epicsMutex.cpp File Reference

#include <new>
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "epicsStdio.h"
#include "epicsThread.h"
#include "valgrind/valgrind.h"
#include "ellLib.h"
#include "errlog.h"
#include "epicsMutex.h"

Include dependency graph for epicsMutex.cpp:

Go to the source code of this file.

Classes
struct	epicsMutexParm
class	epicsMutex::mutexCreateFailed
class	epicsMutex::invalidMutex

Functions
epicsMutexId epicsStdCall	epicsMutexOsiCreate (const char *pFileName, int lineno)
	Internal API, used by epicsMutexCreate(). More...
epicsMutexId epicsStdCall	epicsMutexOsiMustCreate (const char *pFileName, int lineno)
	Internal API, used by epicsMutexMustCreate(). More...
void epicsStdCall	epicsMutexDestroy (epicsMutexId pmutexNode)
	Destroy an epicsMutex semaphore. More...
void epicsStdCall	epicsMutexUnlock (epicsMutexId pmutexNode)
	Release the semaphore. More...
epicsMutexLockStatus epicsStdCall	epicsMutexLock (epicsMutexId pmutexNode)
	Claim the semaphore, waiting until it's free if currently owned owned by a different thread. More...
epicsMutexLockStatus epicsStdCall	epicsMutexTryLock (epicsMutexId pmutexNode)
	Similar to epicsMutexLock() except that the call returns immediately, with the return status indicating if the semaphore is currently owned by this thread or another thread. More...
void	epicsMutexCleanup (void)
void epicsStdCall	epicsMutexShow (epicsMutexId pmutexNode, unsigned int level)
	Display information about the semaphore. More...
void epicsStdCall	epicsMutexShowAll (int onlyLocked, unsigned int level)
	Display information about all epicsMutex semaphores. More...
void	epicsDeadlockDetectMutexInitFunc (void *)

Function Documentation

void epicsDeadlockDetectMutexInitFunc

(

void *

)

Definition at line 308 of file epicsMutex.cpp.

{
    pCurrentMutexLevel = new epicsThreadPrivate < epicsDeadlockDetectMutex > ();
}

void epicsMutexCleanup

(

void

)

Definition at line 176 of file epicsMutex.cpp.

{
    ELLNODE *cur;
    epicsMutexLockStatus lockStat =
        epicsMutexOsdLock(epicsMutexGlobalLock);
    assert ( lockStat == epicsMutexLockOK );

    while((cur=ellGet(&freeList))!=NULL) {
        VALGRIND_MEMPOOL_FREE(&freeList, cur);
        free(cur);
    }

    epicsMutexOsdUnlock(epicsMutexGlobalLock);
}

void epicsStdCall epicsMutexDestroy

(

epicsMutexId

id

)

Destroy an epicsMutex semaphore.

Parameters

id	The mutex identifier.

Definition at line 127 of file epicsMutex.cpp.

{
    epicsMutexLockStatus lockStat =
        epicsMutexOsdLock(epicsMutexGlobalLock);
    assert ( lockStat == epicsMutexLockOK );
    ellDelete(&mutexList,&pmutexNode->node);
    epicsMutexOsdDestroy(pmutexNode->id);
    VALGRIND_MEMPOOL_FREE(&freeList, pmutexNode);
    VALGRIND_MEMPOOL_ALLOC(&freeList, &pmutexNode->node, sizeof(pmutexNode->node));
    ellAdd(&freeList,&pmutexNode->node);
    epicsMutexOsdUnlock(epicsMutexGlobalLock);
}

epicsMutexLockStatus epicsStdCall epicsMutexLock

(

epicsMutexId

id

)

Claim the semaphore, waiting until it's free if currently owned owned by a different thread.

This call blocks until the calling thread can get exclusive access to the semaphore.

Note

After a successful lock(), additional recursive locks may be issued by the same thread, but each must have an associated unlock().

Parameters

id	The mutex identifier.

Returns

Status indicator.

Definition at line 145 of file epicsMutex.cpp.

{
    epicsMutexLockStatus status =
        epicsMutexOsdLock(pmutexNode->id);
#   ifdef LOG_LAST_OWNER
        if ( status == epicsMutexLockOK ) {
            pmutexNode->lastOwner = epicsThreadGetIdSelf();
        }
#   endif
    return status;
}

epicsMutexId epicsStdCall epicsMutexOsiCreate	(	const char *	pFileName,
		int	lineno
	)

Internal API, used by epicsMutexCreate().

Definition at line 85 of file epicsMutex.cpp.

{
    epicsMutexOSD * id;

    epicsThreadOnce(&epicsMutexOsiOnce, epicsMutexOsiInit, NULL);

    id = epicsMutexOsdCreate();
    if(!id) {
        return 0;
    }
    epicsMutexLockStatus lockStat =
        epicsMutexOsdLock(epicsMutexGlobalLock);
    assert ( lockStat == epicsMutexLockOK );
    epicsMutexParm *pmutexNode =
        reinterpret_cast < epicsMutexParm * > ( ellFirst(&freeList) );
    if(pmutexNode) {
        ellDelete(&freeList,&pmutexNode->node);
        VALGRIND_MEMPOOL_FREE(&freeList, pmutexNode);
    } else {
        pmutexNode = static_cast < epicsMutexParm * > ( calloc(1,sizeof(epicsMutexParm)) );
    }
    VALGRIND_MEMPOOL_ALLOC(&freeList, pmutexNode, sizeof(epicsMutexParm));
    pmutexNode->id = id;
#   ifdef LOG_LAST_OWNER
        pmutexNode->lastOwner = 0;
#   endif
    pmutexNode->pFileName = pFileName;
    pmutexNode->lineno = lineno;
    ellAdd(&mutexList,&pmutexNode->node);
    epicsMutexOsdUnlock(epicsMutexGlobalLock);
    return(pmutexNode);
}

epicsMutexId epicsStdCall epicsMutexOsiMustCreate	(	const char *	pFileName,
		int	lineno
	)

Internal API, used by epicsMutexMustCreate().

Definition at line 119 of file epicsMutex.cpp.

{
    epicsMutexId id = epicsMutexOsiCreate(pFileName,lineno);
    assert(id);
    return(id );
}

void epicsStdCall epicsMutexShow	(	epicsMutexId	id,
		unsigned int	level
	)

Display information about the semaphore.

Note

Results are architecture dependant.

Parameters

id	The mutex identifier.
level	Desired information level to report

Definition at line 191 of file epicsMutex.cpp.

{
#   ifdef LOG_LAST_OWNER
        char threadName [255];
        if ( pmutexNode->lastOwner ) {
#           error currently not safe to fetch name for stale thread
            epicsThreadGetName ( pmutexNode->lastOwner,
                threadName, sizeof ( threadName ) );
        }
        else {
            strcpy ( threadName, "<not used>" );
        }
        printf("epicsMutexId %p last owner \"%s\" source %s line %d\n",
            (void *)pmutexNode, threadName,
            pmutexNode->pFileName, pmutexNode->lineno);
#   else
        printf("epicsMutexId %p source %s line %d\n",
            (void *)pmutexNode, pmutexNode->pFileName,
            pmutexNode->lineno);
#   endif
    if ( level > 0 ) {
        epicsMutexOsdShow(pmutexNode->id,level-1);
    }
}

void epicsStdCall epicsMutexShowAll	(	int	onlyLocked,
		unsigned int	level
	)

Display information about all epicsMutex semaphores.

Note

Results are architecture dependant.

Parameters

onlyLocked	Non-zero to show only locked semaphores.
level	Desired information level to report

Definition at line 217 of file epicsMutex.cpp.

{
    epicsMutexParm *pmutexNode;

    if (epicsMutexOsiOnce == EPICS_THREAD_ONCE_INIT)
        return;

    printf("ellCount(&mutexList) %d ellCount(&freeList) %d\n",
        ellCount(&mutexList),ellCount(&freeList));
    epicsMutexLockStatus lockStat =
        epicsMutexOsdLock(epicsMutexGlobalLock);
    assert ( lockStat == epicsMutexLockOK );
    pmutexNode = reinterpret_cast < epicsMutexParm * > ( ellFirst(&mutexList) );
    while(pmutexNode) {
        if(onlyLocked) {
            epicsMutexLockStatus status;
            status = epicsMutexOsdTryLock(pmutexNode->id);
            if(status==epicsMutexLockOK) {
                epicsMutexOsdUnlock(pmutexNode->id);
                pmutexNode =
                    reinterpret_cast < epicsMutexParm * >
                        ( ellNext(&pmutexNode->node) );
                continue;
            }
        }
        epicsMutexShow(pmutexNode, level);
        pmutexNode =
            reinterpret_cast < epicsMutexParm * > ( ellNext(&pmutexNode->node) );
    }
    epicsMutexOsdUnlock(epicsMutexGlobalLock);
}

epicsMutexLockStatus epicsStdCall epicsMutexTryLock

(

epicsMutexId

id

)

Similar to epicsMutexLock() except that the call returns immediately, with the return status indicating if the semaphore is currently owned by this thread or another thread.

Returns

epicsMutexLockOK if the resource is now owned by the caller.

epicsMutexLockTimeout if some other thread owns the resource.

Definition at line 158 of file epicsMutex.cpp.

{
    epicsMutexLockStatus status =
        epicsMutexOsdTryLock(pmutexNode->id);
#   ifdef LOG_LAST_OWNER
        if ( status == epicsMutexLockOK ) {
            pmutexNode->lastOwner = epicsThreadGetIdSelf();
        }
#   endif
    return status;
}

void epicsStdCall epicsMutexUnlock

(

epicsMutexId

id

)

Release the semaphore.

Parameters

id	The mutex identifier.

Note

If a thread issues recursive locks, it must call epicsMutexUnlock() as many times as it calls epicsMutexLock() or equivalents.

Definition at line 140 of file epicsMutex.cpp.

{
    epicsMutexOsdUnlock(pmutexNode->id);
}