/**************************************************************************** * sched/timer/timer_create.c * * Copyright (C) 2007-2009, 2011, 2014-2017 Gregory Nutt. All rights * reserved. * Author: Gregory Nutt * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include #include #include "timer/timer.h" #ifndef CONFIG_DISABLE_POSIX_TIMERS /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: timer_allocate * * Description: * Allocate one POSIX timer and place it into the allocated timer list. * ****************************************************************************/ static FAR struct posix_timer_s *timer_allocate(void) { FAR struct posix_timer_s *ret; irqstate_t flags; uint8_t pt_flags; /* Try to get a preallocated timer from the free list */ #if CONFIG_PREALLOC_TIMERS > 0 flags = enter_critical_section(); ret = (FAR struct posix_timer_s *)sq_remfirst((FAR sq_queue_t *)&g_freetimers); leave_critical_section(flags); /* Did we get one? */ if (ret) { pt_flags = PT_FLAGS_PREALLOCATED; } else #endif { /* Allocate a new timer from the heap */ ret = (FAR struct posix_timer_s *) kmm_malloc(sizeof(struct posix_timer_s)); pt_flags = 0; } /* If we have a timer, then put it into the allocated timer list */ if (ret) { /* Initialize the timer structure */ memset(ret, 0, sizeof(struct posix_timer_s)); ret->pt_flags = pt_flags; /* And add it to the end of the list of allocated timers */ flags = enter_critical_section(); sq_addlast((FAR sq_entry_t *)ret, (FAR sq_queue_t *)&g_alloctimers); leave_critical_section(flags); } return ret; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: timer_create * * Description: * The timer_create() function creates per-thread timer using the * specified clock, clock_id, as the timing base. The timer_create() * function returns, in the location referenced by timerid, a timer ID of * type timer_t used to identify the timer in timer requests. This timer * ID is unique until the timer is deleted. The particular clock, clock_id, * is defined in . The timer whose ID is returned will be in a * disarmed state upon return from timer_create(). * * The evp argument, if non-NULL, points to a sigevent structure. This * structure is allocated by the called and defines the asynchronous * notification to occur. If the evp argument is NULL, the effect is as * if the evp argument pointed to a sigevent structure with the * sigev_notify member having the value SIGEV_SIGNAL, the sigev_signo * having a default signal number, and the sigev_value member having the * value of the timer ID. * * Each implementation defines a set of clocks that can be used as timing * bases for per-thread timers. All implementations shall support a * clock_id of CLOCK_REALTIME. * * Input Parameters: * clockid - Specifies the clock to use as the timing base. * evp - Refers to a user allocated sigevent structure that defines the * asynchronous notification. evp may be NULL (see above). * timerid - The pre-thread timer created by the call to timer_create(). * * Returned Value: * If the call succeeds, timer_create() will return 0 (OK) and update the * location referenced by timerid to a timer_t, which can be passed to the * other per-thread timer calls. If an error occurs, the function will * return a value of -1 (ERROR) and set errno to indicate the error. * * EAGAIN - The system lacks sufficient signal queuing resources to honor * the request. * EAGAIN - The calling process has already created all of the timers it * is allowed by this implementation. * EINVAL - The specified clock ID is not defined. * ENOTSUP - The implementation does not support the creation of a timer * attached to the CPU-time clock that is specified by clock_id and * associated with a thread different thread invoking timer_create(). * * Assumptions: * ****************************************************************************/ int timer_create(clockid_t clockid, FAR struct sigevent *evp, FAR timer_t *timerid) { FAR struct posix_timer_s *ret; WDOG_ID wdog; /* Sanity checks. Also, we support only CLOCK_REALTIME */ if (timerid == NULL || clockid != CLOCK_REALTIME) { set_errno(EINVAL); return ERROR; } /* Allocate a watchdog to provide the underling CLOCK_REALTIME timer */ wdog = wd_create(); if (!wdog) { set_errno(EAGAIN); return ERROR; } /* Allocate a timer instance to contain the watchdog */ ret = timer_allocate(); if (!ret) { wd_delete(wdog); set_errno(EAGAIN); return ERROR; } /* Initialize the timer instance */ ret->pt_crefs = 1; ret->pt_owner = getpid(); ret->pt_delay = 0; ret->pt_wdog = wdog; /* Was a struct sigevent provided? */ if (evp) { /* Yes, copy the entire struct sigevent content */ memcpy(&ret->pt_event, evp, sizeof(struct sigevent)); } else { /* "If the evp argument is NULL, the effect is as if the evp argument * pointed to a sigevent structure with the sigev_notify member * having the value SIGEV_SIGNAL, the sigev_signo having a default * signal number, and the sigev_value member having the value of the * timer ID." */ ret->pt_event.sigev_notify = SIGEV_SIGNAL; ret->pt_event.sigev_signo = SIGALRM; ret->pt_event.sigev_value.sival_ptr = ret; #ifdef CONFIG_SIG_EVTHREAD ret->pt_event.sigev_notify_function = NULL; ret->pt_event.sigev_notify_attributes = NULL; #endif } /* Return the timer */ *timerid = ret; return OK; } #endif /* CONFIG_DISABLE_POSIX_TIMERS */