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Diffstat (limited to 'src/libs/xpcom18a4/nsprpub/pr/include/pripcsem.h')
-rw-r--r-- | src/libs/xpcom18a4/nsprpub/pr/include/pripcsem.h | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/src/libs/xpcom18a4/nsprpub/pr/include/pripcsem.h b/src/libs/xpcom18a4/nsprpub/pr/include/pripcsem.h new file mode 100644 index 00000000..c7450f3a --- /dev/null +++ b/src/libs/xpcom18a4/nsprpub/pr/include/pripcsem.h @@ -0,0 +1,141 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* ***** BEGIN LICENSE BLOCK ***** + * Version: MPL 1.1/GPL 2.0/LGPL 2.1 + * + * 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 the Initial Developer are Copyright (C) 1999-2000 + * the Initial Developer. All Rights Reserved. + * + * Contributor(s): + * + * Alternatively, the contents of this file may be used under the terms of + * either the GNU General Public License Version 2 or later (the "GPL"), or + * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"), + * in which case the provisions of the GPL or the LGPL are applicable instead + * of those above. If you wish to allow use of your version of this file only + * under the terms of either the GPL or the LGPL, and not to allow others to + * use your version of this file under the terms of the MPL, indicate your + * decision by deleting the provisions above and replace them with the notice + * and other provisions required by the GPL or the LGPL. If you do not delete + * the provisions above, a recipient may use your version of this file under + * the terms of any one of the MPL, the GPL or the LGPL. + * + * ***** END LICENSE BLOCK ***** */ + +/* + * 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" + +#ifdef VBOX_WITH_XPCOM_NAMESPACE_CLEANUP +#define PR_OpenSemaphore VBoxNsprPR_OpenSemaphore +#define PR_WaitSemaphore VBoxNsprPR_WaitSemaphore +#define PR_PostSemaphore VBoxNsprPR_PostSemaphore +#define PR_CloseSemaphore VBoxNsprPR_CloseSemaphore +#define PR_DeleteSemaphore VBoxNsprPR_DeleteSemaphore +#endif /* VBOX_WITH_XPCOM_NAMESPACE_CLEANUP */ + +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___ */ |