add timed example and fix timed polling

Signed-off-by: Mattias Andrée <maandree@operamail.com>

10 files changed, 140 insertions, 27 deletions

diff --git a/doc/examples/nonblocking/poll.c b/doc/examples/nonblocking/poll.c
index c918b5b..2b0c266 100644
--- a/doc/examples/nonblocking/poll.c
+++ b/doc/examples/nonblocking/poll.c
@@ -14,9 +14,9 @@ int main()
 	const char *message;
 	long long tick = 0;
 	t(bus_open(&bus, "/tmp/example-bus", BUS_RDONLY));
-	t(bus_poll_start(&bus, BUS_NOWAIT));
+	t(bus_poll_start(&bus));
 	for (;;) {
-		message = bus_poll(&bus);
+		message = bus_poll(&bus, BUS_NOWAIT);
 		if (message == NULL) {
 			t(errno != EAGAIN);
 			printf("waiting... %lli\n", ++tick);
diff --git a/doc/examples/timed/.gitignore b/doc/examples/timed/.gitignore
new file mode 100644
index 0000000..e5c1856
--- /dev/null
+++ b/doc/examples/timed/.gitignore
@@ -0,0 +1,5 @@
+cleanup
+init
+write
+poll
+
diff --git a/doc/examples/timed/Makefile b/doc/examples/timed/Makefile
new file mode 100644
index 0000000..1b1cbd3
--- /dev/null
+++ b/doc/examples/timed/Makefile
@@ -0,0 +1,13 @@
+COMMANDS = init cleanup write poll
+
+all: ${COMMANDS}
+
+%: %.c
+	${CC} -Wall -Wextra -pedantic -std=c99 -lbus -o $@ $<
+
+clean:
+	-rm ${COMMANDS}
+
+
+.PHONY: all clean
+
diff --git a/doc/examples/timed/README b/doc/examples/timed/README
new file mode 100644
index 0000000..b0989bf
--- /dev/null
+++ b/doc/examples/timed/README
@@ -0,0 +1,18 @@
+API usage example
+
+This example shows how to use timed operations.
+
+
+
+First of, run make to build this example.
+
+To start the example run ./init.
+When you are done run ./cleanup.
+
+Running instances of ./poll will wait for new messages
+continuously, but with one second timeouts.
+
+./poll, ./init and ./cleanup are run without any
+additional arguments. ./write is run with the message
+as the second argument.
+
diff --git a/doc/examples/timed/cleanup.c b/doc/examples/timed/cleanup.c
new file mode 100644
index 0000000..00f07bc
--- /dev/null
+++ b/doc/examples/timed/cleanup.c
@@ -0,0 +1,8 @@
+#include <bus.h>
+#include <stdio.h>
+
+int main()
+{
+	return bus_unlink("/tmp/example-bus") && (perror("cleanup"), 1);
+}
+
diff --git a/doc/examples/timed/init.c b/doc/examples/timed/init.c
new file mode 100644
index 0000000..870e10d
--- /dev/null
+++ b/doc/examples/timed/init.c
@@ -0,0 +1,8 @@
+#include <bus.h>
+#include <stdio.h>
+
+int main()
+{
+	return bus_create("/tmp/example-bus", 0, NULL) && (perror("init"), 1);
+}
+
diff --git a/doc/examples/timed/poll.c b/doc/examples/timed/poll.c
new file mode 100644
index 0000000..d8c5aac
--- /dev/null
+++ b/doc/examples/timed/poll.c
@@ -0,0 +1,45 @@
+#include <bus.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+
+#define t(stmt)  if (stmt) goto fail
+
+
+
+int main()
+{
+	bus_t bus;
+	const char *message;
+	long long tick = 0;
+	struct timespec timeout;
+	t(bus_open(&bus, "/tmp/example-bus", BUS_RDONLY));
+	t(bus_poll_start(&bus));
+	for (;;) {
+		t(clock_gettime(CLOCK_MONOTONIC, &timeout));
+		timeout.tv_sec += 1;
+		message = bus_poll_timed(&bus, &timeout, CLOCK_MONOTONIC);
+		if (message == NULL) {
+			t(errno != EAGAIN);
+			printf("waiting... %lli\n", ++tick);
+			sleep(1);
+			continue;
+		}
+		tick = 0;
+		message = strchr(message, ' ') + 1;
+		if (!strcmp(message, "stop"))
+			break;
+		printf("\033[01m%s\033[21m\n", message);
+	}
+	t(bus_poll_stop(&bus));
+	bus_close(&bus);
+	return 0;
+
+fail:
+	perror("poll");
+	bus_poll_stop(&bus);
+	bus_close(&bus);
+	return 1;
+}
+
diff --git a/doc/examples/timed/write.c b/doc/examples/timed/write.c
new file mode 100644
index 0000000..b6b4c16
--- /dev/null
+++ b/doc/examples/timed/write.c
@@ -0,0 +1,32 @@
+#include <bus.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <stdint.h>
+
+#define t(stmt)  if (stmt) goto fail
+
+
+
+static char message[BUS_MEMORY_SIZE];
+
+
+
+int main(int argc, char *argv[])
+{
+	bus_t bus;
+	if (argc < 2) {
+		fprintf(stderr, "%s: USAGE: %s message\n", argv[0], argv[0]);
+		return 2;
+	}
+	sprintf(message, "0 %s", argv[1]);
+	t(bus_open(&bus, "/tmp/example-bus", BUS_WRONLY));
+	t(bus_write(&bus, message, 0));
+	bus_close(&bus);
+	return 0;
+
+fail:
+	perror("write");
+	bus_close(&bus);
+	return 1;
+}
+
diff --git a/src/bus.c b/src/bus.c
index 516def1..0517f7a 100644
--- a/src/bus.c
+++ b/src/bus.c
@@ -985,14 +985,11 @@ done:
  * @return         0 on success, -1 on error
  */
 int
-bus_poll_start(bus_t *bus, int flags)
+bus_poll_start(bus_t *bus)
 {
 	bus->first_poll = 1;
-	bus->flags = flags;
 	t(release_semaphore(bus, S, SEM_UNDO));
-	if (flags & BUS_NOWAIT) {
-		t(release_semaphore(bus, Q, 0));
-	}
+	t(release_semaphore(bus, Q, 0));
 	return 0;
 
 fail:
@@ -1027,7 +1024,7 @@ bus_poll_stop(const bus_t *bus)
  * @return       The received message, `NULL` on error
  */
 const char *
-bus_poll(bus_t *bus)
+bus_poll(bus_t *bus, int flags)
 {
 	int state = 0, saved_errno;
 	if (!bus->first_poll) {
@@ -1039,19 +1036,12 @@ bus_poll(bus_t *bus)
 #endif
 		t(release_semaphore(bus, S, SEM_UNDO));  state--;
 		t(acquire_semaphore(bus, W, SEM_UNDO));  state--;
-		if (bus->flags & BUS_NOWAIT) {
-			t(release_semaphore(bus, Q, 0));
-		}
+		t(release_semaphore(bus, Q, 0));
 	} else {
 		bus->first_poll = 0;
 	}
 	state--;
-	if (bus->flags & BUS_NOWAIT) {
-		t(zero_semaphore(bus, Q, IPC_NOWAIT));
-	} else {
-		t(release_semaphore(bus, Q, 0));
-		t(zero_semaphore(bus, Q, 0));
-	}
+	t(zero_semaphore(bus, Q, F(BUS_NOWAIT, IPC_NOWAIT)));
 	return bus->message;
 
 fail:
@@ -1087,7 +1077,7 @@ const char *bus_poll_timed(bus_t *bus, const struct timespec *timeout, clockid_t
 	int state = 0, saved_errno;
 	struct timespec delta;
 	if (!timeout)
-		return bus_poll(bus);
+		return bus_poll(bus, 0);
 
 	if (!bus->first_poll) {
 		t(release_semaphore(bus, W, SEM_UNDO));  state++;
@@ -1098,13 +1088,12 @@ const char *bus_poll_timed(bus_t *bus, const struct timespec *timeout, clockid_t
 #endif
 		t(release_semaphore(bus, S, SEM_UNDO));  state--;
 		t(acquire_semaphore(bus, W, SEM_UNDO));  state--;
+		t(release_semaphore(bus, Q, 0));
 	} else {
 		bus->first_poll = 0;
 	}
 	state--;
 	DELTA;
-	t(release_semaphore_timed(bus, Q, 0, &delta));
-	DELTA;
 	t(zero_semaphore_timed(bus, Q, 0, &delta));
 	return bus->message;
 
diff --git a/src/bus.h b/src/bus.h
index aa35c7b..9d3b436 100644
--- a/src/bus.h
+++ b/src/bus.h
@@ -107,11 +107,6 @@ typedef struct bus
 	 */
 	int first_poll;
 
-	/**
-	 * Flags used for polling
-	 */
-	int flags;
-
 } bus_t;
 
 
@@ -258,7 +253,7 @@ int bus_read_timed(const bus_t *bus, int (*callback)(const char *message, void *
  *                 the bus when `bus_poll` is called
  * @return         0 on success, -1 on error
  */
-int bus_poll_start(bus_t *bus, int flags);
+int bus_poll_start(bus_t *bus);
 
 /**
  * Announce that the thread has stopped listening on the bus.
@@ -281,7 +276,7 @@ int bus_poll_stop(const bus_t *bus);
  * @param   bus  Bus information
  * @return       The received message, `NULL` on error
  */
-const char *bus_poll(bus_t *bus);
+const char *bus_poll(bus_t *bus, int flags);
 
 /**
  * Wait for a message to be broadcasted on the bus.