diff options
Diffstat (limited to 'src/libs/xpcom18a4/ipc/ipcd/extensions/lock/src/ipcLockService.cpp')
| -rw-r--r-- | src/libs/xpcom18a4/ipc/ipcd/extensions/lock/src/ipcLockService.cpp | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/src/libs/xpcom18a4/ipc/ipcd/extensions/lock/src/ipcLockService.cpp b/src/libs/xpcom18a4/ipc/ipcd/extensions/lock/src/ipcLockService.cpp new file mode 100644 index 00000000..771aa787 --- /dev/null +++ b/src/libs/xpcom18a4/ipc/ipcd/extensions/lock/src/ipcLockService.cpp @@ -0,0 +1,168 @@ +/* vim:set ts=4 sw=4 sts=4 et cindent: */ +/* ***** 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 Mozilla IPC. + * + * The Initial Developer of the Original Code is + * Netscape Communications Corporation. + * Portions created by the Initial Developer are Copyright (C) 2002 + * the Initial Developer. All Rights Reserved. + * + * Contributor(s): + * Darin Fisher <darin@netscape.com> + * + * 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 ***** */ + +#include <stdlib.h> +#include "nsDependentString.h" +#include "nsHashKeys.h" +#include "nsAutoPtr.h" +#include "ipcLockService.h" +#include "ipcLockProtocol.h" +#include "ipcLog.h" +#include "prthread.h" + +static const nsID kLockTargetID = IPC_LOCK_TARGETID; + +//----------------------------------------------------------------------------- + +struct ipcPendingLock +{ + const char *name; + nsresult status; + PRBool complete; +}; + +//----------------------------------------------------------------------------- + +nsresult +ipcLockService::Init() +{ + if (PR_NewThreadPrivateIndex(&mTPIndex, nsnull) != PR_SUCCESS) + return NS_ERROR_OUT_OF_MEMORY; + + // Configure OnMessageAvailable to be called on the IPC thread. This is + // done to allow us to proxy OnAcquireLockComplete events to the right + // thread immediately even if the main thread is blocked waiting to acquire + // some other lock synchronously. + + return IPC_DefineTarget(kLockTargetID, this, PR_FALSE); +} + +NS_IMPL_THREADSAFE_ISUPPORTS2(ipcLockService, ipcILockService, ipcIMessageObserver) + +NS_IMETHODIMP +ipcLockService::AcquireLock(const char *lockName, PRBool waitIfBusy) +{ + LOG(("ipcLockService::AcquireLock [lock=%s wait=%u]\n", lockName, waitIfBusy)); + + ipcLockMsg msg; + msg.opcode = IPC_LOCK_OP_ACQUIRE; + msg.flags = (waitIfBusy ? 0 : IPC_LOCK_FL_NONBLOCKING); + msg.key = lockName; + + PRUint32 bufLen; + nsAutoPtr<PRUint8> buf( IPC_FlattenLockMsg(&msg, &bufLen) ); + if (!buf) + return NS_ERROR_OUT_OF_MEMORY; + + ipcPendingLock pendingLock; + pendingLock.name = lockName; + pendingLock.status = 0xDEADBEEF; // something bogus + pendingLock.complete = PR_FALSE; + if (PR_SetThreadPrivate(mTPIndex, &pendingLock) != PR_SUCCESS) + return NS_ERROR_UNEXPECTED; + + // prevent our OnMessageAvailable from being called until we explicitly ask + // for it to be called via IPC_WaitMessage. + IPC_DISABLE_MESSAGE_OBSERVER_FOR_SCOPE(kLockTargetID); + + nsresult rv = IPC_SendMessage(0, kLockTargetID, buf, bufLen); + if (NS_SUCCEEDED(rv)) { + do { + // block the calling thread until we get a response from the daemon + rv = IPC_WaitMessage(0, kLockTargetID, this, nsnull, PR_INTERVAL_NO_TIMEOUT); + } + while (NS_SUCCEEDED(rv) && !pendingLock.complete); + + if (NS_SUCCEEDED(rv)) + rv = pendingLock.status; + } + + // we could clear the TPD, but that isn't really necessary. + + return rv; +} + +NS_IMETHODIMP +ipcLockService::ReleaseLock(const char *lockName) +{ + LOG(("ipcLockService::ReleaseLock [lock=%s]\n", lockName)); + + ipcLockMsg msg; + msg.opcode = IPC_LOCK_OP_RELEASE; + msg.flags = 0; + msg.key = lockName; + + PRUint32 bufLen; + PRUint8 *buf = IPC_FlattenLockMsg(&msg, &bufLen); + if (!buf) + return NS_ERROR_OUT_OF_MEMORY; + + nsresult rv = IPC_SendMessage(0, kLockTargetID, buf, bufLen); + delete buf; + + if (NS_FAILED(rv)) + return rv; + + return NS_OK; +} + +// called on the same thread that called IPC_WaitMessage +NS_IMETHODIMP +ipcLockService::OnMessageAvailable(PRUint32 unused, const nsID &target, + const PRUint8 *data, PRUint32 dataLen) +{ + ipcLockMsg msg; + IPC_UnflattenLockMsg(data, dataLen, &msg); + + LOG(("ipcLockService::OnMessageAvailable [lock=%s opcode=%u]\n", msg.key, msg.opcode)); + + ipcPendingLock *pendingLock = (ipcPendingLock *) PR_GetThreadPrivate(mTPIndex); + if (strcmp(pendingLock->name, msg.key) == 0) { + pendingLock->complete = PR_TRUE; + if (msg.opcode == IPC_LOCK_OP_STATUS_ACQUIRED) + pendingLock->status = NS_OK; + else + pendingLock->status = NS_ERROR_FAILURE; + return NS_OK; + } + + LOG(("message does not match; waiting for another...\n")); + + // else, we got a message that another thread is waiting to receive. + return IPC_WAIT_NEXT_MESSAGE; +} |