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diff --git a/nsprpub/pr/include/pripcsem.h b/nsprpub/pr/include/pripcsem.h
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+++ b/nsprpub/pr/include/pripcsem.h
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+/* -*- 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: pripcsem.h
+ *
+ * Description: named semaphores for interprocess
+ * synchronization
+ *
+ * Unrelated processes obtain access to a shared semaphore
+ * by specifying its name.
+ *
+ * Our goal is to support named semaphores on at least
+ * Unix and Win32 platforms.  The implementation will use
+ * one of the three native semaphore APIs: POSIX, System V,
+ * and Win32.
+ *
+ * Because POSIX named semaphores have kernel persistence,
+ * we are forced to have a delete function in this API.
+ */
+
+#ifndef pripcsem_h___
+#define pripcsem_h___
+
+#include "prtypes.h"
+#include "prio.h"
+
+PR_BEGIN_EXTERN_C
+
+/*
+ * PRSem is an opaque structure that represents a named
+ * semaphore.
+ */
+typedef struct PRSem PRSem;
+
+/*
+ * PR_OpenSemaphore --
+ *
+ * Create or open a named semaphore with the specified name.
+ * A handle to the semaphore is returned.
+ *
+ * If the named semaphore doesn't exist and the PR_SEM_CREATE
+ * flag is specified, the named semaphore is created.  The
+ * created semaphore needs to be removed from the system with
+ * a PR_DeleteSemaphore call.
+ *
+ * If PR_SEM_CREATE is specified, the third argument is the
+ * access permission bits of the new semaphore (same
+ * interpretation as the mode argument to PR_Open) and the
+ * fourth argument is the initial value of the new semaphore.
+ * If PR_SEM_CREATE is not specified, the third and fourth
+ * arguments are ignored.
+ */
+
+#define PR_SEM_CREATE 0x1  /* create if not exist */
+#define PR_SEM_EXCL   0x2  /* fail if already exists */
+
+NSPR_API(PRSem *) PR_OpenSemaphore(
+    const char *name, PRIntn flags, PRIntn mode, PRUintn value);
+
+/*
+ * PR_WaitSemaphore --
+ *
+ * If the value of the semaphore is > 0, decrement the value and return.
+ * If the value is 0, sleep until the value becomes > 0, then decrement
+ * the value and return.
+ *
+ * The "test and decrement" operation is performed atomically.
+ */
+
+NSPR_API(PRStatus) PR_WaitSemaphore(PRSem *sem);
+
+/*
+ * PR_PostSemaphore --
+ *
+ * Increment the value of the named semaphore by 1.
+ */
+
+NSPR_API(PRStatus) PR_PostSemaphore(PRSem *sem);
+
+/*
+ * PR_CloseSemaphore --
+ *
+ * Close a named semaphore handle.
+ */
+
+NSPR_API(PRStatus) PR_CloseSemaphore(PRSem *sem);
+
+/*
+ * PR_DeleteSemaphore --
+ *
+ * Remove a named semaphore from the system.
+ */
+
+NSPR_API(PRStatus) PR_DeleteSemaphore(const char *name);
+
+PR_END_EXTERN_C
+
+#endif /* pripcsem_h___ */