/* * Copyright (c) 2008-2014 Travis Geiselbrecht * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files * (the "Software"), to deal in the Software without restriction, * including without limitation the rights to use, copy, modify, merge, * publish, distribute, sublicense, and/or sell copies of the Software, * and to permit persons to whom the Software is furnished to do so, * subject to the following conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ #ifndef __KERNEL_EVENT_H #define __KERNEL_EVENT_H #include #include #include #include __BEGIN_CDECLS; #define EVENT_MAGIC (0x65766E74) // "evnt" typedef struct event { int magic; bool signaled; uint flags; wait_queue_t wait; } event_t; #define EVENT_FLAG_AUTOUNSIGNAL 1 #define EVENT_INITIAL_VALUE(e, initial, _flags) \ { \ .magic = EVENT_MAGIC, \ .signaled = initial, \ .flags = _flags, \ .wait = WAIT_QUEUE_INITIAL_VALUE((e).wait), \ } /* Rules for Events: * - Events may be signaled from interrupt context *but* the reschedule * parameter must be false in that case. * - Events may not be waited upon from interrupt context. * - Events without FLAG_AUTOUNSIGNAL: * - Wake up any waiting threads when signaled. * - Continue to do so (no threads will wait) until unsignaled. * - Events with FLAG_AUTOUNSIGNAL: * - If one or more threads are waiting when signaled, one thread will * be woken up and return. The signaled state will not be set. * - If no threads are waiting when signaled, the Event will remain * in the signaled state until a thread attempts to wait (at which * time it will unsignal atomicly and return immediately) or * event_unsignal() is called. */ void event_init(event_t *, bool initial, uint flags); void event_destroy(event_t *); status_t event_wait_timeout(event_t *, lk_time_t); /* wait on the event with a timeout */ status_t event_signal(event_t *, bool reschedule); status_t event_unsignal(event_t *); static inline bool event_initialized(event_t *e) { return e->magic == EVENT_MAGIC; } static inline status_t event_wait(event_t *e) { return event_wait_timeout(e, INFINITE_TIME); } __END_CDECLS; #endif