (i = 0; i < _pr_numCPU; i++) {
+        _PR_MD_WAKEUP_WAITER(NULL);
+    }
+    for (qp = _PR_CPUQ().next; qp != &_PR_CPUQ(); qp = qp->next) {
+        cpu = _PR_CPU_PTR(qp);
+        _PR_MD_JOIN_THREAD(&cpu->thread->md);
+    }
+}
+#endif
+
+static _PRCPUQueue *_PR_CreateCPUQueue(void)
+{
+    PRInt32 index;
+    _PRCPUQueue *cpuQueue;
+    cpuQueue = PR_NEWZAP(_PRCPUQueue);
+ 
+    _MD_NEW_LOCK( &cpuQueue->runQLock );
+    _MD_NEW_LOCK( &cpuQueue->sleepQLock );
+    _MD_NEW_LOCK( &cpuQueue->miscQLock );
+
+    for (index = 0; index < PR_ARRAY_SIZE(cpuQueue->runQ); index++)
+        PR_INIT_CLIST( &(cpuQueue->runQ[index]) );
+    PR_INIT_CLIST( &(cpuQueue->sleepQ) );
+    PR_INIT_CLIST( &(cpuQueue->pauseQ) );
+    PR_INIT_CLIST( &(cpuQueue->suspendQ) );
+    PR_INIT_CLIST( &(cpuQueue->waitingToJoinQ) );
+
+    cpuQueue->numCPUs = 1;
+
+    return cpuQueue;
+}
+
+/*
+ * Create a new CPU.
+ *
+ * This function initializes enough of the _PRCPU structure so
+ * that it can be accessed safely by a global thread or another
+ * CPU.  This function does not create the native thread that
+ * will run the CPU nor does it initialize the parts of _PRCPU
+ * that must be initialized by that native thread.
+ *
+ * The reason we cannot simply have the native thread create
+ * and fully initialize a new CPU is that we need to be able to
+ * create a usable _pr_primordialCPU in _PR_InitCPUs without
+ * assuming that the primordial CPU thread we created can run
+ * during NSPR initialization.  For example, on Windows while
+ * new threads can be created by DllMain, they won't be able
+ * to run during DLL initialization.  If NSPR is initialized
+ * by DllMain, the primordial CPU thread won't run until DLL
+ * initialization is finished.
+ */
+static _PRCPU *_PR_CreateCPU(void)
+{
+    _PRCPU *cpu;
+
+    cpu = PR_NEWZAP(_PRCPU);
+    if (cpu) {
+        cpu->queue = _PR_CreateCPUQueue();
+        if (!cpu->queue) {
+            PR_DELETE(cpu);
+            return NULL;
+        }
+    }
+    return cpu;
+}
+
+/*
+ * Start a new CPU.
+ *
+ * 'cpu' is a _PRCPU structure created by _PR_CreateCPU().
+ * 'thread' is the native thread that will run the CPU.
+ *
+ * If this function fails, 'cpu' is destroyed.
+ */
+static PRStatus _PR_StartCPU(_PRCPU *cpu, PRThread *thread)
+{
+    /*
+    ** Start a new cpu. The assumption this code makes is that the
+    ** underlying operating system creates a stack to go with the new
+    ** native thread. That stack will be used by the cpu when pausing.
+    */
+
+    PR_ASSERT(!_native_threads_only);
+
+    cpu->last_clock = PR_IntervalNow();
+
+    /* Before we create any threads on this CPU we have to
+     * set the current CPU 
+     */
+    _PR_MD_SET_CURRENT_CPU(cpu);
+    _PR_MD_INIT_RUNNING_CPU(cpu);
+    thread->cpu = cpu;
+
+    cpu->idle_thread = _PR_CreateThread(PR_SYSTEM_THREAD,
+                                        _PR_CPU_Idle,
+                                        (void *)cpu,
+                                        PR_PRIORITY_NORMAL,
+                                        PR_LOCAL_THREAD,
+                                        PR_UNJOINABLE_THREAD,
+                                        0,
+                                        _PR_IDLE_THREAD);
+
+    if (!cpu->idle_thread) {
+        /* didn't clean up CPU queue XXXMB */
+        PR_DELETE(cpu);
+        return PR_FAILURE;
+    } 
+    PR_ASSERT(cpu->idle_thread->cpu == cpu);
+
+    cpu->idle_thread->no_sched = 0;
+
+    cpu->thread = thread;
+
+    if (_pr_cpu_affinity_mask)
+        PR_SetThreadAffinityMask(thread, _pr_cpu_affinity_mask);
+
+    /* Created and started a new CPU */
+    _PR_CPU_LIST_LOCK();
+    cpu->id = _pr_cpuID++;
+    PR_APPEND_LINK(&cpu->links, &_PR_CPUQ());
+    _PR_CPU_LIST_UNLOCK();
+
+    return PR_SUCCESS;
+}
+
+#if !defined(_PR_GLOBAL_THREADS_ONLY) && !defined(_PR_LOCAL_THREADS_ONLY)
+/*
+** This code is used during a cpu's initial creation.
+*/
+static void _PR_RunCPU(void *arg)
+{
+    _PRCPU *cpu = (_PRCPU *)arg;
+    PRThread *me = _PR_MD_CURRENT_THREAD();
+
+    PR_ASSERT(NULL != me);
+
+    /*
+     * _PR_StartCPU calls _PR_CreateThread to create the
+     * idle thread.  Because _PR_CreateThread calls PR_Lock,
+     * the current thread has to remain a global thread
+     * during the _PR_StartCPU call so that it can wait for
+     * the lock if the lock is held by another thread.  If
+     * we clear the _PR_GLOBAL_SCOPE flag in
+     * _PR_MD_CREATE_PRIMORDIAL_THREAD, the current thread
+     * will be treated as a local thread and have trouble
+     * waiting for the lock because the CPU is not fully
+     * constructed yet.
+     *
+     * After the CPU is started, it is safe to mark the
+     * current thread as a local thread.
+     */
+
+#ifdef HAVE_CUSTOM_USER_THREADS
+    _PR_MD_CREATE_PRIMORDIAL_USER_THREAD(me);
+#endif
+
+    me->no_sched = 1;
+    _PR_StartCPU(cpu, me);
+
+#ifdef HAVE_CUSTOM_USER_THREADS
+    me->flags &= (~_PR_GLOBAL_SCOPE);
+#endif
+
+    _PR_MD_SET_CURRENT_CPU(cpu);
+    _PR_MD_SET_CURRENT_THREAD(cpu->thread);
+    me->cpu = cpu;
+
+    while(1) {
+        PRInt32 is;
+        if (!_PR_IS_NATIVE_THREAD(me)) _PR_INTSOFF(is);
+	    _PR_MD_START_INTERRUPTS();
+        _PR_MD_SWITCH_CONTEXT(me);
+    }
+}
+#endif
+
+static void PR_CALLBACK _PR_CPU_Idle(void *_cpu)
+{
+    _PRCPU *cpu = (_PRCPU *)_cpu;
+    PRThread *me = _PR_MD_CURRENT_THREAD();
+
+    PR_ASSERT(NULL != me);
+
+    me->cpu = cpu;
+    cpu->idle_thread = me;
+    if (_MD_LAST_THREAD())
+        _MD_LAST_THREAD()->no_sched = 0;
+    if (!_PR_IS_NATIVE_THREAD(me)) _PR_MD_SET_INTSOFF(0);
+    while(1) {
+        PRInt32 is;
+        PRIntervalTime timeout;
+        if (!_PR_IS_NATIVE_THREAD(me)) _PR_INTSOFF(is);
+
+        _PR_RUNQ_LOCK(cpu);
+#if !defined(_PR_LOCAL_THREADS_ONLY) && !defined(_PR_GLOBAL_THREADS_ONLY)
+#ifdef _PR_HAVE_ATOMIC_OPS
+        _PR_MD_ATOMIC_INCREMENT(&_pr_md_idle_cpus);
+#else
+        _PR_MD_LOCK(&_pr_md_idle_cpus_lock);
+        _pr_md_idle_cpus++;
+        _PR_MD_UNLOCK(&_pr_md_idle_cpus_lock);
+#endif /* _PR_HAVE_ATOMIC_OPS */
+#endif
+        /* If someone on runq; do a nonblocking PAUSECPU */
+        if (_PR_RUNQREADYMASK(me->cpu) != 0) {
+            _PR_RUNQ_UNLOCK(cpu);
+            timeout = PR_INTERVAL_NO_WAIT;
+        } else {
+            _PR_RUNQ_UNLOCK(cpu);
+
+            _PR_SLEEPQ_LOCK(cpu);
+            if (PR_CLIST_IS_EMPTY(&_PR_SLEEPQ(me->cpu))) {
+                timeout = PR_INTERVAL_NO_TIMEOUT;
+            } else {
+                PRThread *wakeThread;
+                wakeThread = _PR_THREAD_PTR(_PR_SLEEPQ(me->cpu).next);
+                timeout = wakeThread->sleep;
+            }
+            _PR_SLEEPQ_UNLOCK(cpu);
+        }
+
+        /* Wait for an IO to complete */
+        (void)_PR_MD_PAUSE_CPU(timeout);
+
+#ifdef WINNT
+        if (_pr_cpus_exit) {
+            /* _PR_CleanupCPUs tells us to exit */
+            _PR_MD_END_THREAD();
+        }
+#endif
+
+#if !defined(_PR_LOCAL_THREADS_ONLY) && !defined(_PR_GLOBAL_THREADS_ONLY)
+#ifdef _PR_HAVE_ATOMIC_OPS
+        _PR_MD_ATOMIC_DECREMENT(&_pr_md_idle_cpus);
+#else
+        _PR_MD_LOCK(&_pr_md_idle_cpus_lock);
+        _pr_md_idle_cpus--;
+        _PR_MD_UNLOCK(&_pr_md_idle_cpus_lock);
+#endif /* _PR_HAVE_ATOMIC_OPS */
+#endif
+
+		_PR_ClockInterrupt();
+
+		/* Now schedule any thread that is on the runq
+		 * INTS must be OFF when calling PR_Schedule()
+		 */
+		me->state = _PR_RUNNABLE;
+		_PR_MD_SWITCH_CONTEXT(me);
+		if (!_PR_IS_NATIVE_THREAD(me)) _PR_FAST_INTSON(is);
+    }
+}
+#endif /* _PR_GLOBAL_THREADS_ONLY */
+
+PR_IMPLEMENT(void) PR_SetConcurrency(PRUintn numCPUs)
+{
+#if defined(_PR_GLOBAL_THREADS_ONLY) || defined(_PR_LOCAL_THREADS_ONLY)
+
+    /* do nothing */
+
+#else /* combined, MxN thread model */
+
+    PRUintn newCPU;
+    _PRCPU *cpu;
+    PRThread *thr;
+
+
+    if (!_pr_initialized) _PR_ImplicitInitialization();
+
+	if (_native_threads_only)
+		return;
+    
+    _PR_CPU_LIST_LOCK();
+    if (_pr_numCPU < numCPUs) {
+        newCPU = numCPUs - _pr_numCPU;
+        _pr_numCPU = numCPUs;
+    } else newCPU = 0;
+    _PR_CPU_LIST_UNLOCK();
+
+    for (; newCPU; newCPU--) {
+        cpu = _PR_CreateCPU();
+        thr = _PR_CreateThread(PR_SYSTEM_THREAD,
+                              _PR_RunCPU,
+                              cpu,
+                              PR_PRIORITY_NORMAL,
+                              PR_GLOBAL_THREAD,
+                              PR_UNJOINABLE_THREAD,
+                              0,
+                              _PR_IDLE_THREAD);
+    }
+#endif
+}
+
+PR_IMPLEMENT(_PRCPU *) _PR_GetPrimordialCPU(void)
+{
+    if (_pr_primordialCPU)
+        return _pr_primordialCPU;
+    else
+        return _PR_MD_CURRENT_CPU();
+}
diff --git a/nsprpub/pr/src/threads/combined/prucv.c b/nsprpub/pr/src/threads/combined/prucv.c
new file mode 100644
index 000000000..d0bf4c422
--- /dev/null
+++ b/nsprpub/pr/src/threads/combined/prucv.c
@@ -0,0 +1,655 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+
+#include "primpl.h"
+#include "prinrval.h"
+#include "prtypes.h"
+
+#if defined(WIN95)
+/*
+** Some local variables report warnings on Win95 because the code paths 
+** using them are conditioned on HAVE_CUSTOME_USER_THREADS.
+** The pragma suppresses the warning.
+** 
+*/
+#pragma warning(disable : 4101)
+#endif
+
+
+/*
+** Notify one thread that it has finished waiting on a condition variable
+** Caller must hold the _PR_CVAR_LOCK(cv)
+*/
+PRBool _PR_NotifyThread (PRThread *thread, PRThread *me)
+{
+    PRBool rv;
+
+    PR_ASSERT(_PR_IS_NATIVE_THREAD(me) || _PR_MD_GET_INTSOFF() != 0);
+
+    _PR_THREAD_LOCK(thread);
+    PR_ASSERT(!(thread->flags & _PR_IDLE_THREAD));
+    if ( !_PR_IS_NATIVE_THREAD(thread) ) {
+        if (thread->wait.cvar != NULL) {
+            thread->wait.cvar = NULL;
+
+            _PR_SLEEPQ_LOCK(thread->cpu);
+            /* The notify and timeout can collide; in which case both may
+             * attempt to delete from the sleepQ; only let one do it.
+             */
+            if (thread->flags & (_PR_ON_SLEEPQ|_PR_ON_PAUSEQ))
+                _PR_DEL_SLEEPQ(thread, PR_TRUE);
+            _PR_SLEEPQ_UNLOCK(thread->cpu);
+
+	    if (thread->flags & _PR_SUSPENDING) {
+		/*
+		 * set thread state to SUSPENDED; a Resume operation
+		 * on the thread will move it to the runQ
+		 */
+            	thread->state = _PR_SUSPENDED;
+		_PR_MISCQ_LOCK(thread->cpu);
+		_PR_ADD_SUSPENDQ(thread, thread->cpu);
+		_PR_MISCQ_UNLOCK(thread->cpu);
+            	_PR_THREAD_UNLOCK(thread);
+	    } else {
+            	/* Make thread runnable */
+            	thread->state = _PR_RUNNABLE;
+            	_PR_THREAD_UNLOCK(thread);
+
+                _PR_AddThreadToRunQ(me, thread);
+                _PR_MD_WAKEUP_WAITER(thread);
+            }
+
+            rv = PR_TRUE;
+        } else {
+            /* Thread has already been notified */
+            _PR_THREAD_UNLOCK(thread);
+            rv = PR_FALSE;
+        }
+    } else { /* If the thread is a native thread */
+        if (thread->wait.cvar) {
+            thread->wait.cvar = NULL;
+
+	    if (thread->flags & _PR_SUSPENDING) {
+		/*
+		 * set thread state to SUSPENDED; a Resume operation
+		 * on the thread will enable the thread to run
+		 */
+            	thread->state = _PR_SUSPENDED;
+	     } else
+            	thread->state = _PR_RUNNING;
+            _PR_THREAD_UNLOCK(thread);
+            _PR_MD_WAKEUP_WAITER(thread);
+            rv = PR_TRUE;
+        } else {
+            _PR_THREAD_UNLOCK(thread);
+            rv = PR_FALSE;
+        }    
+    }    
+
+    return rv;
+}
+
+/*
+ * Notify thread waiting on cvar; called when thread is interrupted
+ * 	The thread lock is held on entry and released before return
+ */
+void _PR_NotifyLockedThread (PRThread *thread)
+{
+    PRThread *me = _PR_MD_CURRENT_THREAD();
+    PRCondVar *cvar;
+    PRThreadPriority pri;
+
+    if ( !_PR_IS_NATIVE_THREAD(me))
+    	PR_ASSERT(_PR_MD_GET_INTSOFF() != 0);
+
+    cvar = thread->wait.cvar;
+    thread->wait.cvar = NULL;
+    _PR_THREAD_UNLOCK(thread);
+
+    _PR_CVAR_LOCK(cvar);
+    _PR_THREAD_LOCK(thread);
+
+    if (!_PR_IS_NATIVE_THREAD(thread)) {
+            _PR_SLEEPQ_LOCK(thread->cpu);
+            /* The notify and timeout can collide; in which case both may
+             * attempt to delete from the sleepQ; only let one do it.
+             */
+            if (thread->flags & (_PR_ON_SLEEPQ|_PR_ON_PAUSEQ))
+                _PR_DEL_SLEEPQ(thread, PR_TRUE);
+            _PR_SLEEPQ_UNLOCK(thread->cpu);
+
+	    /* Make thread runnable */
+	    pri = thread->priority;
+	    thread->state = _PR_RUNNABLE;
+
+	    PR_ASSERT(!(thread->flags & _PR_IDLE_THREAD));
+
+            _PR_AddThreadToRunQ(me, thread);
+            _PR_THREAD_UNLOCK(thread);
+
+            _PR_MD_WAKEUP_WAITER(thread);
+    } else {
+	    if (thread->flags & _PR_SUSPENDING) {
+		/*
+		 * set thread state to SUSPENDED; a Resume operation
+		 * on the thread will enable the thread to run
+		 */
+            	thread->state = _PR_SUSPENDED;
+	     } else
+            	thread->state = _PR_RUNNING;
+            _PR_THREAD_UNLOCK(thread);
+            _PR_MD_WAKEUP_WAITER(thread);
+    }    
+
+    _PR_CVAR_UNLOCK(cvar);
+    return;
+}
+
+/*
+** Make the given thread wait for the given condition variable
+*/
+PRStatus _PR_WaitCondVar(
+    PRThread *thread, PRCondVar *cvar, PRLock *lock, PRIntervalTime timeout)
+{
+    PRIntn is;
+    PRStatus rv = PR_SUCCESS;
+
+    PR_ASSERT(thread == _PR_MD_CURRENT_THREAD());
+    PR_ASSERT(!(thread->flags & _PR_IDLE_THREAD));
+
+#ifdef _PR_GLOBAL_THREADS_ONLY
+    if (_PR_PENDING_INTERRUPT(thread)) {
+        PR_SetError(PR_PENDING_INTERRUPT_ERROR, 0);
+        thread->flags &= ~_PR_INTERRUPT;
+        return PR_FAILURE;
+    }
+
+    thread->wait.cvar = cvar;
+    lock->owner = NULL;
+    _PR_MD_WAIT_CV(&cvar->md,&lock->ilock, timeout);
+    thread->wait.cvar = NULL;
+    lock->owner = thread;
+    if (_PR_PENDING_INTERRUPT(thread)) {
+        PR_SetError(PR_PENDING_INTERRUPT_ERROR, 0);
+        thread->flags &= ~_PR_INTERRUPT;
+        return PR_FAILURE;
+    }
+
+    return PR_SUCCESS;
+#else  /* _PR_GLOBAL_THREADS_ONLY */
+
+    if ( !_PR_IS_NATIVE_THREAD(thread))
+    	_PR_INTSOFF(is);
+
+    _PR_CVAR_LOCK(cvar);
+    _PR_THREAD_LOCK(thread);
+
+    if (_PR_PENDING_INTERRUPT(thread)) {
+        PR_SetError(PR_PENDING_INTERRUPT_ERROR, 0);
+        thread->flags &= ~_PR_INTERRUPT;
+    	_PR_CVAR_UNLOCK(cvar);
+    	_PR_THREAD_UNLOCK(thread);
+    	if ( !_PR_IS_NATIVE_THREAD(thread))
+    		_PR_INTSON(is);
+        return PR_FAILURE;
+    }
+
+    thread->state = _PR_COND_WAIT;
+    thread->wait.cvar = cvar;
+
+    /*
+    ** Put the caller thread on the condition variable's wait Q
+    */
+    PR_APPEND_LINK(&thread->waitQLinks, &cvar->condQ);
+
+    /* Note- for global scope threads, we don't put them on the
+     *       global sleepQ, so each global thread must put itself
+     *       to sleep only for the time it wants to.
+     */
+    if ( !_PR_IS_NATIVE_THREAD(thread) ) {
+        _PR_SLEEPQ_LOCK(thread->cpu);
+        _PR_ADD_SLEEPQ(thread, timeout);
+        _PR_SLEEPQ_UNLOCK(thread->cpu);
+    }
+    _PR_CVAR_UNLOCK(cvar);
+    _PR_THREAD_UNLOCK(thread);
+   
+    /* 
+    ** Release lock protecting the condition variable and thereby giving time 
+    ** to the next thread which can potentially notify on the condition variable
+    */
+    PR_Unlock(lock);
+
+    PR_LOG(_pr_cvar_lm, PR_LOG_MIN,
+	   ("PR_Wait: cvar=%p waiting for %d", cvar, timeout));
+
+    rv = _PR_MD_WAIT(thread, timeout);
+
+    _PR_CVAR_LOCK(cvar);
+    PR_REMOVE_LINK(&thread->waitQLinks);
+    _PR_CVAR_UNLOCK(cvar);
+
+    PR_LOG(_pr_cvar_lm, PR_LOG_MIN,
+	   ("PR_Wait: cvar=%p done waiting", cvar));
+
+    if ( !_PR_IS_NATIVE_THREAD(thread))
+    	_PR_INTSON(is);
+
+    /* Acquire lock again that we had just relinquished */
+    PR_Lock(lock);
+
+    if (_PR_PENDING_INTERRUPT(thread)) {
+        PR_SetError(PR_PENDING_INTERRUPT_ERROR, 0);
+        thread->flags &= ~_PR_INTERRUPT;
+        return PR_FAILURE;
+    }
+
+    return rv;
+#endif  /* _PR_GLOBAL_THREADS_ONLY */
+}
+
+void _PR_NotifyCondVar(PRCondVar *cvar, PRThread *me)
+{
+#ifdef _PR_GLOBAL_THREADS_ONLY
+    _PR_MD_NOTIFY_CV(&cvar->md, &cvar->lock->ilock);
+#else  /* _PR_GLOBAL_THREADS_ONLY */
+
+    PRCList *q;
+    PRIntn is;
+
+    if ( !_PR_IS_NATIVE_THREAD(me))
+    	_PR_INTSOFF(is);
+    PR_ASSERT(_PR_IS_NATIVE_THREAD(me) || _PR_MD_GET_INTSOFF() != 0);
+
+    _PR_CVAR_LOCK(cvar);
+    q = cvar->condQ.next;
+    while (q != &cvar->condQ) {
+        PR_LOG(_pr_cvar_lm, PR_LOG_MIN, ("_PR_NotifyCondVar: cvar=%p", cvar));
+        if (_PR_THREAD_CONDQ_PTR(q)->wait.cvar)  {
+            if (_PR_NotifyThread(_PR_THREAD_CONDQ_PTR(q), me) == PR_TRUE)
+                break;
+        }
+        q = q->next;
+    }
+    _PR_CVAR_UNLOCK(cvar);
+
+    if ( !_PR_IS_NATIVE_THREAD(me))
+    	_PR_INTSON(is);
+
+#endif  /* _PR_GLOBAL_THREADS_ONLY */
+}
+
+/*
+** Cndition variable debugging log info.
+*/
+PRUint32 _PR_CondVarToString(PRCondVar *cvar, char *buf, PRUint32 buflen)
+{
+    PRUint32 nb;
+
+    if (cvar->lock->owner) {
+	nb = PR_snprintf(buf, buflen, "[%p] owner=%ld[%p]",
+			 cvar, cvar->lock->owner->id, cvar->lock->owner);
+    } else {
+	nb = PR_snprintf(buf, buflen, "[%p]", cvar);
+    }
+    return nb;
+}
+
+/*
+** Expire condition variable waits that are ready to expire. "now" is the current
+** time.
+*/
+void _PR_ClockInterrupt(void)
+{
+    PRThread *thread, *me = _PR_MD_CURRENT_THREAD();
+    _PRCPU *cpu = me->cpu;
+    PRIntervalTime elapsed, now;
+ 
+    PR_ASSERT(_PR_MD_GET_INTSOFF() != 0);
+    /* Figure out how much time elapsed since the last clock tick */
+    now = PR_IntervalNow();
+    elapsed = now - cpu->last_clock;
+    cpu->last_clock = now;
+
+    PR_LOG(_pr_clock_lm, PR_LOG_MAX,
+	   ("ExpireWaits: elapsed=%lld usec", elapsed));
+
+    while(1) {
+        _PR_SLEEPQ_LOCK(cpu);
+        if (_PR_SLEEPQ(cpu).next == &_PR_SLEEPQ(cpu)) {
+            _PR_SLEEPQ_UNLOCK(cpu);
+            break;
+        }
+
+        thread = _PR_THREAD_PTR(_PR_SLEEPQ(cpu).next);
+        PR_ASSERT(thread->cpu == cpu);
+
+        if (elapsed < thread->sleep) {
+            thread->sleep -= elapsed;
+            _PR_SLEEPQMAX(thread->cpu) -= elapsed;
+            _PR_SLEEPQ_UNLOCK(cpu);
+            break;
+        }
+        _PR_SLEEPQ_UNLOCK(cpu);
+
+        PR_ASSERT(!_PR_IS_NATIVE_THREAD(thread));
+
+        _PR_THREAD_LOCK(thread);
+
+        if (thread->cpu != cpu) {
+            /*
+            ** The thread was switched to another CPU
+            ** between the time we unlocked the sleep
+            ** queue and the time we acquired the thread
+            ** lock, so it is none of our business now.
+            */
+            _PR_THREAD_UNLOCK(thread);
+            continue;
+        }
+
+        /*
+        ** Consume this sleeper's amount of elapsed time from the elapsed
+        ** time value. The next remaining piece of elapsed time will be
+        ** available for the next sleeping thread's timer.
+        */
+        _PR_SLEEPQ_LOCK(cpu);
+        PR_ASSERT(!(thread->flags & _PR_ON_PAUSEQ));
+        if (thread->flags & _PR_ON_SLEEPQ) {
+            _PR_DEL_SLEEPQ(thread, PR_FALSE);
+            elapsed -= thread->sleep;
+            _PR_SLEEPQ_UNLOCK(cpu);
+        } else {
+            /* Thread was already handled; Go get another one */
+            _PR_SLEEPQ_UNLOCK(cpu);
+            _PR_THREAD_UNLOCK(thread);
+            continue;
+        }
+
+        /* Notify the thread waiting on the condition variable */
+        if (thread->flags & _PR_SUSPENDING) {
+		PR_ASSERT((thread->state == _PR_IO_WAIT) ||
+				(thread->state == _PR_COND_WAIT));
+            /*
+            ** Thread is suspended and its condition timeout
+            ** expired. Transfer thread from sleepQ to suspendQ.
+            */
+            thread->wait.cvar = NULL;
+            _PR_MISCQ_LOCK(cpu);
+            thread->state = _PR_SUSPENDED;
+            _PR_ADD_SUSPENDQ(thread, cpu);
+            _PR_MISCQ_UNLOCK(cpu);
+        } else {
+            if (thread->wait.cvar) {
+                PRThreadPriority pri;
+
+                /* Do work very similar to what _PR_NotifyThread does */
+                PR_ASSERT( !_PR_IS_NATIVE_THREAD(thread) );
+
+                /* Make thread runnable */
+                pri = thread->priority;
+                thread->state = _PR_RUNNABLE;
+                PR_ASSERT(!(thread->flags & _PR_IDLE_THREAD));
+
+                PR_ASSERT(thread->cpu == cpu);
+                _PR_RUNQ_LOCK(cpu);
+                _PR_ADD_RUNQ(thread, cpu, pri);
+                _PR_RUNQ_UNLOCK(cpu);
+
+                if (pri > me->priority)
+                    _PR_SET_RESCHED_FLAG();
+
+                thread->wait.cvar = NULL;
+
+                _PR_MD_WAKEUP_WAITER(thread);
+
+            } else if (thread->io_pending == PR_TRUE) {
+                /* Need to put IO sleeper back on runq */
+                int pri = thread->priority;
+
+                thread->io_suspended = PR_TRUE;
+#ifdef WINNT
+				/*
+				 * For NT, record the cpu on which I/O was issued
+				 * I/O cancellation is done on the same cpu
+				 */
+                thread->md.thr_bound_cpu = cpu;
+#endif
+
+				PR_ASSERT(!(thread->flags & _PR_IDLE_THREAD));
+                PR_ASSERT(thread->cpu == cpu);
+                thread->state = _PR_RUNNABLE;
+                _PR_RUNQ_LOCK(cpu);
+                _PR_ADD_RUNQ(thread, cpu, pri);
+                _PR_RUNQ_UNLOCK(cpu);
+            }
+        }
+        _PR_THREAD_UNLOCK(thread);
+    }
+}
+
+/************************************************************************/
+
+/*
+** Create a new condition variable.
+** 	"lock" is the lock to use with the condition variable.
+**
+** Condition variables are synchronization objects that threads can use
+** to wait for some condition to occur.
+**
+** This may fail if memory is tight or if some operating system resource
+** is low.
+*/
+PR_IMPLEMENT(PRCondVar*) PR_NewCondVar(PRLock *lock)
+{
+    PRCondVar *cvar;
+
+    cvar = PR_NEWZAP(PRCondVar);
+    if (cvar) {
+        if (_PR_InitCondVar(cvar, lock) != PR_SUCCESS) {
+            PR_DELETE(cvar);
+            return NULL;
+        }
+    } else {
+        PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
+    }
+    return cvar;
+}
+
+PRStatus _PR_InitCondVar(PRCondVar *cvar, PRLock *lock)
+{
+    PR_ASSERT(lock != NULL);
+
+#ifdef _PR_GLOBAL_THREADS_ONLY
+    if(_PR_MD_NEW_CV(&cvar->md)) {
+        PR_SetError(PR_INSUFFICIENT_RESOURCES_ERROR, 0);
+        return PR_FAILURE;
+    }
+#endif
+    if (_PR_MD_NEW_LOCK(&(cvar->ilock)) != PR_SUCCESS) {
+        PR_SetError(PR_INSUFFICIENT_RESOURCES_ERROR, 0);
+        return PR_FAILURE;
+    }
+    cvar->lock = lock;
+    PR_INIT_CLIST(&cvar->condQ);
+    return PR_SUCCESS;
+}
+
+/*
+** Destroy a condition variable. There must be no thread
+** waiting on the condvar. The caller is responsible for guaranteeing
+** that the condvar is no longer in use.
+**
+*/
+PR_IMPLEMENT(void) PR_DestroyCondVar(PRCondVar *cvar)
+{
+    _PR_FreeCondVar(cvar);
+    PR_DELETE(cvar);
+}
+
+void _PR_FreeCondVar(PRCondVar *cvar)
+{
+    PR_ASSERT(cvar->condQ.next == &cvar->condQ);
+
+#ifdef _PR_GLOBAL_THREADS_ONLY
+    _PR_MD_FREE_CV(&cvar->md);
+#endif
+    _PR_MD_FREE_LOCK(&(cvar->ilock));
+}
+
+/*
+** Wait for a notify on the condition variable. Sleep for "tiemout" amount
+** of ticks (if "timeout" is zero then the sleep is indefinite). While
+** the thread is waiting it unlocks lock. When the wait has
+** finished the thread regains control of the condition variable after
+** locking the associated lock.
+**
+** The thread waiting on the condvar will be resumed when the condvar is
+** notified (assuming the thread is the next in line to receive the
+** notify) or when the timeout elapses.
+**
+** Returns PR_FAILURE if the caller has not locked the lock associated
+** with the condition variable or the thread has been interrupted.
+*/
+extern PRThread *suspendAllThread;
+PR_IMPLEMENT(PRStatus) PR_WaitCondVar(PRCondVar *cvar, PRIntervalTime timeout)
+{
+    PRThread *me = _PR_MD_CURRENT_THREAD();
+
+	PR_ASSERT(cvar->lock->owner == me);
+	PR_ASSERT(me != suspendAllThread);
+    	if (cvar->lock->owner != me) return PR_FAILURE;
+
+	return _PR_WaitCondVar(me, cvar, cvar->lock, timeout);
+}
+
+/*
+** Notify the highest priority thread waiting on the condition
+** variable. If a thread is waiting on the condition variable (using
+** PR_Wait) then it is awakened and begins waiting on the lock.
+*/
+PR_IMPLEMENT(PRStatus) PR_NotifyCondVar(PRCondVar *cvar)
+{
+    PRThread *me = _PR_MD_CURRENT_THREAD();
+
+    PR_ASSERT(cvar->lock->owner == me);
+    PR_ASSERT(me != suspendAllThread);
+    if (cvar->lock->owner != me) return PR_FAILURE;
+
+    _PR_NotifyCondVar(cvar, me);
+    return PR_SUCCESS;
+}
+
+/*
+** Notify all of the threads waiting on the condition variable. All of
+** threads are notified in turn. The highest priority thread will
+** probably acquire the lock.
+*/
+PR_IMPLEMENT(PRStatus) PR_NotifyAllCondVar(PRCondVar *cvar)
+{
+    PRCList *q;
+    PRIntn is;
+    PRThread *me = _PR_MD_CURRENT_THREAD();
+
+    PR_ASSERT(cvar->lock->owner == me);
+    if (cvar->lock->owner != me) return PR_FAILURE;
+
+#ifdef _PR_GLOBAL_THREADS_ONLY
+    _PR_MD_NOTIFYALL_CV(&cvar->md, &cvar->lock->ilock);
+    return PR_SUCCESS;
+#else  /* _PR_GLOBAL_THREADS_ONLY */
+    if ( !_PR_IS_NATIVE_THREAD(me))
+    	_PR_INTSOFF(is);
+    _PR_CVAR_LOCK(cvar);
+    q = cvar->condQ.next;
+    while (q != &cvar->condQ) {
+		PR_LOG(_pr_cvar_lm, PR_LOG_MIN, ("PR_NotifyAll: cvar=%p", cvar));
+		_PR_NotifyThread(_PR_THREAD_CONDQ_PTR(q), me);
+		q = q->next;
+    }
+    _PR_CVAR_UNLOCK(cvar);
+    if (!_PR_IS_NATIVE_THREAD(me))
+    	_PR_INTSON(is);
+
+    return PR_SUCCESS;
+#endif  /* _PR_GLOBAL_THREADS_ONLY */
+}
+
+
+/*********************************************************************/
+/*********************************************************************/
+/********************ROUTINES FOR DCE EMULATION***********************/
+/*********************************************************************/
+/*********************************************************************/
+#include "prpdce.h"
+
+PR_IMPLEMENT(PRCondVar*) PRP_NewNakedCondVar(void)
+{
+    PRCondVar *cvar = PR_NEWZAP(PRCondVar);
+    if (NULL != cvar)
+    {
+        if (_PR_MD_NEW_LOCK(&(cvar->ilock)) == PR_FAILURE)
+        {
+		    PR_DELETE(cvar); cvar = NULL;
+	    }
+	    else
+	    {
+	        PR_INIT_CLIST(&cvar->condQ);
+            cvar->lock = _PR_NAKED_CV_LOCK;
+	    }
+
+    }
+    return cvar;
+}
+
+PR_IMPLEMENT(void) PRP_DestroyNakedCondVar(PRCondVar *cvar)
+{
+    PR_ASSERT(cvar->condQ.next == &cvar->condQ);
+    PR_ASSERT(_PR_NAKED_CV_LOCK == cvar->lock);
+
+    _PR_MD_FREE_LOCK(&(cvar->ilock));
+ 
+    PR_DELETE(cvar);
+}
+
+PR_IMPLEMENT(PRStatus) PRP_NakedWait(
+	PRCondVar *cvar, PRLock *lock, PRIntervalTime timeout)
+{
+    PRThread *me = _PR_MD_CURRENT_THREAD();
+    PR_ASSERT(_PR_NAKED_CV_LOCK == cvar->lock);
+	return _PR_WaitCondVar(me, cvar, lock, timeout);
+}  /* PRP_NakedWait */
+
+PR_IMPLEMENT(PRStatus) PRP_NakedNotify(PRCondVar *cvar)
+{
+    PRThread *me = _PR_MD_CURRENT_THREAD();
+    PR_ASSERT(_PR_NAKED_CV_LOCK == cvar->lock);
+
+    _PR_NotifyCondVar(cvar, me);
+
+    return PR_SUCCESS;
+}  /* PRP_NakedNotify */
+
+PR_IMPLEMENT(PRStatus) PRP_NakedBroadcast(PRCondVar *cvar)
+{
+    PRCList *q;
+    PRIntn is;
+    PRThread *me = _PR_MD_CURRENT_THREAD();
+    PR_ASSERT(_PR_NAKED_CV_LOCK == cvar->lock);
+
+    if ( !_PR_IS_NATIVE_THREAD(me)) _PR_INTSOFF(is);
+	_PR_MD_LOCK( &(cvar->ilock) );
+    q = cvar->condQ.next;
+    while (q != &cvar->condQ) {
+		PR_LOG(_pr_cvar_lm, PR_LOG_MIN, ("PR_NotifyAll: cvar=%p", cvar));
+		_PR_NotifyThread(_PR_THREAD_CONDQ_PTR(q), me);
+		q = q->next;
+    }
+	_PR_MD_UNLOCK( &(cvar->ilock) );
+    if (!_PR_IS_NATIVE_THREAD(me)) _PR_INTSON(is);
+
+    return PR_SUCCESS;
+}  /* PRP_NakedBroadcast */
+
diff --git a/nsprpub/pr/src/threads/combined/prulock.c b/nsprpub/pr/src/threads/combined/prulock.c
new file mode 100644
index 000000000..8b2f41eec
--- /dev/null
+++ b/nsprpub/pr/src/threads/combined/prulock.c
@@ -0,0 +1,446 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "primpl.h"
+
+#if defined(WIN95)
+/*
+** Some local variables report warnings on Win95 because the code paths 
+** using them are conditioned on HAVE_CUSTOME_USER_THREADS.
+** The pragma suppresses the warning.
+** 
+*/
+#pragma warning(disable : 4101)
+#endif
+
+
+void _PR_InitLocks(void)
+{
+	_PR_MD_INIT_LOCKS();
+}
+
+/*
+** Deal with delayed interrupts/requested reschedule during interrupt
+** re-enables.
+*/
+void _PR_IntsOn(_PRCPU *cpu)
+{
+    PRUintn missed, pri, i;
+    _PRInterruptTable *it;
+    PRThread *me;
+
+    PR_ASSERT(cpu);   /* Global threads don't have CPUs */
+    PR_ASSERT(_PR_MD_GET_INTSOFF() > 0);
+	me = _PR_MD_CURRENT_THREAD();
+    PR_ASSERT(!(me->flags & _PR_IDLE_THREAD));
+
+    /*
+    ** Process delayed interrupts. This logic is kinda scary because we
+    ** need to avoid losing an interrupt (it's ok to delay an interrupt
+    ** until later).
+    **
+    ** There are two missed state words. _pr_ints.where indicates to the
+    ** interrupt handler which state word is currently safe for
+    ** modification.
+    **
+    ** This code scans both interrupt state words, using the where flag
+    ** to indicate to the interrupt which state word is safe for writing.
+    ** If an interrupt comes in during a scan the other word will be
+    ** modified. This modification will be noticed during the next
+    ** iteration of the loop or during the next call to this routine.
+    */
+    for (i = 0; i < 2; i++) {
+        cpu->where = (1 - i);
+        missed = cpu->u.missed[i];
+        if (missed != 0) {
+            cpu->u.missed[i] = 0;
+            for (it = _pr_interruptTable; it->name; it++) {
+                if (missed & it->missed_bit) {
+                    PR_LOG(_pr_sched_lm, PR_LOG_MIN,
+                           ("IntsOn[0]: %s intr", it->name));
+                    (*it->handler)();
+                }
+            }
+        }
+    }
+
+    if (cpu->u.missed[3] != 0) {
+        _PRCPU *cpu;
+
+		_PR_THREAD_LOCK(me);
+        me->state = _PR_RUNNABLE;
+        pri = me->priority;
+
+        cpu = me->cpu;
+		_PR_RUNQ_LOCK(cpu);
+        _PR_ADD_RUNQ(me, cpu, pri);
+		_PR_RUNQ_UNLOCK(cpu);
+		_PR_THREAD_UNLOCK(me);
+        _PR_MD_SWITCH_CONTEXT(me);
+    }
+}
+
+/*
+** Unblock the first runnable waiting thread. Skip over
+** threads that are trying to be suspended
+** Note: Caller must hold _PR_LOCK_LOCK()
+*/
+void _PR_UnblockLockWaiter(PRLock *lock)
+{
+    PRThread *t = NULL;
+    PRThread *me;
+    PRCList *q;
+
+    q = lock->waitQ.next;
+    PR_ASSERT(q != &lock->waitQ);
+    while (q != &lock->waitQ) {
+        /* Unblock first waiter */
+        t = _PR_THREAD_CONDQ_PTR(q);
+
+		/* 
+		** We are about to change the thread's state to runnable and for local
+		** threads, we are going to assign a cpu to it.  So, protect thread's
+		** data structure.
+		*/
+        _PR_THREAD_LOCK(t);
+
+        if (t->flags & _PR_SUSPENDING) {
+            q = q->next;
+            _PR_THREAD_UNLOCK(t);
+            continue;
+        }
+
+        /* Found a runnable thread */
+	    PR_ASSERT(t->state == _PR_LOCK_WAIT);
+	    PR_ASSERT(t->wait.lock == lock);
+        t->wait.lock = 0;
+        PR_REMOVE_LINK(&t->waitQLinks);         /* take it off lock's waitQ */
+
+		/*
+		** If this is a native thread, nothing else to do except to wake it
+		** up by calling the machine dependent wakeup routine.
+		**
+		** If this is a local thread, we need to assign it a cpu and
+		** put the thread on that cpu's run queue.  There are two cases to
+		** take care of.  If the currently running thread is also a local
+		** thread, we just assign our own cpu to that thread and put it on
+		** the cpu's run queue.  If the the currently running thread is a
+		** native thread, we assign the primordial cpu to it (on NT,
+		** MD_WAKEUP handles the cpu assignment).  
+		*/
+		
+        if ( !_PR_IS_NATIVE_THREAD(t) ) {
+
+            t->state = _PR_RUNNABLE;
+
+            me = _PR_MD_CURRENT_THREAD();
+
+            _PR_AddThreadToRunQ(me, t);
+            _PR_THREAD_UNLOCK(t);
+        } else {
+            t->state = _PR_RUNNING;
+            _PR_THREAD_UNLOCK(t);
+        }
+        _PR_MD_WAKEUP_WAITER(t);
+        break;
+    }
+    return;
+}
+
+/************************************************************************/
+
+
+PR_IMPLEMENT(PRLock*) PR_NewLock(void)
+{
+    PRLock *lock;
+
+    if (!_pr_initialized) _PR_ImplicitInitialization();
+
+    lock = PR_NEWZAP(PRLock);
+    if (lock) {
+        if (_PR_InitLock(lock) != PR_SUCCESS) {
+            PR_DELETE(lock);
+            return NULL;
+        }
+    }
+    return lock;
+}
+
+PRStatus _PR_InitLock(PRLock *lock)
+{
+    if (_PR_MD_NEW_LOCK(&lock->ilock) != PR_SUCCESS) {
+        return PR_FAILURE;
+    }
+    PR_INIT_CLIST(&lock->links);
+    PR_INIT_CLIST(&lock->waitQ);
+    return PR_SUCCESS;
+}
+
+/*
+** Destroy the given lock "lock". There is no point in making this race
+** free because if some other thread has the pointer to this lock all
+** bets are off.
+*/
+PR_IMPLEMENT(void) PR_DestroyLock(PRLock *lock)
+{
+    _PR_FreeLock(lock);
+    PR_DELETE(lock);
+}
+
+void _PR_FreeLock(PRLock *lock)
+{
+    PR_ASSERT(lock->owner == 0);
+    _PR_MD_FREE_LOCK(&lock->ilock);
+}
+
+extern PRThread *suspendAllThread;
+/*
+** Lock the lock.
+*/
+PR_IMPLEMENT(void) PR_Lock(PRLock *lock)
+{
+    PRThread *me = _PR_MD_CURRENT_THREAD();
+    PRIntn is;
+    PRThread *t;
+    PRCList *q;
+
+    PR_ASSERT(me != suspendAllThread); 
+    PR_ASSERT(!(me->flags & _PR_IDLE_THREAD));
+    PR_ASSERT(lock != NULL);
+#ifdef _PR_GLOBAL_THREADS_ONLY 
+    _PR_MD_LOCK(&lock->ilock);
+    PR_ASSERT(lock->owner == 0);
+    lock->owner = me;
+    return;
+#else  /* _PR_GLOBAL_THREADS_ONLY */
+
+	if (_native_threads_only) {
+		_PR_MD_LOCK(&lock->ilock);
+		PR_ASSERT(lock->owner == 0);
+		lock->owner = me;
+		return;
+	}
+
+    if (!_PR_IS_NATIVE_THREAD(me))
+    	_PR_INTSOFF(is);
+
+    PR_ASSERT(_PR_IS_NATIVE_THREAD(me) || _PR_MD_GET_INTSOFF() != 0);
+
+retry:
+    _PR_LOCK_LOCK(lock);
+    if (lock->owner == 0) {
+        /* Just got the lock */
+        lock->owner = me;
+        lock->priority = me->priority;
+		/* Add the granted lock to this owning thread's lock list */
+        PR_APPEND_LINK(&lock->links, &me->lockList);
+        _PR_LOCK_UNLOCK(lock);
+    	if (!_PR_IS_NATIVE_THREAD(me))
+        	_PR_FAST_INTSON(is);
+        return;
+    }
+
+    /* If this thread already owns this lock, then it is a deadlock */
+    PR_ASSERT(lock->owner != me);
+
+    PR_ASSERT(_PR_IS_NATIVE_THREAD(me) || _PR_MD_GET_INTSOFF() != 0);
+
+#if 0
+    if (me->priority > lock->owner->priority) {
+        /*
+        ** Give the lock owner a priority boost until we get the
+        ** lock. Record the priority we boosted it to.
+        */
+        lock->boostPriority = me->priority;
+        _PR_SetThreadPriority(lock->owner, me->priority);
+    }
+#endif
+
+    /* 
+    Add this thread to the asked for lock's list of waiting threads.  We
+    add this thread thread in the right priority order so when the unlock
+    occurs, the thread with the higher priority will get the lock.
+    */
+    q = lock->waitQ.next;
+    if (q == &lock->waitQ || _PR_THREAD_CONDQ_PTR(q)->priority ==
+      	_PR_THREAD_CONDQ_PTR(lock->waitQ.prev)->priority) {
+		/*
+		 * If all the threads in the lock waitQ have the same priority,
+		 * then avoid scanning the list:  insert the element at the end.
+		 */
+		q = &lock->waitQ;
+    } else {
+		/* Sort thread into lock's waitQ at appropriate point */
+		/* Now scan the list for where to insert this entry */
+		while (q != &lock->waitQ) {
+			t = _PR_THREAD_CONDQ_PTR(lock->waitQ.next);
+			if (me->priority > t->priority) {
+				/* Found a lower priority thread to insert in front of */
+				break;
+			}
+			q = q->next;
+		}
+	}
+    PR_INSERT_BEFORE(&me->waitQLinks, q);
+
+	/* 
+	Now grab the threadLock since we are about to change the state.  We have
+	to do this since a PR_Suspend or PR_SetThreadPriority type call that takes
+	a PRThread* as an argument could be changing the state of this thread from
+	a thread running on a different cpu.
+	*/
+
+    _PR_THREAD_LOCK(me);
+    me->state = _PR_LOCK_WAIT;
+    me->wait.lock = lock;
+    _PR_THREAD_UNLOCK(me);
+
+    _PR_LOCK_UNLOCK(lock);
+
+    _PR_MD_WAIT(me, PR_INTERVAL_NO_TIMEOUT);
+	goto retry;
+
+#endif  /* _PR_GLOBAL_THREADS_ONLY */
+}
+
+/*
+** Unlock the lock.
+*/
+PR_IMPLEMENT(PRStatus) PR_Unlock(PRLock *lock)
+{
+    PRCList *q;
+    PRThreadPriority pri, boost;
+    PRIntn is;
+    PRThread *me = _PR_MD_CURRENT_THREAD();
+
+    PR_ASSERT(lock != NULL);
+    PR_ASSERT(lock->owner == me);
+    PR_ASSERT(me != suspendAllThread); 
+    PR_ASSERT(!(me->flags & _PR_IDLE_THREAD));
+    if (lock->owner != me) {
+        return PR_FAILURE;
+    }
+
+#ifdef _PR_GLOBAL_THREADS_ONLY 
+    lock->owner = 0;
+    _PR_MD_UNLOCK(&lock->ilock);
+    return PR_SUCCESS;
+#else  /* _PR_GLOBAL_THREADS_ONLY */
+
+	if (_native_threads_only) {
+		lock->owner = 0;
+		_PR_MD_UNLOCK(&lock->ilock);
+		return PR_SUCCESS;
+	}
+
+    if (!_PR_IS_NATIVE_THREAD(me))
+    	_PR_INTSOFF(is);
+    _PR_LOCK_LOCK(lock);
+
+	/* Remove the lock from the owning thread's lock list */
+    PR_REMOVE_LINK(&lock->links);
+    pri = lock->priority;
+    boost = lock->boostPriority;
+    if (boost > pri) {
+        /*
+        ** We received a priority boost during the time we held the lock.
+        ** We need to figure out what priority to move to by scanning
+        ** down our list of lock's that we are still holding and using
+        ** the highest boosted priority found.
+        */
+        q = me->lockList.next;
+        while (q != &me->lockList) {
+            PRLock *ll = _PR_LOCK_PTR(q);
+            if (ll->boostPriority > pri) {
+                pri = ll->boostPriority;
+            }
+            q = q->next;
+        }
+        if (pri != me->priority) {
+            _PR_SetThreadPriority(me, pri);
+        }
+    }
+
+    /* Unblock the first waiting thread */
+    q = lock->waitQ.next;
+    if (q != &lock->waitQ)
+        _PR_UnblockLockWaiter(lock);
+    lock->boostPriority = PR_PRIORITY_LOW;
+    lock->owner = 0;
+    _PR_LOCK_UNLOCK(lock);
+    if (!_PR_IS_NATIVE_THREAD(me))
+    	_PR_INTSON(is);
+    return PR_SUCCESS;
+#endif  /* _PR_GLOBAL_THREADS_ONLY */
+}
+
+/*
+**  If the current thread owns |lock|, this assertion is guaranteed to
+**  succeed.  Otherwise, the behavior of this function is undefined.
+*/
+PR_IMPLEMENT(void) PR_AssertCurrentThreadOwnsLock(PRLock *lock)
+{
+    PRThread *me = _PR_MD_CURRENT_THREAD();
+    PR_ASSERT(lock->owner == me);
+}
+
+/*
+** Test and then lock the lock if it's not already locked by some other
+** thread. Return PR_FALSE if some other thread owned the lock at the
+** time of the call.
+*/
+PR_IMPLEMENT(PRBool) PR_TestAndLock(PRLock *lock)
+{
+    PRThread *me = _PR_MD_CURRENT_THREAD();
+    PRBool rv = PR_FALSE;
+    PRIntn is;
+
+#ifdef _PR_GLOBAL_THREADS_ONLY 
+    is = _PR_MD_TEST_AND_LOCK(&lock->ilock);
+    if (is == 0) {
+        lock->owner = me;
+        return PR_TRUE;
+    }
+    return PR_FALSE;
+#else  /* _PR_GLOBAL_THREADS_ONLY */
+
+#ifndef _PR_LOCAL_THREADS_ONLY
+	if (_native_threads_only) {
+		is = _PR_MD_TEST_AND_LOCK(&lock->ilock);
+		if (is == 0) {
+			lock->owner = me;
+			return PR_TRUE;
+		}
+    	return PR_FALSE;
+	}
+#endif
+
+    if (!_PR_IS_NATIVE_THREAD(me))
+    	_PR_INTSOFF(is);
+
+    _PR_LOCK_LOCK(lock);
+    if (lock->owner == 0) {
+        /* Just got the lock */
+        lock->owner = me;
+        lock->priority = me->priority;
+		/* Add the granted lock to this owning thread's lock list */
+        PR_APPEND_LINK(&lock->links, &me->lockList);
+        rv = PR_TRUE;
+    }
+    _PR_LOCK_UNLOCK(lock);
+
+    if (!_PR_IS_NATIVE_THREAD(me))
+    	_PR_INTSON(is);
+    return rv;
+#endif  /* _PR_GLOBAL_THREADS_ONLY */
+}
+
+/************************************************************************/
+/************************************************************************/
+/***********************ROUTINES FOR DCE EMULATION***********************/
+/************************************************************************/
+/************************************************************************/
+PR_IMPLEMENT(PRStatus) PRP_TryLock(PRLock *lock)
+    { return (PR_TestAndLock(lock)) ? PR_SUCCESS : PR_FAILURE; }
diff --git a/nsprpub/pr/src/threads/combined/prustack.c b/nsprpub/pr/src/threads/combined/prustack.c
new file mode 100644
index 000000000..59562bac4
--- /dev/null
+++ b/nsprpub/pr/src/threads/combined/prustack.c
@@ -0,0 +1,174 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "primpl.h"
+
+/* List of free stack virtual memory chunks */
+PRLock *_pr_stackLock;
+PRCList _pr_freeStacks = PR_INIT_STATIC_CLIST(&_pr_freeStacks);
+PRIntn _pr_numFreeStacks;
+PRIntn _pr_maxFreeStacks = 4;
+
+#ifdef DEBUG
+/*
+** A variable that can be set via the debugger...
+*/
+PRBool _pr_debugStacks = PR_FALSE;
+#endif
+
+/* How much space to leave between the stacks, at each end */
+#define REDZONE		(2 << _pr_pageShift)
+
+#define _PR_THREAD_STACK_PTR(_qp) \
+    ((PRThreadStack*) ((char*) (_qp) - offsetof(PRThreadStack,links)))
+
+void _PR_InitStacks(void)
+{
+    _pr_stackLock = PR_NewLock();
+}
+
+void _PR_CleanupStacks(void)
+{
+    if (_pr_stackLock) {
+        PR_DestroyLock(_pr_stackLock);
+        _pr_stackLock = NULL;
+    }
+}
+
+/*
+** Allocate a stack for a thread.
+*/
+PRThreadStack *_PR_NewStack(PRUint32 stackSize)
+{
+    PRCList *qp;
+    PRThreadStack *ts;
+    PRThread *thr;
+
+    /*
+    ** Trim the list of free stacks. Trim it backwards, tossing out the
+    ** oldest stack found first (this way more recent stacks have a
+    ** chance of being present in the data cache).
+    */
+    PR_Lock(_pr_stackLock);
+    qp = _pr_freeStacks.prev;
+    while ((_pr_numFreeStacks > _pr_maxFreeStacks) && (qp != &_pr_freeStacks)) {
+	ts = _PR_THREAD_STACK_PTR(qp);
+	thr = _PR_THREAD_STACK_TO_PTR(ts);
+	qp = qp->prev;
+	/*
+	 * skip stacks which are still being used
+	 */
+	if (thr->no_sched)
+		continue;
+	PR_REMOVE_LINK(&ts->links);
+
+	/* Give platform OS to clear out the stack for debugging */
+	_PR_MD_CLEAR_STACK(ts);
+
+	_pr_numFreeStacks--;
+	_PR_DestroySegment(ts->seg);
+	PR_DELETE(ts);
+    }
+
+    /*
+    ** Find a free thread stack. This searches the list of free'd up
+    ** virtually mapped thread stacks.
+    */
+    qp = _pr_freeStacks.next;
+    ts = 0;
+    while (qp != &_pr_freeStacks) {
+	ts = _PR_THREAD_STACK_PTR(qp);
+	thr = _PR_THREAD_STACK_TO_PTR(ts);
+	qp = qp->next;
+	/*
+	 * skip stacks which are still being used
+	 */
+	if ((!(thr->no_sched)) && ((ts->allocSize - 2*REDZONE) >= stackSize)) {
+	    /*
+	    ** Found a stack that is not in use and is big enough. Change
+	    ** stackSize to fit it.
+	    */
+	    stackSize = ts->allocSize - 2*REDZONE;
+	    PR_REMOVE_LINK(&ts->links);
+	    _pr_numFreeStacks--;
+	    ts->links.next = 0;
+	    ts->links.prev = 0;
+	    PR_Unlock(_pr_stackLock);
+	    goto done;
+	}
+	ts = 0;
+    }
+    PR_Unlock(_pr_stackLock);
+
+    if (!ts) {
+	/* Make a new thread stack object. */
+	ts = PR_NEWZAP(PRThreadStack);
+	if (!ts) {
+	    return NULL;
+	}
+
+	/*
+	** Assign some of the virtual space to the new stack object. We
+	** may not get that piece of VM, but if nothing else we will
+	** advance the pointer so we don't collide (unless the OS screws
+	** up).
+	*/
+	ts->allocSize = stackSize + 2*REDZONE;
+	ts->seg = _PR_NewSegment(ts->allocSize, 0);
+	if (!ts->seg) {
+	    PR_DELETE(ts);
+	    return NULL;
+	}
+	}
+
+  done:
+    ts->allocBase = (char*)ts->seg->vaddr;
+    ts->flags = _PR_STACK_MAPPED;
+    ts->stackSize = stackSize;
+
+#ifdef HAVE_STACK_GROWING_UP
+    ts->stackTop = ts->allocBase + REDZONE;
+    ts->stackBottom = ts->stackTop + stackSize;
+#else
+    ts->stackBottom = ts->allocBase + REDZONE;
+    ts->stackTop = ts->stackBottom + stackSize;
+#endif
+
+    PR_LOG(_pr_thread_lm, PR_LOG_NOTICE,
+	   ("thread stack: base=0x%x limit=0x%x bottom=0x%x top=0x%x\n",
+	    ts->allocBase, ts->allocBase + ts->allocSize - 1,
+	    ts->allocBase + REDZONE,
+	    ts->allocBase + REDZONE + stackSize - 1));
+	    
+    _PR_MD_INIT_STACK(ts,REDZONE);
+
+    return ts;
+}
+
+/*
+** Free the stack for the current thread
+*/
+void _PR_FreeStack(PRThreadStack *ts)
+{
+    if (!ts) {
+	return;
+    }
+    if (ts->flags & _PR_STACK_PRIMORDIAL) {
+	PR_DELETE(ts);
+	return;
+    }
+
+    /*
+    ** Put the stack on the free list. This is done because we are still
+    ** using the stack. Next time a thread is created we will trim the
+    ** list down; it's safe to do it then because we will have had to
+    ** context switch to a live stack before another thread can be
+    ** created.
+    */
+    PR_Lock(_pr_stackLock);
+    PR_APPEND_LINK(&ts->links, _pr_freeStacks.prev);
+    _pr_numFreeStacks++;
+    PR_Unlock(_pr_stackLock);
+}
diff --git a/nsprpub/pr/src/threads/combined/pruthr.c b/nsprpub/pr/src/threads/combined/pruthr.c
new file mode 100644
index 000000000..4625ab246
--- /dev/null
+++ b/nsprpub/pr/src/threads/combined/pruthr.c
@@ -0,0 +1,1889 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "primpl.h"
+#include <signal.h>
+#include <string.h>
+
+#if defined(WIN95)                                                                         
+/*
+** Some local variables report warnings on Win95 because the code paths
+** using them are conditioned on HAVE_CUSTOME_USER_THREADS.
+** The pragma suppresses the warning.
+**
+*/
+#pragma warning(disable : 4101)
+#endif          
+
+/* _pr_activeLock protects the following global variables */
+PRLock *_pr_activeLock;
+PRInt32 _pr_primordialExitCount;   /* In PR_Cleanup(), the primordial thread
+                    * waits until all other user (non-system)
+                    * threads have terminated before it exits.
+                    * So whenever we decrement _pr_userActive,
+                    * it is compared with
+                    * _pr_primordialExitCount.
+                    * If the primordial thread is a system
+                    * thread, then _pr_primordialExitCount
+                    * is 0.  If the primordial thread is
+                    * itself a user thread, then 
+                    * _pr_primordialThread is 1.
+                    */
+PRCondVar *_pr_primordialExitCVar; /* When _pr_userActive is decremented to
+                    * _pr_primordialExitCount, this condition
+                    * variable is notified.
+                    */
+
+PRLock *_pr_deadQLock;
+PRUint32 _pr_numNativeDead;
+PRUint32 _pr_numUserDead;
+PRCList _pr_deadNativeQ;
+PRCList _pr_deadUserQ;
+
+PRUint32 _pr_join_counter;
+
+PRUint32 _pr_local_threads;
+PRUint32 _pr_global_threads;
+
+PRBool suspendAllOn = PR_FALSE;
+PRThread *suspendAllThread = NULL;
+
+extern PRCList _pr_active_global_threadQ;
+extern PRCList _pr_active_local_threadQ;
+
+static void _PR_DecrActiveThreadCount(PRThread *thread);
+static PRThread *_PR_AttachThread(PRThreadType, PRThreadPriority, PRThreadStack *);
+static void _PR_InitializeNativeStack(PRThreadStack *ts);
+static void _PR_InitializeRecycledThread(PRThread *thread);
+static void _PR_UserRunThread(void);
+
+void _PR_InitThreads(PRThreadType type, PRThreadPriority priority,
+    PRUintn maxPTDs)
+{
+    PRThread *thread;
+    PRThreadStack *stack;
+
+    PR_ASSERT(priority == PR_PRIORITY_NORMAL);
+
+    _pr_terminationCVLock = PR_NewLock();
+    _pr_activeLock = PR_NewLock();
+
+#ifndef HAVE_CUSTOM_USER_THREADS
+    stack = PR_NEWZAP(PRThreadStack);
+#ifdef HAVE_STACK_GROWING_UP
+    stack->stackTop = (char*) ((((PRWord)&type) >> _pr_pageShift)
+                  << _pr_pageShift);
+#else
+#if defined(SOLARIS) || defined (UNIXWARE) && defined (USR_SVR4_THREADS)
+    stack->stackTop = (char*) &thread;
+#else
+    stack->stackTop = (char*) ((((PRWord)&type + _pr_pageSize - 1)
+                >> _pr_pageShift) << _pr_pageShift);
+#endif
+#endif
+#else
+    /* If stack is NULL, we're using custom user threads like NT fibers. */
+    stack = PR_NEWZAP(PRThreadStack);
+    if (stack) {
+        stack->stackSize = 0;
+        _PR_InitializeNativeStack(stack);
+    }
+#endif /* HAVE_CUSTOM_USER_THREADS */
+
+    thread = _PR_AttachThread(type, priority, stack);
+    if (thread) {
+        _PR_MD_SET_CURRENT_THREAD(thread);
+
+        if (type == PR_SYSTEM_THREAD) {
+            thread->flags = _PR_SYSTEM;
+            _pr_systemActive++;
+            _pr_primordialExitCount = 0;
+        } else {
+            _pr_userActive++;
+            _pr_primordialExitCount = 1;
+        }
+    thread->no_sched = 1;
+    _pr_primordialExitCVar = PR_NewCondVar(_pr_activeLock);
+    }
+
+    if (!thread) PR_Abort();
+#ifdef _PR_LOCAL_THREADS_ONLY
+    thread->flags |= _PR_PRIMORDIAL;
+#else
+    thread->flags |= _PR_PRIMORDIAL | _PR_GLOBAL_SCOPE;
+#endif
+
+    /*
+     * Needs _PR_PRIMORDIAL flag set before calling
+     * _PR_MD_INIT_THREAD()
+     */
+    if (_PR_MD_INIT_THREAD(thread) == PR_FAILURE) {
+        /*
+         * XXX do what?
+         */
+    }
+
+    if (_PR_IS_NATIVE_THREAD(thread)) {
+        PR_APPEND_LINK(&thread->active, &_PR_ACTIVE_GLOBAL_THREADQ());
+        _pr_global_threads++;
+    } else {
+        PR_APPEND_LINK(&thread->active, &_PR_ACTIVE_LOCAL_THREADQ());
+        _pr_local_threads++;
+    }
+
+    _pr_recycleThreads = 0;
+    _pr_deadQLock = PR_NewLock();
+    _pr_numNativeDead = 0;
+    _pr_numUserDead = 0;
+    PR_INIT_CLIST(&_pr_deadNativeQ);
+    PR_INIT_CLIST(&_pr_deadUserQ);
+}
+
+void _PR_CleanupThreads(void)
+{
+    if (_pr_terminationCVLock) {
+        PR_DestroyLock(_pr_terminationCVLock);
+        _pr_terminationCVLock = NULL;
+    }
+    if (_pr_activeLock) {
+        PR_DestroyLock(_pr_activeLock);
+        _pr_activeLock = NULL;
+    }
+    if (_pr_primordialExitCVar) {
+        PR_DestroyCondVar(_pr_primordialExitCVar);
+        _pr_primordialExitCVar = NULL;
+    }
+    /* TODO _pr_dead{Native,User}Q need to be deleted */
+    if (_pr_deadQLock) {
+        PR_DestroyLock(_pr_deadQLock);
+        _pr_deadQLock = NULL;
+    }
+}
+
+/*
+** Initialize a stack for a native thread
+*/
+static void _PR_InitializeNativeStack(PRThreadStack *ts)
+{
+    if( ts && (ts->stackTop == 0) ) {
+        ts->allocSize = ts->stackSize;
+
+        /*
+        ** Setup stackTop and stackBottom values.
+        */
+#ifdef HAVE_STACK_GROWING_UP
+    ts->allocBase = (char*) ((((PRWord)&ts) >> _pr_pageShift)
+                  << _pr_pageShift);
+        ts->stackBottom = ts->allocBase + ts->stackSize;
+        ts->stackTop = ts->allocBase;
+#else
+        ts->allocBase = (char*) ((((PRWord)&ts + _pr_pageSize - 1)
+                >> _pr_pageShift) << _pr_pageShift);
+        ts->stackTop    = ts->allocBase;
+        ts->stackBottom = ts->allocBase - ts->stackSize;
+#endif
+    }
+}
+
+void _PR_NotifyJoinWaiters(PRThread *thread)
+{
+    /*
+    ** Handle joinable threads.  Change the state to waiting for join.
+    ** Remove from our run Q and put it on global waiting to join Q.
+    ** Notify on our "termination" condition variable so that joining
+    ** thread will know about our termination.  Switch our context and
+    ** come back later on to continue the cleanup.
+    */    
+    PR_ASSERT(thread == _PR_MD_CURRENT_THREAD());
+    if (thread->term != NULL) {
+        PR_Lock(_pr_terminationCVLock);
+        _PR_THREAD_LOCK(thread);
+        thread->state = _PR_JOIN_WAIT;
+        if ( !_PR_IS_NATIVE_THREAD(thread) ) {
+            _PR_MISCQ_LOCK(thread->cpu);
+            _PR_ADD_JOINQ(thread, thread->cpu);
+            _PR_MISCQ_UNLOCK(thread->cpu);
+        }
+        _PR_THREAD_UNLOCK(thread);
+        PR_NotifyCondVar(thread->term);
+        PR_Unlock(_pr_terminationCVLock);
+        _PR_MD_WAIT(thread, PR_INTERVAL_NO_TIMEOUT);
+        PR_ASSERT(thread->state != _PR_JOIN_WAIT);
+    }
+
+}
+
+/*
+ * Zero some of the data members of a recycled thread.
+ *
+ * Note that we can do this either when a dead thread is added to
+ * the dead thread queue or when it is reused.  Here, we are doing
+ * this lazily, when the thread is reused in _PR_CreateThread().
+ */
+static void _PR_InitializeRecycledThread(PRThread *thread)
+{
+    /*
+     * Assert that the following data members are already zeroed
+     * by _PR_CleanupThread().
+     */
+#ifdef DEBUG
+    if (thread->privateData) {
+        unsigned int i;
+        for (i = 0; i < thread->tpdLength; i++) {
+            PR_ASSERT(thread->privateData[i] == NULL);
+        }
+    }
+#endif
+    PR_ASSERT(thread->dumpArg == 0 && thread->dump == 0);
+    PR_ASSERT(thread->errorString == 0 && thread->errorStringSize == 0);
+    PR_ASSERT(thread->errorStringLength == 0);
+    PR_ASSERT(thread->name == 0);
+
+    /* Reset data members in thread structure */
+    thread->errorCode = thread->osErrorCode = 0;
+    thread->io_pending = thread->io_suspended = PR_FALSE;
+    thread->environment = 0;
+    PR_INIT_CLIST(&thread->lockList);
+}
+
+PRStatus _PR_RecycleThread(PRThread *thread)
+{
+    if ( _PR_IS_NATIVE_THREAD(thread) &&
+            _PR_NUM_DEADNATIVE < _pr_recycleThreads) {
+        _PR_DEADQ_LOCK;
+        PR_APPEND_LINK(&thread->links, &_PR_DEADNATIVEQ);
+        _PR_INC_DEADNATIVE;
+        _PR_DEADQ_UNLOCK;
+    return (PR_SUCCESS);
+    } else if ( !_PR_IS_NATIVE_THREAD(thread) &&
+                _PR_NUM_DEADUSER < _pr_recycleThreads) {
+        _PR_DEADQ_LOCK;
+        PR_APPEND_LINK(&thread->links, &_PR_DEADUSERQ);
+        _PR_INC_DEADUSER;
+        _PR_DEADQ_UNLOCK;
+    return (PR_SUCCESS);
+    }
+    return (PR_FAILURE);
+}
+
+/*
+ * Decrement the active thread count, either _pr_systemActive or
+ * _pr_userActive, depending on whether the thread is a system thread
+ * or a user thread.  If all the user threads, except possibly
+ * the primordial thread, have terminated, we notify the primordial
+ * thread of this condition.
+ *
+ * Since this function will lock _pr_activeLock, do not call this
+ * function while holding the _pr_activeLock lock, as this will result
+ * in a deadlock.
+ */
+
+static void
+_PR_DecrActiveThreadCount(PRThread *thread)
+{
+    PR_Lock(_pr_activeLock);
+    if (thread->flags & _PR_SYSTEM) {
+        _pr_systemActive--;
+    } else {
+        _pr_userActive--;
+        if (_pr_userActive == _pr_primordialExitCount) {
+            PR_NotifyCondVar(_pr_primordialExitCVar);
+        }
+    }
+    PR_Unlock(_pr_activeLock);
+}
+
+/*
+** Detach thread structure
+*/
+static void
+_PR_DestroyThread(PRThread *thread)
+{
+    _PR_MD_FREE_LOCK(&thread->threadLock);
+    PR_DELETE(thread);
+}
+
+void
+_PR_NativeDestroyThread(PRThread *thread)
+{
+    if(thread->term) {
+        PR_DestroyCondVar(thread->term);
+        thread->term = 0;
+    }
+    if (NULL != thread->privateData) {
+        PR_ASSERT(0 != thread->tpdLength);
+        PR_DELETE(thread->privateData);
+        thread->tpdLength = 0;
+    }
+    PR_DELETE(thread->stack);
+    _PR_DestroyThread(thread);
+}
+
+void
+_PR_UserDestroyThread(PRThread *thread)
+{
+    if(thread->term) {
+        PR_DestroyCondVar(thread->term);
+        thread->term = 0;
+    }
+    if (NULL != thread->privateData) {
+        PR_ASSERT(0 != thread->tpdLength);
+        PR_DELETE(thread->privateData);
+        thread->tpdLength = 0;
+    }
+    _PR_MD_FREE_LOCK(&thread->threadLock);
+    if (thread->threadAllocatedOnStack == 1) {
+        _PR_MD_CLEAN_THREAD(thread);
+        /*
+         *  Because the no_sched field is set, this thread/stack will
+         *  will not be re-used until the flag is cleared by the thread
+         *  we will context switch to.
+         */
+        _PR_FreeStack(thread->stack);
+    } else {
+#ifdef WINNT
+        _PR_MD_CLEAN_THREAD(thread);
+#else
+        /*
+         * This assertion does not apply to NT.  On NT, every fiber
+         * has its threadAllocatedOnStack equal to 0.  Elsewhere,
+         * only the primordial thread has its threadAllocatedOnStack
+         * equal to 0.
+         */
+        PR_ASSERT(thread->flags & _PR_PRIMORDIAL);
+#endif
+    }
+}
+
+
+/*
+** Run a thread's start function. When the start function returns the
+** thread is done executing and no longer needs the CPU. If there are no
+** more user threads running then we can exit the program.
+*/
+void _PR_NativeRunThread(void *arg)
+{
+    PRThread *thread = (PRThread *)arg;
+
+    _PR_MD_SET_CURRENT_THREAD(thread);
+
+    _PR_MD_SET_CURRENT_CPU(NULL);
+
+    /* Set up the thread stack information */
+    _PR_InitializeNativeStack(thread->stack);
+
+    /* Set up the thread md information */
+    if (_PR_MD_INIT_THREAD(thread) == PR_FAILURE) {
+        /*
+         * thread failed to initialize itself, possibly due to
+         * failure to allocate per-thread resources
+         */
+        return;
+    }
+
+    while(1) {
+        thread->state = _PR_RUNNING;
+
+        /*
+         * Add to list of active threads
+         */
+        PR_Lock(_pr_activeLock);
+        PR_APPEND_LINK(&thread->active, &_PR_ACTIVE_GLOBAL_THREADQ());
+        _pr_global_threads++;
+        PR_Unlock(_pr_activeLock);
+
+        (*thread->startFunc)(thread->arg);
+
+        /*
+         * The following two assertions are meant for NT asynch io.
+         *
+         * The thread should have no asynch io in progress when it
+         * exits, otherwise the overlapped buffer, which is part of
+         * the thread structure, would become invalid.
+         */
+        PR_ASSERT(thread->io_pending == PR_FALSE);
+        /*
+         * This assertion enforces the programming guideline that
+         * if an io function times out or is interrupted, the thread
+         * should close the fd to force the asynch io to abort
+         * before it exits.  Right now, closing the fd is the only
+         * way to clear the io_suspended flag.
+         */
+        PR_ASSERT(thread->io_suspended == PR_FALSE);
+
+        /*
+         * remove thread from list of active threads
+         */
+        PR_Lock(_pr_activeLock);
+        PR_REMOVE_LINK(&thread->active);
+        _pr_global_threads--;
+        PR_Unlock(_pr_activeLock);
+
+        PR_LOG(_pr_thread_lm, PR_LOG_MIN, ("thread exiting"));
+
+        /* All done, time to go away */
+        _PR_CleanupThread(thread);
+
+        _PR_NotifyJoinWaiters(thread);
+
+        _PR_DecrActiveThreadCount(thread);
+
+        thread->state = _PR_DEAD_STATE;
+
+        if (!_pr_recycleThreads || (_PR_RecycleThread(thread) ==
+                        PR_FAILURE)) {
+            /*
+             * thread not recycled
+             * platform-specific thread exit processing
+             *        - for stuff like releasing native-thread resources, etc.
+             */
+            _PR_MD_EXIT_THREAD(thread);
+            /*
+             * Free memory allocated for the thread
+             */
+            _PR_NativeDestroyThread(thread);
+            /*
+             * thread gone, cannot de-reference thread now
+             */
+            return;
+        }
+
+        /* Now wait for someone to activate us again... */
+        _PR_MD_WAIT(thread, PR_INTERVAL_NO_TIMEOUT);
+    }
+}
+
+static void _PR_UserRunThread(void)
+{
+    PRThread *thread = _PR_MD_CURRENT_THREAD();
+    PRIntn is;
+
+    if (_MD_LAST_THREAD())
+    _MD_LAST_THREAD()->no_sched = 0;
+
+#ifdef HAVE_CUSTOM_USER_THREADS
+    if (thread->stack == NULL) {
+        thread->stack = PR_NEWZAP(PRThreadStack);
+        _PR_InitializeNativeStack(thread->stack);
+    }
+#endif /* HAVE_CUSTOM_USER_THREADS */
+
+    while(1) {
+        /* Run thread main */
+        if ( !_PR_IS_NATIVE_THREAD(thread)) _PR_MD_SET_INTSOFF(0);
+
+    /*
+     * Add to list of active threads
+     */
+    if (!(thread->flags & _PR_IDLE_THREAD)) {
+        PR_Lock(_pr_activeLock);
+        PR_APPEND_LINK(&thread->active, &_PR_ACTIVE_LOCAL_THREADQ());
+        _pr_local_threads++;
+        PR_Unlock(_pr_activeLock);
+    }
+
+        (*thread->startFunc)(thread->arg);
+
+        /*
+         * The following two assertions are meant for NT asynch io.
+         *
+         * The thread should have no asynch io in progress when it
+         * exits, otherwise the overlapped buffer, which is part of
+         * the thread structure, would become invalid.
+         */
+        PR_ASSERT(thread->io_pending == PR_FALSE);
+        /*
+         * This assertion enforces the programming guideline that
+         * if an io function times out or is interrupted, the thread
+         * should close the fd to force the asynch io to abort
+         * before it exits.  Right now, closing the fd is the only
+         * way to clear the io_suspended flag.
+         */
+        PR_ASSERT(thread->io_suspended == PR_FALSE);
+
+        PR_Lock(_pr_activeLock);
+    /*
+     * remove thread from list of active threads
+     */
+    if (!(thread->flags & _PR_IDLE_THREAD)) {
+           PR_REMOVE_LINK(&thread->active);
+        _pr_local_threads--;
+    }
+    PR_Unlock(_pr_activeLock);
+        PR_LOG(_pr_thread_lm, PR_LOG_MIN, ("thread exiting"));
+
+        /* All done, time to go away */
+        _PR_CleanupThread(thread);
+
+        _PR_INTSOFF(is);    
+
+        _PR_NotifyJoinWaiters(thread);
+
+    _PR_DecrActiveThreadCount(thread);
+
+        thread->state = _PR_DEAD_STATE;
+
+        if (!_pr_recycleThreads || (_PR_RecycleThread(thread) ==
+                        PR_FAILURE)) {
+            /*
+            ** Destroy the thread resources
+            */
+        _PR_UserDestroyThread(thread);
+        }
+
+        /*
+        ** Find another user thread to run. This cpu has finished the
+        ** previous threads main and is now ready to run another thread.
+        */
+        {
+            PRInt32 is;
+            _PR_INTSOFF(is);
+            _PR_MD_SWITCH_CONTEXT(thread);
+        }
+
+        /* Will land here when we get scheduled again if we are recycling... */
+    }
+}
+
+void _PR_SetThreadPriority(PRThread *thread, PRThreadPriority newPri)
+{
+    PRThread *me = _PR_MD_CURRENT_THREAD();
+    PRIntn is;
+
+    if ( _PR_IS_NATIVE_THREAD(thread) ) {
+        _PR_MD_SET_PRIORITY(&(thread->md), newPri);
+        return;
+    }
+
+    if (!_PR_IS_NATIVE_THREAD(me))
+    _PR_INTSOFF(is);
+    _PR_THREAD_LOCK(thread);
+    if (newPri != thread->priority) {
+    _PRCPU *cpu = thread->cpu;
+
+    switch (thread->state) {
+      case _PR_RUNNING:
+        /* Change my priority */
+
+            _PR_RUNQ_LOCK(cpu);
+        thread->priority = newPri;
+        if (_PR_RUNQREADYMASK(cpu) >> (newPri + 1)) {
+            if (!_PR_IS_NATIVE_THREAD(me))
+                    _PR_SET_RESCHED_FLAG();
+        }
+            _PR_RUNQ_UNLOCK(cpu);
+        break;
+
+      case _PR_RUNNABLE:
+
+        _PR_RUNQ_LOCK(cpu);
+            /* Move to different runQ */
+            _PR_DEL_RUNQ(thread);
+            thread->priority = newPri;
+            PR_ASSERT(!(thread->flags & _PR_IDLE_THREAD));
+            _PR_ADD_RUNQ(thread, cpu, newPri);
+        _PR_RUNQ_UNLOCK(cpu);
+
+            if (newPri > me->priority) {
+            if (!_PR_IS_NATIVE_THREAD(me))
+                    _PR_SET_RESCHED_FLAG();
+            }
+
+        break;
+
+      case _PR_LOCK_WAIT:
+      case _PR_COND_WAIT:
+      case _PR_IO_WAIT:
+      case _PR_SUSPENDED:
+
+        thread->priority = newPri;
+        break;
+    }
+    }
+    _PR_THREAD_UNLOCK(thread);
+    if (!_PR_IS_NATIVE_THREAD(me))
+    _PR_INTSON(is);
+}
+
+/*
+** Suspend the named thread and copy its gc registers into regBuf
+*/
+static void _PR_Suspend(PRThread *thread)
+{
+    PRIntn is;
+    PRThread *me = _PR_MD_CURRENT_THREAD();
+
+    PR_ASSERT(thread != me);
+    PR_ASSERT(!_PR_IS_NATIVE_THREAD(thread) || (!thread->cpu));
+
+    if (!_PR_IS_NATIVE_THREAD(me))
+        _PR_INTSOFF(is);
+    _PR_THREAD_LOCK(thread);
+    switch (thread->state) {
+      case _PR_RUNNABLE:
+        if (!_PR_IS_NATIVE_THREAD(thread)) {
+            _PR_RUNQ_LOCK(thread->cpu);
+            _PR_DEL_RUNQ(thread);
+            _PR_RUNQ_UNLOCK(thread->cpu);
+
+            _PR_MISCQ_LOCK(thread->cpu);
+            _PR_ADD_SUSPENDQ(thread, thread->cpu);
+            _PR_MISCQ_UNLOCK(thread->cpu);
+        } else {
+            /*
+             * Only LOCAL threads are suspended by _PR_Suspend
+             */
+             PR_ASSERT(0);
+        }
+        thread->state = _PR_SUSPENDED;
+        break;
+
+      case _PR_RUNNING:
+        /*
+         * The thread being suspended should be a LOCAL thread with
+         * _pr_numCPUs == 1. Hence, the thread cannot be in RUNNING state
+         */
+        PR_ASSERT(0);
+        break;
+
+      case _PR_LOCK_WAIT:
+      case _PR_IO_WAIT:
+      case _PR_COND_WAIT:
+        if (_PR_IS_NATIVE_THREAD(thread)) {
+            _PR_MD_SUSPEND_THREAD(thread);
+    }
+        thread->flags |= _PR_SUSPENDING;
+        break;
+
+      default:
+        PR_Abort();
+    }
+    _PR_THREAD_UNLOCK(thread);
+    if (!_PR_IS_NATIVE_THREAD(me))
+    _PR_INTSON(is);
+}
+
+static void _PR_Resume(PRThread *thread)
+{
+    PRThreadPriority pri;
+    PRIntn is;
+    PRThread *me = _PR_MD_CURRENT_THREAD();
+
+    if (!_PR_IS_NATIVE_THREAD(me))
+    _PR_INTSOFF(is);
+    _PR_THREAD_LOCK(thread);
+    switch (thread->state) {
+      case _PR_SUSPENDED:
+        thread->state = _PR_RUNNABLE;
+        thread->flags &= ~_PR_SUSPENDING;
+        if (!_PR_IS_NATIVE_THREAD(thread)) {
+            _PR_MISCQ_LOCK(thread->cpu);
+            _PR_DEL_SUSPENDQ(thread);
+            _PR_MISCQ_UNLOCK(thread->cpu);
+
+            pri = thread->priority;
+
+            _PR_RUNQ_LOCK(thread->cpu);
+            _PR_ADD_RUNQ(thread, thread->cpu, pri);
+            _PR_RUNQ_UNLOCK(thread->cpu);
+
+            if (pri > _PR_MD_CURRENT_THREAD()->priority) {
+                if (!_PR_IS_NATIVE_THREAD(me))
+                    _PR_SET_RESCHED_FLAG();
+            }
+        } else {
+            PR_ASSERT(0);
+        }
+        break;
+
+      case _PR_IO_WAIT:
+      case _PR_COND_WAIT:
+        thread->flags &= ~_PR_SUSPENDING;
+/*      PR_ASSERT(thread->wait.monitor->stickyCount == 0); */
+        break;
+
+      case _PR_LOCK_WAIT: 
+      {
+        PRLock *wLock = thread->wait.lock;
+
+        thread->flags &= ~_PR_SUSPENDING;
+ 
+        _PR_LOCK_LOCK(wLock);
+        if (thread->wait.lock->owner == 0) {
+            _PR_UnblockLockWaiter(thread->wait.lock);
+        }
+        _PR_LOCK_UNLOCK(wLock);
+        break;
+      }
+      case _PR_RUNNABLE:
+        break;
+      case _PR_RUNNING:
+        /*
+         * The thread being suspended should be a LOCAL thread with
+         * _pr_numCPUs == 1. Hence, the thread cannot be in RUNNING state
+         */
+        PR_ASSERT(0);
+        break;
+
+      default:
+    /*
+     * thread should have been in one of the above-listed blocked states
+     * (_PR_JOIN_WAIT, _PR_IO_WAIT, _PR_UNBORN, _PR_DEAD_STATE)
+     */
+        PR_Abort();
+    }
+    _PR_THREAD_UNLOCK(thread);
+    if (!_PR_IS_NATIVE_THREAD(me))
+        _PR_INTSON(is);
+
+}
+
+#if !defined(_PR_LOCAL_THREADS_ONLY) && defined(XP_UNIX)
+static PRThread *get_thread(_PRCPU *cpu, PRBool *wakeup_cpus)
+{
+    PRThread *thread;
+    PRIntn pri;
+    PRUint32 r;
+    PRCList *qp;
+    PRIntn priMin, priMax;
+
+    _PR_RUNQ_LOCK(cpu);
+    r = _PR_RUNQREADYMASK(cpu);
+    if (r==0) {
+        priMin = priMax = PR_PRIORITY_FIRST;
+    } else if (r == (1<<PR_PRIORITY_NORMAL) ) {
+        priMin = priMax = PR_PRIORITY_NORMAL;
+    } else {
+        priMin = PR_PRIORITY_FIRST;
+        priMax = PR_PRIORITY_LAST;
+    }
+    thread = NULL;
+    for (pri = priMax; pri >= priMin ; pri-- ) {
+    if (r & (1 << pri)) {
+            for (qp = _PR_RUNQ(cpu)[pri].next; 
+                 qp != &_PR_RUNQ(cpu)[pri];
+                 qp = qp->next) {
+                thread = _PR_THREAD_PTR(qp);
+                /*
+                * skip non-schedulable threads
+                */
+                PR_ASSERT(!(thread->flags & _PR_IDLE_THREAD));
+                if (thread->no_sched) {
+                    thread = NULL;
+                    /*
+                     * Need to wakeup cpus to avoid missing a
+                     * runnable thread
+                     * Waking up all CPU's need happen only once.
+                     */
+
+                    *wakeup_cpus = PR_TRUE;
+                    continue;
+                } else if (thread->flags & _PR_BOUND_THREAD) {
+                    /*
+                     * Thread bound to cpu 0
+                     */
+
+                    thread = NULL;
+#ifdef IRIX
+					_PR_MD_WAKEUP_PRIMORDIAL_CPU();
+#endif
+                    continue;
+                } else if (thread->io_pending == PR_TRUE) {
+                    /*
+                     * A thread that is blocked for I/O needs to run
+                     * on the same cpu on which it was blocked. This is because
+                     * the cpu's ioq is accessed without lock protection and scheduling
+                     * the thread on a different cpu would preclude this optimization.
+                     */
+                    thread = NULL;
+                    continue;
+                } else {
+                    /* Pull thread off of its run queue */
+                    _PR_DEL_RUNQ(thread);
+                    _PR_RUNQ_UNLOCK(cpu);
+                    return(thread);
+                }
+            }
+        }
+        thread = NULL;
+    }
+    _PR_RUNQ_UNLOCK(cpu);
+    return(thread);
+}
+#endif /* !defined(_PR_LOCAL_THREADS_ONLY) && defined(XP_UNIX) */
+
+/*
+** Schedule this native thread by finding the highest priority nspr
+** thread that is ready to run.
+**
+** Note- everyone really needs to call _PR_MD_SWITCH_CONTEXT (which calls
+**       PR_Schedule() rather than calling PR_Schedule.  Otherwise if there
+**       is initialization required for switching from SWITCH_CONTEXT,
+**       it will not get done!
+*/
+void _PR_Schedule(void)
+{
+    PRThread *thread, *me = _PR_MD_CURRENT_THREAD();
+    _PRCPU *cpu = _PR_MD_CURRENT_CPU();
+    PRIntn pri;
+    PRUint32 r;
+    PRCList *qp;
+    PRIntn priMin, priMax;
+#if !defined(_PR_LOCAL_THREADS_ONLY) && defined(XP_UNIX)
+    PRBool wakeup_cpus;
+#endif
+
+    /* Interrupts must be disabled */
+    PR_ASSERT(_PR_IS_NATIVE_THREAD(me) || _PR_MD_GET_INTSOFF() != 0);
+
+    /* Since we are rescheduling, we no longer want to */
+    _PR_CLEAR_RESCHED_FLAG();
+
+    /*
+    ** Find highest priority thread to run. Bigger priority numbers are
+    ** higher priority threads
+    */
+    _PR_RUNQ_LOCK(cpu);
+    /*
+     *  if we are in SuspendAll mode, can schedule only the thread
+     *    that called PR_SuspendAll
+     *
+     *  The thread may be ready to run now, after completing an I/O
+     *  operation, for example
+     */
+    if ((thread = suspendAllThread) != 0) {
+    if ((!(thread->no_sched)) && (thread->state == _PR_RUNNABLE)) {
+            /* Pull thread off of its run queue */
+            _PR_DEL_RUNQ(thread);
+            _PR_RUNQ_UNLOCK(cpu);
+            goto found_thread;
+    } else {
+            thread = NULL;
+            _PR_RUNQ_UNLOCK(cpu);
+            goto idle_thread;
+    }
+    }
+    r = _PR_RUNQREADYMASK(cpu);
+    if (r==0) {
+        priMin = priMax = PR_PRIORITY_FIRST;
+    } else if (r == (1<<PR_PRIORITY_NORMAL) ) {
+        priMin = priMax = PR_PRIORITY_NORMAL;
+    } else {
+        priMin = PR_PRIORITY_FIRST;
+        priMax = PR_PRIORITY_LAST;
+    }
+    thread = NULL;
+    for (pri = priMax; pri >= priMin ; pri-- ) {
+    if (r & (1 << pri)) {
+            for (qp = _PR_RUNQ(cpu)[pri].next; 
+                 qp != &_PR_RUNQ(cpu)[pri];
+                 qp = qp->next) {
+                thread = _PR_THREAD_PTR(qp);
+                /*
+                * skip non-schedulable threads
+                */
+                PR_ASSERT(!(thread->flags & _PR_IDLE_THREAD));
+                if ((thread->no_sched) && (me != thread)){
+                    thread = NULL;
+                    continue;
+                } else {
+                    /* Pull thread off of its run queue */
+                    _PR_DEL_RUNQ(thread);
+                    _PR_RUNQ_UNLOCK(cpu);
+                    goto found_thread;
+                }
+            }
+        }
+        thread = NULL;
+    }
+    _PR_RUNQ_UNLOCK(cpu);
+
+#if !defined(_PR_LOCAL_THREADS_ONLY) && defined(XP_UNIX)
+
+    wakeup_cpus = PR_FALSE;
+    _PR_CPU_LIST_LOCK();
+    for (qp = _PR_CPUQ().next; qp != &_PR_CPUQ(); qp = qp->next) {
+        if (cpu != _PR_CPU_PTR(qp)) {
+            if ((thread = get_thread(_PR_CPU_PTR(qp), &wakeup_cpus))
+                                        != NULL) {
+                thread->cpu = cpu;
+                _PR_CPU_LIST_UNLOCK();
+                if (wakeup_cpus == PR_TRUE)
+                    _PR_MD_WAKEUP_CPUS();
+                goto found_thread;
+            }
+        }
+    }
+    _PR_CPU_LIST_UNLOCK();
+    if (wakeup_cpus == PR_TRUE)
+        _PR_MD_WAKEUP_CPUS();
+
+#endif        /* _PR_LOCAL_THREADS_ONLY */
+
+idle_thread:
+   /*
+    ** There are no threads to run. Switch to the idle thread
+    */
+    PR_LOG(_pr_sched_lm, PR_LOG_MAX, ("pausing"));
+    thread = _PR_MD_CURRENT_CPU()->idle_thread;
+
+found_thread:
+    PR_ASSERT((me == thread) || ((thread->state == _PR_RUNNABLE) &&
+                    (!(thread->no_sched))));
+
+    /* Resume the thread */
+    PR_LOG(_pr_sched_lm, PR_LOG_MAX,
+       ("switching to %d[%p]", thread->id, thread));
+    PR_ASSERT(thread->state != _PR_RUNNING);
+    thread->state = _PR_RUNNING;
+ 
+    /* If we are on the runq, it just means that we went to sleep on some
+     * resource, and by the time we got here another real native thread had
+     * already given us the resource and put us back on the runqueue 
+     */
+	PR_ASSERT(thread->cpu == _PR_MD_CURRENT_CPU());
+    if (thread != me) 
+        _PR_MD_RESTORE_CONTEXT(thread);
+#if 0
+    /* XXXMB; with setjmp/longjmp it is impossible to land here, but 
+     * it is not with fibers... Is this a bad thing?  I believe it is 
+     * still safe.
+     */
+    PR_NOT_REACHED("impossible return from schedule");
+#endif
+}
+
+/*
+** Attaches a thread.  
+** Does not set the _PR_MD_CURRENT_THREAD.  
+** Does not specify the scope of the thread.
+*/
+static PRThread *
+_PR_AttachThread(PRThreadType type, PRThreadPriority priority,
+    PRThreadStack *stack)
+{
+    PRThread *thread;
+    char *mem;
+
+    if (priority > PR_PRIORITY_LAST) {
+        priority = PR_PRIORITY_LAST;
+    } else if (priority < PR_PRIORITY_FIRST) {
+        priority = PR_PRIORITY_FIRST;
+    }
+
+    mem = (char*) PR_CALLOC(sizeof(PRThread));
+    if (mem) {
+        thread = (PRThread*) mem;
+        thread->priority = priority;
+        thread->stack = stack;
+        thread->state = _PR_RUNNING;
+        PR_INIT_CLIST(&thread->lockList);
+        if (_PR_MD_NEW_LOCK(&thread->threadLock) == PR_FAILURE) {
+        PR_DELETE(thread);
+        return 0;
+    }
+
+        return thread;
+    }
+    return 0;
+}
+
+
+
+PR_IMPLEMENT(PRThread*) 
+_PR_NativeCreateThread(PRThreadType type,
+                     void (*start)(void *arg),
+                     void *arg,
+                     PRThreadPriority priority,
+                     PRThreadScope scope,
+                     PRThreadState state,
+                     PRUint32 stackSize,
+                     PRUint32 flags)
+{
+    PRThread *thread;
+
+    thread = _PR_AttachThread(type, priority, NULL);
+
+    if (thread) {
+        PR_Lock(_pr_activeLock);
+        thread->flags = (flags | _PR_GLOBAL_SCOPE);
+        thread->id = ++_pr_utid;
+        if (type == PR_SYSTEM_THREAD) {
+            thread->flags |= _PR_SYSTEM;
+            _pr_systemActive++;
+        } else {
+            _pr_userActive++;
+        }
+        PR_Unlock(_pr_activeLock);
+
+        thread->stack = PR_NEWZAP(PRThreadStack);
+        if (!thread->stack) {
+            PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
+            goto done;
+        }
+        thread->stack->stackSize = stackSize?stackSize:_MD_DEFAULT_STACK_SIZE;
+        thread->stack->thr = thread;
+        thread->startFunc = start;
+        thread->arg = arg;
+
+        /* 
+          Set thread flags related to scope and joinable state. If joinable
+          thread, allocate a "termination" conidition variable.
+         */
+        if (state == PR_JOINABLE_THREAD) {
+            thread->term = PR_NewCondVar(_pr_terminationCVLock);
+        if (thread->term == NULL) {
+        PR_DELETE(thread->stack);
+        goto done;
+        }
+        }
+
+    thread->state = _PR_RUNNING;
+        if (_PR_MD_CREATE_THREAD(thread, _PR_NativeRunThread, priority,
+            scope,state,stackSize) == PR_SUCCESS) {
+            return thread;
+        }
+        if (thread->term) {
+            PR_DestroyCondVar(thread->term);
+            thread->term = NULL;
+        }
+    PR_DELETE(thread->stack);
+    }
+
+done:
+    if (thread) {
+    _PR_DecrActiveThreadCount(thread);
+        _PR_DestroyThread(thread);
+    }
+    return NULL;
+}
+
+/************************************************************************/
+
+PR_IMPLEMENT(PRThread*) _PR_CreateThread(PRThreadType type,
+                     void (*start)(void *arg),
+                     void *arg,
+                     PRThreadPriority priority,
+                     PRThreadScope scope,
+                     PRThreadState state,
+                     PRUint32 stackSize,
+                     PRUint32 flags)
+{
+    PRThread *me;
+    PRThread *thread = NULL;
+    PRThreadStack *stack;
+    char *top;
+    PRIntn is;
+    PRIntn native = 0;
+    PRIntn useRecycled = 0;
+    PRBool status;
+
+    /* 
+    First, pin down the priority.  Not all compilers catch passing out of
+    range enum here.  If we let bad values thru, priority queues won't work.
+    */
+    if (priority > PR_PRIORITY_LAST) {
+        priority = PR_PRIORITY_LAST;
+    } else if (priority < PR_PRIORITY_FIRST) {
+        priority = PR_PRIORITY_FIRST;
+    }
+        
+    if (!_pr_initialized) _PR_ImplicitInitialization();
+
+    if (! (flags & _PR_IDLE_THREAD))
+        me = _PR_MD_CURRENT_THREAD();
+
+#if    defined(_PR_GLOBAL_THREADS_ONLY)
+	/*
+	 * can create global threads only
+	 */
+    if (scope == PR_LOCAL_THREAD)
+    	scope = PR_GLOBAL_THREAD;
+#endif
+
+	if (_native_threads_only)
+		scope = PR_GLOBAL_THREAD;
+
+    native = (((scope == PR_GLOBAL_THREAD)|| (scope == PR_GLOBAL_BOUND_THREAD))
+							&& _PR_IS_NATIVE_THREAD_SUPPORTED());
+
+    _PR_ADJUST_STACKSIZE(stackSize);
+
+    if (native) {
+    /*
+     * clear the IDLE_THREAD flag which applies to LOCAL
+     * threads only
+     */
+    flags &= ~_PR_IDLE_THREAD;
+        flags |= _PR_GLOBAL_SCOPE;
+        if (_PR_NUM_DEADNATIVE > 0) {
+            _PR_DEADQ_LOCK;
+
+            if (_PR_NUM_DEADNATIVE == 0) { /* Thread safe check */
+                _PR_DEADQ_UNLOCK;
+            } else {
+                thread = _PR_THREAD_PTR(_PR_DEADNATIVEQ.next);
+                PR_REMOVE_LINK(&thread->links);
+                _PR_DEC_DEADNATIVE;
+                _PR_DEADQ_UNLOCK;
+
+                _PR_InitializeRecycledThread(thread);
+                thread->startFunc = start;
+                thread->arg = arg;
+            thread->flags = (flags | _PR_GLOBAL_SCOPE);
+            if (type == PR_SYSTEM_THREAD)
+            {
+                thread->flags |= _PR_SYSTEM;
+                PR_ATOMIC_INCREMENT(&_pr_systemActive);
+            }
+            else PR_ATOMIC_INCREMENT(&_pr_userActive);
+
+            if (state == PR_JOINABLE_THREAD) {
+                if (!thread->term) 
+                       thread->term = PR_NewCondVar(_pr_terminationCVLock);
+            }
+        else {
+                if(thread->term) {
+                    PR_DestroyCondVar(thread->term);
+                        thread->term = 0;
+            }
+            }
+
+                thread->priority = priority;
+        _PR_MD_SET_PRIORITY(&(thread->md), priority);
+        /* XXX what about stackSize? */
+        thread->state = _PR_RUNNING;
+                _PR_MD_WAKEUP_WAITER(thread);
+        return thread;
+            }
+        }
+        thread = _PR_NativeCreateThread(type, start, arg, priority, 
+                                            scope, state, stackSize, flags);
+    } else {
+        if (_PR_NUM_DEADUSER > 0) {
+            _PR_DEADQ_LOCK;
+
+            if (_PR_NUM_DEADUSER == 0) {  /* thread safe check */
+                _PR_DEADQ_UNLOCK;
+            } else {
+                PRCList *ptr;
+
+                /* Go down list checking for a recycled thread with a 
+                 * large enough stack.  XXXMB - this has a bad degenerate case.
+                 */
+                ptr = _PR_DEADUSERQ.next;
+                while( ptr != &_PR_DEADUSERQ ) {
+                    thread = _PR_THREAD_PTR(ptr);
+                    if ((thread->stack->stackSize >= stackSize) &&
+                (!thread->no_sched)) {
+                        PR_REMOVE_LINK(&thread->links);
+                        _PR_DEC_DEADUSER;
+                        break;
+                    } else {
+                        ptr = ptr->next;
+                        thread = NULL;
+                    }
+                } 
+
+                _PR_DEADQ_UNLOCK;
+
+               if (thread) {
+                    _PR_InitializeRecycledThread(thread);
+                    thread->startFunc = start;
+                    thread->arg = arg;
+                    thread->priority = priority;
+            if (state == PR_JOINABLE_THREAD) {
+            if (!thread->term) 
+               thread->term = PR_NewCondVar(_pr_terminationCVLock);
+            } else {
+            if(thread->term) {
+               PR_DestroyCondVar(thread->term);
+                thread->term = 0;
+            }
+            }
+                    useRecycled++;
+                }
+            }
+        } 
+        if (thread == NULL) {
+#ifndef HAVE_CUSTOM_USER_THREADS
+            stack = _PR_NewStack(stackSize);
+            if (!stack) {
+                PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
+                return NULL;
+            }
+
+            /* Allocate thread object and per-thread data off the top of the stack*/
+            top = stack->stackTop;
+#ifdef HAVE_STACK_GROWING_UP
+            thread = (PRThread*) top;
+            top = top + sizeof(PRThread);
+            /*
+             * Make stack 64-byte aligned
+             */
+            if ((PRUptrdiff)top & 0x3f) {
+                top = (char*)(((PRUptrdiff)top + 0x40) & ~0x3f);
+            }
+#else
+            top = top - sizeof(PRThread);
+            thread = (PRThread*) top;
+            /*
+             * Make stack 64-byte aligned
+             */
+            if ((PRUptrdiff)top & 0x3f) {
+                top = (char*)((PRUptrdiff)top & ~0x3f);
+            }
+#endif
+            stack->thr = thread;
+            memset(thread, 0, sizeof(PRThread));
+            thread->threadAllocatedOnStack = 1;
+#else
+            thread = _PR_MD_CREATE_USER_THREAD(stackSize, start, arg);
+            if (!thread) {
+                PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
+                return NULL;
+            }
+            thread->threadAllocatedOnStack = 0;
+            stack = NULL;
+            top = NULL;
+#endif
+
+            /* Initialize thread */
+            thread->tpdLength = 0;
+            thread->privateData = NULL;
+            thread->stack = stack;
+            thread->priority = priority;
+            thread->startFunc = start;
+            thread->arg = arg;
+            PR_INIT_CLIST(&thread->lockList);
+
+            if (_PR_MD_INIT_THREAD(thread) == PR_FAILURE) {
+                if (thread->threadAllocatedOnStack == 1)
+                    _PR_FreeStack(thread->stack);
+                else {
+                    PR_DELETE(thread);
+                }
+                PR_SetError(PR_INSUFFICIENT_RESOURCES_ERROR, 0);
+                return NULL;
+            }
+
+            if (_PR_MD_NEW_LOCK(&thread->threadLock) == PR_FAILURE) {
+                if (thread->threadAllocatedOnStack == 1)
+                    _PR_FreeStack(thread->stack);
+                else {
+                    PR_DELETE(thread->privateData);
+                    PR_DELETE(thread);
+                }
+                PR_SetError(PR_INSUFFICIENT_RESOURCES_ERROR, 0);
+                return NULL;
+            }
+
+            _PR_MD_INIT_CONTEXT(thread, top, _PR_UserRunThread, &status);
+
+            if (status == PR_FALSE) {
+                _PR_MD_FREE_LOCK(&thread->threadLock);
+                if (thread->threadAllocatedOnStack == 1)
+                    _PR_FreeStack(thread->stack);
+                else {
+                    PR_DELETE(thread->privateData);
+                    PR_DELETE(thread);
+                }
+                return NULL;
+            }
+
+            /* 
+              Set thread flags related to scope and joinable state. If joinable
+              thread, allocate a "termination" condition variable.
+            */
+            if (state == PR_JOINABLE_THREAD) {
+                thread->term = PR_NewCondVar(_pr_terminationCVLock);
+                if (thread->term == NULL) {
+                    _PR_MD_FREE_LOCK(&thread->threadLock);
+                    if (thread->threadAllocatedOnStack == 1)
+                        _PR_FreeStack(thread->stack);
+                    else {
+                        PR_DELETE(thread->privateData);
+                        PR_DELETE(thread);
+                    }
+                    return NULL;
+                }
+            }
+  
+        }
+  
+        /* Update thread type counter */
+        PR_Lock(_pr_activeLock);
+        thread->flags = flags;
+        thread->id = ++_pr_utid;
+        if (type == PR_SYSTEM_THREAD) {
+            thread->flags |= _PR_SYSTEM;
+            _pr_systemActive++;
+        } else {
+            _pr_userActive++;
+        }
+
+        /* Make thread runnable */
+        thread->state = _PR_RUNNABLE;
+    /*
+     * Add to list of active threads
+     */
+        PR_Unlock(_pr_activeLock);
+
+        if ((! (thread->flags & _PR_IDLE_THREAD)) && _PR_IS_NATIVE_THREAD(me) )
+            thread->cpu = _PR_GetPrimordialCPU();
+        else
+            thread->cpu = _PR_MD_CURRENT_CPU();
+
+        PR_ASSERT(!_PR_IS_NATIVE_THREAD(thread));
+
+        if ((! (thread->flags & _PR_IDLE_THREAD)) && !_PR_IS_NATIVE_THREAD(me)) {
+            _PR_INTSOFF(is);
+            _PR_RUNQ_LOCK(thread->cpu);
+            _PR_ADD_RUNQ(thread, thread->cpu, priority);
+            _PR_RUNQ_UNLOCK(thread->cpu);
+        }
+
+        if (thread->flags & _PR_IDLE_THREAD) {
+            /*
+            ** If the creating thread is a kernel thread, we need to
+            ** awaken the user thread idle thread somehow; potentially
+            ** it could be sleeping in its idle loop, and we need to poke
+            ** it.  To do so, wake the idle thread...  
+            */
+            _PR_MD_WAKEUP_WAITER(NULL);
+        } else if (_PR_IS_NATIVE_THREAD(me)) {
+            _PR_MD_WAKEUP_WAITER(thread);
+        }
+        if ((! (thread->flags & _PR_IDLE_THREAD)) && !_PR_IS_NATIVE_THREAD(me) )
+            _PR_INTSON(is);
+    }
+
+    return thread;
+}
+
+PR_IMPLEMENT(PRThread*) PR_CreateThread(PRThreadType type,
+                     void (*start)(void *arg),
+                     void *arg,
+                     PRThreadPriority priority,
+                     PRThreadScope scope,
+                     PRThreadState state,
+                     PRUint32 stackSize)
+{
+    return _PR_CreateThread(type, start, arg, priority, scope, state, 
+                            stackSize, 0);
+}
+
+/*
+** Associate a thread object with an existing native thread.
+**     "type" is the type of thread object to attach
+**     "priority" is the priority to assign to the thread
+**     "stack" defines the shape of the threads stack
+**
+** This can return NULL if some kind of error occurs, or if memory is
+** tight.
+**
+** This call is not normally needed unless you create your own native
+** thread. PR_Init does this automatically for the primordial thread.
+*/
+PRThread* _PRI_AttachThread(PRThreadType type,
+    PRThreadPriority priority, PRThreadStack *stack, PRUint32 flags)
+{
+    PRThread *thread;
+
+    if ((thread = _PR_MD_GET_ATTACHED_THREAD()) != NULL) {
+        return thread;
+    }
+    _PR_MD_SET_CURRENT_THREAD(NULL);
+
+    /* Clear out any state if this thread was attached before */
+    _PR_MD_SET_CURRENT_CPU(NULL);
+
+    thread = _PR_AttachThread(type, priority, stack);
+    if (thread) {
+        PRIntn is;
+
+        _PR_MD_SET_CURRENT_THREAD(thread);
+
+        thread->flags = flags | _PR_GLOBAL_SCOPE | _PR_ATTACHED;
+
+        if (!stack) {
+            thread->stack = PR_NEWZAP(PRThreadStack);
+            if (!thread->stack) {
+                _PR_DestroyThread(thread);
+                return NULL;
+            }
+            thread->stack->stackSize = _MD_DEFAULT_STACK_SIZE;
+        }
+        PR_INIT_CLIST(&thread->links);
+
+        if (_PR_MD_INIT_ATTACHED_THREAD(thread) == PR_FAILURE) {
+                PR_DELETE(thread->stack);
+                _PR_DestroyThread(thread);
+                return NULL;
+        }
+
+        _PR_MD_SET_CURRENT_CPU(NULL);
+
+        if (_PR_MD_CURRENT_CPU()) {
+            _PR_INTSOFF(is);
+            PR_Lock(_pr_activeLock);
+        }
+        if (type == PR_SYSTEM_THREAD) {
+            thread->flags |= _PR_SYSTEM;
+            _pr_systemActive++;
+        } else {
+            _pr_userActive++;
+        }
+        if (_PR_MD_CURRENT_CPU()) {
+            PR_Unlock(_pr_activeLock);
+            _PR_INTSON(is);
+        }
+    }
+    return thread;
+}
+
+PR_IMPLEMENT(PRThread*) PR_AttachThread(PRThreadType type,
+    PRThreadPriority priority, PRThreadStack *stack)
+{
+    return PR_GetCurrentThread();
+}
+
+PR_IMPLEMENT(void) PR_DetachThread(void)
+{
+    /*
+     * On IRIX, Solaris, and Windows, foreign threads are detached when
+     * they terminate.
+     */
+#if !defined(IRIX) && !defined(WIN32) \
+        && !(defined(SOLARIS) && defined(_PR_GLOBAL_THREADS_ONLY))
+    PRThread *me;
+    if (_pr_initialized) {
+        me = _PR_MD_GET_ATTACHED_THREAD();
+        if ((me != NULL) && (me->flags & _PR_ATTACHED))
+            _PRI_DetachThread();
+    }
+#endif
+}
+
+void _PRI_DetachThread(void)
+{
+    PRThread *me = _PR_MD_CURRENT_THREAD();
+
+	if (me->flags & _PR_PRIMORDIAL) {
+		/*
+		 * ignore, if primordial thread
+		 */
+		return;
+	}
+    PR_ASSERT(me->flags & _PR_ATTACHED);
+    PR_ASSERT(_PR_IS_NATIVE_THREAD(me));
+    _PR_CleanupThread(me);
+    PR_DELETE(me->privateData);
+
+    _PR_DecrActiveThreadCount(me);
+
+    _PR_MD_CLEAN_THREAD(me);
+    _PR_MD_SET_CURRENT_THREAD(NULL);
+    if (!me->threadAllocatedOnStack) 
+        PR_DELETE(me->stack);
+    _PR_MD_FREE_LOCK(&me->threadLock);
+    PR_DELETE(me);
+}
+
+/*
+** Wait for thread termination:
+**     "thread" is the target thread 
+**
+** This can return PR_FAILURE if no joinable thread could be found 
+** corresponding to the specified target thread.
+**
+** The calling thread is suspended until the target thread completes.
+** Several threads cannot wait for the same thread to complete; one thread
+** will complete successfully and others will terminate with an error PR_FAILURE.
+** The calling thread will not be blocked if the target thread has already
+** terminated.
+*/
+PR_IMPLEMENT(PRStatus) PR_JoinThread(PRThread *thread)
+{
+    PRIntn is;
+    PRCondVar *term;
+    PRThread *me = _PR_MD_CURRENT_THREAD();
+
+    if (!_PR_IS_NATIVE_THREAD(me))
+        _PR_INTSOFF(is);
+    term = thread->term;
+    /* can't join a non-joinable thread */
+    if (term == NULL) {
+        PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
+        goto ErrorExit;
+    }
+
+    /* multiple threads can't wait on the same joinable thread */
+    if (term->condQ.next != &term->condQ) {
+        goto ErrorExit;
+    }
+    if (!_PR_IS_NATIVE_THREAD(me))
+        _PR_INTSON(is);
+
+    /* wait for the target thread's termination cv invariant */
+    PR_Lock (_pr_terminationCVLock);
+    while (thread->state != _PR_JOIN_WAIT) {
+        (void) PR_WaitCondVar(term, PR_INTERVAL_NO_TIMEOUT);
+    }
+    (void) PR_Unlock (_pr_terminationCVLock);
+    
+    /* 
+     Remove target thread from global waiting to join Q; make it runnable
+     again and put it back on its run Q.  When it gets scheduled later in
+     _PR_RunThread code, it will clean up its stack.
+    */    
+    if (!_PR_IS_NATIVE_THREAD(me))
+        _PR_INTSOFF(is);
+    thread->state = _PR_RUNNABLE;
+    if ( !_PR_IS_NATIVE_THREAD(thread) ) {
+        _PR_THREAD_LOCK(thread);
+
+        _PR_MISCQ_LOCK(thread->cpu);
+        _PR_DEL_JOINQ(thread);
+        _PR_MISCQ_UNLOCK(thread->cpu);
+
+        _PR_AddThreadToRunQ(me, thread);
+        _PR_THREAD_UNLOCK(thread);
+    }
+    if (!_PR_IS_NATIVE_THREAD(me))
+        _PR_INTSON(is);
+
+    _PR_MD_WAKEUP_WAITER(thread);
+
+    return PR_SUCCESS;
+
+ErrorExit:
+    if ( !_PR_IS_NATIVE_THREAD(me)) _PR_INTSON(is);
+    return PR_FAILURE;   
+}
+
+PR_IMPLEMENT(void) PR_SetThreadPriority(PRThread *thread,
+    PRThreadPriority newPri)
+{
+
+    /* 
+    First, pin down the priority.  Not all compilers catch passing out of
+    range enum here.  If we let bad values thru, priority queues won't work.
+    */
+    if ((PRIntn)newPri > (PRIntn)PR_PRIORITY_LAST) {
+        newPri = PR_PRIORITY_LAST;
+    } else if ((PRIntn)newPri < (PRIntn)PR_PRIORITY_FIRST) {
+        newPri = PR_PRIORITY_FIRST;
+    }
+        
+    if ( _PR_IS_NATIVE_THREAD(thread) ) {
+        thread->priority = newPri;
+        _PR_MD_SET_PRIORITY(&(thread->md), newPri);
+    } else _PR_SetThreadPriority(thread, newPri);
+}
+
+PR_IMPLEMENT(PRStatus) PR_SetCurrentThreadName(const char *name)
+{
+    PRThread *thread;
+    size_t nameLen;
+
+    if (!name) {
+        PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
+        return PR_FAILURE;
+    }
+
+    thread = PR_GetCurrentThread();
+    if (!thread)
+        return PR_FAILURE;
+
+    PR_Free(thread->name);
+    nameLen = strlen(name);
+    thread->name = (char *)PR_Malloc(nameLen + 1);
+    if (!thread->name)
+        return PR_FAILURE;
+    memcpy(thread->name, name, nameLen + 1);
+    _PR_MD_SET_CURRENT_THREAD_NAME(thread->name);
+    return PR_SUCCESS;
+}
+
+PR_IMPLEMENT(const char *) PR_GetThreadName(const PRThread *thread)
+{
+    if (!thread)
+        return NULL;
+    return thread->name;
+}
+
+
+/*
+** This routine prevents all other threads from running. This call is needed by 
+** the garbage collector.
+*/
+PR_IMPLEMENT(void) PR_SuspendAll(void)
+{
+    PRThread *me = _PR_MD_CURRENT_THREAD();
+    PRCList *qp;
+
+    /*
+     * Stop all user and native threads which are marked GC able.
+     */
+    PR_Lock(_pr_activeLock);
+    suspendAllOn = PR_TRUE;
+    suspendAllThread = _PR_MD_CURRENT_THREAD();
+    _PR_MD_BEGIN_SUSPEND_ALL();
+    for (qp = _PR_ACTIVE_LOCAL_THREADQ().next;
+        qp != &_PR_ACTIVE_LOCAL_THREADQ(); qp = qp->next) {
+        if ((me != _PR_ACTIVE_THREAD_PTR(qp)) && 
+            _PR_IS_GCABLE_THREAD(_PR_ACTIVE_THREAD_PTR(qp))) {
+            _PR_Suspend(_PR_ACTIVE_THREAD_PTR(qp));
+                PR_ASSERT((_PR_ACTIVE_THREAD_PTR(qp))->state != _PR_RUNNING);
+            }
+    }
+    for (qp = _PR_ACTIVE_GLOBAL_THREADQ().next;
+        qp != &_PR_ACTIVE_GLOBAL_THREADQ(); qp = qp->next) {
+        if ((me != _PR_ACTIVE_THREAD_PTR(qp)) &&
+            _PR_IS_GCABLE_THREAD(_PR_ACTIVE_THREAD_PTR(qp)))
+            /* PR_Suspend(_PR_ACTIVE_THREAD_PTR(qp)); */
+                _PR_MD_SUSPEND_THREAD(_PR_ACTIVE_THREAD_PTR(qp)); 
+    }
+    _PR_MD_END_SUSPEND_ALL();
+}
+
+/*
+** This routine unblocks all other threads that were suspended from running by 
+** PR_SuspendAll(). This call is needed by the garbage collector.
+*/
+PR_IMPLEMENT(void) PR_ResumeAll(void)
+{
+    PRThread *me = _PR_MD_CURRENT_THREAD();
+    PRCList *qp;
+
+    /*
+     * Resume all user and native threads which are marked GC able.
+     */
+    _PR_MD_BEGIN_RESUME_ALL();
+    for (qp = _PR_ACTIVE_LOCAL_THREADQ().next;
+        qp != &_PR_ACTIVE_LOCAL_THREADQ(); qp = qp->next) {
+        if ((me != _PR_ACTIVE_THREAD_PTR(qp)) && 
+            _PR_IS_GCABLE_THREAD(_PR_ACTIVE_THREAD_PTR(qp)))
+            _PR_Resume(_PR_ACTIVE_THREAD_PTR(qp));
+    }
+    for (qp = _PR_ACTIVE_GLOBAL_THREADQ().next;
+        qp != &_PR_ACTIVE_GLOBAL_THREADQ(); qp = qp->next) {
+        if ((me != _PR_ACTIVE_THREAD_PTR(qp)) &&
+            _PR_IS_GCABLE_THREAD(_PR_ACTIVE_THREAD_PTR(qp)))
+                _PR_MD_RESUME_THREAD(_PR_ACTIVE_THREAD_PTR(qp));
+    }
+    _PR_MD_END_RESUME_ALL();
+    suspendAllThread = NULL;
+    suspendAllOn = PR_FALSE;
+    PR_Unlock(_pr_activeLock);
+}
+
+PR_IMPLEMENT(PRStatus) PR_EnumerateThreads(PREnumerator func, void *arg)
+{
+    PRCList *qp, *qp_next;
+    PRIntn i = 0;
+    PRStatus rv = PR_SUCCESS;
+    PRThread* t;
+
+    /*
+    ** Currently Enumerate threads happen only with suspension and
+    ** pr_activeLock held
+    */
+    PR_ASSERT(suspendAllOn);
+
+    /* Steve Morse, 4-23-97: Note that we can't walk a queue by taking
+     * qp->next after applying the function "func".  In particular, "func"
+     * might remove the thread from the queue and put it into another one in
+     * which case qp->next no longer points to the next entry in the original
+     * queue.
+     *
+     * To get around this problem, we save qp->next in qp_next before applying
+     * "func" and use that saved value as the next value after applying "func".
+     */
+
+    /*
+     * Traverse the list of local and global threads
+     */
+    for (qp = _PR_ACTIVE_LOCAL_THREADQ().next;
+         qp != &_PR_ACTIVE_LOCAL_THREADQ(); qp = qp_next)
+    {
+        qp_next = qp->next;
+        t = _PR_ACTIVE_THREAD_PTR(qp);
+        if (_PR_IS_GCABLE_THREAD(t))
+        {
+            rv = (*func)(t, i, arg);
+            if (rv != PR_SUCCESS)
+                return rv;
+            i++;
+        }
+    }
+    for (qp = _PR_ACTIVE_GLOBAL_THREADQ().next;
+         qp != &_PR_ACTIVE_GLOBAL_THREADQ(); qp = qp_next)
+    {
+        qp_next = qp->next;
+        t = _PR_ACTIVE_THREAD_PTR(qp);
+        if (_PR_IS_GCABLE_THREAD(t))
+        {
+            rv = (*func)(t, i, arg);
+            if (rv != PR_SUCCESS)
+                return rv;
+            i++;
+        }
+    }
+    return rv;
+}
+
+/* FUNCTION: _PR_AddSleepQ
+** DESCRIPTION:
+**    Adds a thread to the sleep/pauseQ.
+** RESTRICTIONS:
+**    Caller must have the RUNQ lock.
+**    Caller must be a user level thread
+*/
+PR_IMPLEMENT(void)
+_PR_AddSleepQ(PRThread *thread, PRIntervalTime timeout)
+{
+    _PRCPU *cpu = thread->cpu;
+
+    if (timeout == PR_INTERVAL_NO_TIMEOUT) {
+        /* append the thread to the global pause Q */
+        PR_APPEND_LINK(&thread->links, &_PR_PAUSEQ(thread->cpu));
+        thread->flags |= _PR_ON_PAUSEQ;
+    } else {
+        PRIntervalTime sleep;
+        PRCList *q;
+        PRThread *t;
+
+        /* sort onto global sleepQ */
+        sleep = timeout;
+
+        /* Check if we are longest timeout */
+        if (timeout >= _PR_SLEEPQMAX(cpu)) {
+            PR_INSERT_BEFORE(&thread->links, &_PR_SLEEPQ(cpu));
+            thread->sleep = timeout - _PR_SLEEPQMAX(cpu);
+            _PR_SLEEPQMAX(cpu) = timeout;
+        } else {
+            /* Sort thread into global sleepQ at appropriate point */
+            q = _PR_SLEEPQ(cpu).next;
+
+            /* Now scan the list for where to insert this entry */
+            while (q != &_PR_SLEEPQ(cpu)) {
+                t = _PR_THREAD_PTR(q);
+                if (sleep < t->sleep) {
+                    /* Found sleeper to insert in front of */
+                    break;
+                }
+                sleep -= t->sleep;
+                q = q->next;
+            }
+            thread->sleep = sleep;
+            PR_INSERT_BEFORE(&thread->links, q);
+
+            /*
+            ** Subtract our sleep time from the sleeper that follows us (there
+            ** must be one) so that they remain relative to us.
+            */
+            PR_ASSERT (thread->links.next != &_PR_SLEEPQ(cpu));
+          
+            t = _PR_THREAD_PTR(thread->links.next);
+            PR_ASSERT(_PR_THREAD_PTR(t->links.prev) == thread);
+            t->sleep -= sleep;
+        }
+
+        thread->flags |= _PR_ON_SLEEPQ;
+    }
+}
+
+/* FUNCTION: _PR_DelSleepQ
+** DESCRIPTION:
+**    Removes a thread from the sleep/pauseQ.
+** INPUTS:
+**    If propogate_time is true, then the thread following the deleted
+**    thread will be get the time from the deleted thread.  This is used
+**    when deleting a sleeper that has not timed out.
+** RESTRICTIONS:
+**    Caller must have the RUNQ lock.
+**    Caller must be a user level thread
+*/
+PR_IMPLEMENT(void)
+_PR_DelSleepQ(PRThread *thread, PRBool propogate_time)
+{
+    _PRCPU *cpu = thread->cpu;
+
+    /* Remove from pauseQ/sleepQ */
+    if (thread->flags & (_PR_ON_PAUSEQ|_PR_ON_SLEEPQ)) {
+        if (thread->flags & _PR_ON_SLEEPQ) {
+            PRCList *q = thread->links.next;
+            if (q != &_PR_SLEEPQ(cpu)) {
+                if (propogate_time == PR_TRUE) {
+                    PRThread *after = _PR_THREAD_PTR(q);
+                    after->sleep += thread->sleep;
+                } else 
+                    _PR_SLEEPQMAX(cpu) -= thread->sleep;
+            } else {
+                /* Check if prev is the beggining of the list; if so,
+                 * we are the only element on the list.  
+                 */
+                if (thread->links.prev != &_PR_SLEEPQ(cpu))
+                    _PR_SLEEPQMAX(cpu) -= thread->sleep;
+                else
+                    _PR_SLEEPQMAX(cpu) = 0;
+            }
+            thread->flags &= ~_PR_ON_SLEEPQ;
+        } else {
+            thread->flags &= ~_PR_ON_PAUSEQ;
+        }
+        PR_REMOVE_LINK(&thread->links);
+    } else 
+        PR_ASSERT(0);
+}
+
+void
+_PR_AddThreadToRunQ(
+    PRThread *me,     /* the current thread */
+    PRThread *thread) /* the local thread to be added to a run queue */
+{
+    PRThreadPriority pri = thread->priority;
+    _PRCPU *cpu = thread->cpu;
+
+    PR_ASSERT(!_PR_IS_NATIVE_THREAD(thread));
+
+#if defined(WINNT)
+    /*
+     * On NT, we can only reliably know that the current CPU
+     * is not idle.  We add the awakened thread to the run
+     * queue of its CPU if its CPU is the current CPU.
+     * For any other CPU, we don't really know whether it
+     * is busy or idle.  So in all other cases, we just
+     * "post" the awakened thread to the IO completion port
+     * for the next idle CPU to execute (this is done in
+     * _PR_MD_WAKEUP_WAITER).
+	 * Threads with a suspended I/O operation remain bound to
+	 * the same cpu until I/O is cancelled
+     *
+     * NOTE: the boolean expression below must be the exact
+     * opposite of the corresponding boolean expression in
+     * _PR_MD_WAKEUP_WAITER.
+     */
+    if ((!_PR_IS_NATIVE_THREAD(me) && (cpu == me->cpu)) ||
+					(thread->md.thr_bound_cpu)) {
+		PR_ASSERT(!thread->md.thr_bound_cpu ||
+							(thread->md.thr_bound_cpu == cpu));
+        _PR_RUNQ_LOCK(cpu);
+        _PR_ADD_RUNQ(thread, cpu, pri);
+        _PR_RUNQ_UNLOCK(cpu);
+    }
+#else
+    _PR_RUNQ_LOCK(cpu);
+    _PR_ADD_RUNQ(thread, cpu, pri);
+    _PR_RUNQ_UNLOCK(cpu);
+    if (!_PR_IS_NATIVE_THREAD(me) && (cpu == me->cpu)) {
+        if (pri > me->priority) {
+            _PR_SET_RESCHED_FLAG();
+        }
+    }
+#endif
+}