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authorwolfbeast <mcwerewolf@gmail.com>2018-05-03 05:55:15 +0200
committerwolfbeast <mcwerewolf@gmail.com>2018-05-03 05:55:15 +0200
commit43f7a588f96aaf88e7b69441c3b50bc9c7b20df7 (patch)
tree07d9b26b2f357ee9de04fea0e5e4b8b9a1ff93a4 /security/sandbox/chromium/base/synchronization
parent4613b91ecac2745252c40be64e73de5ff920b02b (diff)
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Nuke the sandbox
Diffstat (limited to 'security/sandbox/chromium/base/synchronization')
-rw-r--r--security/sandbox/chromium/base/synchronization/condition_variable.h118
-rw-r--r--security/sandbox/chromium/base/synchronization/condition_variable_posix.cc137
-rw-r--r--security/sandbox/chromium/base/synchronization/lock.cc38
-rw-r--r--security/sandbox/chromium/base/synchronization/lock.h140
-rw-r--r--security/sandbox/chromium/base/synchronization/lock_impl.h60
-rw-r--r--security/sandbox/chromium/base/synchronization/lock_impl_posix.cc55
-rw-r--r--security/sandbox/chromium/base/synchronization/lock_impl_win.cc36
-rw-r--r--security/sandbox/chromium/base/synchronization/waitable_event.h189
-rw-r--r--security/sandbox/chromium/base/synchronization/waitable_event_posix.cc417
9 files changed, 0 insertions, 1190 deletions
diff --git a/security/sandbox/chromium/base/synchronization/condition_variable.h b/security/sandbox/chromium/base/synchronization/condition_variable.h
deleted file mode 100644
index a41b2ba5a..000000000
--- a/security/sandbox/chromium/base/synchronization/condition_variable.h
+++ /dev/null
@@ -1,118 +0,0 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// ConditionVariable wraps pthreads condition variable synchronization or, on
-// Windows, simulates it. This functionality is very helpful for having
-// several threads wait for an event, as is common with a thread pool managed
-// by a master. The meaning of such an event in the (worker) thread pool
-// scenario is that additional tasks are now available for processing. It is
-// used in Chrome in the DNS prefetching system to notify worker threads that
-// a queue now has items (tasks) which need to be tended to. A related use
-// would have a pool manager waiting on a ConditionVariable, waiting for a
-// thread in the pool to announce (signal) that there is now more room in a
-// (bounded size) communications queue for the manager to deposit tasks, or,
-// as a second example, that the queue of tasks is completely empty and all
-// workers are waiting.
-//
-// USAGE NOTE 1: spurious signal events are possible with this and
-// most implementations of condition variables. As a result, be
-// *sure* to retest your condition before proceeding. The following
-// is a good example of doing this correctly:
-//
-// while (!work_to_be_done()) Wait(...);
-//
-// In contrast do NOT do the following:
-//
-// if (!work_to_be_done()) Wait(...); // Don't do this.
-//
-// Especially avoid the above if you are relying on some other thread only
-// issuing a signal up *if* there is work-to-do. There can/will
-// be spurious signals. Recheck state on waiting thread before
-// assuming the signal was intentional. Caveat caller ;-).
-//
-// USAGE NOTE 2: Broadcast() frees up all waiting threads at once,
-// which leads to contention for the locks they all held when they
-// called Wait(). This results in POOR performance. A much better
-// approach to getting a lot of threads out of Wait() is to have each
-// thread (upon exiting Wait()) call Signal() to free up another
-// Wait'ing thread. Look at condition_variable_unittest.cc for
-// both examples.
-//
-// Broadcast() can be used nicely during teardown, as it gets the job
-// done, and leaves no sleeping threads... and performance is less
-// critical at that point.
-//
-// The semantics of Broadcast() are carefully crafted so that *all*
-// threads that were waiting when the request was made will indeed
-// get signaled. Some implementations mess up, and don't signal them
-// all, while others allow the wait to be effectively turned off (for
-// a while while waiting threads come around). This implementation
-// appears correct, as it will not "lose" any signals, and will guarantee
-// that all threads get signaled by Broadcast().
-//
-// This implementation offers support for "performance" in its selection of
-// which thread to revive. Performance, in direct contrast with "fairness,"
-// assures that the thread that most recently began to Wait() is selected by
-// Signal to revive. Fairness would (if publicly supported) assure that the
-// thread that has Wait()ed the longest is selected. The default policy
-// may improve performance, as the selected thread may have a greater chance of
-// having some of its stack data in various CPU caches.
-//
-// For a discussion of the many very subtle implementation details, see the FAQ
-// at the end of condition_variable_win.cc.
-
-#ifndef BASE_SYNCHRONIZATION_CONDITION_VARIABLE_H_
-#define BASE_SYNCHRONIZATION_CONDITION_VARIABLE_H_
-
-#include "base/base_export.h"
-#include "base/logging.h"
-#include "base/macros.h"
-#include "base/synchronization/lock.h"
-#include "build/build_config.h"
-
-#if defined(OS_POSIX)
-#include <pthread.h>
-#endif
-
-namespace base {
-
-class ConditionVarImpl;
-class TimeDelta;
-
-class BASE_EXPORT ConditionVariable {
- public:
- // Construct a cv for use with ONLY one user lock.
- explicit ConditionVariable(Lock* user_lock);
-
- ~ConditionVariable();
-
- // Wait() releases the caller's critical section atomically as it starts to
- // sleep, and the reacquires it when it is signaled.
- void Wait();
- void TimedWait(const TimeDelta& max_time);
-
- // Broadcast() revives all waiting threads.
- void Broadcast();
- // Signal() revives one waiting thread.
- void Signal();
-
- private:
-
-#if defined(OS_WIN)
- ConditionVarImpl* impl_;
-#elif defined(OS_POSIX)
- pthread_cond_t condition_;
- pthread_mutex_t* user_mutex_;
-#if DCHECK_IS_ON()
- base::Lock* user_lock_; // Needed to adjust shadow lock state on wait.
-#endif
-
-#endif
-
- DISALLOW_COPY_AND_ASSIGN(ConditionVariable);
-};
-
-} // namespace base
-
-#endif // BASE_SYNCHRONIZATION_CONDITION_VARIABLE_H_
diff --git a/security/sandbox/chromium/base/synchronization/condition_variable_posix.cc b/security/sandbox/chromium/base/synchronization/condition_variable_posix.cc
deleted file mode 100644
index d86fd180e..000000000
--- a/security/sandbox/chromium/base/synchronization/condition_variable_posix.cc
+++ /dev/null
@@ -1,137 +0,0 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "base/synchronization/condition_variable.h"
-
-#include <errno.h>
-#include <stdint.h>
-#include <sys/time.h>
-
-#include "base/synchronization/lock.h"
-#include "base/threading/thread_restrictions.h"
-#include "base/time/time.h"
-#include "build/build_config.h"
-
-namespace base {
-
-ConditionVariable::ConditionVariable(Lock* user_lock)
- : user_mutex_(user_lock->lock_.native_handle())
-#if DCHECK_IS_ON()
- , user_lock_(user_lock)
-#endif
-{
- int rv = 0;
- // http://crbug.com/293736
- // NaCl doesn't support monotonic clock based absolute deadlines.
- // On older Android platform versions, it's supported through the
- // non-standard pthread_cond_timedwait_monotonic_np. Newer platform
- // versions have pthread_condattr_setclock.
- // Mac can use relative time deadlines.
-#if !defined(OS_MACOSX) && !defined(OS_NACL) && \
- !(defined(OS_ANDROID) && defined(HAVE_PTHREAD_COND_TIMEDWAIT_MONOTONIC))
- pthread_condattr_t attrs;
- rv = pthread_condattr_init(&attrs);
- DCHECK_EQ(0, rv);
- pthread_condattr_setclock(&attrs, CLOCK_MONOTONIC);
- rv = pthread_cond_init(&condition_, &attrs);
- pthread_condattr_destroy(&attrs);
-#else
- rv = pthread_cond_init(&condition_, NULL);
-#endif
- DCHECK_EQ(0, rv);
-}
-
-ConditionVariable::~ConditionVariable() {
-#if defined(OS_MACOSX)
- // This hack is necessary to avoid a fatal pthreads subsystem bug in the
- // Darwin kernel. http://crbug.com/517681.
- {
- base::Lock lock;
- base::AutoLock l(lock);
- struct timespec ts;
- ts.tv_sec = 0;
- ts.tv_nsec = 1;
- pthread_cond_timedwait_relative_np(&condition_, lock.lock_.native_handle(),
- &ts);
- }
-#endif
-
- int rv = pthread_cond_destroy(&condition_);
- DCHECK_EQ(0, rv);
-}
-
-void ConditionVariable::Wait() {
- base::ThreadRestrictions::AssertWaitAllowed();
-#if DCHECK_IS_ON()
- user_lock_->CheckHeldAndUnmark();
-#endif
- int rv = pthread_cond_wait(&condition_, user_mutex_);
- DCHECK_EQ(0, rv);
-#if DCHECK_IS_ON()
- user_lock_->CheckUnheldAndMark();
-#endif
-}
-
-void ConditionVariable::TimedWait(const TimeDelta& max_time) {
- base::ThreadRestrictions::AssertWaitAllowed();
- int64_t usecs = max_time.InMicroseconds();
- struct timespec relative_time;
- relative_time.tv_sec = usecs / Time::kMicrosecondsPerSecond;
- relative_time.tv_nsec =
- (usecs % Time::kMicrosecondsPerSecond) * Time::kNanosecondsPerMicrosecond;
-
-#if DCHECK_IS_ON()
- user_lock_->CheckHeldAndUnmark();
-#endif
-
-#if defined(OS_MACOSX)
- int rv = pthread_cond_timedwait_relative_np(
- &condition_, user_mutex_, &relative_time);
-#else
- // The timeout argument to pthread_cond_timedwait is in absolute time.
- struct timespec absolute_time;
-#if defined(OS_NACL)
- // See comment in constructor for why this is different in NaCl.
- struct timeval now;
- gettimeofday(&now, NULL);
- absolute_time.tv_sec = now.tv_sec;
- absolute_time.tv_nsec = now.tv_usec * Time::kNanosecondsPerMicrosecond;
-#else
- struct timespec now;
- clock_gettime(CLOCK_MONOTONIC, &now);
- absolute_time.tv_sec = now.tv_sec;
- absolute_time.tv_nsec = now.tv_nsec;
-#endif
-
- absolute_time.tv_sec += relative_time.tv_sec;
- absolute_time.tv_nsec += relative_time.tv_nsec;
- absolute_time.tv_sec += absolute_time.tv_nsec / Time::kNanosecondsPerSecond;
- absolute_time.tv_nsec %= Time::kNanosecondsPerSecond;
- DCHECK_GE(absolute_time.tv_sec, now.tv_sec); // Overflow paranoia
-
-#if defined(OS_ANDROID) && defined(HAVE_PTHREAD_COND_TIMEDWAIT_MONOTONIC)
- int rv = pthread_cond_timedwait_monotonic_np(
- &condition_, user_mutex_, &absolute_time);
-#else
- int rv = pthread_cond_timedwait(&condition_, user_mutex_, &absolute_time);
-#endif // OS_ANDROID && HAVE_PTHREAD_COND_TIMEDWAIT_MONOTONIC
-#endif // OS_MACOSX
-
- DCHECK(rv == 0 || rv == ETIMEDOUT);
-#if DCHECK_IS_ON()
- user_lock_->CheckUnheldAndMark();
-#endif
-}
-
-void ConditionVariable::Broadcast() {
- int rv = pthread_cond_broadcast(&condition_);
- DCHECK_EQ(0, rv);
-}
-
-void ConditionVariable::Signal() {
- int rv = pthread_cond_signal(&condition_);
- DCHECK_EQ(0, rv);
-}
-
-} // namespace base
diff --git a/security/sandbox/chromium/base/synchronization/lock.cc b/security/sandbox/chromium/base/synchronization/lock.cc
deleted file mode 100644
index 03297ada5..000000000
--- a/security/sandbox/chromium/base/synchronization/lock.cc
+++ /dev/null
@@ -1,38 +0,0 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// This file is used for debugging assertion support. The Lock class
-// is functionally a wrapper around the LockImpl class, so the only
-// real intelligence in the class is in the debugging logic.
-
-#include "base/synchronization/lock.h"
-
-#if DCHECK_IS_ON()
-
-namespace base {
-
-Lock::Lock() : lock_() {
-}
-
-Lock::~Lock() {
- DCHECK(owning_thread_ref_.is_null());
-}
-
-void Lock::AssertAcquired() const {
- DCHECK(owning_thread_ref_ == PlatformThread::CurrentRef());
-}
-
-void Lock::CheckHeldAndUnmark() {
- DCHECK(owning_thread_ref_ == PlatformThread::CurrentRef());
- owning_thread_ref_ = PlatformThreadRef();
-}
-
-void Lock::CheckUnheldAndMark() {
- DCHECK(owning_thread_ref_.is_null());
- owning_thread_ref_ = PlatformThread::CurrentRef();
-}
-
-} // namespace base
-
-#endif // DCHECK_IS_ON()
diff --git a/security/sandbox/chromium/base/synchronization/lock.h b/security/sandbox/chromium/base/synchronization/lock.h
deleted file mode 100644
index f7dd35dcc..000000000
--- a/security/sandbox/chromium/base/synchronization/lock.h
+++ /dev/null
@@ -1,140 +0,0 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef BASE_SYNCHRONIZATION_LOCK_H_
-#define BASE_SYNCHRONIZATION_LOCK_H_
-
-#include "base/base_export.h"
-#include "base/logging.h"
-#include "base/macros.h"
-#include "base/synchronization/lock_impl.h"
-#include "base/threading/platform_thread.h"
-#include "build/build_config.h"
-
-namespace base {
-
-// A convenient wrapper for an OS specific critical section. The only real
-// intelligence in this class is in debug mode for the support for the
-// AssertAcquired() method.
-class BASE_EXPORT Lock {
- public:
-#if !DCHECK_IS_ON()
- // Optimized wrapper implementation
- Lock() : lock_() {}
- ~Lock() {}
- void Acquire() { lock_.Lock(); }
- void Release() { lock_.Unlock(); }
-
- // If the lock is not held, take it and return true. If the lock is already
- // held by another thread, immediately return false. This must not be called
- // by a thread already holding the lock (what happens is undefined and an
- // assertion may fail).
- bool Try() { return lock_.Try(); }
-
- // Null implementation if not debug.
- void AssertAcquired() const {}
-#else
- Lock();
- ~Lock();
-
- // NOTE: Although windows critical sections support recursive locks, we do not
- // allow this, and we will commonly fire a DCHECK() if a thread attempts to
- // acquire the lock a second time (while already holding it).
- void Acquire() {
- lock_.Lock();
- CheckUnheldAndMark();
- }
- void Release() {
- CheckHeldAndUnmark();
- lock_.Unlock();
- }
-
- bool Try() {
- bool rv = lock_.Try();
- if (rv) {
- CheckUnheldAndMark();
- }
- return rv;
- }
-
- void AssertAcquired() const;
-#endif // DCHECK_IS_ON()
-
-#if defined(OS_POSIX)
- // The posix implementation of ConditionVariable needs to be able
- // to see our lock and tweak our debugging counters, as it releases
- // and acquires locks inside of pthread_cond_{timed,}wait.
- friend class ConditionVariable;
-#elif defined(OS_WIN)
- // The Windows Vista implementation of ConditionVariable needs the
- // native handle of the critical section.
- friend class WinVistaCondVar;
-#endif
-
- private:
-#if DCHECK_IS_ON()
- // Members and routines taking care of locks assertions.
- // Note that this checks for recursive locks and allows them
- // if the variable is set. This is allowed by the underlying implementation
- // on windows but not on Posix, so we're doing unneeded checks on Posix.
- // It's worth it to share the code.
- void CheckHeldAndUnmark();
- void CheckUnheldAndMark();
-
- // All private data is implicitly protected by lock_.
- // Be VERY careful to only access members under that lock.
- base::PlatformThreadRef owning_thread_ref_;
-#endif // DCHECK_IS_ON()
-
- // Platform specific underlying lock implementation.
- internal::LockImpl lock_;
-
- DISALLOW_COPY_AND_ASSIGN(Lock);
-};
-
-// A helper class that acquires the given Lock while the AutoLock is in scope.
-class AutoLock {
- public:
- struct AlreadyAcquired {};
-
- explicit AutoLock(Lock& lock) : lock_(lock) {
- lock_.Acquire();
- }
-
- AutoLock(Lock& lock, const AlreadyAcquired&) : lock_(lock) {
- lock_.AssertAcquired();
- }
-
- ~AutoLock() {
- lock_.AssertAcquired();
- lock_.Release();
- }
-
- private:
- Lock& lock_;
- DISALLOW_COPY_AND_ASSIGN(AutoLock);
-};
-
-// AutoUnlock is a helper that will Release() the |lock| argument in the
-// constructor, and re-Acquire() it in the destructor.
-class AutoUnlock {
- public:
- explicit AutoUnlock(Lock& lock) : lock_(lock) {
- // We require our caller to have the lock.
- lock_.AssertAcquired();
- lock_.Release();
- }
-
- ~AutoUnlock() {
- lock_.Acquire();
- }
-
- private:
- Lock& lock_;
- DISALLOW_COPY_AND_ASSIGN(AutoUnlock);
-};
-
-} // namespace base
-
-#endif // BASE_SYNCHRONIZATION_LOCK_H_
diff --git a/security/sandbox/chromium/base/synchronization/lock_impl.h b/security/sandbox/chromium/base/synchronization/lock_impl.h
deleted file mode 100644
index ed85987b3..000000000
--- a/security/sandbox/chromium/base/synchronization/lock_impl.h
+++ /dev/null
@@ -1,60 +0,0 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef BASE_SYNCHRONIZATION_LOCK_IMPL_H_
-#define BASE_SYNCHRONIZATION_LOCK_IMPL_H_
-
-#include "base/base_export.h"
-#include "base/macros.h"
-#include "build/build_config.h"
-
-#if defined(OS_WIN)
-#include <windows.h>
-#elif defined(OS_POSIX)
-#include <pthread.h>
-#endif
-
-namespace base {
-namespace internal {
-
-// This class implements the underlying platform-specific spin-lock mechanism
-// used for the Lock class. Most users should not use LockImpl directly, but
-// should instead use Lock.
-class BASE_EXPORT LockImpl {
- public:
-#if defined(OS_WIN)
- typedef CRITICAL_SECTION NativeHandle;
-#elif defined(OS_POSIX)
- typedef pthread_mutex_t NativeHandle;
-#endif
-
- LockImpl();
- ~LockImpl();
-
- // If the lock is not held, take it and return true. If the lock is already
- // held by something else, immediately return false.
- bool Try();
-
- // Take the lock, blocking until it is available if necessary.
- void Lock();
-
- // Release the lock. This must only be called by the lock's holder: after
- // a successful call to Try, or a call to Lock.
- void Unlock();
-
- // Return the native underlying lock.
- // TODO(awalker): refactor lock and condition variables so that this is
- // unnecessary.
- NativeHandle* native_handle() { return &native_handle_; }
-
- private:
- NativeHandle native_handle_;
-
- DISALLOW_COPY_AND_ASSIGN(LockImpl);
-};
-
-} // namespace internal
-} // namespace base
-
-#endif // BASE_SYNCHRONIZATION_LOCK_IMPL_H_
diff --git a/security/sandbox/chromium/base/synchronization/lock_impl_posix.cc b/security/sandbox/chromium/base/synchronization/lock_impl_posix.cc
deleted file mode 100644
index 5619adaf5..000000000
--- a/security/sandbox/chromium/base/synchronization/lock_impl_posix.cc
+++ /dev/null
@@ -1,55 +0,0 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "base/synchronization/lock_impl.h"
-
-#include <errno.h>
-#include <string.h>
-
-#include "base/logging.h"
-
-namespace base {
-namespace internal {
-
-LockImpl::LockImpl() {
-#ifndef NDEBUG
- // In debug, setup attributes for lock error checking.
- pthread_mutexattr_t mta;
- int rv = pthread_mutexattr_init(&mta);
- DCHECK_EQ(rv, 0) << ". " << strerror(rv);
- rv = pthread_mutexattr_settype(&mta, PTHREAD_MUTEX_ERRORCHECK);
- DCHECK_EQ(rv, 0) << ". " << strerror(rv);
- rv = pthread_mutex_init(&native_handle_, &mta);
- DCHECK_EQ(rv, 0) << ". " << strerror(rv);
- rv = pthread_mutexattr_destroy(&mta);
- DCHECK_EQ(rv, 0) << ". " << strerror(rv);
-#else
- // In release, go with the default lock attributes.
- pthread_mutex_init(&native_handle_, NULL);
-#endif
-}
-
-LockImpl::~LockImpl() {
- int rv = pthread_mutex_destroy(&native_handle_);
- DCHECK_EQ(rv, 0) << ". " << strerror(rv);
-}
-
-bool LockImpl::Try() {
- int rv = pthread_mutex_trylock(&native_handle_);
- DCHECK(rv == 0 || rv == EBUSY) << ". " << strerror(rv);
- return rv == 0;
-}
-
-void LockImpl::Lock() {
- int rv = pthread_mutex_lock(&native_handle_);
- DCHECK_EQ(rv, 0) << ". " << strerror(rv);
-}
-
-void LockImpl::Unlock() {
- int rv = pthread_mutex_unlock(&native_handle_);
- DCHECK_EQ(rv, 0) << ". " << strerror(rv);
-}
-
-} // namespace internal
-} // namespace base
diff --git a/security/sandbox/chromium/base/synchronization/lock_impl_win.cc b/security/sandbox/chromium/base/synchronization/lock_impl_win.cc
deleted file mode 100644
index fbc1bdd46..000000000
--- a/security/sandbox/chromium/base/synchronization/lock_impl_win.cc
+++ /dev/null
@@ -1,36 +0,0 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "base/synchronization/lock_impl.h"
-
-namespace base {
-namespace internal {
-
-LockImpl::LockImpl() {
- // The second parameter is the spin count, for short-held locks it avoid the
- // contending thread from going to sleep which helps performance greatly.
- ::InitializeCriticalSectionAndSpinCount(&native_handle_, 2000);
-}
-
-LockImpl::~LockImpl() {
- ::DeleteCriticalSection(&native_handle_);
-}
-
-bool LockImpl::Try() {
- if (::TryEnterCriticalSection(&native_handle_) != FALSE) {
- return true;
- }
- return false;
-}
-
-void LockImpl::Lock() {
- ::EnterCriticalSection(&native_handle_);
-}
-
-void LockImpl::Unlock() {
- ::LeaveCriticalSection(&native_handle_);
-}
-
-} // namespace internal
-} // namespace base
diff --git a/security/sandbox/chromium/base/synchronization/waitable_event.h b/security/sandbox/chromium/base/synchronization/waitable_event.h
deleted file mode 100644
index b5d91d00b..000000000
--- a/security/sandbox/chromium/base/synchronization/waitable_event.h
+++ /dev/null
@@ -1,189 +0,0 @@
-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef BASE_SYNCHRONIZATION_WAITABLE_EVENT_H_
-#define BASE_SYNCHRONIZATION_WAITABLE_EVENT_H_
-
-#include <stddef.h>
-
-#include "base/base_export.h"
-#include "base/macros.h"
-#include "build/build_config.h"
-
-#if defined(OS_WIN)
-#include "base/win/scoped_handle.h"
-#endif
-
-#if defined(OS_POSIX)
-#include <list>
-#include <utility>
-#include "base/memory/ref_counted.h"
-#include "base/synchronization/lock.h"
-#endif
-
-namespace base {
-
-class TimeDelta;
-
-// A WaitableEvent can be a useful thread synchronization tool when you want to
-// allow one thread to wait for another thread to finish some work. For
-// non-Windows systems, this can only be used from within a single address
-// space.
-//
-// Use a WaitableEvent when you would otherwise use a Lock+ConditionVariable to
-// protect a simple boolean value. However, if you find yourself using a
-// WaitableEvent in conjunction with a Lock to wait for a more complex state
-// change (e.g., for an item to be added to a queue), then you should probably
-// be using a ConditionVariable instead of a WaitableEvent.
-//
-// NOTE: On Windows, this class provides a subset of the functionality afforded
-// by a Windows event object. This is intentional. If you are writing Windows
-// specific code and you need other features of a Windows event, then you might
-// be better off just using an Windows event directly.
-class BASE_EXPORT WaitableEvent {
- public:
- // If manual_reset is true, then to set the event state to non-signaled, a
- // consumer must call the Reset method. If this parameter is false, then the
- // system automatically resets the event state to non-signaled after a single
- // waiting thread has been released.
- WaitableEvent(bool manual_reset, bool initially_signaled);
-
-#if defined(OS_WIN)
- // Create a WaitableEvent from an Event HANDLE which has already been
- // created. This objects takes ownership of the HANDLE and will close it when
- // deleted.
- explicit WaitableEvent(win::ScopedHandle event_handle);
-#endif
-
- ~WaitableEvent();
-
- // Put the event in the un-signaled state.
- void Reset();
-
- // Put the event in the signaled state. Causing any thread blocked on Wait
- // to be woken up.
- void Signal();
-
- // Returns true if the event is in the signaled state, else false. If this
- // is not a manual reset event, then this test will cause a reset.
- bool IsSignaled();
-
- // Wait indefinitely for the event to be signaled. Wait's return "happens
- // after" |Signal| has completed. This means that it's safe for a
- // WaitableEvent to synchronise its own destruction, like this:
- //
- // WaitableEvent *e = new WaitableEvent;
- // SendToOtherThread(e);
- // e->Wait();
- // delete e;
- void Wait();
-
- // Wait up until max_time has passed for the event to be signaled. Returns
- // true if the event was signaled. If this method returns false, then it
- // does not necessarily mean that max_time was exceeded.
- //
- // TimedWait can synchronise its own destruction like |Wait|.
- bool TimedWait(const TimeDelta& max_time);
-
-#if defined(OS_WIN)
- HANDLE handle() const { return handle_.Get(); }
-#endif
-
- // Wait, synchronously, on multiple events.
- // waitables: an array of WaitableEvent pointers
- // count: the number of elements in @waitables
- //
- // returns: the index of a WaitableEvent which has been signaled.
- //
- // You MUST NOT delete any of the WaitableEvent objects while this wait is
- // happening, however WaitMany's return "happens after" the |Signal| call
- // that caused it has completed, like |Wait|.
- static size_t WaitMany(WaitableEvent** waitables, size_t count);
-
- // For asynchronous waiting, see WaitableEventWatcher
-
- // This is a private helper class. It's here because it's used by friends of
- // this class (such as WaitableEventWatcher) to be able to enqueue elements
- // of the wait-list
- class Waiter {
- public:
- // Signal the waiter to wake up.
- //
- // Consider the case of a Waiter which is in multiple WaitableEvent's
- // wait-lists. Each WaitableEvent is automatic-reset and two of them are
- // signaled at the same time. Now, each will wake only the first waiter in
- // the wake-list before resetting. However, if those two waiters happen to
- // be the same object (as can happen if another thread didn't have a chance
- // to dequeue the waiter from the other wait-list in time), two auto-resets
- // will have happened, but only one waiter has been signaled!
- //
- // Because of this, a Waiter may "reject" a wake by returning false. In
- // this case, the auto-reset WaitableEvent shouldn't act as if anything has
- // been notified.
- virtual bool Fire(WaitableEvent* signaling_event) = 0;
-
- // Waiters may implement this in order to provide an extra condition for
- // two Waiters to be considered equal. In WaitableEvent::Dequeue, if the
- // pointers match then this function is called as a final check. See the
- // comments in ~Handle for why.
- virtual bool Compare(void* tag) = 0;
-
- protected:
- virtual ~Waiter() {}
- };
-
- private:
- friend class WaitableEventWatcher;
-
-#if defined(OS_WIN)
- win::ScopedHandle handle_;
-#else
- // On Windows, one can close a HANDLE which is currently being waited on. The
- // MSDN documentation says that the resulting behaviour is 'undefined', but
- // it doesn't crash. However, if we were to include the following members
- // directly then, on POSIX, one couldn't use WaitableEventWatcher to watch an
- // event which gets deleted. This mismatch has bitten us several times now,
- // so we have a kernel of the WaitableEvent, which is reference counted.
- // WaitableEventWatchers may then take a reference and thus match the Windows
- // behaviour.
- struct WaitableEventKernel :
- public RefCountedThreadSafe<WaitableEventKernel> {
- public:
- WaitableEventKernel(bool manual_reset, bool initially_signaled);
-
- bool Dequeue(Waiter* waiter, void* tag);
-
- base::Lock lock_;
- const bool manual_reset_;
- bool signaled_;
- std::list<Waiter*> waiters_;
-
- private:
- friend class RefCountedThreadSafe<WaitableEventKernel>;
- ~WaitableEventKernel();
- };
-
- typedef std::pair<WaitableEvent*, size_t> WaiterAndIndex;
-
- // When dealing with arrays of WaitableEvent*, we want to sort by the address
- // of the WaitableEvent in order to have a globally consistent locking order.
- // In that case we keep them, in sorted order, in an array of pairs where the
- // second element is the index of the WaitableEvent in the original,
- // unsorted, array.
- static size_t EnqueueMany(WaiterAndIndex* waitables,
- size_t count, Waiter* waiter);
-
- bool SignalAll();
- bool SignalOne();
- void Enqueue(Waiter* waiter);
-
- scoped_refptr<WaitableEventKernel> kernel_;
-#endif
-
- DISALLOW_COPY_AND_ASSIGN(WaitableEvent);
-};
-
-} // namespace base
-
-#endif // BASE_SYNCHRONIZATION_WAITABLE_EVENT_H_
diff --git a/security/sandbox/chromium/base/synchronization/waitable_event_posix.cc b/security/sandbox/chromium/base/synchronization/waitable_event_posix.cc
deleted file mode 100644
index 64d4376fe..000000000
--- a/security/sandbox/chromium/base/synchronization/waitable_event_posix.cc
+++ /dev/null
@@ -1,417 +0,0 @@
-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include <stddef.h>
-
-#include <algorithm>
-#include <vector>
-
-#include "base/logging.h"
-#include "base/synchronization/condition_variable.h"
-#include "base/synchronization/lock.h"
-#include "base/synchronization/waitable_event.h"
-#include "base/threading/thread_restrictions.h"
-
-// -----------------------------------------------------------------------------
-// A WaitableEvent on POSIX is implemented as a wait-list. Currently we don't
-// support cross-process events (where one process can signal an event which
-// others are waiting on). Because of this, we can avoid having one thread per
-// listener in several cases.
-//
-// The WaitableEvent maintains a list of waiters, protected by a lock. Each
-// waiter is either an async wait, in which case we have a Task and the
-// MessageLoop to run it on, or a blocking wait, in which case we have the
-// condition variable to signal.
-//
-// Waiting involves grabbing the lock and adding oneself to the wait list. Async
-// waits can be canceled, which means grabbing the lock and removing oneself
-// from the list.
-//
-// Waiting on multiple events is handled by adding a single, synchronous wait to
-// the wait-list of many events. An event passes a pointer to itself when
-// firing a waiter and so we can store that pointer to find out which event
-// triggered.
-// -----------------------------------------------------------------------------
-
-namespace base {
-
-// -----------------------------------------------------------------------------
-// This is just an abstract base class for waking the two types of waiters
-// -----------------------------------------------------------------------------
-WaitableEvent::WaitableEvent(bool manual_reset, bool initially_signaled)
- : kernel_(new WaitableEventKernel(manual_reset, initially_signaled)) {
-}
-
-WaitableEvent::~WaitableEvent() {
-}
-
-void WaitableEvent::Reset() {
- base::AutoLock locked(kernel_->lock_);
- kernel_->signaled_ = false;
-}
-
-void WaitableEvent::Signal() {
- base::AutoLock locked(kernel_->lock_);
-
- if (kernel_->signaled_)
- return;
-
- if (kernel_->manual_reset_) {
- SignalAll();
- kernel_->signaled_ = true;
- } else {
- // In the case of auto reset, if no waiters were woken, we remain
- // signaled.
- if (!SignalOne())
- kernel_->signaled_ = true;
- }
-}
-
-bool WaitableEvent::IsSignaled() {
- base::AutoLock locked(kernel_->lock_);
-
- const bool result = kernel_->signaled_;
- if (result && !kernel_->manual_reset_)
- kernel_->signaled_ = false;
- return result;
-}
-
-// -----------------------------------------------------------------------------
-// Synchronous waits
-
-// -----------------------------------------------------------------------------
-// This is a synchronous waiter. The thread is waiting on the given condition
-// variable and the fired flag in this object.
-// -----------------------------------------------------------------------------
-class SyncWaiter : public WaitableEvent::Waiter {
- public:
- SyncWaiter()
- : fired_(false),
- signaling_event_(NULL),
- lock_(),
- cv_(&lock_) {
- }
-
- bool Fire(WaitableEvent* signaling_event) override {
- base::AutoLock locked(lock_);
-
- if (fired_)
- return false;
-
- fired_ = true;
- signaling_event_ = signaling_event;
-
- cv_.Broadcast();
-
- // Unlike AsyncWaiter objects, SyncWaiter objects are stack-allocated on
- // the blocking thread's stack. There is no |delete this;| in Fire. The
- // SyncWaiter object is destroyed when it goes out of scope.
-
- return true;
- }
-
- WaitableEvent* signaling_event() const {
- return signaling_event_;
- }
-
- // ---------------------------------------------------------------------------
- // These waiters are always stack allocated and don't delete themselves. Thus
- // there's no problem and the ABA tag is the same as the object pointer.
- // ---------------------------------------------------------------------------
- bool Compare(void* tag) override { return this == tag; }
-
- // ---------------------------------------------------------------------------
- // Called with lock held.
- // ---------------------------------------------------------------------------
- bool fired() const {
- return fired_;
- }
-
- // ---------------------------------------------------------------------------
- // During a TimedWait, we need a way to make sure that an auto-reset
- // WaitableEvent doesn't think that this event has been signaled between
- // unlocking it and removing it from the wait-list. Called with lock held.
- // ---------------------------------------------------------------------------
- void Disable() {
- fired_ = true;
- }
-
- base::Lock* lock() {
- return &lock_;
- }
-
- base::ConditionVariable* cv() {
- return &cv_;
- }
-
- private:
- bool fired_;
- WaitableEvent* signaling_event_; // The WaitableEvent which woke us
- base::Lock lock_;
- base::ConditionVariable cv_;
-};
-
-void WaitableEvent::Wait() {
- bool result = TimedWait(TimeDelta::FromSeconds(-1));
- DCHECK(result) << "TimedWait() should never fail with infinite timeout";
-}
-
-bool WaitableEvent::TimedWait(const TimeDelta& max_time) {
- base::ThreadRestrictions::AssertWaitAllowed();
- const TimeTicks end_time(TimeTicks::Now() + max_time);
- const bool finite_time = max_time.ToInternalValue() >= 0;
-
- kernel_->lock_.Acquire();
- if (kernel_->signaled_) {
- if (!kernel_->manual_reset_) {
- // In this case we were signaled when we had no waiters. Now that
- // someone has waited upon us, we can automatically reset.
- kernel_->signaled_ = false;
- }
-
- kernel_->lock_.Release();
- return true;
- }
-
- SyncWaiter sw;
- sw.lock()->Acquire();
-
- Enqueue(&sw);
- kernel_->lock_.Release();
- // We are violating locking order here by holding the SyncWaiter lock but not
- // the WaitableEvent lock. However, this is safe because we don't lock @lock_
- // again before unlocking it.
-
- for (;;) {
- const TimeTicks current_time(TimeTicks::Now());
-
- if (sw.fired() || (finite_time && current_time >= end_time)) {
- const bool return_value = sw.fired();
-
- // We can't acquire @lock_ before releasing the SyncWaiter lock (because
- // of locking order), however, in between the two a signal could be fired
- // and @sw would accept it, however we will still return false, so the
- // signal would be lost on an auto-reset WaitableEvent. Thus we call
- // Disable which makes sw::Fire return false.
- sw.Disable();
- sw.lock()->Release();
-
- // This is a bug that has been enshrined in the interface of
- // WaitableEvent now: |Dequeue| is called even when |sw.fired()| is true,
- // even though it'll always return false in that case. However, taking
- // the lock ensures that |Signal| has completed before we return and
- // means that a WaitableEvent can synchronise its own destruction.
- kernel_->lock_.Acquire();
- kernel_->Dequeue(&sw, &sw);
- kernel_->lock_.Release();
-
- return return_value;
- }
-
- if (finite_time) {
- const TimeDelta max_wait(end_time - current_time);
- sw.cv()->TimedWait(max_wait);
- } else {
- sw.cv()->Wait();
- }
- }
-}
-
-// -----------------------------------------------------------------------------
-// Synchronous waiting on multiple objects.
-
-static bool // StrictWeakOrdering
-cmp_fst_addr(const std::pair<WaitableEvent*, unsigned> &a,
- const std::pair<WaitableEvent*, unsigned> &b) {
- return a.first < b.first;
-}
-
-// static
-size_t WaitableEvent::WaitMany(WaitableEvent** raw_waitables,
- size_t count) {
- base::ThreadRestrictions::AssertWaitAllowed();
- DCHECK(count) << "Cannot wait on no events";
-
- // We need to acquire the locks in a globally consistent order. Thus we sort
- // the array of waitables by address. We actually sort a pairs so that we can
- // map back to the original index values later.
- std::vector<std::pair<WaitableEvent*, size_t> > waitables;
- waitables.reserve(count);
- for (size_t i = 0; i < count; ++i)
- waitables.push_back(std::make_pair(raw_waitables[i], i));
-
- DCHECK_EQ(count, waitables.size());
-
- sort(waitables.begin(), waitables.end(), cmp_fst_addr);
-
- // The set of waitables must be distinct. Since we have just sorted by
- // address, we can check this cheaply by comparing pairs of consecutive
- // elements.
- for (size_t i = 0; i < waitables.size() - 1; ++i) {
- DCHECK(waitables[i].first != waitables[i+1].first);
- }
-
- SyncWaiter sw;
-
- const size_t r = EnqueueMany(&waitables[0], count, &sw);
- if (r) {
- // One of the events is already signaled. The SyncWaiter has not been
- // enqueued anywhere. EnqueueMany returns the count of remaining waitables
- // when the signaled one was seen, so the index of the signaled event is
- // @count - @r.
- return waitables[count - r].second;
- }
-
- // At this point, we hold the locks on all the WaitableEvents and we have
- // enqueued our waiter in them all.
- sw.lock()->Acquire();
- // Release the WaitableEvent locks in the reverse order
- for (size_t i = 0; i < count; ++i) {
- waitables[count - (1 + i)].first->kernel_->lock_.Release();
- }
-
- for (;;) {
- if (sw.fired())
- break;
-
- sw.cv()->Wait();
- }
- sw.lock()->Release();
-
- // The address of the WaitableEvent which fired is stored in the SyncWaiter.
- WaitableEvent *const signaled_event = sw.signaling_event();
- // This will store the index of the raw_waitables which fired.
- size_t signaled_index = 0;
-
- // Take the locks of each WaitableEvent in turn (except the signaled one) and
- // remove our SyncWaiter from the wait-list
- for (size_t i = 0; i < count; ++i) {
- if (raw_waitables[i] != signaled_event) {
- raw_waitables[i]->kernel_->lock_.Acquire();
- // There's no possible ABA issue with the address of the SyncWaiter here
- // because it lives on the stack. Thus the tag value is just the pointer
- // value again.
- raw_waitables[i]->kernel_->Dequeue(&sw, &sw);
- raw_waitables[i]->kernel_->lock_.Release();
- } else {
- // By taking this lock here we ensure that |Signal| has completed by the
- // time we return, because |Signal| holds this lock. This matches the
- // behaviour of |Wait| and |TimedWait|.
- raw_waitables[i]->kernel_->lock_.Acquire();
- raw_waitables[i]->kernel_->lock_.Release();
- signaled_index = i;
- }
- }
-
- return signaled_index;
-}
-
-// -----------------------------------------------------------------------------
-// If return value == 0:
-// The locks of the WaitableEvents have been taken in order and the Waiter has
-// been enqueued in the wait-list of each. None of the WaitableEvents are
-// currently signaled
-// else:
-// None of the WaitableEvent locks are held. The Waiter has not been enqueued
-// in any of them and the return value is the index of the first WaitableEvent
-// which was signaled, from the end of the array.
-// -----------------------------------------------------------------------------
-// static
-size_t WaitableEvent::EnqueueMany
- (std::pair<WaitableEvent*, size_t>* waitables,
- size_t count, Waiter* waiter) {
- if (!count)
- return 0;
-
- waitables[0].first->kernel_->lock_.Acquire();
- if (waitables[0].first->kernel_->signaled_) {
- if (!waitables[0].first->kernel_->manual_reset_)
- waitables[0].first->kernel_->signaled_ = false;
- waitables[0].first->kernel_->lock_.Release();
- return count;
- }
-
- const size_t r = EnqueueMany(waitables + 1, count - 1, waiter);
- if (r) {
- waitables[0].first->kernel_->lock_.Release();
- } else {
- waitables[0].first->Enqueue(waiter);
- }
-
- return r;
-}
-
-// -----------------------------------------------------------------------------
-
-
-// -----------------------------------------------------------------------------
-// Private functions...
-
-WaitableEvent::WaitableEventKernel::WaitableEventKernel(bool manual_reset,
- bool initially_signaled)
- : manual_reset_(manual_reset),
- signaled_(initially_signaled) {
-}
-
-WaitableEvent::WaitableEventKernel::~WaitableEventKernel() {
-}
-
-// -----------------------------------------------------------------------------
-// Wake all waiting waiters. Called with lock held.
-// -----------------------------------------------------------------------------
-bool WaitableEvent::SignalAll() {
- bool signaled_at_least_one = false;
-
- for (std::list<Waiter*>::iterator
- i = kernel_->waiters_.begin(); i != kernel_->waiters_.end(); ++i) {
- if ((*i)->Fire(this))
- signaled_at_least_one = true;
- }
-
- kernel_->waiters_.clear();
- return signaled_at_least_one;
-}
-
-// ---------------------------------------------------------------------------
-// Try to wake a single waiter. Return true if one was woken. Called with lock
-// held.
-// ---------------------------------------------------------------------------
-bool WaitableEvent::SignalOne() {
- for (;;) {
- if (kernel_->waiters_.empty())
- return false;
-
- const bool r = (*kernel_->waiters_.begin())->Fire(this);
- kernel_->waiters_.pop_front();
- if (r)
- return true;
- }
-}
-
-// -----------------------------------------------------------------------------
-// Add a waiter to the list of those waiting. Called with lock held.
-// -----------------------------------------------------------------------------
-void WaitableEvent::Enqueue(Waiter* waiter) {
- kernel_->waiters_.push_back(waiter);
-}
-
-// -----------------------------------------------------------------------------
-// Remove a waiter from the list of those waiting. Return true if the waiter was
-// actually removed. Called with lock held.
-// -----------------------------------------------------------------------------
-bool WaitableEvent::WaitableEventKernel::Dequeue(Waiter* waiter, void* tag) {
- for (std::list<Waiter*>::iterator
- i = waiters_.begin(); i != waiters_.end(); ++i) {
- if (*i == waiter && (*i)->Compare(tag)) {
- waiters_.erase(i);
- return true;
- }
- }
-
- return false;
-}
-
-// -----------------------------------------------------------------------------
-
-} // namespace base