From 770d9ab313a5234345e77f7b3c02874b42885ff4 Mon Sep 17 00:00:00 2001
From: Michael Davidsaver <mdavidsaver@bnl.gov>
Date: Mon, 21 Dec 2015 13:44:23 -0500
Subject: [PATCH] freeListLib: instrument with valgrind

---
 src/libCom/freeList/freeListLib.c | 32 ++++++++++++++++++++++++++++---
 1 file changed, 29 insertions(+), 3 deletions(-)

diff --git a/src/libCom/freeList/freeListLib.c b/src/libCom/freeList/freeListLib.c
index 77cd566b1..a0ae73837 100644
--- a/src/libCom/freeList/freeListLib.c
+++ b/src/libCom/freeList/freeListLib.c
@@ -15,6 +15,15 @@
 #include <stdlib.h>
 #include <stddef.h>
 
+#include "valgrind/valgrind.h"
+
+#ifndef NVALGRIND
+/* buffer around allocations to detect out of bounds access */
+#define REDZONE sizeof(double)
+#else
+#define REDZONE 0
+#endif
+
 #define epicsExportSharedSymbols
 #include "cantProceed.h"
 #include "epicsMutex.h"
@@ -47,6 +56,7 @@ epicsShareFunc void epicsShareAPI
     pfl->nBlocksAvailable = 0u;
     pfl->lock = epicsMutexMustCreate();
     *ppvt = (void *)pfl;
+    VALGRIND_CREATE_MEMPOOL(pfl, REDZONE, 0);
     return;
 }
 
@@ -78,7 +88,14 @@ epicsShareFunc void * epicsShareAPI freeListMalloc(void *pvt)
     epicsMutexMustLock(pfl->lock);
     ptemp = pfl->head;
     if(ptemp==0) {
-        ptemp = (void *)malloc(pfl->nmalloc*pfl->size);
+        /* layout of each block. nmalloc+1 REDZONEs for nmallocs.
+         * The first sizeof(void*) bytes are used to store a pointer
+         * to the next free block.
+         *
+         * | RED | size0 ------ | RED | size1 | ... | RED |
+         * |     | next | ----- |
+         */
+        ptemp = (void *)malloc(pfl->nmalloc*(pfl->size+REDZONE)+REDZONE);
         if(ptemp==0) {
             epicsMutexUnlock(pfl->lock);
             return(0);
@@ -89,15 +106,17 @@ epicsShareFunc void * epicsShareAPI freeListMalloc(void *pvt)
             free(ptemp);
             return(0);
         }
-        pallocmem->memory = ptemp;
+        pallocmem->memory = ptemp; /* real allocation */
+        ptemp += REDZONE; /* skip first REDZONE */
         if(pfl->mallochead)
             pallocmem->next = pfl->mallochead;
         pfl->mallochead = pallocmem;
         for(i=0; i<pfl->nmalloc; i++) {
             ppnext = ptemp;
+            VALGRIND_MEMPOOL_ALLOC(pfl, ptemp, sizeof(void*));
             *ppnext = pfl->head;
             pfl->head = ptemp;
-            ptemp = ((char *)ptemp) + pfl->size;
+            ptemp = ((char *)ptemp) + pfl->size+REDZONE;
         }
         ptemp = pfl->head;
         pfl->nBlocksAvailable += pfl->nmalloc;
@@ -106,6 +125,8 @@ epicsShareFunc void * epicsShareAPI freeListMalloc(void *pvt)
     pfl->head = *ppnext;
     pfl->nBlocksAvailable--;
     epicsMutexUnlock(pfl->lock);
+    VALGRIND_MEMPOOL_FREE(pfl, ptemp);
+    VALGRIND_MEMPOOL_ALLOC(pfl, ptemp, pfl->size);
     return(ptemp);
 #   endif
 }
@@ -119,6 +140,9 @@ epicsShareFunc void epicsShareAPI freeListFree(void *pvt,void*pmem)
 #   else
     void	**ppnext;
 
+    VALGRIND_MEMPOOL_FREE(pvt, pmem);
+    VALGRIND_MEMPOOL_ALLOC(pvt, pmem, sizeof(void*));
+
     epicsMutexMustLock(pfl->lock);
     ppnext = pmem;
     *ppnext = pfl->head;
@@ -134,6 +158,8 @@ epicsShareFunc void epicsShareAPI freeListCleanup(void *pvt)
     allocMem	*phead;
     allocMem	*pnext;
 
+    VALGRIND_DESTROY_MEMPOOL(pvt);
+
     phead = pfl->mallochead;
     while(phead) {
         pnext = phead->next;