--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nspr/pr/src/md/windows/w32ipcsem.c	Mon Jul 28 10:47:06 2014 +0200
@@ -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;
+}