osdEvent.c File Reference

#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <pthread.h>
#include "epicsEvent.h"
#include "epicsTime.h"
#include "errlog.h"

Include dependency graph for osdEvent.c:

Go to the source code of this file.

Classes
struct	epicsEventOSD

Macros
#define	printStatus(status, routine, func)   errlogPrintf("%s: %s failed: %s\n", (func), (routine), strerror(status))
#define	checkStatus(status, routine, func)
#define	checkStatusReturn(status, routine, func)

Functions
LIBCOM_API epicsEventId	epicsEventCreate (epicsEventInitialState init)
	Create an epicsEvent for use from C code, or return NULL. More...
LIBCOM_API void	epicsEventDestroy (epicsEventId pevent)
	Destroy an epicsEvent and any resources it holds. More...
LIBCOM_API epicsEventStatus	epicsEventTrigger (epicsEventId pevent)
	Trigger an event i.e. ensures the next or current call to wait completes. More...
LIBCOM_API epicsEventStatus	epicsEventWait (epicsEventId pevent)
	Wait for an event. More...
LIBCOM_API epicsEventStatus	epicsEventWaitWithTimeout (epicsEventId pevent, double timeout)
	Wait an the event or until the specified timeout period is over. More...
LIBCOM_API epicsEventStatus	epicsEventTryWait (epicsEventId id)
	Similar to wait() except that if the event is currenly empty the call will return immediately with status epicsEventWaitTimeout. More...
LIBCOM_API void	epicsEventShow (epicsEventId pevent, unsigned int level)
	Display information about the semaphore. More...

Macro Definition Documentation

#define checkStatus	(		status,
			routine,
			func
	)

Value:

if (status) { \
        printStatus(status, routine, func); \
    }

Definition at line 35 of file osdEvent.c.

#define checkStatusReturn	(		status,
			routine,
			func
	)

Value:

if (status) { \
        printStatus(status, routine, func); \
        return epicsEventError; \
    }

Definition at line 40 of file osdEvent.c.

#define printStatus	(		status,
			routine,
			func
	)		errlogPrintf("%s: %s failed: %s\n", (func), (routine), strerror(status))

Definition at line 32 of file osdEvent.c.

Function Documentation

LIBCOM_API epicsEventId epicsEventCreate

(

epicsEventInitialState

initialState

)

Create an epicsEvent for use from C code, or return NULL.

Parameters

initialState

Starting state, epicsEventEmpty or epicsEventFull.

Returns

An identifier for the new event, or NULL if one not be created.

Definition at line 47 of file osdEvent.c.

{
    epicsEventId pevent = malloc(sizeof(*pevent));

    if (pevent) {
        int status = pthread_mutex_init(&pevent->mutex, 0);

        pevent->isFull = (init == epicsEventFull);
        if (status) {
            printStatus(status, "pthread_mutex_init", "epicsEventCreate");
        } else {
            status = pthread_cond_init(&pevent->cond, 0);
            if (!status)
                return pevent;
            printStatus(status, "pthread_cond_init", "epicsEventCreate");
            status = pthread_mutex_destroy(&pevent->mutex);
            checkStatus(status, "pthread_mutex_destroy", "epicsEventCreate");
        }
        free(pevent);
    }
    return NULL;
}

LIBCOM_API void epicsEventDestroy

(

epicsEventId

id

)

Destroy an epicsEvent and any resources it holds.

No calls to any epicsEventWait routines can be active when this call is made.

Parameters

id	The event identifier.

Definition at line 70 of file osdEvent.c.

{
    int status = pthread_mutex_destroy(&pevent->mutex);

    checkStatus(status, "pthread_mutex_destroy", "epicsEventDestroy");
    status = pthread_cond_destroy(&pevent->cond);
    checkStatus(status, "pthread_cond_destroy", "epicsEventDestroy");
    free(pevent);
}

LIBCOM_API void epicsEventShow	(	epicsEventId	id,
		unsigned int	level
	)

Display information about the semaphore.

Note

The information displayed is architecture dependant.

Parameters

id	The event identifier.
level	An unsigned int for the level of information to be displayed.

Definition at line 150 of file osdEvent.c.

{
    printf("epicsEvent %p: %s\n", pevent,
        pevent->isFull ? "full" : "empty");
    if (level > 0)
        printf("    pthread_mutex = %p, pthread_cond = %p\n",
            &pevent->mutex, &pevent->cond);
}

LIBCOM_API epicsEventStatus epicsEventTrigger

(

epicsEventId

id

)

Trigger an event i.e. ensures the next or current call to wait completes.

Note

This method may be called from a VxWorks or RTEMS interrupt handler.

Parameters

id	The event identifier.

Returns

Status indicator.

Definition at line 80 of file osdEvent.c.

{
    int status = pthread_mutex_lock(&pevent->mutex);

    checkStatusReturn(status, "pthread_mutex_lock", "epicsEventTrigger");
    if (!pevent->isFull) {
        pevent->isFull = 1;
        status = pthread_cond_signal(&pevent->cond);
        checkStatus(status, "pthread_cond_signal", "epicsEventTrigger");
    }
    status = pthread_mutex_unlock(&pevent->mutex);
    checkStatusReturn(status, "pthread_mutex_unlock", "epicsEventTrigger");
    return epicsEventOK;
}

LIBCOM_API epicsEventStatus epicsEventTryWait

(

epicsEventId

id

)

Similar to wait() except that if the event is currenly empty the call will return immediately with status epicsEventWaitTimeout.

Parameters

id	The event identifier.

Returns

Status indicator, epicsEventWaitTimeout when the event is empty.

Definition at line 145 of file osdEvent.c.

{
    return epicsEventWaitWithTimeout(id, 0.0);
}

LIBCOM_API epicsEventStatus epicsEventWait

(

epicsEventId

id

)

Wait for an event.

Note

Blocks until full.

Parameters

id	The event identifier.

Returns

Status indicator.

Definition at line 95 of file osdEvent.c.

{
    epicsEventStatus result = epicsEventOK;
    int status = pthread_mutex_lock(&pevent->mutex);

    checkStatusReturn(status, "pthread_mutex_lock", "epicsEventWait");
    while (!pevent->isFull) {
        status = pthread_cond_wait(&pevent->cond, &pevent->mutex);
        if (status) {
            printStatus(status, "pthread_cond_wait", "epicsEventWait");
            result = epicsEventError;
            goto release;
        }
    }
    pevent->isFull = 0;
    result = epicsEventOK;
release:
    status = pthread_mutex_unlock(&pevent->mutex);
    checkStatusReturn(status, "pthread_mutex_unlock", "epicsEventWait");
    return result;
}

LIBCOM_API epicsEventStatus epicsEventWaitWithTimeout	(	epicsEventId	id,
		double	timeOut
	)

Wait an the event or until the specified timeout period is over.

Note

Blocks until full or timeout.

Parameters

id	The event identifier.
timeOut	The timeout delay in seconds.

Returns

Status indicator.

Definition at line 117 of file osdEvent.c.

{
    epicsEventStatus result = epicsEventOK;
    int status = pthread_mutex_lock(&pevent->mutex);

    checkStatusReturn(status, "pthread_mutex_lock", "epicsEventWaitWithTimeout");
    if (!pevent->isFull) {
        struct timespec wakeTime;

        convertDoubleToWakeTime(timeout, &wakeTime);
        while (!status && !pevent->isFull) {
            status = pthread_cond_timedwait(&pevent->cond, &pevent->mutex,
                &wakeTime);
        }
        if (status) {
            result = (status == ETIMEDOUT) ?
                epicsEventWaitTimeout : epicsEventError;
            goto release;
        }
    }
    pevent->isFull = 0;
release:
    status = pthread_mutex_unlock(&pevent->mutex);
    checkStatusReturn(status, "pthread_mutex_unlock", "epicsEventWaitWithTimeout");
    return result;
}