gecko/js/src/jstask.cpp

127 lines
3.4 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set ts=4 sw=4 et tw=99 ft=cpp:
*
* ***** 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 SpiderMonkey JavaScript 1.9.1 code, released
* June 30, 2009.
*
* The Initial Developer of the Original Code is
* Andreas Gal <gal@mozilla.com>
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either of 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 "jstask.h"
#ifdef JS_THREADSAFE
static void start(void* arg) {
((JSBackgroundThread*)arg)->work();
}
JSBackgroundThread::JSBackgroundThread()
: thread(NULL), stack(NULL), lock(NULL), wakeup(NULL), shutdown(false)
{
}
JSBackgroundThread::~JSBackgroundThread()
{
if (wakeup)
PR_DestroyCondVar(wakeup);
if (lock)
PR_DestroyLock(lock);
/* PR_DestroyThread is not necessary. */
}
bool
JSBackgroundThread::init()
{
if (!(lock = PR_NewLock()))
return false;
if (!(wakeup = PR_NewCondVar(lock)))
return false;
thread = PR_CreateThread(PR_USER_THREAD, start, this, PR_PRIORITY_LOW,
PR_LOCAL_THREAD, PR_JOINABLE_THREAD, 0);
return !!thread;
}
void
JSBackgroundThread::cancel()
{
PR_Lock(lock);
if (shutdown) {
PR_Unlock(lock);
return;
}
shutdown = true;
PR_NotifyCondVar(wakeup);
PR_Unlock(lock);
PR_JoinThread(thread);
}
void
JSBackgroundThread::work()
{
PR_Lock(lock);
while (!shutdown) {
PR_WaitCondVar(wakeup, PR_INTERVAL_NO_TIMEOUT);
JSBackgroundTask* t;
while ((t = stack) != NULL) {
stack = t->next;
PR_Unlock(lock);
t->run();
delete t;
PR_Lock(lock);
}
}
PR_Unlock(lock);
}
bool
JSBackgroundThread::busy()
{
return !!stack; // we tolerate some racing here
}
void
JSBackgroundThread::schedule(JSBackgroundTask* task)
{
PR_Lock(lock);
if (shutdown) {
PR_Unlock(lock);
task->run();
delete task;
return;
}
task->next = stack;
stack = task;
PR_NotifyCondVar(wakeup);
PR_Unlock(lock);
}
#endif