struct tevent_timer;
struct tevent_immediate;
struct tevent_signal;
+struct tevent_thread_proxy;
+struct tevent_threaded_context;
+
+/**
+ * @defgroup tevent The tevent API
+ *
+ * The tevent low-level API
+ *
+ * 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,
void *siginfo,
void *private_data);
+/**
+ * @brief Create a event_context structure.
+ *
+ * This must be the first events call, and all subsequent calls pass this
+ * event_context as the first element. Event handlers also receive this as
+ * their first argument.
+ *
+ * @param[in] mem_ctx The memory context to use.
+ *
+ * @return An allocated tevent context, NULL on error.
+ *
+ * @see tevent_context_init()
+ */
struct tevent_context *tevent_context_init(TALLOC_CTX *mem_ctx);
+
+/**
+ * @brief Create a event_context structure and select a specific backend.
+ *
+ * This must be the first events call, and all subsequent calls pass this
+ * event_context as the first element. Event handlers also receive this as
+ * their first argument.
+ *
+ * @param[in] mem_ctx The memory context to use.
+ *
+ * @param[in] name The name of the backend to use.
+ *
+ * @return An allocated tevent context, NULL on error.
+ */
struct tevent_context *tevent_context_init_byname(TALLOC_CTX *mem_ctx, const char *name);
+
+/**
+ * @brief Create a custom event context
+ *
+ * @param[in] mem_ctx The memory context to use.
+ * @param[in] ops The function pointer table of the backend.
+ * @param[in] additional_data The additional/private data to this instance
+ *
+ * @return An allocated tevent context, NULL on error.
+ *
+ */
+struct tevent_context *tevent_context_init_ops(TALLOC_CTX *mem_ctx,
+ const struct tevent_ops *ops,
+ void *additional_data);
+
+/**
+ * @brief List available backends.
+ *
+ * @param[in] mem_ctx The memory context to use.
+ *
+ * @return A string vector with a terminating NULL element, NULL
+ * on error.
+ */
const char **tevent_backend_list(TALLOC_CTX *mem_ctx);
+
+/**
+ * @brief Set the default tevent backend.
+ *
+ * @param[in] backend The name of the backend to set.
+ */
void tevent_set_default_backend(const char *backend);
+#ifdef DOXYGEN
+/**
+ * @brief Add a file descriptor based event.
+ *
+ * @param[in] ev The event context to work on.
+ *
+ * @param[in] mem_ctx The talloc memory context to use.
+ *
+ * @param[in] fd The file descriptor to base the event on.
+ *
+ * @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.
+ *
+ * @return The file descriptor based event, NULL on error.
+ *
+ * @note To cancel the monitoring of a file descriptor, call talloc_free()
+ * on the object returned by this function.
+ *
+ * @note The caller should avoid closing the file descriptor before
+ * calling talloc_free()! Otherwise the behaviour is undefined which
+ * might result in crashes. See https://bugzilla.samba.org/show_bug.cgi?id=11141
+ * for an example.
+ */
+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);
+#else
struct tevent_fd *_tevent_add_fd(struct tevent_context *ev,
TALLOC_CTX *mem_ctx,
int fd,
#define tevent_add_fd(ev, mem_ctx, fd, flags, handler, private_data) \
_tevent_add_fd(ev, mem_ctx, fd, flags, handler, private_data, \
#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,
#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
+
+/**
+ * @brief Set the time a tevent_timer fires
+ *
+ * @param[in] te The timer event to reset
+ *
+ * @param[in] next_event Timeval specifying the absolute time to fire this
+ * event. This is not an offset.
+ */
+void tevent_update_timer(struct tevent_timer *te, struct timeval next_event);
+#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,
#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.
+ *
+ * @see tevent_num_signals, tevent_sa_info_queue_count
+ */
+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,
#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
+
+/**
+ * @brief the number of supported signals
+ *
+ * This returns value of the configure time TEVENT_NUM_SIGNALS constant.
+ *
+ * The 'signum' argument of tevent_add_signal() must be less than
+ * TEVENT_NUM_SIGNALS.
+ *
+ * @see tevent_add_signal
+ */
+size_t tevent_num_signals(void);
+/**
+ * @brief the number of pending realtime signals
+ *
+ * This returns value of TEVENT_SA_INFO_QUEUE_COUNT.
+ *
+ * The tevent internals remember the last TEVENT_SA_INFO_QUEUE_COUNT
+ * siginfo_t structures for SA_SIGINFO signals. If the system generates
+ * more some signals get lost.
+ *
+ * @see tevent_add_signal
+ */
+size_t tevent_sa_info_queue_count(void);
+
+#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 data to be read
+ */
#define TEVENT_FD_READ 1
+/**
+ * Monitor a file descriptor for writeability
+ */
#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)
-/* DEBUG */
+/**
+ * Debug level of tevent
+ */
enum tevent_debug_level {
TEVENT_DEBUG_FATAL,
TEVENT_DEBUG_ERROR,
TEVENT_DEBUG_TRACE
};
+/**
+ * @brief The tevent debug callbac.
+ *
+ * @param[in] context The memory context to use.
+ *
+ * @param[in] level The debug level.
+ *
+ * @param[in] fmt The format string.
+ *
+ * @param[in] ap The arguments for the format string.
+ */
+typedef void (*tevent_debug_fn)(void *context,
+ enum tevent_debug_level level,
+ const char *fmt,
+ va_list ap) PRINTF_ATTRIBUTE(3,0);
+
+/**
+ * Set destination for tevent debug messages
+ *
+ * @param[in] ev Event context to debug
+ * @param[in] debug Function to handle output printing
+ * @param[in] context The context to pass to the debug function.
+ *
+ * @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),
+ tevent_debug_fn debug,
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);
+enum tevent_trace_point {
+ /**
+ * Corresponds to a trace point just before waiting
+ */
+ TEVENT_TRACE_BEFORE_WAIT,
+ /**
+ * Corresponds to a trace point just after waiting
+ */
+ TEVENT_TRACE_AFTER_WAIT,
+#define TEVENT_HAS_LOOP_ONCE_TRACE_POINTS 1
+ /**
+ * Corresponds to a trace point just before calling
+ * the loop_once() backend function.
+ */
+ TEVENT_TRACE_BEFORE_LOOP_ONCE,
+ /**
+ * Corresponds to a trace point right after the
+ * loop_once() backend function has returned.
+ */
+ TEVENT_TRACE_AFTER_LOOP_ONCE,
+};
+
+typedef void (*tevent_trace_callback_t)(enum tevent_trace_point,
+ void *private_data);
+
+/**
+ * Register a callback to be called at certain trace points
+ *
+ * @param[in] ev Event context
+ * @param[in] cb Trace callback
+ * @param[in] private_data Data to be passed to callback
+ *
+ * @note The callback will be called at trace points defined by
+ * tevent_trace_point. Call with NULL to reset.
+ */
+void tevent_set_trace_callback(struct tevent_context *ev,
+ tevent_trace_callback_t cb,
+ void *private_data);
+
+/**
+ * Retrieve the current trace callback
+ *
+ * @param[in] ev Event context
+ * @param[out] cb Registered trace callback
+ * @param[out] private_data Registered data to be passed to callback
+ *
+ * @note This can be used to allow one component that wants to
+ * register a callback to respect the callback that another component
+ * has already registered.
+ */
+void tevent_get_trace_callback(struct tevent_context *ev,
+ tevent_trace_callback_t *cb,
+ void *private_data);
+
+/**
+ * @}
+ */
+
+/**
+ * @defgroup tevent_request The tevent request functions.
+ * @ingroup tevent
+ *
+ * A tevent_req represents an asynchronous computation.
+ *
+ * The tevent_req group of API calls is the recommended way of
+ * programming async computations within tevent. In particular the
+ * file descriptor (tevent_add_fd) and timer (tevent_add_timed) events
+ * are considered too low-level to be used in larger computations. To
+ * read and write from and to sockets, Samba provides two calls on top
+ * of tevent_add_fd: tstream_read_packet_send/recv and tstream_writev_send/recv.
+ * These requests are much easier to compose than the low-level event
+ * handlers called from tevent_add_fd.
+ *
+ * A lot of the simplicity tevent_req has brought to the notoriously
+ * hairy async programming came via a set of conventions that every
+ * async computation programmed should follow. One central piece of
+ * these conventions is the naming of routines and variables.
+ *
+ * Every async computation needs a name (sensibly called "computation"
+ * down from here). From this name quite a few naming conventions are
+ * derived.
+ *
+ * Every computation that requires local state needs a
+ * @code
+ * struct computation_state {
+ * int local_var;
+ * };
+ * @endcode
+ * Even if no local variables are required, such a state struct should
+ * be created containing a dummy variable. Quite a few helper
+ * functions and macros (for example tevent_req_create()) assume such
+ * a state struct.
+ *
+ * An async computation is started by a computation_send
+ * function. When it is finished, its result can be received by a
+ * computation_recv function. For an example how to set up an async
+ * computation, see the code example in the documentation for
+ * tevent_req_create() and tevent_req_post(). The prototypes for _send
+ * and _recv functions should follow some conventions:
+ *
+ * @code
+ * struct tevent_req *computation_send(TALLOC_CTX *mem_ctx,
+ * struct tevent_req *ev,
+ * ... further args);
+ * int computation_recv(struct tevent_req *req, ... further output args);
+ * @endcode
+ *
+ * The "int" result of computation_recv() depends on the result the
+ * sync version of the function would have, "int" is just an example
+ * here.
+ *
+ * Another important piece of the conventions is that the program flow
+ * is interrupted as little as possible. Because a blocking
+ * sub-computation requires that the flow needs to continue in a
+ * separate function that is the logical sequel of some computation,
+ * it should lexically follow sending off the blocking
+ * sub-computation. Setting the callback function via
+ * tevent_req_set_callback() requires referencing a function lexically
+ * below the call to tevent_req_set_callback(), forward declarations
+ * are required. A lot of the async computations thus begin with a
+ * sequence of declarations such as
+ *
+ * @code
+ * static void computation_step1_done(struct tevent_req *subreq);
+ * static void computation_step2_done(struct tevent_req *subreq);
+ * static void computation_step3_done(struct tevent_req *subreq);
+ * @endcode
+ *
+ * It really helps readability a lot to do these forward declarations,
+ * because the lexically sequential program flow makes the async
+ * computations almost as clear to read as a normal, sync program
+ * flow.
+ *
+ * It is up to the user of the async computation to talloc_free it
+ * after it has finished. If an async computation should be aborted,
+ * the tevent_req structure can be talloc_free'ed. After it has
+ * finished, it should talloc_free'ed by the API user.
+ *
+ * @{
+ */
+
/**
- * An async request moves between the following 4 states:
+ * An async request moves from TEVENT_REQ_INIT to
+ * TEVENT_REQ_IN_PROGRESS. All other states are valid after a request
+ * has finished.
*/
enum tevent_req_state {
/**
- * we are creating the request
+ * We are creating the request
*/
TEVENT_REQ_INIT,
/**
- * we are waiting the request to complete
+ * We are waiting the request to complete
*/
TEVENT_REQ_IN_PROGRESS,
/**
- * the request is finished
+ * The request is finished successfully
*/
TEVENT_REQ_DONE,
/**
- * A user error has occured
+ * A user error has occurred. The user error has been
+ * indicated by tevent_req_error(), it can be retrieved via
+ * tevent_req_is_error().
*/
TEVENT_REQ_USER_ERROR,
/**
- * Request timed out
+ * Request timed out after the timeout set by tevent_req_set_endtime.
*/
TEVENT_REQ_TIMED_OUT,
/**
- * No memory in between
+ * An internal allocation has failed, or tevent_req_nomem has
+ * been given a NULL pointer as the first argument.
*/
TEVENT_REQ_NO_MEMORY,
/**
- * the request is already received by the caller
+ * The request has been received by the caller. No further
+ * action is valid.
*/
TEVENT_REQ_RECEIVED
};
/**
* @brief An async request
- *
- * This represents an async request being processed by callbacks via an event
- * context. A user can issue for example a write request to a socket, giving
- * an implementation function the fd, the buffer and the number of bytes to
- * transfer. The function issuing the request will immediately return without
- * blocking most likely without having sent anything. The API user then fills
- * in req->async.fn and req->async.private_data, functions that are called
- * when the request is finished.
- *
- * It is up to the user of the async request to talloc_free it after it has
- * finished. This can happen while the completion function is called.
*/
-
struct tevent_req;
-typedef void (*tevent_req_fn)(struct tevent_req *);
+/**
+ * @brief A tevent request callback function.
+ *
+ * @param[in] req The tevent async request which executed this callback.
+ */
+typedef void (*tevent_req_fn)(struct tevent_req *req);
+/**
+ * @brief Set an async request callback.
+ *
+ * See the documentation of tevent_req_post() for an example how this
+ * is supposed to be used.
+ *
+ * @param[in] req The async request to set the callback.
+ *
+ * @param[in] fn The callback function to set.
+ *
+ * @param[in] pvt A pointer to private data to pass to the async request
+ * callback.
+ */
void tevent_req_set_callback(struct tevent_req *req, tevent_req_fn fn, void *pvt);
-void *_tevent_req_callback_data(struct tevent_req *req);
-void *_tevent_req_data(struct tevent_req *req);
+#ifdef DOXYGEN
+/**
+ * @brief Get the private data cast to the given type for a callback from
+ * a tevent request structure.
+ *
+ * @code
+ * static void computation_done(struct tevent_req *subreq) {
+ * struct tevent_req *req = tevent_req_callback_data(subreq, struct tevent_req);
+ * struct computation_state *state = tevent_req_data(req, struct computation_state);
+ * .... more things, eventually maybe call tevent_req_done(req);
+ * }
+ * @endcode
+ *
+ * @param[in] req The structure to get the callback data from.
+ *
+ * @param[in] type The type of the private callback data to get.
+ *
+ * @return The type casted private data set NULL if not set.
+ */
+void *tevent_req_callback_data(struct tevent_req *req, #type);
+#else
+void *_tevent_req_callback_data(struct tevent_req *req);
#define tevent_req_callback_data(_req, _type) \
talloc_get_type_abort(_tevent_req_callback_data(_req), _type)
+#endif
+
+#ifdef DOXYGEN
+/**
+ * @brief Get the private data for a callback from a tevent request structure.
+ *
+ * @param[in] req The structure to get the callback data from.
+ *
+ * @param[in] req The structure to get the data from.
+ *
+ * @return The private data or NULL if not set.
+ */
+void *tevent_req_callback_data_void(struct tevent_req *req);
+#else
#define tevent_req_callback_data_void(_req) \
_tevent_req_callback_data(_req)
+#endif
+
+#ifdef DOXYGEN
+/**
+ * @brief Get the private data from a tevent request structure.
+ *
+ * When the tevent_req has been created by tevent_req_create, the
+ * result of tevent_req_data() is the state variable created by
+ * tevent_req_create() as a child of the req.
+ *
+ * @param[in] req The structure to get the private data from.
+ *
+ * @param[in] type The type of the private data
+ *
+ * @return The private data or NULL if not set.
+ */
+void *tevent_req_data(struct tevent_req *req, #type);
+#else
+void *_tevent_req_data(struct tevent_req *req);
#define tevent_req_data(_req, _type) \
talloc_get_type_abort(_tevent_req_data(_req), _type)
+#endif
-typedef char *(*tevent_req_print_fn)(struct tevent_req *, TALLOC_CTX *);
+/**
+ * @brief The print function which can be set for a tevent async request.
+ *
+ * @param[in] req The tevent async request.
+ *
+ * @param[in] ctx A talloc memory context which can be uses to allocate
+ * memory.
+ *
+ * @return An allocated string buffer to print.
+ *
+ * Example:
+ * @code
+ * static char *my_print(struct tevent_req *req, TALLOC_CTX *mem_ctx)
+ * {
+ * struct my_data *data = tevent_req_data(req, struct my_data);
+ * char *result;
+ *
+ * result = tevent_req_default_print(mem_ctx, req);
+ * if (result == NULL) {
+ * return NULL;
+ * }
+ *
+ * return talloc_asprintf_append_buffer(result, "foo=%d, bar=%d",
+ * data->foo, data->bar);
+ * }
+ * @endcode
+ */
+typedef char *(*tevent_req_print_fn)(struct tevent_req *req, TALLOC_CTX *ctx);
+/**
+ * @brief This function sets a print function for the given request.
+ *
+ * This function can be used to setup a print function for the given request.
+ * This will be triggered if the tevent_req_print() function was
+ * called on the given request.
+ *
+ * @param[in] req The request to use.
+ *
+ * @param[in] fn A pointer to the print function
+ *
+ * @note This function should only be used for debugging.
+ */
void tevent_req_set_print_fn(struct tevent_req *req, tevent_req_print_fn fn);
+/**
+ * @brief The default print function for creating debug messages.
+ *
+ * The function should not be used by users of the async API,
+ * but custom print function can use it and append custom text
+ * to the string.
+ *
+ * @param[in] req The request to be printed.
+ *
+ * @param[in] mem_ctx The memory context for the result.
+ *
+ * @return Text representation of request.
+ *
+ */
char *tevent_req_default_print(struct tevent_req *req, TALLOC_CTX *mem_ctx);
+/**
+ * @brief Print an tevent_req structure in debug messages.
+ *
+ * This function should be used by callers of the async API.
+ *
+ * @param[in] mem_ctx The memory context for the result.
+ *
+ * @param[in] req The request to be printed.
+ *
+ * @return Text representation of request.
+ */
char *tevent_req_print(TALLOC_CTX *mem_ctx, struct tevent_req *req);
+/**
+ * @brief A typedef for a cancel function for a tevent request.
+ *
+ * @param[in] req The tevent request calling this function.
+ *
+ * @return True if the request could be canceled, false if not.
+ */
+typedef bool (*tevent_req_cancel_fn)(struct tevent_req *req);
+
+/**
+ * @brief This function sets a cancel function for the given tevent request.
+ *
+ * This function can be used to setup a cancel function for the given request.
+ * This will be triggered if the tevent_req_cancel() function was
+ * called on the given request.
+ *
+ * @param[in] req The request to use.
+ *
+ * @param[in] fn A pointer to the cancel function.
+ */
+void tevent_req_set_cancel_fn(struct tevent_req *req, tevent_req_cancel_fn fn);
+
+#ifdef DOXYGEN
+/**
+ * @brief Try to cancel the given tevent request.
+ *
+ * This function can be used to cancel the given request.
+ *
+ * It is only possible to cancel a request when the implementation
+ * has registered a cancel function via the tevent_req_set_cancel_fn().
+ *
+ * @param[in] req The request to use.
+ *
+ * @return This function returns true is the request is cancelable,
+ * othererwise false is returned.
+ *
+ * @note Even if the function returns true, the caller need to wait
+ * for the function to complete normally.
+ * Only the _recv() function of the given request indicates
+ * if the request was really canceled.
+ */
+bool tevent_req_cancel(struct tevent_req *req);
+#else
+bool _tevent_req_cancel(struct tevent_req *req, const char *location);
+#define tevent_req_cancel(req) \
+ _tevent_req_cancel(req, __location__)
+#endif
+
+/**
+ * @brief A typedef for a cleanup function for a tevent request.
+ *
+ * @param[in] req The tevent request calling this function.
+ *
+ * @param[in] req_state The current tevent_req_state.
+ *
+ */
+typedef void (*tevent_req_cleanup_fn)(struct tevent_req *req,
+ enum tevent_req_state req_state);
+
+/**
+ * @brief This function sets a cleanup function for the given tevent request.
+ *
+ * This function can be used to setup a cleanup function for the given request.
+ * This will be triggered when the tevent_req_done() or tevent_req_error()
+ * function was called, before notifying the callers callback function,
+ * and also before scheduling the deferred trigger.
+ *
+ * This might be useful if more than one tevent_req belong together
+ * and need to finish both requests at the same time.
+ *
+ * The cleanup function is able to call tevent_req_done() or tevent_req_error()
+ * recursively, the cleanup function is only triggered the first time.
+ *
+ * The cleanup function is also called by tevent_req_received()
+ * (possibly triggered from tevent_req_destructor()) before destroying
+ * the private data of the tevent_req.
+ *
+ * @param[in] req The request to use.
+ *
+ * @param[in] fn A pointer to the cancel function.
+ */
+void tevent_req_set_cleanup_fn(struct tevent_req *req, tevent_req_cleanup_fn fn);
+
+#ifdef DOXYGEN
+/**
+ * @brief Create an async tevent request.
+ *
+ * The new async request will be initialized in state TEVENT_REQ_IN_PROGRESS.
+ *
+ * @code
+ * struct tevent_req *req;
+ * struct computation_state *state;
+ * req = tevent_req_create(mem_ctx, &state, struct computation_state);
+ * @endcode
+ *
+ * Tevent_req_create() allocates and zeros the state variable as a talloc
+ * child of its result. The state variable should be used as the talloc
+ * parent for all temporary variables that are allocated during the async
+ * computation. This way, when the user of the async computation frees
+ * the request, the state as a talloc child will be free'd along with
+ * all the temporary variables hanging off the state.
+ *
+ * @param[in] mem_ctx The memory context for the result.
+ * @param[in] pstate Pointer to the private request state.
+ * @param[in] type The name of the request.
+ *
+ * @return A new async request. NULL on error.
+ */
+struct tevent_req *tevent_req_create(TALLOC_CTX *mem_ctx,
+ void **pstate, #type);
+#else
struct tevent_req *_tevent_req_create(TALLOC_CTX *mem_ctx,
void *pstate,
size_t state_size,
#define tevent_req_create(_mem_ctx, _pstate, _type) \
_tevent_req_create((_mem_ctx), (_pstate), sizeof(_type), \
#_type, __location__)
+#endif
+/**
+ * @brief Set a timeout for an async request.
+ *
+ * @param[in] req The request to set the timeout for.
+ *
+ * @param[in] ev The event context to use for the timer.
+ *
+ * @param[in] endtime The endtime of the request.
+ *
+ * @return True if succeeded, false if not.
+ */
bool tevent_req_set_endtime(struct tevent_req *req,
struct tevent_context *ev,
struct timeval endtime);
+/**
+ * @brief Reset the timer set by tevent_req_set_endtime.
+ *
+ * @param[in] req The request to reset the timeout for
+ */
+void tevent_req_reset_endtime(struct tevent_req *req);
+
+#ifdef DOXYGEN
+/**
+ * @brief Call the notify callback of the given tevent request manually.
+ *
+ * @param[in] req The tevent request to call the notify function from.
+ *
+ * @see tevent_req_set_callback()
+ */
+void tevent_req_notify_callback(struct tevent_req *req);
+#else
+void _tevent_req_notify_callback(struct tevent_req *req, const char *location);
+#define tevent_req_notify_callback(req) \
+ _tevent_req_notify_callback(req, __location__)
+#endif
+
+#ifdef DOXYGEN
+/**
+ * @brief An async request has successfully finished.
+ *
+ * This function is to be used by implementors of async requests. When a
+ * request is successfully finished, this function calls the user's completion
+ * function.
+ *
+ * @param[in] req The finished request.
+ */
+void tevent_req_done(struct tevent_req *req);
+#else
void _tevent_req_done(struct tevent_req *req,
const char *location);
#define tevent_req_done(req) \
_tevent_req_done(req, __location__)
+#endif
+#ifdef DOXYGEN
+/**
+ * @brief An async request has seen an error.
+ *
+ * This function is to be used by implementors of async requests. When a
+ * request can not successfully completed, the implementation should call this
+ * function with the appropriate status code.
+ *
+ * If error is 0 the function returns false and does nothing more.
+ *
+ * @param[in] req The request with an error.
+ *
+ * @param[in] error The error code.
+ *
+ * @return On success true is returned, false if error is 0.
+ *
+ * @code
+ * int error = first_function();
+ * if (tevent_req_error(req, error)) {
+ * return;
+ * }
+ *
+ * error = second_function();
+ * if (tevent_req_error(req, error)) {
+ * return;
+ * }
+ *
+ * tevent_req_done(req);
+ * return;
+ * @endcode
+ */
+bool tevent_req_error(struct tevent_req *req,
+ uint64_t error);
+#else
bool _tevent_req_error(struct tevent_req *req,
uint64_t error,
const char *location);
#define tevent_req_error(req, error) \
_tevent_req_error(req, error, __location__)
+#endif
+#ifdef DOXYGEN
+/**
+ * @brief Helper function for nomem check.
+ *
+ * Convenience helper to easily check alloc failure within a callback
+ * implementing the next step of an async request.
+ *
+ * @param[in] p The pointer to be checked.
+ *
+ * @param[in] req The request being processed.
+ *
+ * @code
+ * p = talloc(mem_ctx, bla);
+ * if (tevent_req_nomem(p, req)) {
+ * return;
+ * }
+ * @endcode
+ */
+bool tevent_req_nomem(const void *p,
+ struct tevent_req *req);
+#else
bool _tevent_req_nomem(const void *p,
struct tevent_req *req,
const char *location);
#define tevent_req_nomem(p, req) \
_tevent_req_nomem(p, req, __location__)
+#endif
+
+#ifdef DOXYGEN
+/**
+ * @brief Indicate out of memory to a request
+ *
+ * @param[in] req The request being processed.
+ */
+void tevent_req_oom(struct tevent_req *req);
+#else
+void _tevent_req_oom(struct tevent_req *req,
+ const char *location);
+#define tevent_req_oom(req) \
+ _tevent_req_oom(req, __location__)
+#endif
+/**
+ * @brief Finish a request before the caller had the change to set the callback.
+ *
+ * An implementation of an async request might find that it can either finish
+ * the request without waiting for an external event, or it can not even start
+ * the engine. To present the illusion of a callback to the user of the API,
+ * the implementation can call this helper function which triggers an
+ * immediate event. This way the caller can use the same calling
+ * conventions, independent of whether the request was actually deferred.
+ *
+ * @code
+ * struct tevent_req *computation_send(TALLOC_CTX *mem_ctx,
+ * struct tevent_context *ev)
+ * {
+ * struct tevent_req *req, *subreq;
+ * struct computation_state *state;
+ * req = tevent_req_create(mem_ctx, &state, struct computation_state);
+ * if (req == NULL) {
+ * return NULL;
+ * }
+ * subreq = subcomputation_send(state, ev);
+ * if (tevent_req_nomem(subreq, req)) {
+ * return tevent_req_post(req, ev);
+ * }
+ * tevent_req_set_callback(subreq, computation_done, req);
+ * return req;
+ * }
+ * @endcode
+ *
+ * @param[in] req The finished request.
+ *
+ * @param[in] ev The tevent_context for the immediate event.
+ *
+ * @return The given request will be returned.
+ */
struct tevent_req *tevent_req_post(struct tevent_req *req,
struct tevent_context *ev);
+/**
+ * @brief Finish multiple requests within one function
+ *
+ * Normally tevent_req_notify_callback() and all wrappers
+ * (e.g. tevent_req_done() and tevent_req_error())
+ * need to be the last thing an event handler should call.
+ * This is because the callback is likely to destroy the
+ * context of the current function.
+ *
+ * If a function wants to notify more than one caller,
+ * it is dangerous if it just triggers multiple callbacks
+ * in a row. With tevent_req_defer_callback() it is possible
+ * to set an event context that will be used to defer the callback
+ * via an immediate event (similar to tevent_req_post()).
+ *
+ * @code
+ * struct complete_state {
+ * struct tevent_context *ev;
+ *
+ * struct tevent_req **reqs;
+ * };
+ *
+ * void complete(struct complete_state *state)
+ * {
+ * size_t i, c = talloc_array_length(state->reqs);
+ *
+ * for (i=0; i < c; i++) {
+ * tevent_req_defer_callback(state->reqs[i], state->ev);
+ * tevent_req_done(state->reqs[i]);
+ * }
+ * }
+ * @endcode
+ *
+ * @param[in] req The finished request.
+ *
+ * @param[in] ev The tevent_context for the immediate event.
+ *
+ * @return The given request will be returned.
+ */
+void tevent_req_defer_callback(struct tevent_req *req,
+ struct tevent_context *ev);
+
+/**
+ * @brief Check if the given request is still in progress.
+ *
+ * It is typically used by sync wrapper functions.
+ *
+ * @param[in] req The request to poll.
+ *
+ * @return The boolean form of "is in progress".
+ */
bool tevent_req_is_in_progress(struct tevent_req *req);
+/**
+ * @brief Actively poll for the given request to finish.
+ *
+ * This function is typically used by sync wrapper functions.
+ *
+ * @param[in] req The request to poll.
+ *
+ * @param[in] ev The tevent_context to be used.
+ *
+ * @return On success true is returned. If a critical error has
+ * happened in the tevent loop layer false is returned.
+ * This is not the return value of the given request!
+ *
+ * @note This should only be used if the given tevent context was created by the
+ * caller, to avoid event loop nesting.
+ *
+ * @code
+ * req = tstream_writev_queue_send(mem_ctx,
+ * ev_ctx,
+ * tstream,
+ * send_queue,
+ * iov, 2);
+ * ok = tevent_req_poll(req, tctx->ev);
+ * rc = tstream_writev_queue_recv(req, &sys_errno);
+ * TALLOC_FREE(req);
+ * @endcode
+ */
bool tevent_req_poll(struct tevent_req *req,
struct tevent_context *ev);
+/**
+ * @brief Get the tevent request state and the actual error set by
+ * tevent_req_error.
+ *
+ * @code
+ * int computation_recv(struct tevent_req *req, uint64_t *perr)
+ * {
+ * enum tevent_req_state state;
+ * uint64_t err;
+ * if (tevent_req_is_error(req, &state, &err)) {
+ * *perr = err;
+ * return -1;
+ * }
+ * return 0;
+ * }
+ * @endcode
+ *
+ * @param[in] req The tevent request to get the error from.
+ *
+ * @param[out] state A pointer to store the tevent request error state.
+ *
+ * @param[out] error A pointer to store the error set by tevent_req_error().
+ *
+ * @return True if the function could set error and state, false
+ * otherwise.
+ *
+ * @see tevent_req_error()
+ */
bool tevent_req_is_error(struct tevent_req *req,
enum tevent_req_state *state,
uint64_t *error);
+/**
+ * @brief Use as the last action of a _recv() function.
+ *
+ * This function destroys the attached private data.
+ *
+ * @param[in] req The finished request.
+ */
void tevent_req_received(struct tevent_req *req);
+/**
+ * @brief Create a tevent subrequest at a given time.
+ *
+ * The idea is that always the same syntax for tevent requests.
+ *
+ * @param[in] mem_ctx The talloc memory context to use.
+ *
+ * @param[in] ev The event handle to setup the request.
+ *
+ * @param[in] wakeup_time The time to wakeup and execute the request.
+ *
+ * @return The new subrequest, NULL on error.
+ *
+ * Example:
+ * @code
+ * static void my_callback_wakeup_done(tevent_req *subreq)
+ * {
+ * struct tevent_req *req = tevent_req_callback_data(subreq,
+ * struct tevent_req);
+ * bool ok;
+ *
+ * ok = tevent_wakeup_recv(subreq);
+ * TALLOC_FREE(subreq);
+ * if (!ok) {
+ * tevent_req_error(req, -1);
+ * return;
+ * }
+ * ...
+ * }
+ * @endcode
+ *
+ * @code
+ * subreq = tevent_wakeup_send(mem_ctx, ev, wakeup_time);
+ * if (tevent_req_nomem(subreq, req)) {
+ * return false;
+ * }
+ * tevent_set_callback(subreq, my_callback_wakeup_done, req);
+ * @endcode
+ *
+ * @see tevent_wakeup_recv()
+ */
struct tevent_req *tevent_wakeup_send(TALLOC_CTX *mem_ctx,
struct tevent_context *ev,
struct timeval wakeup_time);
+
+/**
+ * @brief Check if the wakeup has been correctly executed.
+ *
+ * This function needs to be called in the callback function set after calling
+ * tevent_wakeup_send().
+ *
+ * @param[in] req The tevent request to check.
+ *
+ * @return True on success, false otherwise.
+ *
+ * @see tevent_wakeup_recv()
+ */
bool tevent_wakeup_recv(struct tevent_req *req);
+/* @} */
+
+/**
+ * @defgroup tevent_helpers The tevent helper functions
+ * @ingroup tevent
+ *
+ * @todo description
+ *
+ * @{
+ */
+
+/**
+ * @brief Compare two timeval values.
+ *
+ * @param[in] tv1 The first timeval value to compare.
+ *
+ * @param[in] tv2 The second timeval value to compare.
+ *
+ * @return 0 if they are equal.
+ * 1 if the first time is greater than the second.
+ * -1 if the first time is smaller than the second.
+ */
int tevent_timeval_compare(const struct timeval *tv1,
const struct timeval *tv2);
+/**
+ * @brief Get a zero timeval value.
+ *
+ * @return A zero timeval value.
+ */
struct timeval tevent_timeval_zero(void);
+/**
+ * @brief Get a timeval value for the current time.
+ *
+ * @return A timeval value with the current time.
+ */
struct timeval tevent_timeval_current(void);
+/**
+ * @brief Get a timeval structure with the given values.
+ *
+ * @param[in] secs The seconds to set.
+ *
+ * @param[in] usecs The microseconds to set.
+ *
+ * @return A timeval structure with the given values.
+ */
struct timeval tevent_timeval_set(uint32_t secs, uint32_t usecs);
+/**
+ * @brief Get the difference between two timeval values.
+ *
+ * @param[in] tv1 The first timeval.
+ *
+ * @param[in] tv2 The second timeval.
+ *
+ * @return A timeval structure with the difference between the
+ * first and the second value.
+ */
struct timeval tevent_timeval_until(const struct timeval *tv1,
const struct timeval *tv2);
+/**
+ * @brief Check if a given timeval structure is zero.
+ *
+ * @param[in] tv The timeval to check if it is zero.
+ *
+ * @return True if it is zero, false otherwise.
+ */
bool tevent_timeval_is_zero(const struct timeval *tv);
+/**
+ * @brief Add the given amount of time to a timeval structure.
+ *
+ * @param[in] tv The timeval structure to add the time.
+ *
+ * @param[in] secs The seconds to add to the timeval.
+ *
+ * @param[in] usecs The microseconds to add to the timeval.
+ *
+ * @return The timeval structure with the new time.
+ */
struct timeval tevent_timeval_add(const struct timeval *tv, uint32_t secs,
uint32_t usecs);
+/**
+ * @brief Get a timeval in the future with a specified offset from now.
+ *
+ * @param[in] secs The seconds of the offset from now.
+ *
+ * @param[in] usecs The microseconds of the offset from now.
+ *
+ * @return A timval with the given offset in the future.
+ */
struct timeval tevent_timeval_current_ofs(uint32_t secs, uint32_t usecs);
+/* @} */
+
+
+/**
+ * @defgroup tevent_queue The tevent queue functions
+ * @ingroup tevent
+ *
+ * A tevent_queue is used to queue up async requests that must be
+ * serialized. For example writing buffers into a socket must be
+ * serialized. Writing a large lump of data into a socket can require
+ * multiple write(2) or send(2) system calls. If more than one async
+ * request is outstanding to write large buffers into a socket, every
+ * request must individually be completed before the next one begins,
+ * even if multiple syscalls are required.
+ *
+ * Take a look at @ref tevent_queue_tutorial for more details.
+ * @{
+ */
+
struct tevent_queue;
+struct tevent_queue_entry;
+#ifdef DOXYGEN
+/**
+ * @brief Create and start a tevent queue.
+ *
+ * @param[in] mem_ctx The talloc memory context to allocate the queue.
+ *
+ * @param[in] name The name to use to identify the queue.
+ *
+ * @return An allocated tevent queue on success, NULL on error.
+ *
+ * @see tevent_queue_start()
+ * @see tevent_queue_stop()
+ */
+struct tevent_queue *tevent_queue_create(TALLOC_CTX *mem_ctx,
+ const char *name);
+#else
struct tevent_queue *_tevent_queue_create(TALLOC_CTX *mem_ctx,
const char *name,
const char *location);
#define tevent_queue_create(_mem_ctx, _name) \
_tevent_queue_create((_mem_ctx), (_name), __location__)
+#endif
+/**
+ * @brief A callback trigger function run by the queue.
+ *
+ * @param[in] req The tevent request the trigger function is executed on.
+ *
+ * @param[in] private_data The private data pointer specified by
+ * tevent_queue_add().
+ *
+ * @see tevent_queue_add()
+ * @see tevent_queue_add_entry()
+ * @see tevent_queue_add_optimize_empty()
+ */
typedef void (*tevent_queue_trigger_fn_t)(struct tevent_req *req,
void *private_data);
+
+/**
+ * @brief Add a tevent request to the queue.
+ *
+ * @param[in] queue The queue to add the request.
+ *
+ * @param[in] ev The event handle to use for the request.
+ *
+ * @param[in] req The tevent request to add to the queue.
+ *
+ * @param[in] trigger The function triggered by the queue when the request
+ * is called. Since tevent 0.9.14 it's possible to
+ * pass NULL, in order to just add a "blocker" to the
+ * queue.
+ *
+ * @param[in] private_data The private data passed to the trigger function.
+ *
+ * @return True if the request has been successfully added, false
+ * otherwise.
+ */
bool tevent_queue_add(struct tevent_queue *queue,
struct tevent_context *ev,
struct tevent_req *req,
tevent_queue_trigger_fn_t trigger,
void *private_data);
+
+/**
+ * @brief Add a tevent request to the queue.
+ *
+ * The request can be removed from the queue by calling talloc_free()
+ * (or a similar function) on the returned queue entry. This
+ * is the only difference to tevent_queue_add().
+ *
+ * @param[in] queue The queue to add the request.
+ *
+ * @param[in] ev The event handle to use for the request.
+ *
+ * @param[in] req The tevent request to add to the queue.
+ *
+ * @param[in] trigger The function triggered by the queue when the request
+ * is called. Since tevent 0.9.14 it's possible to
+ * pass NULL, in order to just add a "blocker" to the
+ * queue.
+ *
+ * @param[in] private_data The private data passed to the trigger function.
+ *
+ * @return a pointer to the tevent_queue_entry if the request
+ * has been successfully added, NULL otherwise.
+ *
+ * @see tevent_queue_add()
+ * @see tevent_queue_add_optimize_empty()
+ */
+struct tevent_queue_entry *tevent_queue_add_entry(
+ struct tevent_queue *queue,
+ struct tevent_context *ev,
+ struct tevent_req *req,
+ tevent_queue_trigger_fn_t trigger,
+ void *private_data);
+
+/**
+ * @brief Add a tevent request to the queue using a possible optimization.
+ *
+ * This tries to optimize for the empty queue case and may calls
+ * the trigger function directly. This is the only difference compared
+ * to tevent_queue_add_entry().
+ *
+ * The caller needs to be prepared that the trigger function has
+ * already called tevent_req_notify_callback(), tevent_req_error(),
+ * tevent_req_done() or a similar function.
+ *
+ * The request can be removed from the queue by calling talloc_free()
+ * (or a similar function) on the returned queue entry.
+ *
+ * @param[in] queue The queue to add the request.
+ *
+ * @param[in] ev The event handle to use for the request.
+ *
+ * @param[in] req The tevent request to add to the queue.
+ *
+ * @param[in] trigger The function triggered by the queue when the request
+ * is called. Since tevent 0.9.14 it's possible to
+ * pass NULL, in order to just add a "blocker" to the
+ * queue.
+ *
+ * @param[in] private_data The private data passed to the trigger function.
+ *
+ * @return a pointer to the tevent_queue_entry if the request
+ * has been successfully added, NULL otherwise.
+ *
+ * @see tevent_queue_add()
+ * @see tevent_queue_add_entry()
+ */
+struct tevent_queue_entry *tevent_queue_add_optimize_empty(
+ struct tevent_queue *queue,
+ struct tevent_context *ev,
+ struct tevent_req *req,
+ tevent_queue_trigger_fn_t trigger,
+ void *private_data);
+
+/**
+ * @brief Start a tevent queue.
+ *
+ * The queue is started by default.
+ *
+ * @param[in] queue The queue to start.
+ */
void tevent_queue_start(struct tevent_queue *queue);
+
+/**
+ * @brief Stop a tevent queue.
+ *
+ * The queue is started by default.
+ *
+ * @param[in] queue The queue to stop.
+ */
void tevent_queue_stop(struct tevent_queue *queue);
+/**
+ * @brief Get the length of the queue.
+ *
+ * @param[in] queue The queue to get the length from.
+ *
+ * @return The number of elements.
+ */
size_t tevent_queue_length(struct tevent_queue *queue);
+/**
+ * @brief Is the tevent queue running.
+ *
+ * The queue is started by default.
+ *
+ * @param[in] queue The queue.
+ *
+ * @return Wether the queue is running or not..
+ */
+bool tevent_queue_running(struct tevent_queue *queue);
+
+/**
+ * @brief Create a tevent subrequest that waits in a tevent_queue
+ *
+ * The idea is that always the same syntax for tevent requests.
+ *
+ * @param[in] mem_ctx The talloc memory context to use.
+ *
+ * @param[in] ev The event handle to setup the request.
+ *
+ * @param[in] queue The queue to wait in.
+ *
+ * @return The new subrequest, NULL on error.
+ *
+ * @see tevent_queue_wait_recv()
+ */
+struct tevent_req *tevent_queue_wait_send(TALLOC_CTX *mem_ctx,
+ struct tevent_context *ev,
+ struct tevent_queue *queue);
+
+/**
+ * @brief Check if we no longer need to wait in the queue.
+ *
+ * This function needs to be called in the callback function set after calling
+ * tevent_queue_wait_send().
+ *
+ * @param[in] req The tevent request to check.
+ *
+ * @return True on success, false otherwise.
+ *
+ * @see tevent_queue_wait_send()
+ */
+bool tevent_queue_wait_recv(struct tevent_req *req);
+
typedef int (*tevent_nesting_hook)(struct tevent_context *ev,
void *private_data,
uint32_t level,
bool begin,
void *stack_ptr,
const char *location);
+
+/**
+ * @brief Create a tevent_thread_proxy for message passing between threads.
+ *
+ * The tevent_context must have been allocated on the NULL
+ * talloc context, and talloc_disable_null_tracking() must
+ * have been called.
+ *
+ * @param[in] dest_ev_ctx The tevent_context to receive events.
+ *
+ * @return An allocated tevent_thread_proxy, NULL on error.
+ * If tevent was compiled without PTHREAD support
+ * NULL is always returned and errno set to ENOSYS.
+ *
+ * @see tevent_thread_proxy_schedule()
+ */
+struct tevent_thread_proxy *tevent_thread_proxy_create(
+ struct tevent_context *dest_ev_ctx);
+
+/**
+ * @brief Schedule an immediate event on an event context from another thread.
+ *
+ * Causes dest_ev_ctx, being run by another thread, to receive an
+ * immediate event calling the handler with the *pp_private parameter.
+ *
+ * *pp_im must be a pointer to an immediate event talloced on a context owned
+ * by the calling thread, or the NULL context. Ownership will
+ * be transferred to the tevent_thread_proxy and *pp_im will be returned as NULL.
+ *
+ * *pp_private_data must be a talloced area of memory with no destructors.
+ * Ownership of this memory will be transferred to the tevent library and
+ * *pp_private_data will be set to NULL on successful completion of
+ * the call. Set pp_private to NULL if no parameter transfer
+ * needed (a pure callback). This is an asynchronous request, caller
+ * does not wait for callback to be completed before returning.
+ *
+ * @param[in] tp The tevent_thread_proxy to use.
+ *
+ * @param[in] pp_im Pointer to immediate event pointer.
+ *
+ * @param[in] handler The function that will be called.
+ *
+ * @param[in] pp_private_data The talloced memory to transfer.
+ *
+ * @see tevent_thread_proxy_create()
+ */
+void tevent_thread_proxy_schedule(struct tevent_thread_proxy *tp,
+ struct tevent_immediate **pp_im,
+ tevent_immediate_handler_t handler,
+ void *pp_private_data);
+
+/*
+ * @brief Create a context for threaded activation of immediates
+ *
+ * A tevent_treaded_context provides a link into an event
+ * context. Using tevent_threaded_schedule_immediate, it is possible
+ * to activate an immediate event from within a thread.
+ *
+ * It is the duty of the caller of tevent_threaded_context_create() to
+ * keep the event context around longer than any
+ * tevent_threaded_context. tevent will abort if ev is talllc_free'ed
+ * with an active tevent_threaded_context.
+ *
+ * If tevent is build without pthread support, this always returns
+ * NULL with errno=ENOSYS.
+ *
+ * @param[in] mem_ctx The talloc memory context to use.
+ * @param[in] ev The event context to link this to.
+ * @return The threaded context, or NULL with errno set.
+ *
+ * @see tevent_threaded_schedule_immediate()
+ *
+ * @note Available as of tevent 0.9.30
+ */
+struct tevent_threaded_context *tevent_threaded_context_create(
+ TALLOC_CTX *mem_ctx, struct tevent_context *ev);
+
+#ifdef DOXYGEN
+/*
+ * @brief Activate an immediate from a thread
+ *
+ * Activate an immediate from within a thread.
+ *
+ * This routine does not watch out for talloc hierarchies. This means
+ * that it is highly recommended to create the tevent_immediate in the
+ * thread owning tctx, allocate a threaded job description for the
+ * thread, hand over both pointers to a helper thread and not touch it
+ * in the main thread at all anymore.
+ *
+ * tevent_threaded_schedule_immediate is intended as a job completion
+ * indicator for simple threaded helpers.
+ *
+ * Please be aware that tevent_threaded_schedule_immediate is very
+ * picky about its arguments: An immediate may not already be
+ * activated and the handler must exist. With
+ * tevent_threaded_schedule_immediate memory ownership is transferred
+ * to the main thread holding the tevent context behind tctx, the
+ * helper thread can't access it anymore.
+ *
+ * @param[in] tctx The threaded context to go through
+ * @param[in] im The immediate event to activate
+ * @param[in] handler The immediate handler to call in the main thread
+ * @param[in] private_data Pointer for the immediate handler
+ *
+ * @see tevent_threaded_context_create()
+ *
+ * @note Available as of tevent 0.9.30
+ */
+void tevent_threaded_schedule_immediate(struct tevent_threaded_context *tctx,
+ struct tevent_immediate *im,
+ tevent_immediate_handler_t handler,
+ void *private_data);
+#else
+void _tevent_threaded_schedule_immediate(struct tevent_threaded_context *tctx,
+ struct tevent_immediate *im,
+ tevent_immediate_handler_t handler,
+ void *private_data,
+ const char *handler_name,
+ const char *location);
+#define tevent_threaded_schedule_immediate(tctx, im, handler, private_data) \
+ _tevent_threaded_schedule_immediate(tctx, im, handler, private_data, \
+ #handler, __location__);
+#endif
+
#ifdef TEVENT_DEPRECATED
#ifndef _DEPRECATED_
-#if (__GNUC__ >= 3) && (__GNUC_MINOR__ >= 1 )
+#ifdef HAVE___ATTRIBUTE__
#define _DEPRECATED_ __attribute__ ((deprecated))
#else
#define _DEPRECATED_
_tevent_loop_until(ev, finished, private_data, __location__)
#endif
+int tevent_re_initialise(struct tevent_context *ev);
+
+/* @} */
+
+/**
+ * @defgroup tevent_ops The tevent operation functions
+ * @ingroup tevent
+ *
+ * The following structure and registration functions are exclusively
+ * needed for people writing and pluggin a different event engine.
+ * There is nothing useful for normal tevent user in here.
+ * @{
+ */
+
+struct tevent_ops {
+ /* context init */
+ int (*context_init)(struct tevent_context *ev);
+
+ /* fd_event functions */
+ struct tevent_fd *(*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,
+ const char *location);
+ void (*set_fd_close_fn)(struct tevent_fd *fde,
+ tevent_fd_close_fn_t close_fn);
+ uint16_t (*get_fd_flags)(struct tevent_fd *fde);
+ void (*set_fd_flags)(struct tevent_fd *fde, uint16_t flags);
+
+ /* timed_event functions */
+ struct tevent_timer *(*add_timer)(struct tevent_context *ev,
+ TALLOC_CTX *mem_ctx,
+ struct timeval next_event,
+ tevent_timer_handler_t handler,
+ void *private_data,
+ const char *handler_name,
+ const char *location);
+
+ /* immediate event functions */
+ void (*schedule_immediate)(struct tevent_immediate *im,
+ struct tevent_context *ev,
+ tevent_immediate_handler_t handler,
+ void *private_data,
+ const char *handler_name,
+ const char *location);
+
+ /* signal functions */
+ struct tevent_signal *(*add_signal)(struct tevent_context *ev,
+ TALLOC_CTX *mem_ctx,
+ int signum, int sa_flags,
+ tevent_signal_handler_t handler,
+ void *private_data,
+ const char *handler_name,
+ const char *location);
+
+ /* loop functions */
+ int (*loop_once)(struct tevent_context *ev, const char *location);
+ int (*loop_wait)(struct tevent_context *ev, const char *location);
+};
+
+bool tevent_register_backend(const char *name, const struct tevent_ops *ops);
+
+/* @} */
+
+/**
+ * @defgroup tevent_compat The tevent compatibility functions
+ * @ingroup tevent
+ *
+ * The following definitions are usueful only for compatibility with the
+ * implementation originally developed within the samba4 code and will be
+ * soon removed. Please NEVER use in new code.
+ *
+ * @todo Ignore it?
+ *
+ * @{
+ */
+
#ifdef TEVENT_COMPAT_DEFINES
#define event_context tevent_context
#endif /* TEVENT_COMPAT_DEFINES */
+/* @} */
+
#endif /* __TEVENT_H__ */
git.samba.org / sfrench / samba-autobuild / .git / blobdiff