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Diffstat (limited to 'erts/emulator/sys/common/erl_poll_api.h')
-rw-r--r-- | erts/emulator/sys/common/erl_poll_api.h | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/erts/emulator/sys/common/erl_poll_api.h b/erts/emulator/sys/common/erl_poll_api.h new file mode 100644 index 0000000000..04beb37d1c --- /dev/null +++ b/erts/emulator/sys/common/erl_poll_api.h @@ -0,0 +1,122 @@ +/* + * %CopyrightBegin% + * + * Copyright Ericsson AB 2006-2016. All Rights Reserved. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + * %CopyrightEnd% + */ +/** + * @description: Poll interface functions + * @author Lukas Larsson + * + * The functions in the header are used to interact with the poll + * implementation. Iff the kernel-poll implementation needs a fallback + * pollset, then all functions are exported twice. Once with a _flbk + * suffix and once without any suffix. If no fallback is needed, then + * only the non-suffix version is exported. + */ + +/** + * Initialize the poll implementation. Has to be called before any other function. + * @param[out] concurrent_waiters if not NULL, set to 1 if more then one thread + * is allowed to wait in the pollsets at the same time. + */ +void ERTS_POLL_EXPORT(erts_poll_init)(int *concurrent_waiters); +/** + * @brief Create a new pollset. + * @param id The unique debug id of this pollset. + */ +ErtsPollSet *ERTS_POLL_EXPORT(erts_poll_create_pollset)(int id); + +/** + * Modify the contents of a pollset. This function can be called while one + * (or possibly more) thread is waiting in the pollset. + * + * @param ps the pollset to modify + * @param fd the file descriptor to modify + * @param op the type of operation to do. Normal usage is ADD,MOD...MOD,DEL. + * @param evts the events that we are changing interest to. Ignored if op is DEL. + * @param[in] wake_poller if set to 1 any thread waiting in the pollset will be woken. + * This parameter is ignored if the pollset supports concurrent waiters. + * @param[out] wake_poller set to 1 if the waiting thread was woken. + * @return The events set, or ERTS_POLL_EV_NVAL if it was not possible to add the + * fd to the pollset. + */ +ErtsPollEvents ERTS_POLL_EXPORT(erts_poll_control)(ErtsPollSet *ps, + ErtsSysFdType fd, + ErtsPollOp op, + ErtsPollEvents evts, + int *wake_poller); + +/** + * Wait for events to be ready in the pollset. If the erts_poll_init call + * set concurrent_waiters to 1, then multiple threads are allowed to call + * this function at the same time. + * + * When an event has been triggered on a fd, that event is disabled. To + * re-enable it the implementation has to call erts_poll_control again. + * + * @param ps the pollset to wait for events in + * @param res an array of fd results that the ready fds are put in. + * @param[in] length the length of the res array + * @param[out] length the number of ready events returned in res + * @return 0 on success, else the ERRNO of the error that happened. + */ +int ERTS_POLL_EXPORT(erts_poll_wait)(ErtsPollSet *ps, + ErtsPollResFd res[], + int *length); +/** + * Interrupt the thread waiting in the pollset. This function should be called + * with set = 0 before any thread calls erts_poll_wait in order to clear any + * interrupts that have happened while the thread was awake. + * + * This function has no effect on pollsets that support concurrent waiters. + * + * @param ps the pollset to wake + * @param set if 1, interrupt the pollset, if 0 clear the interrupt flag. + */ +void ERTS_POLL_EXPORT(erts_poll_interrupt)(ErtsPollSet *ps, int set); + +/* Debug functions */ + +/** + * Get the maximum number of fds supported by the pollset + */ +int ERTS_POLL_EXPORT(erts_poll_max_fds)(void); +/** + * Get information about the given pollset + */ +void ERTS_POLL_EXPORT(erts_poll_info)(ErtsPollSet *ps, + ErtsPollInfo *info); +/** + * Get information about which events are currently selected. + * + * The unix fd is used to index into the array, so naturally this function does + * not work on windows. If the pollset cannot figure out what the selected + * events for a given fd is, it is set to ERTS_POLL_EV_NONE. + * + * @param ps the pollset to get events from + * @param evts an array of which events are selected on. + */ +void ERTS_POLL_EXPORT(erts_poll_get_selected_events)(ErtsPollSet *ps, + ErtsPollEvents evts[], + int length); + +#ifdef ERTS_ENABLE_LOCK_COUNT +/** + * Enable lock counting of any locks within the pollset. + */ +void ERTS_POLL_EXPORT(erts_lcnt_enable_pollset_lock_count)(ErtsPollSet *, int enable); +#endif |