bool
ThreadPool::init()
{
#ifdef JS_THREADSAFE
// Compute desired number of workers based on env var or # of CPUs.
size_t numWorkers = 0;
char *pathreads = getenv("PATHREADS");
if (pathreads != NULL)
numWorkers = strtol(pathreads, NULL, 10);
else
numWorkers = GetCPUCount() - 1;
// Allocate workers array and then start the worker threads.
// Ensure that the field numWorkers_ always tracks the number of
// *successfully initialized* workers.
for (size_t workerId = 0; workerId < numWorkers; workerId++) {
ThreadPoolWorker *worker = js_new<ThreadPoolWorker>(workerId, this);
if (!worker->init()) {
js_delete(worker);
return false;
}
if (!workers_.append(worker)) {
js_delete(worker);
return false;
}
if (!worker->start())
return false;
}
#endif
return true;
}
void
ThreadPool::terminateWorkers()
{
while (workers_.length() > 0) {
ThreadPoolWorker *worker = workers_.popCopy();
worker->terminate();
js_delete(worker);
}
}
bool
ThreadPool::lazyStartWorkers(JSContext *cx)
{
// Starts the workers if they have not already been started. If
// something goes wrong, reports an error and ensures that all
// partially started threads are terminated. Therefore, upon exit
// from this function, the workers array is either full (upon
// success) or empty (upon failure).
#ifndef JS_THREADSAFE
return true;
#else
if (!workers_.empty()) {
JS_ASSERT(workers_.length() == numWorkers());
return true;
}
// Allocate workers array and then start the worker threads.
// Note that numWorkers() is the number of *desired* workers,
// but workers_.length() is the number of *successfully
// initialized* workers.
for (size_t workerId = 0; workerId < numWorkers(); workerId++) {
ThreadPoolWorker *worker = js_new<ThreadPoolWorker>(workerId);
if (!worker) {
terminateWorkersAndReportOOM(cx);
return false;
}
if (!worker->init() || !workers_.append(worker)) {
js_delete(worker);
terminateWorkersAndReportOOM(cx);
return false;
}
if (!worker->start()) {
// Note: do not delete worker here because it has been
// added to the array and hence will be deleted by
// |terminateWorkersAndReportOOM()|.
terminateWorkersAndReportOOM(cx);
return false;
}
}
return true;
#endif
}
void
ThreadPoolWorker::ThreadMain(void *arg)
{
ThreadPoolWorker *thread = (ThreadPoolWorker*) arg;
thread->run();
}