libCom/osi: add epicsSpin with default, posix, and vxWorks implementations

- posix uses pthread_spin_ interface when supported, pthread_mutex_ otherwise
- default uses epicsMutex
- vxWorks (single core) uses intLock()

src/libCom/osi/Makefile

@@ -20,6 +20,7 @@ INC += osdInterrupt.h
 
 INC += epicsMutex.h
 INC += osdMutex.h
+INC += epicsSpin.h
 INC += epicsEvent.h
 INC += osdEvent.h
 INC += epicsMath.h
@@ -107,6 +108,7 @@ Com_SRCS += osdThread.c
 Com_SRCS += osdThreadExtra.c
 Com_SRCS += osdThreadHooks.c
 Com_SRCS += osdMutex.c
+Com_SRCS += osdSpin.c
 Com_SRCS += osdEvent.c
 Com_SRCS += osdTime.cpp
 Com_SRCS += osdProcess.c

src/libCom/osi/epicsSpin.h

@@ -0,0 +1,31 @@
+/*************************************************************************\
+* Copyright (c) 2012 Helmholtz-Zentrum Berlin
+*     fuer Materialien und Energie GmbH.
+* Copyright (c) 2012 ITER Organization.
+* EPICS BASE is distributed subject to a Software License Agreement found
+* in file LICENSE that is included with this distribution.
+\*************************************************************************/
+
+#ifndef epicsSpinh
+#define epicsSpinh
+
+#include "shareLib.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct epicsSpin *epicsSpinId;
+
+epicsShareFunc epicsSpinId epicsSpinCreate();
+epicsShareFunc void epicsSpinDestroy(epicsSpinId);
+
+epicsShareFunc void epicsSpinLock(epicsSpinId);
+epicsShareFunc int epicsSpinTryLock(epicsSpinId);
+epicsShareFunc void epicsSpinUnlock(epicsSpinId);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* epicsSpinh */

src/libCom/osi/os/default/osdSpin.c

@@ -0,0 +1,71 @@
+/*************************************************************************\
+* Copyright (c) 2012 Helmholtz-Zentrum Berlin
+*     fuer Materialien und Energie GmbH.
+* Copyright (c) 2012 ITER Organization.
+* EPICS BASE is distributed subject to a Software License Agreement found
+* in file LICENSE that is included with this distribution.
+\*************************************************************************/
+
+/*
+ * Author:  Ralph Lange <Ralph.Lange@gmx.de>
+ */
+
+#include "errlog.h"
+#include "epicsMutex.h"
+#include "epicsSpin.h"
+
+/*
+ *  Default: EPICS MUTEX IMPLEMENTATION
+ */
+
+typedef struct epicsSpin {
+    epicsMutexId lock;
+} epicsSpin;
+
+epicsSpinId epicsSpinCreate() {
+    epicsSpin *spin;
+
+    spin = calloc(1, sizeof(*spin));
+    if (!spin)
+        goto fail;
+
+    spin->lock = epicsMutexCreate();
+    if (!spin->lock)
+        goto fail;
+
+    return spin;
+
+fail:
+    free(spin);
+    return NULL;
+}
+
+void epicsSpinDestroy(epicsSpinId spin) {
+    epicsMutexDestroy(spin->lock);
+    free(spin);
+}
+
+void epicsSpinLock(epicsSpinId spin) {
+    epicsMutexLockStatus status;
+
+    status = epicsMutexLock(spin->lock);
+    if (status != epicsMutexLockOK) {
+        errlogPrintf("epicsSpin epicsMutexLock failed: error %s\n",
+                     status == epicsMutexLockTimeout ? "epicsMutexLockTimeout" : "epicsMutexLockError");
+    }
+}
+
+int epicsSpinTryLock(epicsSpinId spin) {
+    epicsMutexLockStatus status;
+
+    status = epicsMutexTryLock(spin->lock);
+    if (status == epicsMutexLockOK) return 0;
+    if (status == epicsMutexLockTimeout) return 1;
+
+    errlogPrintf("epicsSpin epicsMutexTryLock failed: error epicsMutexLockError\n");
+    return 2;
+}
+
+void epicsSpinUnlock(epicsSpinId spin) {
+    epicsMutexUnlock(spin->lock);
+}

src/libCom/osi/os/posix/osdSpin.c

@@ -0,0 +1,154 @@
+/*************************************************************************\
+* Copyright (c) 2012 Helmholtz-Zentrum Berlin
+*     fuer Materialien und Energie GmbH.
+* Copyright (c) 2012 ITER Organization.
+* EPICS BASE is distributed subject to a Software License Agreement found
+* in file LICENSE that is included with this distribution.
+\*************************************************************************/
+
+/*
+ * Author:  Ralph Lange <Ralph.Lange@gmx.de>
+ */
+
+#include <unistd.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <pthread.h>
+
+#include "errlog.h"
+#include "epicsSpin.h"
+
+#define checkStatus(status,message) \
+    if ((status)) { \
+        errlogPrintf("epicsSpin %s failed: error %s\n", \
+            (message), strerror((status))); \
+    }
+
+#if defined(_POSIX_SPIN_LOCKS) && (_POSIX_SPIN_LOCKS > 1)
+
+/*
+ *  POSIX SPIN LOCKS IMPLEMENTATION
+ */
+
+typedef struct epicsSpin {
+    pthread_spinlock_t lock;
+} epicsSpin;
+
+epicsSpinId epicsSpinCreate() {
+    epicsSpin *spin;
+    int status;
+
+    spin = calloc(1, sizeof(*spin));
+    if (!spin)
+        goto fail;
+
+    status = pthread_spin_init(&spin->lock, PTHREAD_PROCESS_PRIVATE);
+    checkStatus(status, "pthread_spin_init");
+    if (status)
+        goto fail;
+
+    return spin;
+
+fail:
+    free(spin);
+    return NULL;
+}
+
+void epicsSpinDestroy(epicsSpinId spin) {
+    int status;
+
+    status = pthread_spin_destroy(&spin->lock);
+    checkStatus(status, "pthread_spin_destroy");
+
+    free(spin);
+}
+
+void epicsSpinLock(epicsSpinId spin) {
+    int status;
+
+    status = pthread_spin_lock(&spin->lock);
+    checkStatus(status, "pthread_spin_lock");
+}
+
+int epicsSpinTryLock(epicsSpinId spin) {
+    int status;
+
+    status = pthread_spin_trylock(&spin->lock);
+    if (status == EBUSY)
+        return 1;
+    checkStatus(status, "pthread_spin_trylock");
+    return 0;
+}
+
+void epicsSpinUnlock(epicsSpinId spin) {
+    int status;
+
+    status = pthread_spin_unlock(&spin->lock);
+    checkStatus(status, "pthread_spin_unlock");
+}
+
+#else /* defined(_POSIX_SPIN_LOCKS) && (_POSIX_SPIN_LOCKS > 1) */
+
+/*
+ *  POSIX MUTEX IMPLEMENTATION
+ */
+
+typedef struct epicsSpin {
+    pthread_mutex_t lock;
+} epicsSpin;
+
+epicsSpinId epicsSpinCreate() {
+    epicsSpin *spin;
+    int status;
+
+    spin = calloc(1, sizeof(*spin));
+    if (!spin)
+        goto fail;
+
+    status = pthread_mutex_init(&spin->lock, NULL);
+    checkStatus(status, "pthread_mutex_init");
+    if (status)
+        goto fail;
+
+    return spin;
+
+fail:
+    free(spin);
+    return NULL;
+}
+
+void epicsSpinDestroy(epicsSpinId spin) {
+    int status;
+
+    status = pthread_mutex_destroy(&spin->lock);
+    checkStatus(status, "pthread_mutex_destroy");
+
+    free(spin);
+}
+
+void epicsSpinLock(epicsSpinId spin) {
+    int status;
+
+    status = pthread_mutex_lock(&spin->lock);
+    checkStatus(status, "pthread_mutex_lock");
+}
+
+int epicsSpinTryLock(epicsSpinId spin) {
+    int status;
+
+    status = pthread_mutex_trylock(&spin->lock);
+    if (status == EBUSY)
+        return 1;
+    checkStatus(status, "pthread_mutex_trylock");
+    return 0;
+}
+
+void epicsSpinUnlock(epicsSpinId spin) {
+    int status;
+
+    status = pthread_mutex_unlock(&spin->lock);
+    checkStatus(status, "pthread_mutex_unlock");
+}
+
+#endif /* defined(_POSIX_SPIN_LOCKS) && (_POSIX_SPIN_LOCKS > 1) */

src/libCom/osi/os/vxWorks/osdSpin.c

@@ -0,0 +1,52 @@
+/*************************************************************************\
+* Copyright (c) 2012 Helmholtz-Zentrum Berlin
+*     fuer Materialien und Energie GmbH.
+* Copyright (c) 2012 ITER Organization.
+* EPICS BASE is distributed subject to a Software License Agreement found
+* in file LICENSE that is included with this distribution.
+\*************************************************************************/
+
+/*
+ * Author:  Ralph Lange <Ralph.Lange@gmx.de>
+ *
+ * based on epicsInterrupt.c (vxWorks implementation) by Marty Kraimer
+ */
+
+/*
+ * vxWorks (single CPU): LOCK INTERRUPT
+ *
+ * CAVEAT:
+ * This implementation will break on vxWorks SMP architectures.
+ * These architectures provide spinlocks, which will have to be used.
+ *
+ */
+
+#include <vxWorks.h>
+#include <intLib.h>
+
+#include "epicsSpin.h"
+
+typedef struct epicsSpin {
+    int key;
+} epicsSpin;
+
+epicsSpinId epicsSpinCreate() {
+    return calloc(1, sizeof(*spin));
+}
+
+void epicsSpinDestroy(epicsSpinId spin) {
+    free(spin);
+}
+
+void epicsSpinLock(epicsSpinId spin) {
+    spin->key = intLock();
+}
+
+int epicsSpinTryLock(epicsSpinId spin) {
+    epicsSpinLock(spin);
+    return 0;
+}
+
+void epicsSpinUnlock(epicsSpinId spin) {
+    intUnlock(spin->key);
+}