Remove errlogBufResize in favour of allowing errlogInit[2] to be called repeatedly

modules/libcom/src/error/errlog.c

@@ -556,9 +556,37 @@ struct initArgs {
     size_t maxMsgSize;
 };
 
+static
+int errlogClampConfig(struct initArgs *config)
+{
+    int clamped = 0;
+
+    if (config->bufsize < MIN_BUFFER_SIZE)
+    {
+        clamped = 1;
+        config->bufsize = MIN_BUFFER_SIZE;
+    }
+
+    if (config->maxMsgSize > MAX_MESSAGE_SIZE(config->bufsize))
+    {
+        clamped = 1;
+        config->maxMsgSize = MAX_MESSAGE_SIZE(config->bufsize);
+    }
+    if (config->maxMsgSize < MIN_MESSAGE_SIZE)
+    {
+        clamped = 1;
+        config->maxMsgSize = MIN_MESSAGE_SIZE;
+    }
+
+    return clamped;
+}
+
 static void errlogInitPvt(void *arg)
 {
     struct initArgs *pconfig = (struct initArgs *) arg;
+
+    errlogClampConfig(pconfig);
+
     epicsThreadId tid = NULL;
     epicsThreadOpts topts = EPICS_THREAD_OPTS_INIT;
 
@@ -611,81 +639,33 @@ static void errlogInitPvt(void *arg)
     }
 }
 
+// This function must be called with pvt.bufSizeLock held
 static
-int errlogClampConfig(struct initArgs *config, int bufsize, int maxMsgSize)
+void errlogBufResize(struct initArgs config)
 {
-    int clamped = 0;
-
-    if (bufsize < MIN_BUFFER_SIZE)
-    {
-        // This is to deal with the fact that errlogInit() is often called with arg 0
-        clamped = bufsize == 0 ? 0 : 1;
-        bufsize = MIN_BUFFER_SIZE;
+    if (config.bufsize < pvt.bufSize) {
+        fprintf(stderr, "Warning: Cannot shrink buffer size.\n");
+        return;
     }
-    config->bufsize = bufsize;
 
-    if (maxMsgSize > MAX_MESSAGE_SIZE(bufsize))
-    {
-        clamped = 1;
-        maxMsgSize = MAX_MESSAGE_SIZE(bufsize);
-    }
-    if (maxMsgSize < MIN_MESSAGE_SIZE)
-    {
-        clamped = 1;
-        maxMsgSize = MIN_MESSAGE_SIZE;
-    }
-    config->maxMsgSize = maxMsgSize;
-
-    return clamped;
-}
-
-int errlogInit2(int bufsize, int maxMsgSize)
-{
-    static epicsThreadOnceId errlogOnceFlag = EPICS_THREAD_ONCE_INIT;
-    struct initArgs config;
-
-    if (pvt.atExit)
-        return 0;
-
-    if (errlogClampConfig(&config, bufsize, maxMsgSize)) {
+    size_t bufsize = config.bufsize;
+    size_t maxMsgSize = config.maxMsgSize;
+    if (errlogClampConfig(&config)) {
         fprintf(stderr, "Warning: errlog config clamped from (%zu, %zu) to (%zu, %zu)\n", bufsize, maxMsgSize, config.bufsize, config.maxMsgSize);
     }
 
-    epicsThreadOnce(&errlogOnceFlag, errlogInitPvt, &config);
-    if (pvt.errlogInitFailed) {
-        fprintf(stderr,"errlogInit failed\n");
-        exit(1);
+    char *logbuf = calloc(1, config.bufsize);
+    if (!logbuf) {
+        fprintf(stderr, ERL_ERROR ": Failed to allocated errlog log buffer.\n");
+        return;
     }
-    return 0;
-}
-
-int errlogInit(int bufsize)
-{
-    return errlogInit2(bufsize, DEFAULT_MAX_MSG_SIZE);
-}
-
-int errlogBufResize(int bufsize, int maxMsgSize)
-{
-    char* logbuf = NULL;
-    char* printbuf = NULL;
-    struct initArgs config;
-
-    epicsMutexMustLock(pvt.bufSizeLock);
-
-    // Only increasing the buffer size is allowed!
-    if (bufsize < pvt.bufSize) {
-        epicsMutexUnlock(pvt.bufSizeLock);
-        fprintf(stderr, "Shrinking the errorlog buffer is not allowed.\n");
-        return -1;
+    char *printbuf = calloc(1, config.bufsize);
+    if (!printbuf) {
+        free(logbuf);
+        fprintf(stderr, ERL_ERROR ": Failed to allocated errlog print buffer.\n");
+        return;
     }
 
-    if (errlogClampConfig(&config, bufsize, maxMsgSize)) {
-        fprintf(stderr, "Warning: errlog config clamped from (%zu, %zu) to (%zu, %zu)\n", bufsize, maxMsgSize, config.bufsize, config.maxMsgSize);
-    }
-
-    logbuf = calloc(1, config.bufsize);
-    printbuf = calloc(1, config.bufsize);
-
     epicsMutexMustLock(pvt.msgQueueLock);
 
     memcpy(logbuf, pvt.log->base, pvt.bufSize);
@@ -700,7 +680,37 @@ int errlogBufResize(int bufsize, int maxMsgSize)
     pvt.maxMsgSize = config.maxMsgSize;
 
     epicsMutexUnlock(pvt.msgQueueLock);
+}
+
+int errlogInit2(int bufsize, int maxMsgSize)
+{
+    static epicsThreadOnceId errlogOnceFlag = EPICS_THREAD_ONCE_INIT;
+    struct initArgs config = {bufsize, maxMsgSize};
+
+    if (pvt.atExit)
+        return 0;
+
+    epicsThreadOnce(&errlogOnceFlag, errlogInitPvt, &config);
+    if (pvt.errlogInitFailed) {
+        fprintf(stderr,"errlogInit failed\n");
+        exit(1);
+    }
+
+    // Don't resize the buffer for any of the calls to errlogInit(0)
+    if (bufsize == 0) return 0;
+
+    epicsMutexMustLock(pvt.bufSizeLock);
+    if (pvt.bufSize != config.bufsize || pvt.maxMsgSize != config.maxMsgSize) {
+        // We are resizing the buffer after initialisation
+        errlogBufResize(config);
+    }
     epicsMutexUnlock(pvt.bufSizeLock);
+    return 0;
+}
+
+int errlogInit(int bufsize)
+{
+    return errlogInit2(bufsize, DEFAULT_MAX_MSG_SIZE);
 }
 
 void errlogShow(int level)

modules/libcom/src/error/errlog.h

@@ -224,15 +224,6 @@ LIBCOM_API int errlogInit(int bufsize);
  */
 LIBCOM_API int errlogInit2(int bufsize, int maxMsgSize);
 
-/**
- * errlogBufResize can be used to reinitialize the error logging system with a larger buffer and maximum message size.
- * The default buffer size is 1280 bytes, and the default maximum message size is 256.
- *
- * \param bufsize The desired buffer size
- * \param maxMsgSize The desired max message size
- */
-LIBCOM_API int errlogBufResize(int bufsize, int maxMsgSize);
-
 /** Wakes up the errlog task and then waits until all messages are flushed from the queue. */
 LIBCOM_API void errlogFlush(void);
 

modules/libcom/src/iocsh/libComRegister.c

@@ -291,22 +291,6 @@ static void errlogInit2CallFunc(const iocshArgBuf *args)
     errlogInit2(args[0].ival, args[1].ival);
 }
 
-/* errlogBufResize */
-static const iocshArg errlogBufResizeArg0 = { "bufSize",iocshArgInt};
-static const iocshArg errlogBufResizeArg1 = { "maxMsgSize",iocshArgInt};
-static const iocshArg * const errlogBufResizeArgs[] =
-    {&errlogBufResizeArg0, &errlogBufResizeArg1};
-static const iocshFuncDef errlogBufResizeFuncDef = {
-    "errlogBufResize", 2, errlogBufResizeArgs,
-    "Reinitialize error log client buffer size and maximum message size\n"
-    "  bufSize    - size of circular buffer       (default = 1280 bytes)\n"
-    "  maxMsgSize - maximum size of error message (default =  256 bytes)\n"
-};
-static void errlogBufResizeCallFunc(const iocshArgBuf *args)
-{
-    iocshSetError(errlogBufResize(args[0].ival, args[1].ival));
-}
-
 /* errlogShow */
 static const iocshArg errlogShowArg0 = { "level",iocshArgInt};
 static const iocshArg * const errlogShowArgs[1] = {&errlogShowArg0};
@@ -536,7 +520,6 @@ void epicsStdCall libComRegister(void)
     iocshRegister(&eltcFuncDef, eltcCallFunc);
     iocshRegister(&errlogInitFuncDef,errlogInitCallFunc);
     iocshRegister(&errlogInit2FuncDef,errlogInit2CallFunc);
-    iocshRegister(&errlogBufResizeFuncDef,errlogBufResizeCallFunc);
     iocshRegister(&errlogShowFuncDef,errlogShowCallFunc);
     iocshRegister(&errlogFuncDef, errlogCallFunc);
     iocshRegister(&iocLogPrefixFuncDef, iocLogPrefixCallFunc);