- added libdrawtext

[demo_prior] / libs / drawtext / src / tpool.h

diff --git a/libs/drawtext/src/tpool.h b/libs/drawtext/src/tpool.h
new file mode 100644 (file)
index 0000000..5cd73cc
--- /dev/null
+++ b/libs/drawtext/src/tpool.h
@@ -0,0 +1,61 @@
+/* worker thread pool based on POSIX threads
+ * author: John Tsiombikas <nuclear@member.fsf.org>
+ * This code is public domain.
+ */
+#ifndef THREADPOOL_H_
+#define THREADPOOL_H_
+
+struct dtx_thread_pool;
+
+/* type of the function accepted as work or completion callback */
+typedef void (*dtx_tpool_callback)(void*);
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* if num_threads == 0, auto-detect how many threads to spawn */
+struct dtx_thread_pool *dtx_tpool_create(int num_threads);
+void dtx_tpool_destroy(struct dtx_thread_pool *tpool);
+
+/* if begin_batch is called before an enqueue, the worker threads will not be
+ * signalled to start working until end_batch is called.
+ */
+void dtx_tpool_begin_batch(struct dtx_thread_pool *tpool);
+void dtx_tpool_end_batch(struct dtx_thread_pool *tpool);
+
+/* if enqueue is called without calling begin_batch first, it will immediately
+ * wake up the worker threads to start working on the enqueued item
+ */
+int dtx_tpool_enqueue(struct dtx_thread_pool *tpool, void *data,
+               dtx_tpool_callback work_func, dtx_tpool_callback done_func);
+/* clear the work queue. does not cancel any currently running jobs */
+void dtx_tpool_clear(struct dtx_thread_pool *tpool);
+
+/* returns the number of queued work items */
+int dtx_tpool_queued_jobs(struct dtx_thread_pool *tpool);
+/* returns the number of active (working) threads */
+int dtx_tpool_active_jobs(struct dtx_thread_pool *tpool);
+/* returns the number of pending jobs, both in queue and active */
+int dtx_tpool_pending_jobs(struct dtx_thread_pool *tpool);
+
+/* wait for all pending jobs to be completed */
+void dtx_tpool_wait(struct dtx_thread_pool *tpool);
+/* wait until the pending jobs are down to the target specified
+ * for example, to wait until a single job has been completed:
+ *   dtx_tpool_wait_pending(tpool, dtx_tpool_pending_jobs(tpool) - 1);
+ * this interface is slightly awkward to avoid race conditions. */
+void dtx_tpool_wait_pending(struct dtx_thread_pool *tpool, int pending_target);
+/* wait for all pending jobs to be completed for up to "timeout" milliseconds */
+long dtx_tpool_timedwait(struct dtx_thread_pool *tpool, long timeout);
+
+/* returns the number of processors on the system.
+ * individual cores in multi-core processors are counted as processors.
+ */
+int dtx_tpool_num_processors(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* THREADPOOL_H_ */