// Wait for some event bool event_poll(int32_t ms) { bool timed_out; uv_run_mode run_mode = UV_RUN_ONCE; if (input_ready()) { // If there's a pending input event to be consumed, do it now return true; } input_start(); timed_out = false; if (ms > 0) { // Timeout passed as argument to the timer timer.data = &timed_out; // We only start the timer after the loop is running, for that we // use an prepare handle(pass the interval as data to it) timer_prepare.data = &ms; uv_prepare_start(&timer_prepare, timer_prepare_cb); } else if (ms == 0) { // For ms == 0, we need to do a non-blocking event poll by // setting the run mode to UV_RUN_NOWAIT. run_mode = UV_RUN_NOWAIT; } do { // Run one event loop iteration, blocking for events if run_mode is // UV_RUN_ONCE uv_run(uv_default_loop(), run_mode); } while ( // Continue running if ... !input_ready() && // we have no input kl_empty(event_queue) && // no events are waiting to be processed run_mode != UV_RUN_NOWAIT && // ms != 0 !timed_out); // we didn't get a timeout input_stop(); if (ms > 0) { // Stop the timer uv_timer_stop(&timer); } return input_ready() || event_is_pending(); }
// Wait for some event bool event_poll(int32_t ms) { uv_run_mode run_mode = UV_RUN_ONCE; if (input_ready()) { // If there's a pending input event to be consumed, do it now return true; } static int recursive = 0; if (!(recursive++)) { // Only needs to start the libuv handle the first time we enter here input_start(); } uv_timer_t timer; uv_prepare_t timer_prepare; TimerData timer_data = {.ms = ms, .timed_out = false, .timer = &timer}; if (ms > 0) { uv_timer_init(uv_default_loop(), &timer); // This prepare handle that actually starts the timer uv_prepare_init(uv_default_loop(), &timer_prepare); // Timeout passed as argument to the timer timer.data = &timer_data; // We only start the timer after the loop is running, for that we // use a prepare handle(pass the interval as data to it) timer_prepare.data = &timer_data; uv_prepare_start(&timer_prepare, timer_prepare_cb); } else if (ms == 0) { // For ms == 0, we need to do a non-blocking event poll by // setting the run mode to UV_RUN_NOWAIT. run_mode = UV_RUN_NOWAIT; } do { // Run one event loop iteration, blocking for events if run_mode is // UV_RUN_ONCE uv_run(uv_default_loop(), run_mode); // Process immediate events outside uv_run since libuv event loop not // support recursion(processing events may cause a recursive event_poll // call) event_process(false); } while ( // Continue running if ... !input_ready() && // we have no input !event_has_deferred() && // no events are waiting to be processed run_mode != UV_RUN_NOWAIT && // ms != 0 !timer_data.timed_out); // we didn't get a timeout if (!(--recursive)) { // Again, only stop when we leave the top-level invocation input_stop(); } if (ms > 0) { // Ensure the timer-related handles are closed and run the event loop // once more to let libuv perform it's cleanup uv_close((uv_handle_t *)&timer, NULL); uv_close((uv_handle_t *)&timer_prepare, NULL); uv_run(uv_default_loop(), UV_RUN_NOWAIT); event_process(false); } return input_ready() || event_has_deferred(); } bool event_has_deferred() { return !kl_empty(get_queue(true)); } // Push an event to the queue void event_push(Event event, bool deferred) { *kl_pushp(Event, get_queue(deferred)) = event; }
bool event_has_deferred(void) { return deferred_events_allowed && !kl_empty(deferred_events); }
bool event_is_pending() { return !kl_empty(event_queue); }