--- /dev/null
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/*
+ * The contents of this file are subject to the Mozilla Public
+ * License Version 1.1 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS
+ * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * rights and limitations under the License.
+ *
+ * The Original Code is the Netscape Portable Runtime (NSPR).
+ *
+ * The Initial Developer of the Original Code is Netscape
+ * Communications Corporation. Portions created by Netscape are
+ * Copyright (C) 1998-2000 Netscape Communications Corporation. All
+ * Rights Reserved.
+ *
+ * Contributor(s):
+ *
+ * Alternatively, the contents of this file may be used under the
+ * terms of the GNU General Public License Version 2 or later (the
+ * "GPL"), in which case the provisions of the GPL are applicable
+ * instead of those above. If you wish to allow use of your
+ * version of this file only under the terms of the GPL and not to
+ * allow others to use your version of this file under the MPL,
+ * indicate your decision by deleting the provisions above and
+ * replace them with the notice and other provisions required by
+ * the GPL. If you do not delete the provisions above, a recipient
+ * may use your version of this file under either the MPL or the
+ * GPL.
+ */
+
+/*
+** File: prlock.h
+** Description: API to basic locking functions of NSPR.
+**
+**
+** NSPR provides basic locking mechanisms for thread synchronization. Locks
+** are lightweight resource contention controls that prevent multiple threads
+** from accessing something (code/data) simultaneously.
+**/
+
+#ifndef prlock_h___
+#define prlock_h___
+
+#include <security_asn1/prtypes.h>
+
+PR_BEGIN_EXTERN_C
+
+/**********************************************************************/
+/************************* TYPES AND CONSTANTS ************************/
+/**********************************************************************/
+
+/*
+ * PRLock --
+ *
+ * NSPR represents the lock as an opaque entity to the client of the
+ * API. All routines operate on a pointer to this opaque entity.
+ */
+
+#if defined(__APPLE_) & defined(__GNUC__)
+/* dmitch - actually a pthread_mutex_t */
+typedef void PRLock;
+#else
+typedef struct PRLock PRLock;
+#endif
+
+/**********************************************************************/
+/****************************** FUNCTIONS *****************************/
+/**********************************************************************/
+
+/***********************************************************************
+** FUNCTION: PR_NewLock
+** DESCRIPTION:
+** Returns a pointer to a newly created opaque lock object.
+** INPUTS: void
+** OUTPUTS: void
+** RETURN: PRLock*
+** If the lock can not be created because of resource constraints, NULL
+** is returned.
+**
+***********************************************************************/
+NSPR_API(PRLock*) PR_NewLock(void);
+
+/***********************************************************************
+** FUNCTION: PR_DestroyLock
+** DESCRIPTION:
+** Destroys a given opaque lock object.
+** INPUTS: PRLock *lock
+** Lock to be freed.
+** OUTPUTS: void
+** RETURN: None
+***********************************************************************/
+NSPR_API(void) PR_DestroyLock(PRLock *lock);
+
+/***********************************************************************
+** FUNCTION: PR_Lock
+** DESCRIPTION:
+** Lock a lock.
+** INPUTS: PRLock *lock
+** Lock to locked.
+** OUTPUTS: void
+** RETURN: None
+***********************************************************************/
+NSPR_API(void) PR_Lock(PRLock *lock);
+
+/***********************************************************************
+** FUNCTION: PR_Unlock
+** DESCRIPTION:
+** Unlock a lock. Unlocking an unlocked lock has undefined results.
+** INPUTS: PRLock *lock
+** Lock to unlocked.
+** OUTPUTS: void
+** RETURN: PR_STATUS
+** Returns PR_FAILURE if the caller does not own the lock.
+***********************************************************************/
+NSPR_API(PRStatus) PR_Unlock(PRLock *lock);
+
+PR_END_EXTERN_C
+
+#endif /* prlock_h___ */