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Diffstat (limited to 'nuttx/sched/timer_create.c')
| -rw-r--r-- | nuttx/sched/timer_create.c | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/nuttx/sched/timer_create.c b/nuttx/sched/timer_create.c new file mode 100644 index 000000000..edfb01080 --- /dev/null +++ b/nuttx/sched/timer_create.c @@ -0,0 +1,237 @@ +/******************************************************************************** + * sched/timer_create.c + * + * Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <gnutt@nuttx.org> + * + * 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 <nuttx/config.h> + +#include <stdint.h> +#include <unistd.h> +#include <time.h> +#include <string.h> +#include <wdog.h> +#include <errno.h> + +#include <nuttx/kmalloc.h> + +#include "timer_internal.h" + +#ifndef CONFIG_DISABLE_POSIX_TIMERS + +/******************************************************************************** + * Definitions + ********************************************************************************/ + +/******************************************************************************** + * Private Data + ********************************************************************************/ + +/******************************************************************************** + * Public Data + ********************************************************************************/ + +/******************************************************************************** + * Private Functions + ********************************************************************************/ + +/******************************************************************************** + * Name: timer_allocate + * + * Description: + * Allocate one POSIX timer and place it into the allocated timer list. + * + ********************************************************************************/ + +static struct posix_timer_s *timer_allocate(void) +{ + 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 = irqsave(); + ret = (struct posix_timer_s*)sq_remfirst((sq_queue_t*)&g_freetimers); + irqrestore(flags); + + /* Did we get one? */ + + if (ret) + { + pt_flags = PT_FLAGS_PREALLOCATED; + } + else +#endif + { + /* Allocate a new timer from the heap */ + + ret = (struct posix_timer_s*)kmalloc(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 = irqsave(); + sq_addlast((sq_entry_t*)ret, (sq_queue_t*)&g_alloctimers); + irqrestore(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 <time.h>. 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. + * + * 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(). + * + * Return 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) +{ + struct posix_timer_s *ret; + WDOG_ID wdog; + + /* Sanity checks. Also, we support only CLOCK_REALTIME */ + + if (!timerid || clockid != CLOCK_REALTIME) + { + errno = EINVAL; + return ERROR; + } + + /* Allocate a watchdog to provide the underling CLOCK_REALTIME timer */ + + wdog = wd_create(); + if (!wdog) + { + errno = EAGAIN; + return ERROR; + } + + /* Allocate a timer instance to contain the watchdog */ + + ret = timer_allocate(); + if (!ret) + { + errno = EAGAIN; + return ERROR; + } + + /* Initialize the timer instance */ + + ret->pt_crefs = 1; + ret->pt_owner = getpid(); + ret->pt_delay = 0; + ret->pt_wdog = wdog; + + if (evp) + { + ret->pt_signo = evp->sigev_signo; +#ifdef CONFIG_CAN_PASS_STRUCTS + ret->pt_value = evp->sigev_value; +#else + ret->pt_value.sival_ptr = evp->sigev_value.sival_ptr; +#endif + } + else + { + ret->pt_signo = SIGALRM; + ret->pt_value.sival_ptr = ret; + } + + /* Return the timer */ + + *timerid = ret; + return OK; +} + +#endif /* CONFIG_DISABLE_POSIX_TIMERS */ |