X-Git-Url: http://git.samba.org/samba.git/?a=blobdiff_plain;f=lib%2Ftevent%2Ftevent.h;h=2ec7330e249fe626c8d5fe18ea0d00f46e2be6b5;hb=4b4ae005b2029d55ad95809a535d13eb5ff51174;hp=82c14831e57671e895a8e417691676e2bf436820;hpb=3f43b7e54205298766d38f250afe0c9285ed427d;p=nivanova%2Fsamba-autobuild%2F.git diff --git a/lib/tevent/tevent.h b/lib/tevent/tevent.h index 82c14831e57..2ec7330e249 100644 --- a/lib/tevent/tevent.h +++ b/lib/tevent/tevent.h @@ -39,6 +39,8 @@ struct tevent_fd; struct tevent_timer; struct tevent_immediate; struct tevent_signal; +struct tevent_thread_proxy; +struct tevent_threaded_context; /** * @defgroup tevent The tevent API @@ -111,7 +113,7 @@ typedef void (*tevent_signal_handler_t)(struct tevent_context *ev, struct tevent_context *tevent_context_init(TALLOC_CTX *mem_ctx); /** - * @brief Create a event_context structure and name it. + * @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 @@ -119,12 +121,26 @@ struct tevent_context *tevent_context_init(TALLOC_CTX *mem_ctx); * * @param[in] mem_ctx The memory context to use. * - * @param[in] name The name for the tevent context. + * @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. * @@ -136,7 +152,7 @@ struct tevent_context *tevent_context_init_byname(TALLOC_CTX *mem_ctx, const cha const char **tevent_backend_list(TALLOC_CTX *mem_ctx); /** - * @brief Set the default tevent backent. + * @brief Set the default tevent backend. * * @param[in] backend The name of the backend to set. */ @@ -162,6 +178,11 @@ void tevent_set_default_backend(const char *backend); * * @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, @@ -231,6 +252,16 @@ struct tevent_timer *_tevent_add_timer(struct tevent_context *ev, #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 @@ -305,6 +336,8 @@ void _tevent_schedule_immediate(struct tevent_immediate *im, * * @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, @@ -326,6 +359,31 @@ struct tevent_signal *_tevent_add_signal(struct tevent_context *ev, #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 @@ -371,6 +429,12 @@ int _tevent_loop_wait(struct tevent_context *ev, const char *location); * * @param[in] fde File descriptor event on which to set the destructor * @param[in] close_fn Destructor to execute when fde is freed + * + * @note That the close_fn() on tevent_fd is *NOT* wrapped on contexts + * created by tevent_context_wrapper_create()! + * + * @see tevent_fd_set_close_fn + * @see tevent_context_wrapper_create */ void tevent_fd_set_close_fn(struct tevent_fd *fde, tevent_fd_close_fn_t close_fn); @@ -381,6 +445,8 @@ void tevent_fd_set_close_fn(struct tevent_fd *fde, * This function calls close(fd) internally. * * @param[in] fde File descriptor event to auto-close + * + * @see tevent_fd_set_close_fn */ void tevent_fd_set_auto_close(struct tevent_fd *fde); @@ -417,11 +483,11 @@ void tevent_set_abort_fn(void (*abort_fn)(const char *reason)); /* bits for file descriptor event flags */ /** - * Monitor a file descriptor for write availability + * Monitor a file descriptor for data to be read */ #define TEVENT_FD_READ 1 /** - * Monitor a file descriptor for data to be read + * Monitor a file descriptor for writeability */ #define TEVENT_FD_WRITE 2 @@ -501,6 +567,60 @@ int tevent_set_debug(struct tevent_context *ev, */ 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); + /** * @} */ @@ -509,50 +629,137 @@ int tevent_set_debug_stderr(struct tevent_context *ev); * @defgroup tevent_request The tevent request functions. * @ingroup tevent * - * 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. + * 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. + * + * tevent_req variable naming conventions: + * + * The name of the variable pointing to the tevent_req structure + * returned by a _send() function SHOULD be named differently between + * implementation and caller. * - * 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. + * From the point of view of the implementation (of the _send() and + * _recv() functions) the variable returned by tevent_req_create() is + * always called @em req. + * + * While the caller of the _send() function should use @em subreq to + * hold the result. + * + * @see tevent_req_create() + * @see tevent_req_fn() * * @{ */ /** - * 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 occurred + * 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 }; @@ -565,13 +772,16 @@ struct tevent_req; /** * @brief A tevent request callback function. * - * @param[in] req The tevent async request which executed this callback. + * @param[in] subreq The tevent async request which executed this callback. */ -typedef void (*tevent_req_fn)(struct tevent_req *req); +typedef void (*tevent_req_fn)(struct tevent_req *subreq); /** * @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. @@ -583,9 +793,17 @@ void tevent_req_set_callback(struct tevent_req *req, tevent_req_fn fn, void *pvt #ifdef DOXYGEN /** - * @brief Get the private data casted to the given type for a callback from + * @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. @@ -605,8 +823,6 @@ void *_tevent_req_callback_data(struct tevent_req *req); * * @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); @@ -619,11 +835,17 @@ void *tevent_req_callback_data_void(struct tevent_req *req); /** * @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); +void *tevent_req_data(struct tevent_req *req, #type); #else void *_tevent_req_data(struct tevent_req *req); #define tevent_req_data(_req, _type) \ @@ -736,8 +958,8 @@ void tevent_req_set_cancel_fn(struct tevent_req *req, tevent_req_cancel_fn fn); * * @param[in] req The request to use. * - * @return This function returns true is the request is cancelable, - * othererwise false is returned. + * @return This function returns true if the request is + * cancelable, otherwise false is returned. * * @note Even if the function returns true, the caller need to wait * for the function to complete normally. @@ -751,26 +973,68 @@ bool _tevent_req_cancel(struct tevent_req *req, const char *location); _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 ASYNC_REQ_IN_PROGRESS. + * The new async request will be initialized in state TEVENT_REQ_IN_PROGRESS. * - * @param[in] mem_ctx The memory context for the result. - * - * @param[in] pstate The private state of the request. + * @code + * struct tevent_req *req; + * struct computation_state *state; + * req = tevent_req_create(mem_ctx, &state, struct computation_state); + * @endcode * - * @param[in] state_size The size of the private state of the request. + * 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, - size_t state_size, - const char *type); + void **pstate, #type); #else struct tevent_req *_tevent_req_create(TALLOC_CTX *mem_ctx, void *pstate, @@ -784,7 +1048,8 @@ struct tevent_req *_tevent_req_create(TALLOC_CTX *mem_ctx, #endif /** - * @brief Set a timeout for an async request. + * @brief Set a timeout for an async request. On failure, "req" is already + * set to state TEVENT_REQ_NO_MEMORY. * * @param[in] req The request to set the timeout for. * @@ -798,6 +1063,13 @@ 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. @@ -900,25 +1172,100 @@ bool _tevent_req_nomem(const void *p, _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. + * @brief Finish a request before the caller had a chance 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't even start + * 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 timed event. This way the caller can use the same calling + * 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 timed event. + * @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. * @@ -961,7 +1308,21 @@ bool tevent_req_poll(struct tevent_req *req, struct tevent_context *ev); /** - * @brief Get the tevent request and the actual error code you've set. + * @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. * @@ -987,6 +1348,191 @@ bool tevent_req_is_error(struct tevent_req *req, */ void tevent_req_received(struct tevent_req *req); +/** + * @brief Mark a tevent_req for profiling + * + * This will turn on profiling for this tevent_req an all subreqs that + * are directly started as helper requests off this + * tevent_req. subreqs are chained by walking up the talloc_parent + * hierarchy at a subreq's tevent_req_create. This means to get the + * profiling chain right the subreq that needs to be profiled as part + * of this tevent_req's profile must be a talloc child of the requests + * state variable. + * + * @param[in] req The request to do tracing for + * + * @return False if the profile could not be activated + */ +bool tevent_req_set_profile(struct tevent_req *req); + +struct tevent_req_profile; + +/** + * @brief Get the a request's profile for inspection + * + * @param[in] req The request to get the profile from + * + * @return The request's profile + */ +const struct tevent_req_profile *tevent_req_get_profile( + struct tevent_req *req); + +/** + * @brief Move the profile out of a request + * + * This function detaches the request's profile from the request, so + * that the profile can outlive the request in a _recv function. + * + * @param[in] req The request to move the profile out of + * @param[in] mem_ctx The new talloc context for the profile + * + * @return The moved profile + */ + +struct tevent_req_profile *tevent_req_move_profile(struct tevent_req *req, + TALLOC_CTX *mem_ctx); + +/** + * @brief Get a profile description + * + * @param[in] profile The profile to be queried + * @param[in] req_name The name of the request (state's name) + * + * "req_name" after this call is still in talloc-posession of "profile" + */ +void tevent_req_profile_get_name(const struct tevent_req_profile *profile, + const char **req_name); + +/** + * @brief Get a profile's start event data + * + * @param[in] profile The profile to be queried + * @param[in] start_location The location where this event started + * @param[in] start_time The time this event started + * + * "start_location" after this call is still in talloc-posession of "profile" + */ +void tevent_req_profile_get_start(const struct tevent_req_profile *profile, + const char **start_location, + struct timeval *start_time); + +/** + * @brief Get a profile's stop event data + * + * @param[in] profile The profile to be queried + * @param[in] stop_location The location where this event stopped + * @param[in] stop_time The time this event stopped + * + * "stop_location" after this call is still in talloc-posession of "profile" + */ +void tevent_req_profile_get_stop(const struct tevent_req_profile *profile, + const char **stop_location, + struct timeval *stop_time); + +/** + * @brief Get a profile's result data + * + * @param[in] pid The process where this profile was taken + * @param[in] state The status the profile's tevent_req finished with + * @param[in] user_error The user error of the profile's tevent_req + */ +void tevent_req_profile_get_status(const struct tevent_req_profile *profile, + pid_t *pid, + enum tevent_req_state *state, + uint64_t *user_error); + +/** + * @brief Retrieve the first subreq's profile from a profile + * + * @param[in] profile The profile to query + * + * @return The first tevent subreq's profile + */ +const struct tevent_req_profile *tevent_req_profile_get_subprofiles( + const struct tevent_req_profile *profile); + +/** + * @brief Walk the chain of subreqs + * + * @param[in] profile The subreq's profile to walk + * + * @return The next subprofile in the list + */ +const struct tevent_req_profile *tevent_req_profile_next( + const struct tevent_req_profile *profile); + +/** + * @brief Create a fresh tevent_req_profile + * + * @param[in] mem_ctx The talloc context to hang the fresh struct off + * + * @return The fresh struct + */ +struct tevent_req_profile *tevent_req_profile_create(TALLOC_CTX *mem_ctx); + +/** + * @brief Set a profile's name + * + * @param[in] profile The profile to set the name for + * @param[in] name The new name for the profile + * + * @return True if the internal talloc_strdup succeeded + */ +bool tevent_req_profile_set_name(struct tevent_req_profile *profile, + const char *name); + +/** + * @brief Set a profile's start event + * + * @param[in] profile The profile to set the start data for + * @param[in] start_location The new start location + * @param[in] start_time The new start time + * + * @return True if the internal talloc_strdup succeeded + */ +bool tevent_req_profile_set_start(struct tevent_req_profile *profile, + const char *start_location, + struct timeval start_time); + +/** + * @brief Set a profile's stop event + * + * @param[in] profile The profile to set the stop data for + * @param[in] stop_location The new stop location + * @param[in] stop_time The new stop time + * + * @return True if the internal talloc_strdup succeeded + */ +bool tevent_req_profile_set_stop(struct tevent_req_profile *profile, + const char *stop_location, + struct timeval stop_time); + +/** + * @brief Set a profile's exit status + * + * @param[in] profile The profile to set the exit status for + * @param[in] pid The process where this profile was taken + * @param[in] state The status the profile's tevent_req finished with + * @param[in] user_error The user error of the profile's tevent_req + */ +void tevent_req_profile_set_status(struct tevent_req_profile *profile, + pid_t pid, + enum tevent_req_state state, + uint64_t user_error); + +/** + * @brief Add a subprofile to a profile + * + * @param[in] parent_profile The profile to be modified + * @param[in] sub_profile The subreqs profile profile to be added + * + * "subreq" is talloc_move'ed into "parent_profile", so the talloc + * ownership of "sub_profile" changes + */ + +void tevent_req_profile_append_sub(struct tevent_req_profile *parent_profile, + struct tevent_req_profile **sub_profile); + /** * @brief Create a tevent subrequest at a given time. * @@ -1002,7 +1548,7 @@ void tevent_req_received(struct tevent_req *req); * * Example: * @code - * static my_callback_wakeup_done(tevent_req *req) + * static void my_callback_wakeup_done(tevent_req *subreq) * { * struct tevent_req *req = tevent_req_callback_data(subreq, * struct tevent_req); @@ -1049,7 +1595,7 @@ bool tevent_wakeup_recv(struct tevent_req *req); /* @} */ /** - * @defgroup tevent_helpers The tevent helper functiions + * @defgroup tevent_helpers The tevent helper functions * @ingroup tevent * * @todo description @@ -1072,16 +1618,16 @@ int tevent_timeval_compare(const struct timeval *tv1, const struct timeval *tv2); /** - * @brief Get a zero timval value. + * @brief Get a zero timeval value. * - * @return A zero timval value. + * @return A zero timeval value. */ struct timeval tevent_timeval_zero(void); /** * @brief Get a timeval value for the current time. * - * @return A timval value with the current time. + * @return A timeval value with the current time. */ struct timeval tevent_timeval_current(void); @@ -1090,7 +1636,7 @@ struct timeval tevent_timeval_current(void); * * @param[in] secs The seconds to set. * - * @param[in] usecs The milliseconds to set. + * @param[in] usecs The microseconds to set. * * @return A timeval structure with the given values. */ @@ -1125,7 +1671,7 @@ bool tevent_timeval_is_zero(const struct timeval *tv); * * @param[in] secs The seconds to add to the timeval. * - * @param[in] usecs The milliseconds to add to the timeval. + * @param[in] usecs The microseconds to add to the timeval. * * @return The timeval structure with the new time. */ @@ -1137,7 +1683,7 @@ struct timeval tevent_timeval_add(const struct timeval *tv, uint32_t secs, * * @param[in] secs The seconds of the offset from now. * - * @param[in] usecs The milliseconds 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. */ @@ -1163,6 +1709,7 @@ struct timeval tevent_timeval_current_ofs(uint32_t secs, uint32_t usecs); */ struct tevent_queue; +struct tevent_queue_entry; #ifdef DOXYGEN /** @@ -1174,8 +1721,8 @@ struct tevent_queue; * * @return An allocated tevent queue on success, NULL on error. * - * @see tevent_start() - * @see tevent_stop() + * @see tevent_queue_start() + * @see tevent_queue_stop() */ struct tevent_queue *tevent_queue_create(TALLOC_CTX *mem_ctx, const char *name); @@ -1197,6 +1744,8 @@ struct tevent_queue *_tevent_queue_create(TALLOC_CTX *mem_ctx, * 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); @@ -1211,7 +1760,9 @@ typedef void (*tevent_queue_trigger_fn_t)(struct tevent_req *req, * @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. + * 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. * @@ -1224,6 +1775,104 @@ bool tevent_queue_add(struct tevent_queue *queue, 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 trigger function has no chance to see the returned + * queue_entry in the optimized case. + * + * 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 Untrigger an already triggered queue entry. + * + * If a trigger function detects that it needs to remain + * in the queue, it needs to call tevent_queue_stop() + * followed by tevent_queue_entry_untrigger(). + * + * @note In order to call tevent_queue_entry_untrigger() + * the queue must be already stopped and the given queue_entry + * must be the first one in the queue! Otherwise it calls abort(). + * + * @note You can't use this together with tevent_queue_add_optimize_empty() + * because the trigger function don't have access to the quene entry + * in the case of an empty queue. + * + * @param[in] queue_entry The queue entry to rearm. + * + * @see tevent_queue_add_entry() + * @see tevent_queue_stop() + */ +void tevent_queue_entry_untrigger(struct tevent_queue_entry *entry); + /** * @brief Start a tevent queue. * @@ -1251,15 +1900,183 @@ void tevent_queue_stop(struct tevent_queue *queue); */ 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 Whether 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 talloc_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_ @@ -1343,6 +2160,265 @@ bool tevent_register_backend(const char *name, const struct tevent_ops *ops); /* @} */ +#ifdef TEVENT_DEPRECATED +/** + * @defgroup tevent_wrapper_ops The tevent wrapper operation functions + * @ingroup tevent + * + * The following structure and registration functions are exclusively + * needed for people writing wrapper functions for event handlers + * e.g. wrappers can be used for debugging/profiling or impersonation. + * + * There is nothing useful for normal tevent user in here. + * + * @note That the close_fn() on tevent_fd is *NOT* wrapped! + * + * @see tevent_context_wrapper_create + * @see tevent_fd_set_auto_close + * @{ + */ + +struct tevent_wrapper_ops { + const char *name; + + bool (*before_use)(struct tevent_context *wrap_ev, + void *private_state, + struct tevent_context *main_ev, + const char *location); + void (*after_use)(struct tevent_context *wrap_ev, + void *private_state, + struct tevent_context *main_ev, + const char *location); + + void (*before_fd_handler)(struct tevent_context *wrap_ev, + void *private_state, + struct tevent_context *main_ev, + struct tevent_fd *fde, + uint16_t flags, + const char *handler_name, + const char *location); + void (*after_fd_handler)(struct tevent_context *wrap_ev, + void *private_state, + struct tevent_context *main_ev, + struct tevent_fd *fde, + uint16_t flags, + const char *handler_name, + const char *location); + + void (*before_timer_handler)(struct tevent_context *wrap_ev, + void *private_state, + struct tevent_context *main_ev, + struct tevent_timer *te, + struct timeval requested_time, + struct timeval trigger_time, + const char *handler_name, + const char *location); + void (*after_timer_handler)(struct tevent_context *wrap_ev, + void *private_state, + struct tevent_context *main_ev, + struct tevent_timer *te, + struct timeval requested_time, + struct timeval trigger_time, + const char *handler_name, + const char *location); + + void (*before_immediate_handler)(struct tevent_context *wrap_ev, + void *private_state, + struct tevent_context *main_ev, + struct tevent_immediate *im, + const char *handler_name, + const char *location); + void (*after_immediate_handler)(struct tevent_context *wrap_ev, + void *private_state, + struct tevent_context *main_ev, + struct tevent_immediate *im, + const char *handler_name, + const char *location); + + void (*before_signal_handler)(struct tevent_context *wrap_ev, + void *private_state, + struct tevent_context *main_ev, + struct tevent_signal *se, + int signum, + int count, + void *siginfo, + const char *handler_name, + const char *location); + void (*after_signal_handler)(struct tevent_context *wrap_ev, + void *private_state, + struct tevent_context *main_ev, + struct tevent_signal *se, + int signum, + int count, + void *siginfo, + const char *handler_name, + const char *location); +}; + +#ifdef DOXYGEN +/** + * @brief Create a wrapper tevent_context. + * + * @param[in] main_ev The main event context to work on. + * + * @param[in] mem_ctx The talloc memory context to use. + * + * @param[in] ops The tevent_wrapper_ops function table. + * + * @param[out] private_state The private state use by the wrapper functions. + * + * @param[in] private_type The talloc type of the private_state. + * + * @return The wrapper event context, NULL on error. + * + * @note Available as of tevent 0.9.37 + * @note Deprecated as of tevent 0.9.38 + */ +struct tevent_context *tevent_context_wrapper_create(struct tevent_context *main_ev, + TALLOC_CTX *mem_ctx, + const struct tevent_wrapper_ops *ops, + void **private_state, + const char *private_type); +#else +struct tevent_context *_tevent_context_wrapper_create(struct tevent_context *main_ev, + TALLOC_CTX *mem_ctx, + const struct tevent_wrapper_ops *ops, + void *pstate, + size_t psize, + const char *type, + const char *location) _DEPRECATED_; +#define tevent_context_wrapper_create(main_ev, mem_ctx, ops, state, type) \ + _tevent_context_wrapper_create(main_ev, mem_ctx, ops, \ + state, sizeof(type), #type, __location__) +#endif + +/** + * @brief Check if the event context is a wrapper event context. + * + * @param[in] ev The event context to work on. + * + * @return Is a wrapper (true), otherwise (false). + * + * @see tevent_context_wrapper_create() + * + * @note Available as of tevent 0.9.37 + * @note Deprecated as of tevent 0.9.38 + */ +bool tevent_context_is_wrapper(struct tevent_context *ev) _DEPRECATED_; + +#ifdef DOXYGEN +/** + * @brief Prepare the environment of a (wrapper) event context. + * + * A caller might call this before passing a wrapper event context + * to a tevent_req based *_send() function. + * + * The wrapper event context might do something like impersonation. + * + * tevent_context_push_use() must always be used in combination + * with tevent_context_pop_use(). + * + * There is a global stack of currently active/busy wrapper event contexts. + * Each wrapper can only appear once on that global stack! + * The stack size is limited to 32 elements, which should be enough + * for all useful scenarios. + * + * In addition to an explicit tevent_context_push_use() also + * the invocation of an immediate, timer or fd handler implicitly + * pushes the wrapper on the stack. + * + * Therefore there are some strict constraints for the usage of + * tevent_context_push_use(): + * - It must not be called from within an event handler + * that already acts on the wrapper. + * - tevent_context_pop_use() must be called before + * leaving the code block that called tevent_context_push_use(). + * - The caller is responsible ensure the correct stack ordering + * - Any violation of these constraints results in calling + * the abort handler of the given tevent context. + * + * Calling tevent_context_push_use() on a raw event context + * still consumes an element on the stack, but it's otherwise + * a no-op. + * + * If tevent_context_push_use() returns false, it means + * that the wrapper's before_use() hook returned this failure, + * in that case you must not call tevent_context_pop_use() as + * the wrapper is not pushed onto the stack. + * + * @param[in] ev The event context to work on. + * + * @return Success (true) or failure (false). + * + * @note This is only needed if wrapper event contexts are in use. + * + * @see tevent_context_pop_use + * + * @note Available as of tevent 0.9.37 + * @note Deprecated as of tevent 0.9.38 + */ +bool tevent_context_push_use(struct tevent_context *ev); +#else +bool _tevent_context_push_use(struct tevent_context *ev, + const char *location) _DEPRECATED_; +#define tevent_context_push_use(ev) \ + _tevent_context_push_use(ev, __location__) +#endif + +#ifdef DOXYGEN +/** + * @brief Release the environment of a (wrapper) event context. + * + * The wrapper event context might undo something like impersonation. + * + * This must be called after a succesful tevent_context_push_use(). + * Any ordering violation results in calling + * the abort handler of the given tevent context. + * + * This basically calls the wrapper's after_use() hook. + * + * @param[in] ev The event context to work on. + * + * @note This is only needed if wrapper event contexts are in use. + * + * @see tevent_context_push_use + * + * @note Available as of tevent 0.9.37 + * @note Deprecated as of tevent 0.9.38 + */ +void tevent_context_pop_use(struct tevent_context *ev); +#else +void _tevent_context_pop_use(struct tevent_context *ev, + const char *location) _DEPRECATED_; +#define tevent_context_pop_use(ev) \ + _tevent_context_pop_use(ev, __location__) +#endif + +/** + * @brief Check is the two context pointers belong to the same low level loop + * + * With the introduction of wrapper contexts it's not trivial + * to check if two context pointers belong to the same low level + * event loop. Some code may need to know this in order + * to make some caching decisions. + * + * @param[in] ev1 The first event context. + * @param[in] ev2 The second event context. + * + * @return true if both contexts belong to the same (still existing) context + * loop, false otherwise. + * + * @see tevent_context_wrapper_create + * + * @note Available as of tevent 0.9.37 + * @note Deprecated as of tevent 0.9.38 + */ +bool tevent_context_same_loop(struct tevent_context *ev1, + struct tevent_context *ev2) _DEPRECATED_; + +/* @} */ +#endif /* TEVENT_DEPRECATED */ + /** * @defgroup tevent_compat The tevent compatibility functions * @ingroup tevent