Add commandline utility to resize buffer after being initialised

modules/libcom/src/error/errlog.c

@@ -77,6 +77,7 @@ typedef struct {
 } buffer_t;
 
 static struct {
+    epicsMutexId bufSizeLock;
     /* const after errlogInit() */
     size_t maxMsgSize;
     /* alloc size of both buffer_t::base */
@@ -570,6 +571,7 @@ static void errlogInitPvt(void *arg)
      */
 
     pvt.errlogInitFailed = TRUE;
+    pvt.bufSizeLock = epicsMutexCreate();
     pvt.bufSize = pconfig->bufsize;
     pvt.maxMsgSize = pconfig->maxMsgSize;
     ellInit(&pvt.listenerList);
@@ -594,6 +596,7 @@ static void errlogInitPvt(void *arg)
     errSymBld();    /* Better not to do this lazily... */
 
     if(pvt.waitForWork
+            && pvt.bufSizeLock
             && pvt.listenerLock
             && pvt.msgQueueLock
             && pvt.waitForSeq
@@ -640,6 +643,32 @@ int errlogInit(int bufsize)
     return errlogInit2(bufsize, DEFAULT_MAX_MSG_SIZE);
 }
 
+void errlogBufResize(int bufsize, int maxMsgSize)
+{
+    if (bufsize < MIN_BUFFER_SIZE)
+        bufsize = MIN_BUFFER_SIZE;
+    if (maxMsgSize < MIN_MESSAGE_SIZE)
+        maxMsgSize = MIN_MESSAGE_SIZE;
+    else if (maxMsgSize > MAX_MESSAGE_SIZE)
+        maxMsgSize = MAX_MESSAGE_SIZE;
+
+    errlogFlush();
+
+    epicsMutexMustLock(pvt.bufSizeLock);
+    epicsMutexMustLock(pvt.msgQueueLock);
+
+    pvt.bufSize = bufsize;
+    pvt.maxMsgSize = maxMsgSize;
+
+    free(pvt.log->base);
+    pvt.log->base = callocMustSucceed(1, pvt.bufSize, "Failed to allocate memory for errorlog buffer");
+    free(pvt.print->base);
+    pvt.print->base = callocMustSucceed(1, pvt.bufSize, "Failed to allocate memory for errorlog buffer");
+
+    epicsMutexUnlock(pvt.msgQueueLock);
+    epicsMutexUnlock(pvt.bufSizeLock);
+}
+
 void errlogFlush(void)
 {
     /* wait for both buffers to be handled to know that all currently

modules/libcom/src/error/errlog.h

@@ -224,6 +224,15 @@ 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 void 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);