1 files changed, 141 insertions, 0 deletions
diff --git a/nsprpub/pr/src/threads/prsem.c b/nsprpub/pr/src/threads/prsem.c
new file mode 100644
index 0000000000..120075b0cb
--- /dev/null
+++ b/nsprpub/pr/src/threads/prsem.c
@@ -0,0 +1,141 @@
+/* -*- 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 "obsolete/prsem.h"
+
+/************************************************************************/
+
+/*
+** Create a new semaphore.
+*/
+PR_IMPLEMENT(PRSemaphore*) PR_NewSem(PRUintn value)
+{
+    PRSemaphore *sem;
+    PRCondVar *cvar;
+    PRLock *lock;
+
+    sem = PR_NEWZAP(PRSemaphore);
+    if (sem) {
+#ifdef HAVE_CVAR_BUILT_ON_SEM
+        _PR_MD_NEW_SEM(&sem->md, value);
+#else
+        lock = PR_NewLock();
+        if (!lock) {
+            PR_DELETE(sem);
+            return NULL;
+        }
+
+        cvar = PR_NewCondVar(lock);
+        if (!cvar) {
+            PR_DestroyLock(lock);
+            PR_DELETE(sem);
+            return NULL;
+        }
+        sem->cvar = cvar;
+        sem->count = value;
+#endif
+    }
+    return sem;
+}
+
+/*
+** Destroy a semaphore. There must be no thread waiting on the semaphore.
+** The caller is responsible for guaranteeing that the semaphore is
+** no longer in use.
+*/
+PR_IMPLEMENT(void) PR_DestroySem(PRSemaphore *sem)
+{
+#ifdef HAVE_CVAR_BUILT_ON_SEM
+    _PR_MD_DESTROY_SEM(&sem->md);
+#else
+    PR_ASSERT(sem->waiters == 0);
+
+    PR_DestroyLock(sem->cvar->lock);
+    PR_DestroyCondVar(sem->cvar);
+#endif
+    PR_DELETE(sem);
+}
+
+/*
+** Wait on a Semaphore.
+**
+** This routine allows a calling thread to wait or proceed depending upon the
+** state of the semahore sem. The thread can proceed only if the counter value
+** of the semaphore sem is currently greater than 0. If the value of semaphore
+** sem is positive, it is decremented by one and the routine returns immediately
+** allowing the calling thread to continue. If the value of semaphore sem is 0,
+** the calling thread blocks awaiting the semaphore to be released by another
+** thread.
+**
+** This routine can return PR_PENDING_INTERRUPT if the waiting thread
+** has been interrupted.
+*/
+PR_IMPLEMENT(PRStatus) PR_WaitSem(PRSemaphore *sem)
+{
+    PRStatus status = PR_SUCCESS;
+
+#ifdef HAVE_CVAR_BUILT_ON_SEM
+    return _PR_MD_WAIT_SEM(&sem->md);
+#else
+    PR_Lock(sem->cvar->lock);
+    while (sem->count == 0) {
+        sem->waiters++;
+        status = PR_WaitCondVar(sem->cvar, PR_INTERVAL_NO_TIMEOUT);
+        sem->waiters--;
+        if (status != PR_SUCCESS) {
+            break;
+        }
+    }
+    if (status == PR_SUCCESS) {
+        sem->count--;
+    }
+    PR_Unlock(sem->cvar->lock);
+#endif
+
+    return (status);
+}
+
+/*
+** This routine increments the counter value of the semaphore. If other threads
+** are blocked for the semaphore, then the scheduler will determine which ONE
+** thread will be unblocked.
+*/
+PR_IMPLEMENT(void) PR_PostSem(PRSemaphore *sem)
+{
+#ifdef HAVE_CVAR_BUILT_ON_SEM
+    _PR_MD_POST_SEM(&sem->md);
+#else
+    PR_Lock(sem->cvar->lock);
+    if (sem->waiters) {
+        PR_NotifyCondVar(sem->cvar);
+    }
+    sem->count++;
+    PR_Unlock(sem->cvar->lock);
+#endif
+}
+
+#if DEBUG
+/*
+** Returns the value of the semaphore referenced by sem without affecting
+** the state of the semaphore.  The value represents the semaphore vaule
+** at the time of the call, but may not be the actual value when the
+** caller inspects it. (FOR DEBUGGING ONLY)
+*/
+PR_IMPLEMENT(PRUintn) PR_GetValueSem(PRSemaphore *sem)
+{
+    PRUintn rv;
+
+#ifdef HAVE_CVAR_BUILT_ON_SEM
+    rv = _PR_MD_GET_VALUE_SEM(&sem->md);
+#else
+    PR_Lock(sem->cvar->lock);
+    rv = sem->count;
+    PR_Unlock(sem->cvar->lock);
+#endif
+
+    return rv;
+}
+#endif