/* 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 * * 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 #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 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, 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; }