fix a bug in buffrevent read water marks and add a test for them

svn:r731

ChangeLog

@@ -72,6 +72,7 @@ Changes in current version:
  o New functions (event_assign, event_new, event_free) for use by apps that want to be safely threadsafe, or want to remain ignorant of the contents of struct event.
  o introduce bufferevent_read_buffer; allows reading without memory copy.
  o expose bufferevent_setwatermark via header files and fix high watermark on read
+ o fix a bug in buffrevent read water marks and add a test for them
 
 Changes in 1.4.0:
  o allow \r or \n individually to separate HTTP headers instead of the standard "\r\n"; from Charles Kerr.

evbuffer.c

@@ -147,9 +147,8 @@ bufferevent_readcb(evutil_socket_t fd, short event, void *arg)
 		struct evbuffer *buf = bufev->input;
 		event_del(&bufev->ev_read);
 
-		/* Now schedule a callback for us */
+		/* Now schedule a callback for us when the buffer changes */
 		evbuffer_setcb(buf, bufferevent_read_pressure_cb, bufev);
-		return;
 	}
 
 	/* Invoke the user callback - must always be called last */

test/regress.c

@@ -1302,6 +1302,10 @@ test_evbuffer_find(void)
 	evbuffer_free(buf);
 }
 
+/*
+ * simple bufferevent test
+ */
+
 static void
 readcb(struct bufferevent *bev, void *arg)
 {
@@ -1365,6 +1369,80 @@ test_bufferevent(void)
 	cleanup_test();
 }
 
+/*
+ * test watermarks and bufferevent
+ */
+
+static void
+wm_readcb(struct bufferevent *bev, void *arg)
+{
+	struct evbuffer *evbuf = evbuffer_new();
+	int len = EVBUFFER_LENGTH(bev->input);
+	static int nread;
+
+	assert(len >= 10 && len <= 20);
+
+	assert(evbuf != NULL);
+
+	/* gratuitous test of bufferevent_read_buffer */
+	bufferevent_read_buffer(bev, evbuf);
+
+	nread += len;
+	if (nread == 65000) {
+		bufferevent_disable(bev, EV_READ);
+		test_ok++;
+	}
+
+	evbuffer_free(evbuf);
+}
+
+static void
+wm_writecb(struct bufferevent *bev, void *arg)
+{
+	if (EVBUFFER_LENGTH(bev->output) == 0)
+		test_ok++;
+}
+
+static void
+wm_errorcb(struct bufferevent *bev, short what, void *arg)
+{
+	test_ok = -2;
+}
+
+static void
+test_bufferevent_watermarks(void)
+{
+	struct bufferevent *bev1, *bev2;
+	char buffer[65000];
+	int i;
+
+	setup_test("Bufferevent Watermarks: ");
+
+	bev1 = bufferevent_new(pair[0], NULL, wm_writecb, wm_errorcb, NULL);
+	bev2 = bufferevent_new(pair[1], wm_readcb, NULL, wm_errorcb, NULL);
+
+	bufferevent_disable(bev1, EV_READ);
+	bufferevent_enable(bev2, EV_READ);
+
+	for (i = 0; i < sizeof(buffer); i++)
+		buffer[i] = i;
+
+	bufferevent_write(bev1, buffer, sizeof(buffer));
+
+	/* limit the reading on the receiving bufferevent */
+	bufferevent_setwatermark(bev2, EV_READ, 10, 20);
+
+	event_dispatch();
+
+	bufferevent_free(bev1);
+	bufferevent_free(bev2);
+
+	if (test_ok != 2)
+		test_ok = 0;
+
+	cleanup_test();
+}
+
 struct test_pri_event {
 	struct event ev;
 	int count;
@@ -1865,6 +1943,7 @@ main (int argc, char **argv)
 	test_evbuffer_find();
 	
 	test_bufferevent();
+	test_bufferevent_watermarks();
 
 	test_free_active_base();