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Diffstat (limited to 'tevent_internal.h')
| -rw-r--r-- | tevent_internal.h | 950 |
1 files changed, 950 insertions, 0 deletions
diff --git a/tevent_internal.h b/tevent_internal.h new file mode 100644 index 0000000..75ae114 --- /dev/null +++ b/tevent_internal.h @@ -0,0 +1,950 @@ +/* + Unix SMB/CIFS implementation. + + generalised event loop handling + + INTERNAL STRUCTS. THERE ARE NO API GUARANTEES. + External users should only ever have to include this header when + implementing new tevent backends. + + Copyright (C) Stefan Metzmacher 2005-2009 + + ** NOTE! The following LGPL license applies to the tevent + ** library. This does NOT imply that all of Samba is released + ** under the LGPL + + This library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 3 of the License, or (at your option) any later version. + + This library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with this library; if not, see <http://www.gnu.org/licenses/>. +*/ + +struct tevent_req { + /** + * @brief What to do on completion + * + * This is used for the user of an async request, fn is called when + * the request completes, either successfully or with an error. + */ + struct { + /** + * @brief Completion function + * Completion function, to be filled by the API user + */ + tevent_req_fn fn; + /** + * @brief Private data for the completion function + */ + void *private_data; + /** + * @brief The completion function name, for flow tracing. + */ + const char *fn_name; + } async; + + /** + * @brief Private state pointer for the actual implementation + * + * The implementation doing the work for the async request needs to + * keep around current data like for example a fd event. The user of + * an async request should not touch this. + */ + void *data; + + /** + * @brief A function to overwrite the default print function + * + * The implementation doing the work may want to implement a + * custom function to print the text representation of the async + * request. + */ + tevent_req_print_fn private_print; + + /** + * @brief A function to cancel the request + * + * The implementation might want to set a function + * that is called when the tevent_req_cancel() function + * was called. + */ + struct { + tevent_req_cancel_fn fn; + const char *fn_name; + } private_cancel; + + /** + * @brief A function to cleanup the request + * + * The implementation might want to set a function + * that is called before the tevent_req_done() and tevent_req_error() + * trigger the callers callback function. + */ + struct { + tevent_req_cleanup_fn fn; + const char *fn_name; + enum tevent_req_state state; + } private_cleanup; + + /** + * @brief Internal state of the request + * + * Callers should only access this via functions and never directly. + */ + struct { + /** + * @brief The talloc type of the data pointer + * + * This is filled by the tevent_req_create() macro. + * + * This for debugging only. + */ + const char *private_type; + + /** + * @brief The location where the request was created + * + * This uses the __location__ macro via the tevent_req_create() + * macro. + * + * This for debugging only. + */ + const char *create_location; + + /** + * @brief The location where the request was finished + * + * This uses the __location__ macro via the tevent_req_done(), + * tevent_req_error() or tevent_req_nomem() macro. + * + * This for debugging only. + */ + const char *finish_location; + + /** + * @brief The location where the request was canceled + * + * This uses the __location__ macro via the + * tevent_req_cancel() macro. + * + * This for debugging only. + */ + const char *cancel_location; + + /** + * @brief The external state - will be queried by the caller + * + * While the async request is being processed, state will remain in + * TEVENT_REQ_IN_PROGRESS. A request is finished if + * req->state>=TEVENT_REQ_DONE. + */ + enum tevent_req_state state; + + /** + * @brief status code when finished + * + * This status can be queried in the async completion function. It + * will be set to 0 when everything went fine. + */ + uint64_t error; + + /** + * @brief the immediate event used by tevent_req_post + * + */ + struct tevent_immediate *trigger; + + /** + * @brief An event context which will be used to + * defer the _tevent_req_notify_callback(). + */ + struct tevent_context *defer_callback_ev; + + /** + * @brief the timer event if tevent_req_set_endtime was used + * + */ + struct tevent_timer *timer; + + /** + * @brief The place where profiling data is kept + */ + struct tevent_req_profile *profile; + + size_t call_depth; + } internal; +}; + +struct tevent_req_profile { + struct tevent_req_profile *prev, *next; + struct tevent_req_profile *parent; + const char *req_name; + pid_t pid; + const char *start_location; + struct timeval start_time; + const char *stop_location; + struct timeval stop_time; + enum tevent_req_state state; + uint64_t user_error; + struct tevent_req_profile *subprofiles; +}; + +struct tevent_fd { + struct tevent_fd *prev, *next; + struct tevent_context *event_ctx; + struct tevent_wrapper_glue *wrapper; + bool busy; + bool destroyed; + int fd; + uint16_t flags; /* see TEVENT_FD_* flags */ + tevent_fd_handler_t handler; + tevent_fd_close_fn_t close_fn; + /* this is private for the specific handler */ + void *private_data; + /* this is for debugging only! */ + const char *handler_name; + const char *location; + /* this is private for the events_ops implementation */ + uint64_t additional_flags; + void *additional_data; + /* custom tag that can be set by caller */ + uint64_t tag; + struct tevent_fd_mpx { + struct tevent_fd_mpx *prev, *next; + struct tevent_fd *fde; + struct tevent_fd *primary; + struct tevent_fd_mpx *list; + uint16_t total_flags; + bool has_mpx; + } mpx; +}; + +struct tevent_timer { + struct tevent_timer *prev, *next; + struct tevent_context *event_ctx; + struct tevent_wrapper_glue *wrapper; + bool busy; + bool destroyed; + struct timeval next_event; + tevent_timer_handler_t handler; + /* this is private for the specific handler */ + void *private_data; + /* this is for debugging only! */ + const char *handler_name; + const char *location; + /* this is private for the events_ops implementation */ + void *additional_data; + /* custom tag that can be set by caller */ + uint64_t tag; +}; + +struct tevent_immediate { + struct tevent_immediate *prev, *next; + struct tevent_context *event_ctx; + struct tevent_wrapper_glue *wrapper; + bool busy; + bool destroyed; + struct tevent_context *detach_ev_ctx; + tevent_immediate_handler_t handler; + /* this is private for the specific handler */ + void *private_data; + /* this is for debugging only! */ + const char *handler_name; + const char *create_location; + const char *schedule_location; + /* this is private for the events_ops implementation */ + void (*cancel_fn)(struct tevent_immediate *im); + void *additional_data; + /* custom tag that can be set by caller */ + uint64_t tag; +}; + +struct tevent_signal { + struct tevent_signal *prev, *next; + struct tevent_context *event_ctx; + struct tevent_wrapper_glue *wrapper; + bool busy; + bool destroyed; + int signum; + int sa_flags; + tevent_signal_handler_t handler; + /* this is private for the specific handler */ + void *private_data; + /* this is for debugging only! */ + const char *handler_name; + const char *location; + /* this is private for the events_ops implementation */ + void *additional_data; + /* custom tag that can be set by caller */ + uint64_t tag; +}; + +struct tevent_threaded_context { + struct tevent_threaded_context *next, *prev; + +#ifdef HAVE_PTHREAD + pthread_mutex_t event_ctx_mutex; +#endif + struct tevent_context *event_ctx; +}; + +struct tevent_debug_ops { + enum tevent_debug_level max_level; + void (*debug)(void *context, enum tevent_debug_level level, + const char *fmt, va_list ap) PRINTF_ATTRIBUTE(3,0); + void *context; +}; + +void tevent_debug(struct tevent_context *ev, enum tevent_debug_level level, + const char *fmt, ...) PRINTF_ATTRIBUTE(3,4); +#define TEVENT_DEBUG(__ev, __level, __fmt, ...) do { \ + if (unlikely((__ev) != NULL && \ + (__level) <= (__ev)->debug_ops.max_level)) \ + { \ + tevent_debug((__ev), (__level), (__fmt), __VA_ARGS__); \ + } \ +} while(0) + +void tevent_abort(struct tevent_context *ev, const char *reason); + +void tevent_common_check_double_free(TALLOC_CTX *ptr, const char *reason); + +struct tevent_context { + /* the specific events implementation */ + const struct tevent_ops *ops; + + /* + * The following three pointers are queried on every loop_once + * in the order in which they appear here. Not measured, but + * hopefully putting them at the top together with "ops" + * should make tevent a *bit* more cache-friendly than before. + */ + + /* list of signal events - used by common code */ + struct tevent_signal *signal_events; + + /* List of threaded job indicators */ + struct tevent_threaded_context *threaded_contexts; + + /* list of immediate events - used by common code */ + struct tevent_immediate *immediate_events; + + /* list of fd events - used by common code */ + struct tevent_fd *fd_events; + + /* list of timed events - used by common code */ + struct tevent_timer *timer_events; + + /* List of scheduled immediates */ + pthread_mutex_t scheduled_mutex; + struct tevent_immediate *scheduled_immediates; + + /* this is private for the events_ops implementation */ + void *additional_data; + + /* pipe hack used with signal handlers */ + struct tevent_fd *wakeup_fde; + int wakeup_fd; /* fd to write into */ +#ifndef HAVE_EVENT_FD + int wakeup_read_fd; +#endif + + /* debugging operations */ + struct tevent_debug_ops debug_ops; + + /* info about the nesting status */ + struct { + bool allowed; + uint32_t level; + tevent_nesting_hook hook_fn; + void *hook_private; + } nesting; + + struct { + struct { + tevent_trace_callback_t callback; + void *private_data; + } point; + + struct { + tevent_trace_fd_callback_t callback; + void *private_data; + } fde; + + struct { + tevent_trace_signal_callback_t callback; + void *private_data; + } se; + + struct { + tevent_trace_timer_callback_t callback; + void *private_data; + } te; + + struct { + tevent_trace_immediate_callback_t callback; + void *private_data; + } im; + + struct { + tevent_trace_queue_callback_t callback; + void *private_data; + } qe; + } tracing; + + struct { + /* + * This is used on the main event context + */ + struct tevent_wrapper_glue *list; + + /* + * This is used on the wrapper event context + */ + struct tevent_wrapper_glue *glue; + } wrapper; + + /* + * an optimization pointer into timer_events + * used by used by common code via + * tevent_common_add_timer_v2() + */ + struct tevent_timer *last_zero_timer; + +#ifdef HAVE_PTHREAD + struct tevent_context *prev, *next; +#endif +}; + +int tevent_common_context_destructor(struct tevent_context *ev); +int tevent_common_loop_wait(struct tevent_context *ev, + const char *location); + +struct tevent_common_fd_buf { + char buf[128]; +}; + +const char *tevent_common_fd_str(struct tevent_common_fd_buf *buf, + const char *description, + const struct tevent_fd *fde); + +int tevent_common_fd_destructor(struct tevent_fd *fde); +struct tevent_fd *tevent_common_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 tevent_common_fd_set_close_fn(struct tevent_fd *fde, + tevent_fd_close_fn_t close_fn); +uint16_t tevent_common_fd_get_flags(struct tevent_fd *fde); +void tevent_common_fd_set_flags(struct tevent_fd *fde, uint16_t flags); +int tevent_common_invoke_fd_handler(struct tevent_fd *fde, uint16_t flags, + bool *removed); + +struct tevent_timer *tevent_common_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); +struct tevent_timer *tevent_common_add_timer_v2(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); +struct timeval tevent_common_loop_timer_delay(struct tevent_context *); +int tevent_common_invoke_timer_handler(struct tevent_timer *te, + struct timeval current_time, + bool *removed); + +void tevent_common_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); +int tevent_common_invoke_immediate_handler(struct tevent_immediate *im, + bool *removed); +bool tevent_common_loop_immediate(struct tevent_context *ev); +void tevent_common_threaded_activate_immediate(struct tevent_context *ev); + +bool tevent_common_have_events(struct tevent_context *ev); +int tevent_common_wakeup_init(struct tevent_context *ev); +int tevent_common_wakeup_fd(int fd); +int tevent_common_wakeup(struct tevent_context *ev); + +struct tevent_signal *tevent_common_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); +int tevent_common_check_signal(struct tevent_context *ev); +void tevent_cleanup_pending_signal_handlers(struct tevent_signal *se); +int tevent_common_invoke_signal_handler(struct tevent_signal *se, + int signum, int count, void *siginfo, + bool *removed); + +struct tevent_context *tevent_wrapper_main_ev(struct tevent_context *ev); + +struct tevent_wrapper_ops; + +struct tevent_wrapper_glue { + struct tevent_wrapper_glue *prev, *next; + struct tevent_context *wrap_ev; + struct tevent_context *main_ev; + bool busy; + bool destroyed; + const struct tevent_wrapper_ops *ops; + void *private_state; +}; + +void tevent_wrapper_push_use_internal(struct tevent_context *ev, + struct tevent_wrapper_glue *wrapper); +void tevent_wrapper_pop_use_internal(const struct tevent_context *__ev_ptr, + struct tevent_wrapper_glue *wrapper); + +bool tevent_standard_init(void); +bool tevent_poll_init(void); +bool tevent_poll_event_add_fd_internal(struct tevent_context *ev, + struct tevent_fd *fde); +bool tevent_poll_mt_init(void); +#ifdef HAVE_EPOLL +bool tevent_epoll_init(void); +void tevent_epoll_set_panic_fallback(struct tevent_context *ev, + bool (*panic_fallback)(struct tevent_context *ev, + bool replay)); +#endif + +static inline void tevent_thread_call_depth_notify( + enum tevent_thread_call_depth_cmd cmd, + struct tevent_req *req, + size_t depth, + const char *fname) +{ + if (tevent_thread_call_depth_state_g.cb != NULL) { + tevent_thread_call_depth_state_g.cb( + tevent_thread_call_depth_state_g.cb_private, + cmd, + req, + depth, + fname); + } +} + +void tevent_trace_point_callback(struct tevent_context *ev, + enum tevent_trace_point); + +void tevent_trace_fd_callback(struct tevent_context *ev, + struct tevent_fd *fde, + enum tevent_event_trace_point); + +void tevent_trace_signal_callback(struct tevent_context *ev, + struct tevent_signal *se, + enum tevent_event_trace_point); + +void tevent_trace_timer_callback(struct tevent_context *ev, + struct tevent_timer *te, + enum tevent_event_trace_point); + +void tevent_trace_immediate_callback(struct tevent_context *ev, + struct tevent_immediate *im, + enum tevent_event_trace_point); + +void tevent_trace_queue_callback(struct tevent_context *ev, + struct tevent_queue_entry *qe, + enum tevent_event_trace_point); + +#include "tevent_dlinklist.h" + +static inline void tevent_common_fd_mpx_reinit(struct tevent_fd *fde) +{ + fde->mpx = (struct tevent_fd_mpx) { .fde = fde, }; +} + +static inline void tevent_common_fd_disarm(struct tevent_fd *fde) +{ + if (fde->event_ctx != NULL) { + tevent_trace_fd_callback(fde->event_ctx, fde, + TEVENT_EVENT_TRACE_DETACH); + DLIST_REMOVE(fde->event_ctx->fd_events, fde); + fde->event_ctx = NULL; + } + tevent_common_fd_mpx_reinit(fde); + fde->wrapper = NULL; +} + +/* + * tevent_common_fd_mpx_primary() returns the fde that is responsible + * for the low level state. + * + * By default (when there's no multiplexing) it just returns 'any_fde'. + * + * Note it always returns a valid pointer. + */ +static inline +struct tevent_fd *tevent_common_fd_mpx_primary(struct tevent_fd *any_fde) +{ + struct tevent_fd *primary = NULL; + + if (any_fde->mpx.primary != NULL) { + primary = any_fde->mpx.primary; + } else { + primary = any_fde; + } + + return primary; +} + +/* + * tevent_common_fd_mpx_update_flags() needs to be called + * if update_fde->flags has changed. It is needed in + * order to let tevent_common_fd_mpx_flags() return a valid + * result. + */ +static inline +void tevent_common_fd_mpx_update_flags(struct tevent_fd *update_fde) +{ + struct tevent_fd *primary = tevent_common_fd_mpx_primary(update_fde); + struct tevent_fd_mpx *mpx = NULL; + uint16_t new_total_flags = 0; + + if (!primary->mpx.has_mpx) { + primary->mpx.total_flags = primary->flags; + return; + } + + for (mpx = primary->mpx.list; mpx != NULL; mpx = mpx->next) { + struct tevent_fd *mpx_fde = mpx->fde; + /* we don't care that mpx_fde might be == primary */ + new_total_flags |= mpx_fde->flags; + } + + primary->mpx.total_flags = new_total_flags; +} + +/* + * tevent_common_fd_mpx_flags() return the effective flags + * (TEVEND_FD_*) of the primary fde and all multiplexed fdes. + * + * Valid after tevent_common_fd_mpx_update_flags() was called + */ +static inline +uint16_t tevent_common_fd_mpx_flags(struct tevent_fd *any_fde) +{ + struct tevent_fd *primary = tevent_common_fd_mpx_primary(any_fde); + + return primary->mpx.total_flags; +} + +/* + * tevent_common_fd_mpx_clear_writeable() clears TEVENT_FD_WRITE + * from all fdes belonging together. + */ +static inline +void tevent_common_fd_mpx_clear_writeable(struct tevent_fd *any_fde) +{ + struct tevent_fd *primary = tevent_common_fd_mpx_primary(any_fde); + struct tevent_fd_mpx *mpx = NULL; + + primary->flags &= ~TEVENT_FD_WRITE; + + for (mpx = primary->mpx.list; mpx != NULL; mpx = mpx->next) { + struct tevent_fd *mpx_fde = mpx->fde; + /* we don't care that mpx_fde might be == primary */ + mpx_fde->flags &= ~TEVENT_FD_WRITE; + } + + primary->mpx.total_flags &= ~TEVENT_FD_WRITE; +} + +/* + * tevent_common_fd_mpx_additional_flags() modifies + * fde->additional_flags for all fdes belonging together. + */ +static inline +void tevent_common_fd_mpx_additional_flags(struct tevent_fd *any_fde, + uint64_t clear_flags, + uint64_t add_flags) +{ + struct tevent_fd *primary = tevent_common_fd_mpx_primary(any_fde); + struct tevent_fd_mpx *mpx = NULL; + + primary->additional_flags &= ~clear_flags; + primary->additional_flags |= add_flags; + + for (mpx = primary->mpx.list; mpx != NULL; mpx = mpx->next) { + struct tevent_fd *mpx_fde = mpx->fde; + /* we don't care that mpx_fde might be == primary */ + mpx_fde->additional_flags &= ~clear_flags; + mpx_fde->additional_flags |= add_flags; + } +} + +/* + * tevent_common_fd_mpx_disarm_all() detaches + * all fdes currently belonging together from each other + * and also from the tevent_context, which means their + * handler will never be called again. + */ +static inline +void tevent_common_fd_mpx_disarm_all(struct tevent_fd *any_fde) +{ + struct tevent_fd *primary = tevent_common_fd_mpx_primary(any_fde); + struct tevent_fd_mpx *mpx = NULL, *next = NULL; + + for (mpx = primary->mpx.list; mpx != NULL; mpx = next) { + struct tevent_fd *mpx_fde = mpx->fde; + + next = mpx->next; + DLIST_REMOVE(primary->mpx.list, mpx); + + if (mpx_fde == primary) { + /* primary is handled below */ + continue; + } + + tevent_common_fd_disarm(mpx_fde); + } + + tevent_common_fd_disarm(primary); +} + +/* + * tevent_common_fd_mpx_select() selects the handler that + * should be called for the given low level event. + * + * Note it's important to pass the primary fde! + */ +static inline +struct tevent_fd *tevent_common_fd_mpx_select(struct tevent_fd *primary, + uint16_t flags, + bool got_error) +{ + struct tevent_fd_mpx *mpx = NULL; + struct tevent_fd *selected = NULL; + + /* optimize for the single event case. */ + if (!primary->mpx.has_mpx) { + /* + * If we got an error, we won't report it if + * the caller only asked for TEVENT_FD_WRITE. + */ + if (got_error && + !(primary->flags & (TEVENT_FD_READ|TEVENT_FD_ERROR))) + { + return NULL; + } + + if (flags & primary->flags) { + return primary; + } + + return NULL; + } + + for (mpx = primary->mpx.list; mpx != NULL; mpx = mpx->next) { + struct tevent_fd *mpx_fde = mpx->fde; + + /* + * If we got an error, we won't report it if + * the caller only asked for TEVENT_FD_WRITE. + */ + if (got_error && + !(mpx_fde->flags & (TEVENT_FD_READ|TEVENT_FD_ERROR))) + { + continue; + } + + if (flags & mpx_fde->flags) { + selected = mpx_fde; + break; + } + } + + if (selected == NULL) { + return NULL; + } + + /* + * Maintain fairness and demote the just selected fde + */ + DLIST_DEMOTE_SHORT(primary->mpx.list, &selected->mpx); + return selected; +} + +/* + * tevent_common_fd_mpx_add() searches for an existing (active) fde + * for the same low level fd and adds the given 'add_fde' + * as multiplexed to the found fde. + * + * If another fde was found it is returned. + * NULL is returned to indicate no match + */ +static inline +struct tevent_fd *tevent_common_fd_mpx_add(struct tevent_fd *add_fde) +{ + struct tevent_context *ev = add_fde->event_ctx; + struct tevent_fd *add_primary = tevent_common_fd_mpx_primary(add_fde); + uint16_t add_flags = tevent_common_fd_mpx_flags(add_primary); + struct tevent_fd *mpx_fde = NULL; + struct tevent_fd *mpx_primary = NULL; + struct tevent_fd_mpx *tmp = NULL; + struct tevent_fd_mpx *next = NULL; + + /* Find the existing fde that caused the EEXIST error. */ + for (mpx_fde = ev->fd_events; mpx_fde; mpx_fde = mpx_fde->next) { + mpx_primary = tevent_common_fd_mpx_primary(mpx_fde); + + if (mpx_primary->fd != add_primary->fd) { + mpx_primary = NULL; + continue; + } + + if (mpx_primary == add_primary) { + mpx_primary = NULL; + continue; + } + + if (add_flags != 0 && + tevent_common_fd_mpx_flags(mpx_primary) == 0) + { + /* + * only active events should match + */ + mpx_primary = NULL; + continue; + } + break; + } + if (mpx_primary == NULL) { + tevent_debug(ev, TEVENT_DEBUG_FATAL, + "can't find multiplex fde for fd[%d]", + add_fde->fd); + return NULL; + } + + /* + * If add_primary is not in it's own list + * we add it in order to simplify the loop below. + */ + + if (add_primary->mpx.prev == NULL && add_primary->mpx.next == NULL) { + DLIST_ADD_END(add_primary->mpx.list, &add_primary->mpx); + } + + /* + * Add the new mpx_primary to its own list before others, + * if it is not already added. + */ + if (mpx_primary->mpx.prev == NULL && mpx_primary->mpx.next == NULL) { + DLIST_ADD_END(mpx_primary->mpx.list, &mpx_primary->mpx); + } + + /* + * Now we clear all entries and move them to the + * new primary + */ + for (tmp = add_primary->mpx.list; tmp != NULL; tmp = next) { + struct tevent_fd *tmp_fde = tmp->fde; + + next = tmp->next; + + DLIST_REMOVE(add_primary->mpx.list, tmp); + tevent_common_fd_mpx_reinit(tmp_fde); + DLIST_ADD_END(mpx_primary->mpx.list, tmp); + tmp->primary = mpx_primary; + tmp->has_mpx = true; + } + + mpx_primary->mpx.has_mpx = true; + return mpx_primary; +} + +/* + * tevent_common_fd_mpx_update() calls tevent_common_fd_mpx_update_flags() + * and compares tevent_common_fd_mpx_flags() before and after. + * + * When there's a low level update needed the primary fde, + * otherwise NULL is returned. + */ +static inline +struct tevent_fd *tevent_common_fd_mpx_update(struct tevent_fd *update_fde) +{ + struct tevent_fd *primary = tevent_common_fd_mpx_primary(update_fde); + uint16_t old_total_flags; + uint16_t new_total_flags; + + old_total_flags = primary->mpx.total_flags; + tevent_common_fd_mpx_update_flags(primary); + new_total_flags = primary->mpx.total_flags; + + if (old_total_flags == new_total_flags) { + /* No update needed */ + return NULL; + } + + return primary; +} + +/* + * tevent_common_fd_mpx_remove() removes remove_fde from its possible primary, + * if remove_fde is a primary itself, a new primary is selected. + * + * The remaining primary or NULL is returned. + */ +static inline +struct tevent_fd *tevent_common_fd_mpx_remove(struct tevent_fd *remove_fde) +{ + struct tevent_fd *primary = tevent_common_fd_mpx_primary(remove_fde); + struct tevent_fd_mpx *mpx = NULL, *next = NULL; + struct tevent_fd *new_primary = NULL; + + DLIST_REMOVE(primary->mpx.list, &remove_fde->mpx); + + if (primary != remove_fde) { + tevent_common_fd_mpx_reinit(remove_fde); + return primary; + } + + for (mpx = primary->mpx.list; mpx != NULL; mpx = next) { + struct tevent_fd *mpx_fde = mpx->fde; + + next = mpx->next; + + DLIST_REMOVE(primary->mpx.list, &mpx_fde->mpx); + tevent_common_fd_mpx_reinit(mpx_fde); + mpx->primary = new_primary; + if (new_primary == NULL) { + /* + * Select the first one as the new primary and add + * itself as the first mpx-fde to the mpx list + */ + new_primary = mpx_fde; + DLIST_ADD(new_primary->mpx.list, &mpx_fde->mpx); + continue; + } + new_primary->mpx.has_mpx = true; + mpx->has_mpx = true; + DLIST_ADD_END(new_primary->mpx.list, &mpx_fde->mpx); + } + + /* primary == remove_fde */ + tevent_common_fd_mpx_reinit(primary); + return new_primary; +} |