From 66c5606e34bd290954b8a918028ede344bccc27a Mon Sep 17 00:00:00 2001
From: Joachim Nilsson <troglobit@gmail.com>
Date: Sun, 4 Aug 2013 17:26:33 +0200
Subject: [PATCH] Add support for UEV_ONCE and UEV_NONBLOCK run flags to
 uev_run()

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>
---
 main.c | 18 ++++++++++++++----
 test.c |  2 +-
 uev.h  | 15 +++++++++------
 3 files changed, 24 insertions(+), 11 deletions(-)

diff --git a/main.c b/main.c
index eeae857..d4b5ff3 100644
--- a/main.c
+++ b/main.c
@@ -31,6 +31,8 @@
 
 #include "uev.h"
 
+#define UNUSED(arg) arg __attribute__ ((unused))
+
 /* Private to libuev, do not use directly! */
 int uev_watcher_init(uev_ctx_t *ctx, uev_t *w, uev_type_t type, uev_cb_t *cb, void *arg, int fd, int events)
 {
@@ -160,13 +162,14 @@ int uev_exit(uev_ctx_t *ctx)
 
 /**
  * Start the event loop
- * @param ctx  A valid libuev context
+ * @param ctx    A valid libuev context
+ * @param flags  A mask of %UEV_ONCE and %UEV_NONBLOCK, or zero
  *
  * @return POSIX OK(0) upon successful termination of the event loop, or non-zero on error.
  */
-int uev_run(uev_ctx_t *ctx)
+int uev_run(uev_ctx_t *ctx, int flags)
 {
-	int result = 0;
+	int result = 0, timeout = -1;
 	uev_t *w;
 
         if (!ctx || ctx->fd < 0) {
@@ -174,6 +177,9 @@ int uev_run(uev_ctx_t *ctx)
                 return -1;
 	}
 
+	if (flags & UEV_NONBLOCK)
+		timeout = 0;
+
 	/* Start the event loop */
 	ctx->running = 1;
 
@@ -187,7 +193,7 @@ int uev_run(uev_ctx_t *ctx)
 		int i, nfds;
 		struct epoll_event events[UEV_MAX_EVENTS];
 
-		while ((nfds = epoll_wait(ctx->fd, events, UEV_MAX_EVENTS, -1)) < 0) {
+		while ((nfds = epoll_wait(ctx->fd, events, UEV_MAX_EVENTS, timeout)) < 0) {
 			if (!ctx->running)
 				break;
 
@@ -230,11 +236,15 @@ int uev_run(uev_ctx_t *ctx)
 					uev_timer_stop(w);
 			}
 		}
+
+		if ((flags & UEV_ONCE) || LIST_EMPTY(&ctx->watchers))
+			break;
 	}
 
 	return result;
 }
 
+
 /**
  * Local Variables:
  *  version-control: t
diff --git a/test.c b/test.c
index 0553533..ed4f6e0 100644
--- a/test.c
+++ b/test.c
@@ -136,7 +136,7 @@ int main(void)
 	uev_timer_init(&ctx, &periodic, periodic_task, NULL, 200, 200);
 
 	/* Start event loop */
-	uev_run(&ctx);
+	uev_run(&ctx, 0);
 
 	fprintf(stderr, "Period is %d must be 10: %s\n", period, 10 == period ? "OK" : "ERROR!");
 	if (10 != period)
diff --git a/uev.h b/uev.h
index 5733d59..3d85b02 100644
--- a/uev.h
+++ b/uev.h
@@ -31,12 +31,16 @@
 #include <sys/queue.h>
 
 /* Max. number of simulateneous events */
-#define UEV_MAX_EVENTS 10
+#define UEV_MAX_EVENTS  10
 
 /* I/O events, for signals and timers revents will always be UEV_READ */
-#define UEV_NONE    0
-#define UEV_READ    EPOLLIN
-#define UEV_WRITE   EPOLLOUT
+#define UEV_NONE        0
+#define UEV_READ        EPOLLIN
+#define UEV_WRITE       EPOLLOUT
+
+/* Run flags */
+#define UEV_ONCE        1
+#define UEV_NONBLOCK    2
 
 /* I/O, timer, or signal watcher */
 typedef enum {
@@ -89,8 +93,7 @@ int uev_watcher_stop   (uev_t *w);
 /* Public interface */
 int uev_init           (uev_ctx_t *ctx);
 int uev_exit           (uev_ctx_t *ctx);
-
-int uev_run            (uev_ctx_t *ctx);
+int uev_run            (uev_ctx_t *ctx, int flags);
 
 int uev_io_init        (uev_ctx_t *ctx, uev_t *w, uev_cb_t *cb, void *arg, int fd, int events);
 int uev_io_set         (uev_t *w, int fd, int events);