added proper code to trace garbage collection

lgc.c

@@ -1,5 +1,5 @@
 /*
-** $Id: lgc.c,v 2.74 2010/03/26 20:58:11 roberto Exp roberto $
+** $Id: lgc.c,v 2.75 2010/03/29 17:43:14 roberto Exp roberto $
 ** Garbage Collector
 ** See Copyright Notice in lua.h
 */
@@ -825,10 +825,7 @@ void luaC_runtilstate (lua_State *L, int statesmask) {
 
 
 static void generationalcollection (lua_State *L) {
-static int c = 0;
-static int prev = 0;
   global_State *g = G(L);
-int a = g->totalbytes;
   lua_assert(g->gcstate == GCSpropagate);
   if (g->lastmajormem == 0) {  /* signal for another major collection? */
     luaC_fullgc(L, 0);  /* perform a full regular collection */
@@ -841,9 +838,6 @@ int a = g->totalbytes;
       g->lastmajormem = 0;  /* signal for a major collection */
   }
   g->GCthreshold = (g->totalbytes/100) * g->gcpause;
-/*printf("count: %d  old: %d  new: %d  dif: %d  lim: %d  threshold: %d\n",
-c++, a, g->totalbytes, g->totalbytes - prev, g->lastmajormem, g->GCthreshold);*/
-prev = g->totalbytes;
 }
 
 

lmem.c

@@ -1,5 +1,5 @@
 /*
-** $Id: lmem.c,v 1.73 2006/09/14 18:42:28 roberto Exp roberto $
+** $Id: lmem.c,v 1.74 2009/12/16 16:42:58 roberto Exp roberto $
 ** Interface to Memory Manager
 ** See Copyright Notice in lua.h
 */
@@ -94,6 +94,28 @@ void *luaM_realloc_ (lua_State *L, void *block, size_t osize, size_t nsize) {
   }
   lua_assert((nsize == 0) == (newblock == NULL));
   g->totalbytes = (g->totalbytes - realosize) + nsize;
+#if defined(TRACEMEM)
+  { /* auxiliar patch to monitor garbage collection.
+    ** To plot, gnuplot with following command:
+    ** plot TRACEMEM using 1:2 with lines, TRACEMEM using 1:3 with lines
+    */
+    static unsigned long total = 0;  /* our "time" */
+    static lu_mem last = 0;  /* last totalmem that generated an output */
+    static FILE *f = NULL;  /* output file */
+    if (nsize <= osize) total += 1;  /* "time" always grow */
+    else total += (nsize - osize);
+    if ((int)g->totalbytes - (int)last > 1000 ||
+        (int)g->totalbytes - (int)last < -1000) {
+      last = g->totalbytes;
+      if (f == NULL) f = fopen(TRACEMEM, "w");
+      fprintf(f, "%lu %u %u %d\n", total,
+              g->totalbytes,
+              g->GCthreshold < MAX_LUMEM ? g->GCthreshold : 0,
+              g->gcstate);
+    }
+  }
+#endif
+
   return newblock;
 }