1 files changed, 166 insertions, 0 deletions
diff --git a/src/til_threads.c b/src/til_threads.c
new file mode 100644
index 0000000..7c68d52
--- /dev/null
+++ b/src/til_threads.c
@@ -0,0 +1,166 @@
+#include <assert.h>
+#include <pthread.h>
+#include <stdlib.h>
+
+#include "til.h"
+#include "til_fb.h"
+#include "til_threads.h"
+#include "til_util.h"
+
+typedef struct til_thread_t {
+	til_threads_t	*threads;
+	pthread_t	pthread;
+	unsigned	id;
+} til_thread_t;
+
+typedef struct til_threads_t {
+	unsigned		n_threads;
+
+	pthread_mutex_t		idle_mutex;
+	pthread_cond_t		idle_cond;
+	unsigned		n_idle;
+
+	pthread_mutex_t		frame_mutex;
+	pthread_cond_t		frame_cond;
+	void			(*render_fragment_func)(void *context, unsigned ticks, unsigned cpu, til_fb_fragment_t *fragment);
+	void			*context;
+	til_fb_fragment_t	*fragment;
+	til_fragmenter_t	fragmenter;
+	unsigned		ticks;
+
+	unsigned		next_fragment;
+	unsigned		frame_num;
+
+	til_thread_t		threads[];
+} til_threads_t;
+
+
+/* render fragments using the supplied render function */
+static void * thread_func(void *_thread)
+{
+	til_thread_t	*thread = _thread;
+	til_threads_t	*threads = thread->threads;
+	unsigned	prev_frame_num = 0;
+
+	pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL);
+
+	for (;;) {
+
+		/* wait for a new frame */
+		pthread_mutex_lock(&threads->frame_mutex);
+		pthread_cleanup_push((void (*)(void *))pthread_mutex_unlock, &threads->frame_mutex);
+		while (threads->frame_num == prev_frame_num)
+			pthread_cond_wait(&threads->frame_cond, &threads->frame_mutex);
+		prev_frame_num = threads->frame_num;
+		pthread_cleanup_pop(1);
+
+		/* render fragments */
+		for (;;) {
+			unsigned		frag_num;
+			til_fb_fragment_t	fragment;
+
+			frag_num = __sync_fetch_and_add(&threads->next_fragment, 1);
+
+			if (!threads->fragmenter(threads->context, threads->fragment, frag_num, &fragment))
+				break;
+
+			threads->render_fragment_func(threads->context, threads->ticks, thread->id, &fragment);
+		}
+
+		/* report as idle */
+		pthread_mutex_lock(&threads->idle_mutex);
+		pthread_cleanup_push((void (*)(void *))pthread_mutex_unlock, &threads->idle_mutex);
+		threads->n_idle++;
+		if (threads->n_idle == threads->n_threads)	/* Frame finished! Notify potential waiter. */
+			pthread_cond_signal(&threads->idle_cond);
+		pthread_cleanup_pop(1);
+	}
+
+	return NULL;
+}
+
+
+/* wait for all threads to be idle */
+void til_threads_wait_idle(til_threads_t *threads)
+{
+	pthread_mutex_lock(&threads->idle_mutex);
+	pthread_cleanup_push((void (*)(void *))pthread_mutex_unlock, &threads->idle_mutex);
+	while (threads->n_idle < threads->n_threads)
+		pthread_cond_wait(&threads->idle_cond, &threads->idle_mutex);
+	pthread_cleanup_pop(1);
+}
+
+
+/* submit a frame's fragments to the threads */
+void til_threads_frame_submit(til_threads_t *threads, til_fb_fragment_t *fragment, til_fragmenter_t fragmenter, void (*render_fragment_func)(void *context, unsigned ticks, unsigned cpu, til_fb_fragment_t *fragment), void *context, unsigned ticks)
+{
+	til_threads_wait_idle(threads);	/* XXX: likely non-blocking; already happens pre page flip */
+
+	pthread_mutex_lock(&threads->frame_mutex);
+	pthread_cleanup_push((void (*)(void *))pthread_mutex_unlock, &threads->frame_mutex);
+	threads->fragment = fragment;
+	threads->fragmenter = fragmenter;
+	threads->render_fragment_func = render_fragment_func;
+	threads->context = context;
+	threads->ticks = ticks;
+	threads->frame_num++;
+	threads->n_idle = threads->next_fragment = 0;
+	pthread_cond_broadcast(&threads->frame_cond);
+	pthread_cleanup_pop(1);
+}
+
+
+/* create threads instance, a thread per cpu is created */
+til_threads_t * til_threads_create(void)
+{
+	unsigned	num = til_get_ncpus();
+	til_threads_t	*threads;
+
+	threads = calloc(1, sizeof(til_threads_t) + sizeof(til_thread_t) * num);
+	if (!threads)
+		return NULL;
+
+	threads->n_idle = threads->n_threads = num;
+
+	pthread_mutex_init(&threads->idle_mutex, NULL);
+	pthread_cond_init(&threads->idle_cond, NULL);
+
+	pthread_mutex_init(&threads->frame_mutex, NULL);
+	pthread_cond_init(&threads->frame_cond, NULL);
+
+	for (unsigned i = 0; i < num; i++) {
+		til_thread_t	*thread = &threads->threads[i];
+
+		thread->threads = threads;
+		thread->id = i;
+		pthread_create(&thread->pthread, NULL, thread_func, thread);
+	}
+
+	return threads;
+}
+
+
+/* destroy a threads instance */
+void til_threads_destroy(til_threads_t *threads)
+{
+	for (unsigned i = 0; i < threads->n_threads; i++)
+		pthread_cancel(threads->threads[i].pthread);
+
+	for (unsigned i = 0; i < threads->n_threads; i++)
+		pthread_join(threads->threads[i].pthread, NULL);
+
+	pthread_mutex_destroy(&threads->idle_mutex);
+	pthread_cond_destroy(&threads->idle_cond);
+
+	pthread_mutex_destroy(&threads->frame_mutex);
+	pthread_cond_destroy(&threads->frame_cond);
+
+	free(threads);
+}
+
+
+/* return the number of threads */
+unsigned til_threads_num_threads(til_threads_t *threads)
+{
+	return threads->n_threads;
+}