void iothread_perform_on_main(void_function_t &&func) {
if (is_main_thread()) {
func();
return;
}
// Make a new request. Note we are synchronous, so this can be stack allocated!
main_thread_request_t req(std::move(func));
// Append it. Do not delete the nested scope as it is crucial to the proper functioning of this
// code by virtue of the lock management.
{
scoped_lock queue_lock(s_main_thread_request_q_lock);
s_main_thread_request_queue.push(&req);
}
// Tell the pipe.
const char wakeup_byte = IO_SERVICE_MAIN_THREAD_REQUEST_QUEUE;
assert_with_errno(write_loop(s_write_pipe, &wakeup_byte, sizeof wakeup_byte) != -1);
// Wait on the condition, until we're done.
std::unique_lock<std::mutex> perform_lock(s_main_thread_performer_lock);
while (!req.done) {
// It would be nice to support checking for cancellation here, but the clients need a
// deterministic way to clean up to avoid leaks
s_main_thread_performer_cond.wait(perform_lock);
}
// Ok, the request must now be done.
assert(req.done);
}
int iothread_perform_on_main_base(int (*handler)(void *), void *context) {
// If this is the main thread, just do it.
if (is_main_thread()) {
return handler(context);
}
// Make a new request. Note we are synchronous, so this can be stack allocated!
MainThreadRequest_t req;
req.handler = handler;
req.context = context;
req.handlerResult = 0;
req.done = false;
// Append it. Do not delete the nested scope as it is crucial to the proper functioning of this
// code by virtue of the lock management.
{
scoped_lock queue_lock(s_main_thread_request_queue_lock);
s_main_thread_request_queue.push(&req);
}
// Tell the pipe.
const char wakeup_byte = IO_SERVICE_MAIN_THREAD_REQUEST_QUEUE;
VOMIT_ON_FAILURE(!write_loop(s_write_pipe, &wakeup_byte, sizeof wakeup_byte));
// Wait on the condition, until we're done.
scoped_lock perform_lock(s_main_thread_performer_lock);
while (!req.done) {
// It would be nice to support checking for cancellation here, but the clients need a
// deterministic way to clean up to avoid leaks
VOMIT_ON_FAILURE(
pthread_cond_wait(&s_main_thread_performer_condition, &s_main_thread_performer_lock));
}
// Ok, the request must now be done.
assert(req.done);
return req.handlerResult;
}