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authorStephen Gallagher <sgallagh@redhat.com>2010-01-15 10:38:24 -0500
committerAndreas Schneider <asn@samba.org>2010-05-05 09:28:04 +0200
commite286966bbabf41a7b1ef45da52b789c716ea9940 (patch)
treeef03a131d0d0b62cfe02988228550cfa56c829ec /lib/tevent
parent098221e8860d22b590671eddd6af6c143fca49b4 (diff)
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tevent: Added more documentation.
Diffstat (limited to 'lib/tevent')
-rw-r--r--lib/tevent/tevent.h258
1 files changed, 247 insertions, 11 deletions
diff --git a/lib/tevent/tevent.h b/lib/tevent/tevent.h
index b0a9fd8d62..3252423b34 100644
--- a/lib/tevent/tevent.h
+++ b/lib/tevent/tevent.h
@@ -45,27 +45,49 @@ struct tevent_signal;
*
* The tevent low-level API
*
- * @todo description
+ * This API provides the public interface to manage events in the tevent
+ * mainloop. Functions are provided for managing low-level events such
+ * as timer events, fd events and signal handling.
*
* @{
*/
/* event handler types */
+/**
+ * Called when a file descriptor monitored by tevent has
+ * data to be read or written on it.
+ */
typedef void (*tevent_fd_handler_t)(struct tevent_context *ev,
struct tevent_fd *fde,
uint16_t flags,
void *private_data);
+
+/**
+ * Called when tevent is ceasing the monitoring of a file descriptor.
+ */
typedef void (*tevent_fd_close_fn_t)(struct tevent_context *ev,
struct tevent_fd *fde,
int fd,
void *private_data);
+
+/**
+ * Called when a tevent timer has fired.
+ */
typedef void (*tevent_timer_handler_t)(struct tevent_context *ev,
struct tevent_timer *te,
struct timeval current_time,
void *private_data);
+
+/**
+ * Called when a tevent immediate event is invoked.
+ */
typedef void (*tevent_immediate_handler_t)(struct tevent_context *ctx,
struct tevent_immediate *im,
void *private_data);
+
+/**
+ * Called after tevent detects the specified signal.
+ */
typedef void (*tevent_signal_handler_t)(struct tevent_context *ev,
struct tevent_signal *se,
int signum,
@@ -120,7 +142,7 @@ const char **tevent_backend_list(TALLOC_CTX *mem_ctx);
*/
void tevent_set_default_backend(const char *backend);
-#if DOXYGEN
+#ifdef DOXYGEN
/**
* @brief Add a file descriptor based event.
*
@@ -130,25 +152,23 @@ void tevent_set_default_backend(const char *backend);
*
* @param[in] fd The file descriptor to base the event on.
*
- * @param[in] flags
+ * @param[in] flags #TEVENT_FD_READ or #TEVENT_FD_WRITE
*
* @param[in] handler The callback handler for the event.
*
* @param[in] private_data The private data passed to the callback handler.
*
- * @param[in] handler_name The name to identify the callback handler.
- *
* @return The file descriptor based event, NULL on error.
*
- * @todo Document flags
+ * @note To cancel the monitoring of a file descriptor, call talloc_free()
+ * on the object returned by this function.
*/
struct tevent_fd *tevent_add_fd(struct tevent_context *ev,
TALLOC_CTX *mem_ctx,
int fd,
uint16_t flags,
tevent_fd_handler_t handler,
- void *private_data,
- const char *handler_name);
+ void *private_data);
#else
struct tevent_fd *_tevent_add_fd(struct tevent_context *ev,
TALLOC_CTX *mem_ctx,
@@ -163,6 +183,42 @@ struct tevent_fd *_tevent_add_fd(struct tevent_context *ev,
#handler, __location__)
#endif
+#ifdef DOXYGEN
+/**
+ * @brief Add a timed event
+ *
+ * @param[in] ev The event context to work on.
+ *
+ * @param[in] mem_ctx The talloc memory context to use.
+ *
+ * @param[in] next_event Timeval specifying the absolute time to fire this
+ * event. This is not an offset.
+ *
+ * @param[in] handler The callback handler for the event.
+ *
+ * @param[in] private_data The private data passed to the callback handler.
+ *
+ * @return The newly-created timer event, or NULL on error.
+ *
+ * @note To cancel a timer event before it fires, call talloc_free() on the
+ * event returned from this function. This event is automatically
+ * talloc_free()-ed after its event handler files, if it hasn't been freed yet.
+ *
+ * @note Unlike some mainloops, tevent timers are one-time events. To set up
+ * a recurring event, it is necessary to call tevent_add_timer() again during
+ * the handler processing.
+ *
+ * @note Due to the internal mainloop processing, a timer set to run
+ * immediately will do so after any other pending timers fire, but before
+ * any further file descriptor or signal handling events fire. Callers should
+ * not rely on this behavior!
+ */
+struct tevent_timer *tevent_add_timer(struct tevent_context *ev,
+ TALLOC_CTX *mem_ctx,
+ struct timeval next_event,
+ tevent_timer_handler_t handler,
+ void *private_data);
+#else
struct tevent_timer *_tevent_add_timer(struct tevent_context *ev,
TALLOC_CTX *mem_ctx,
struct timeval next_event,
@@ -173,12 +229,47 @@ struct tevent_timer *_tevent_add_timer(struct tevent_context *ev,
#define tevent_add_timer(ev, mem_ctx, next_event, handler, private_data) \
_tevent_add_timer(ev, mem_ctx, next_event, handler, private_data, \
#handler, __location__)
+#endif
+#ifdef DOXYGEN
+/**
+ * Initialize an immediate event object
+ *
+ * This object can be used to trigger an event to occur immediately after
+ * returning from the current event (before any other event occurs)
+ *
+ * @param[in] mem_ctx The talloc memory context to use as the parent
+ *
+ * @return An empty tevent_immediate object. Use tevent_schedule_immediate
+ * to populate and use it.
+ *
+ * @note Available as of tevent 0.9.8
+ */
+struct tevent_immediate *tevent_create_immediate(TALLOC_CTX *mem_ctx);
+#else
struct tevent_immediate *_tevent_create_immediate(TALLOC_CTX *mem_ctx,
const char *location);
#define tevent_create_immediate(mem_ctx) \
_tevent_create_immediate(mem_ctx, __location__)
+#endif
+
+#ifdef DOXYGEN
+/**
+ * Schedule an event for immediate execution. This event will occur
+ * immediately after returning from the current event (before any other
+ * event occurs)
+ *
+ * @param[in] im The tevent_immediate object to populate and use
+ * @param[in] ctx The tevent_context to run this event
+ * @param[in] handler The event handler to run when this event fires
+ * @param[in] private_data Data to pass to the event handler
+ */
+void tevent_schedule_immediate(struct tevent_immediate *im,
+ struct tevent_context *ctx,
+ tevent_immediate_handler_t handler,
+ void *private_data);
+#else
void _tevent_schedule_immediate(struct tevent_immediate *im,
struct tevent_context *ctx,
tevent_immediate_handler_t handler,
@@ -188,7 +279,40 @@ void _tevent_schedule_immediate(struct tevent_immediate *im,
#define tevent_schedule_immediate(im, ctx, handler, private_data) \
_tevent_schedule_immediate(im, ctx, handler, private_data, \
#handler, __location__);
+#endif
+#ifdef DOXYGEN
+/**
+ * @brief Add a tevent signal handler
+ *
+ * tevent_add_signal() creates a new event for handling a signal the next
+ * time through the mainloop. It implements a very simple traditional signal
+ * handler whose only purpose is to add the handler event into the mainloop.
+ *
+ * @param[in] ev The event context to work on.
+ *
+ * @param[in] mem_ctx The talloc memory context to use.
+ *
+ * @param[in] signum The signal to trap
+ *
+ * @param[in] handler The callback handler for the signal.
+ *
+ * @param[in] sa_flags sigaction flags for this signal handler.
+ *
+ * @param[in] private_data The private data passed to the callback handler.
+ *
+ * @return The newly-created signal handler event, or NULL on error.
+ *
+ * @note To cancel a signal handler, call talloc_free() on the event returned
+ * from this function.
+ */
+struct tevent_signal *tevent_add_signal(struct tevent_context *ev,
+ TALLOC_CTX *mem_ctx,
+ int signum,
+ int sa_flags,
+ tevent_signal_handler_t handler,
+ void *private_data);
+#else
struct tevent_signal *_tevent_add_signal(struct tevent_context *ev,
TALLOC_CTX *mem_ctx,
int signum,
@@ -200,36 +324,128 @@ struct tevent_signal *_tevent_add_signal(struct tevent_context *ev,
#define tevent_add_signal(ev, mem_ctx, signum, sa_flags, handler, private_data) \
_tevent_add_signal(ev, mem_ctx, signum, sa_flags, handler, private_data, \
#handler, __location__)
+#endif
+#ifdef DOXYGEN
+/**
+ * @brief Pass a single time through the mainloop
+ *
+ * This will process any appropriate signal, immediate, fd and timer events
+ *
+ * @param[in] ev The event context to process
+ *
+ * @return Zero on success, nonzero if an internal error occurred
+ */
+int tevent_loop_once(struct tevent_context *ev);
+#else
int _tevent_loop_once(struct tevent_context *ev, const char *location);
#define tevent_loop_once(ev) \
- _tevent_loop_once(ev, __location__) \
+ _tevent_loop_once(ev, __location__)
+#endif
+#ifdef DOXYGEN
+/**
+ * @brief Run the mainloop
+ *
+ * The mainloop will run until there are no events remaining to be processed
+ *
+ * @param[in] ev The event context to process
+ *
+ * @return Zero if all events have been processed. Nonzero if an internal
+ * error occurred.
+ */
+int tevent_loop_wait(struct tevent_context *ev);
+#else
int _tevent_loop_wait(struct tevent_context *ev, const char *location);
#define tevent_loop_wait(ev) \
- _tevent_loop_wait(ev, __location__) \
+ _tevent_loop_wait(ev, __location__)
+#endif
+
+/**
+ * Assign a function to run when a tevent_fd is freed
+ *
+ * This function is a destructor for the tevent_fd. It does not automatically
+ * close the file descriptor. If this is the desired behavior, then it must be
+ * performed by the close_fn.
+ *
+ * @param[in] fde File descriptor event on which to set the destructor
+ * @param[in] close_fn Destructor to execute when fde is freed
+ */
void tevent_fd_set_close_fn(struct tevent_fd *fde,
tevent_fd_close_fn_t close_fn);
+
+/**
+ * Automatically close the file descriptor when the tevent_fd is freed
+ *
+ * This function calls close(fd) internally.
+ *
+ * @param[in] fde File descriptor event to auto-close
+ */
void tevent_fd_set_auto_close(struct tevent_fd *fde);
+
+/**
+ * Return the flags set on this file descriptor event
+ *
+ * @param[in] fde File descriptor event to query
+ *
+ * @return The flags set on the event. See #TEVENT_FD_READ and
+ * #TEVENT_FD_WRITE
+ */
uint16_t tevent_fd_get_flags(struct tevent_fd *fde);
+
+/**
+ * Set flags on a file descriptor event
+ *
+ * @param[in] fde File descriptor event to set
+ * @param[in] flags Flags to set on the event. See #TEVENT_FD_READ and
+ * #TEVENT_FD_WRITE
+ */
void tevent_fd_set_flags(struct tevent_fd *fde, uint16_t flags);
+/**
+ * Query whether tevent supports signal handling
+ *
+ * @param[in] ev An initialized tevent context
+ *
+ * @return True if this platform and tevent context support signal handling
+ */
bool tevent_signal_support(struct tevent_context *ev);
void tevent_set_abort_fn(void (*abort_fn)(const char *reason));
/* bits for file descriptor event flags */
+
+/**
+ * Monitor a file descriptor for write availability
+ */
#define TEVENT_FD_READ 1
+/**
+ * Monitor a file descriptor for data to be read
+ */
#define TEVENT_FD_WRITE 2
+/**
+ * Convenience function for declaring a tevent_fd writable
+ */
#define TEVENT_FD_WRITEABLE(fde) \
tevent_fd_set_flags(fde, tevent_fd_get_flags(fde) | TEVENT_FD_WRITE)
+
+/**
+ * Convenience function for declaring a tevent_fd readable
+ */
#define TEVENT_FD_READABLE(fde) \
tevent_fd_set_flags(fde, tevent_fd_get_flags(fde) | TEVENT_FD_READ)
+/**
+ * Convenience function for declaring a tevent_fd non-writable
+ */
#define TEVENT_FD_NOT_WRITEABLE(fde) \
tevent_fd_set_flags(fde, tevent_fd_get_flags(fde) & ~TEVENT_FD_WRITE)
+
+/**
+ * Convenience function for declaring a tevent_fd non-readable
+ */
#define TEVENT_FD_NOT_READABLE(fde) \
tevent_fd_set_flags(fde, tevent_fd_get_flags(fde) & ~TEVENT_FD_READ)
@@ -243,12 +459,32 @@ enum tevent_debug_level {
TEVENT_DEBUG_TRACE
};
+/**
+ * Set destination for tevent debug messages
+ *
+ * @param[in] ev Event context to debug
+ * @param[in] debug Function to handle output printing
+ *
+ * @return Always returns 0 as of version 0.9.8
+ *
+ * @note Default is to emit no debug messages
+ */
int tevent_set_debug(struct tevent_context *ev,
void (*debug)(void *context,
enum tevent_debug_level level,
const char *fmt,
va_list ap) PRINTF_ATTRIBUTE(3,0),
void *context);
+
+/**
+ * Designate stderr for debug message output
+ *
+ * @param[in] ev Event context to debug
+ *
+ * @note This function will only output TEVENT_DEBUG_FATAL, TEVENT_DEBUG_ERROR
+ * and TEVENT_DEBUG_WARNING messages. For TEVENT_DEBUG_TRACE, please define a
+ * function for tevent_set_debug()
+ */
int tevent_set_debug_stderr(struct tevent_context *ev);
/**
@@ -414,7 +650,7 @@ bool _tevent_req_cancel(struct tevent_req *req, const char *location);
_tevent_req_cancel(req, __location__)
#endif
-#if DOXYGEN
+#ifdef DOXYGEN
/**
* @brief Create an async tevent request.
*