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-rw-r--r--nsprpub/pr/src/md/windows/w32ipcsem.c228
1 files changed, 228 insertions, 0 deletions
diff --git a/nsprpub/pr/src/md/windows/w32ipcsem.c b/nsprpub/pr/src/md/windows/w32ipcsem.c
new file mode 100644
index 000000000..954591002
--- /dev/null
+++ b/nsprpub/pr/src/md/windows/w32ipcsem.c
@@ -0,0 +1,228 @@
+/* -*- 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/. */
+
+/*
+ * File: w32ipcsem.c
+ * Description: implements named semaphores for NT and WIN95.
+ */
+
+#include "primpl.h"
+
+#ifdef WINCE
+static HANDLE OpenSemaphore(DWORD inDesiredAccess,
+ BOOL inInheritHandle,
+ const char *inName)
+{
+ HANDLE retval = NULL;
+ HANDLE semaphore = NULL;
+ PRUnichar wideName[MAX_PATH]; /* name size is limited to MAX_PATH */
+
+ MultiByteToWideChar(CP_ACP, 0, inName, -1, wideName, MAX_PATH);
+ /* 0x7fffffff is the max count for our semaphore */
+ semaphore = CreateSemaphoreW(NULL, 0, 0x7fffffff, wideName);
+ if (NULL != semaphore) {
+ DWORD lastErr = GetLastError();
+
+ if (ERROR_ALREADY_EXISTS != lastErr)
+ CloseHandle(semaphore);
+ else
+ retval = semaphore;
+ }
+ return retval;
+}
+#endif
+
+/*
+ * NSPR-to-NT access right mapping table for semaphore objects.
+ *
+ * The SYNCHRONIZE access is required by WaitForSingleObject.
+ * The SEMAPHORE_MODIFY_STATE access is required by ReleaseSemaphore.
+ * The OR of these three access masks must equal SEMAPHORE_ALL_ACCESS.
+ * This is because if a semaphore object with the specified name
+ * exists, CreateSemaphore requests SEMAPHORE_ALL_ACCESS access to
+ * the existing object.
+ */
+static DWORD semAccessTable[] = {
+ STANDARD_RIGHTS_REQUIRED|0x1, /* read (0x1 is "query state") */
+ STANDARD_RIGHTS_REQUIRED|SYNCHRONIZE|SEMAPHORE_MODIFY_STATE, /* write */
+ 0 /* execute */
+};
+
+#ifndef _PR_GLOBAL_THREADS_ONLY
+
+/*
+ * A fiber cannot call WaitForSingleObject because that
+ * will block the other fibers running on the same thread.
+ * If a fiber needs to wait on a (semaphore) handle, we
+ * create a native thread to call WaitForSingleObject and
+ * have the fiber join the native thread.
+ */
+
+/*
+ * Arguments, return value, and error code for WaitForSingleObject
+ */
+struct WaitSingleArg {
+ HANDLE handle;
+ DWORD timeout;
+ DWORD rv;
+ DWORD error;
+};
+
+static void WaitSingleThread(void *arg)
+{
+ struct WaitSingleArg *warg = (struct WaitSingleArg *) arg;
+
+ warg->rv = WaitForSingleObject(warg->handle, warg->timeout);
+ if (warg->rv == WAIT_FAILED) {
+ warg->error = GetLastError();
+ }
+}
+
+static DWORD FiberSafeWaitForSingleObject(
+ HANDLE hHandle,
+ DWORD dwMilliseconds
+)
+{
+ PRThread *me = _PR_MD_CURRENT_THREAD();
+
+ if (_PR_IS_NATIVE_THREAD(me)) {
+ return WaitForSingleObject(hHandle, dwMilliseconds);
+ } else {
+ PRThread *waitThread;
+ struct WaitSingleArg warg;
+ PRStatus rv;
+
+ warg.handle = hHandle;
+ warg.timeout = dwMilliseconds;
+ waitThread = PR_CreateThread(
+ PR_USER_THREAD, WaitSingleThread, &warg,
+ PR_PRIORITY_NORMAL, PR_GLOBAL_THREAD, PR_JOINABLE_THREAD, 0);
+ if (waitThread == NULL) {
+ return WAIT_FAILED;
+ }
+
+ rv = PR_JoinThread(waitThread);
+ PR_ASSERT(rv == PR_SUCCESS);
+ if (rv == PR_FAILURE) {
+ return WAIT_FAILED;
+ }
+ if (warg.rv == WAIT_FAILED) {
+ SetLastError(warg.error);
+ }
+ return warg.rv;
+ }
+}
+
+#endif /* !_PR_GLOBAL_THREADS_ONLY */
+
+PRSem *_PR_MD_OPEN_SEMAPHORE(
+ const char *osname, PRIntn flags, PRIntn mode, PRUintn value)
+{
+ PRSem *sem;
+ SECURITY_ATTRIBUTES sa;
+ LPSECURITY_ATTRIBUTES lpSA = NULL;
+ PSECURITY_DESCRIPTOR pSD = NULL;
+ PACL pACL = NULL;
+
+ sem = PR_NEW(PRSem);
+ if (sem == NULL) {
+ PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
+ return NULL;
+ }
+ if (flags & PR_SEM_CREATE) {
+ if (_PR_NT_MakeSecurityDescriptorACL(mode, semAccessTable,
+ &pSD, &pACL) == PR_SUCCESS) {
+ sa.nLength = sizeof(sa);
+ sa.lpSecurityDescriptor = pSD;
+ sa.bInheritHandle = FALSE;
+ lpSA = &sa;
+ }
+#ifdef WINCE
+ {
+ /* The size of a sem's name is limited to MAX_PATH. */
+ PRUnichar wosname[MAX_PATH];
+ MultiByteToWideChar(CP_ACP, 0, osname, -1, wosname, MAX_PATH);
+ sem->sem = CreateSemaphoreW(lpSA, value, 0x7fffffff, wosname);
+ }
+#else
+ sem->sem = CreateSemaphoreA(lpSA, value, 0x7fffffff, osname);
+#endif
+ if (lpSA != NULL) {
+ _PR_NT_FreeSecurityDescriptorACL(pSD, pACL);
+ }
+ if (sem->sem == NULL) {
+ _PR_MD_MAP_DEFAULT_ERROR(GetLastError());
+ PR_DELETE(sem);
+ return NULL;
+ }
+ if ((flags & PR_SEM_EXCL) && (GetLastError() == ERROR_ALREADY_EXISTS)) {
+ PR_SetError(PR_FILE_EXISTS_ERROR, ERROR_ALREADY_EXISTS);
+ CloseHandle(sem->sem);
+ PR_DELETE(sem);
+ return NULL;
+ }
+ } else {
+ sem->sem = OpenSemaphore(
+ SEMAPHORE_MODIFY_STATE|SYNCHRONIZE, FALSE, osname);
+ if (sem->sem == NULL) {
+ DWORD err = GetLastError();
+
+ /*
+ * If we open a nonexistent named semaphore, NT
+ * returns ERROR_FILE_NOT_FOUND, while Win95
+ * returns ERROR_INVALID_NAME
+ */
+ if (err == ERROR_INVALID_NAME) {
+ PR_SetError(PR_FILE_NOT_FOUND_ERROR, err);
+ } else {
+ _PR_MD_MAP_DEFAULT_ERROR(GetLastError());
+ }
+ PR_DELETE(sem);
+ return NULL;
+ }
+ }
+ return sem;
+}
+
+PRStatus _PR_MD_WAIT_SEMAPHORE(PRSem *sem)
+{
+ DWORD rv;
+
+#ifdef _PR_GLOBAL_THREADS_ONLY
+ rv = WaitForSingleObject(sem->sem, INFINITE);
+#else
+ rv = FiberSafeWaitForSingleObject(sem->sem, INFINITE);
+#endif
+ PR_ASSERT(rv == WAIT_FAILED || rv == WAIT_OBJECT_0);
+ if (rv == WAIT_FAILED) {
+ _PR_MD_MAP_DEFAULT_ERROR(GetLastError());
+ return PR_FAILURE;
+ }
+ if (rv != WAIT_OBJECT_0) {
+ /* Should not happen */
+ PR_SetError(PR_UNKNOWN_ERROR, 0);
+ return PR_FAILURE;
+ }
+ return PR_SUCCESS;
+}
+
+PRStatus _PR_MD_POST_SEMAPHORE(PRSem *sem)
+{
+ if (ReleaseSemaphore(sem->sem, 1, NULL) == FALSE) {
+ _PR_MD_MAP_DEFAULT_ERROR(GetLastError());
+ return PR_FAILURE;
+ }
+ return PR_SUCCESS;
+}
+
+PRStatus _PR_MD_CLOSE_SEMAPHORE(PRSem *sem)
+{
+ if (CloseHandle(sem->sem) == FALSE) {
+ _PR_MD_MAP_CLOSE_ERROR(GetLastError());
+ return PR_FAILURE;
+ }
+ PR_DELETE(sem);
+ return PR_SUCCESS;
+}