specifications for timed functions + fix manpage formatting

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

1 files changed, 135 insertions, 19 deletions

diff --git a/src/bus.c b/src/bus.c
index 6705854..06c708a 100644
--- a/src/bus.c
+++ b/src/bus.c
@@ -33,6 +33,7 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
+#include <time.h>
 
 #include <sys/ipc.h>
 #include <sys/sem.h>
@@ -422,6 +423,36 @@ mkdirs(char *pathname, mode_t mode)
 }
 
 
+/**
+ * Convert an absolute time to a relative time
+ * 
+ * @param   delta     Output parameter for the relative time
+ * @param   absolute  The absolute time
+ * @param   clockid   The ID of the clock the time is measured in
+ * @return            0 on success, -1 on error
+ */
+static int
+absolute_time_to_delta_time(struct timespec *delta, const struct timespec *absolute, clockid_t clockid)
+{
+	if (clock_gettime(clockid, delta) < 0)
+		return -1;
+
+	delta->tv_sec  = absolute->tv_sec  - delta->tv_sec;
+	delta->tv_nsec = absolute->tv_nsec - delta->tv_nsec;
+
+	if (delta->tv_nsec < 0L) {
+		delta->tv_nsec += 1000000000L;
+		delta->tv_sec -= 1;
+	}
+	if (delta->tv_nsec >= 1000000000L) {
+		delta->tv_nsec -= 1000000000L;
+		delta->tv_sec += 1;
+	}
+
+	return 0;
+}
+
+
 
 /**
  * Create a new bus
@@ -632,7 +663,7 @@ fail:
 
 
 /**
- * Broadcast a message a bus
+ * Broadcast a message on a bus
  * 
  * @param   bus      Bus information
  * @param   message  The message to write, may not be longer than
@@ -677,26 +708,49 @@ fail:
 
 
 /**
+ * Broadcast a message on a bus
+ * 
+ * @param   bus      Bus information
+ * @param   message  The message to write, may not be longer than
+ *                   `BUS_MEMORY_SIZE` including the NUL-termination
+ * @param   timeout  The time the operation shall fail with errno set
+ *                   to `EAGAIN` if not completed
+ * @param   clockid  The ID of the clock the `timeout` is measured with,
+ *                   it most be a predictable clock
+ * @return           0 on success, -1 on error
+ */
+int bus_write_timed(const bus_t *bus, const char *message,
+		    const struct timespec *timeout, clockid_t clockid)
+{
+	/* TODO bus_write_timed */
+	if (!timeout)
+		return bus_write(bus, message, 0);
+	(void) bus, (void) message, (void) timeout, (void) clockid;
+}
+
+
+/**
  * Listen (in a loop, forever) for new message on a bus
  * 
- * @param   bus       Bus information
- * @param   callback  Function to call when a message is received, the
- *                    input parameters will be the read message and
- *                    `user_data` from `bus_read`'s parameter with the
- *                    same name. The message must have been parsed or
- *                    copied when `callback` returns as it may be over
- *                    overridden after that time. `callback` should
- *                    return either of the the values:
- *                      *  0:  stop listening
- *                      *  1:  continue listening
- *                      * -1:  an error has occurred
- *		      However, the function [`bus_read`] will invoke
- *                    `callback` with `message` set to `NULL`one time
- *                    directly after it has started listening on the
- *                    bus. This is to the the program now it can safely
- *                    continue with any action that requires that the
- *                    programs is listening on the bus.
- * @return            0 on success, -1 on error
+ * @param   bus        Bus information
+ * @param   callback   Function to call when a message is received, the
+ *                     input parameters will be the read message and
+ *                     `user_data` from `bus_read`'s parameter with the
+ *                     same name. The message must have been parsed or
+ *                     copied when `callback` returns as it may be over
+ *                     overridden after that time. `callback` should
+ *                     return either of the the values:
+ *                       *  0:  stop listening
+ *                       *  1:  continue listening
+ *                       * -1:  an error has occurred
+ *                     However, the function [`bus_read`] will invoke
+ *                     `callback` with `message` set to `NULL`one time
+ *                     directly after it has started listening on the
+ *                     bus. This is to the the program now it can safely
+ *                     continue with any action that requires that the
+ *                     programs is listening on the bus.
+ * @param   user_data  Parameter passed to `callback`
+ * @return             0 on success, -1 on error
  */
 int
 bus_read(const bus_t *bus, int (*callback)(const char *message, void *user_data), void *user_data)
@@ -738,6 +792,44 @@ done:
 
 
 /**
+ * Listen (in a loop, forever) for new message on a bus
+ * 
+ * @param   bus        Bus information
+ * @param   callback   Function to call when a message is received, the
+ *                     input parameters will be the read message and
+ *                     `user_data` from `bus_read`'s parameter with the
+ *                     same name. The message must have been parsed or
+ *                     copied when `callback` returns as it may be over
+ *                     overridden after that time. `callback` should
+ *                     return either of the the values:
+ *                       *  0:  stop listening
+ *                       *  1:  continue listening
+ *                       * -1:  an error has occurred
+ *                     However, the function [`bus_read`] will invoke
+ *                     `callback` with `message` set to `NULL`one time
+ *                     directly after it has started listening on the
+ *                     bus. This is to the the program now it can safely
+ *                     continue with any action that requires that the
+ *                     programs is listening on the bus.
+ * @param   user_data  Parameter passed to `callback`
+ * @param   timeout    The time the operation shall fail with errno set
+ *                     to `EAGAIN` if not completed, note that the callback
+ *                     function may or may not have been called
+ * @param   clockid    The ID of the clock the `timeout` is measured with,
+ *                     it most be a predictable clock
+ * @return             0 on success, -1 on error
+ */
+int bus_read_timed(const bus_t *bus, int (*callback)(const char *message, void *user_data),
+		   void *user_data, const struct timespec *timeout, clockid_t clockid)
+{
+	/* TODO bus_read_timed */
+	if (!timeout)
+		return bus_read(bus, callback, user_data);
+	(void) bus, (void) callback, (void) user_data, (void) timeout, (void) clockid;
+}
+
+
+/**
  * Announce that the thread is listening on the bus.
  * This is required so the will does not miss any
  * messages due to race conditions. Additionally,
@@ -835,6 +927,30 @@ fail:
 
 
 /**
+ * Wait for a message to be broadcasted on the bus.
+ * The caller should make a copy of the received message,
+ * without freeing the original copy, and parse it in a
+ * separate thread. When the new thread has started be
+ * started, the caller of this function should then
+ * either call `bus_poll_timed` again or `bus_poll_stop`.
+ * 
+ * @param   bus      Bus information
+ * @param   timeout  The time the operation shall fail with errno set
+ *                   to `EAGAIN` if not completed
+ * @param   clockid  The ID of the clock the `timeout` is measured with,
+ *                   it most be a predictable clock
+ * @return           The received message, `NULL` on error
+ */
+const char *bus_poll_timed(bus_t *bus, const struct timespec *timeout, clockid_t clockid)
+{
+	/* TODO bus_poll_timed */
+	if (!timeout)
+		return bus_poll(bus);
+	(void) bus, (void) timeout, (void) clockid;
+}
+
+
+/**
  * Change the ownership of a bus
  * 
  * `stat(2)` can be used of the bus's associated file to get the bus's ownership