[Chicken-hackers] [PATCH] C_reclaim cleanups and debug output for m-stack resize

[Felix]

The attached patch adds debug-output when the mutation-stack is
resized (and debug-mode is enabled). The m-stack grows by twice its
current size instead of growing by a fixed rate. Also, some variables
(incorrectly) reported by gcc/valgrind as being uninitialized in
C_reclaim are set to appropriate values. Thanks to Joerg Wittenberger
for his help in locating these warnings.


cheers,
felix

>From 44d6eedc809899b6eb520daf463c7f48697b5d25 Mon Sep 17 00:00:00 2001
From: felix <address@hidden>
Date: Tue, 25 Oct 2011 13:26:28 +0200
Subject: [PATCH] cleaning up uninitialized variables in C_reclaim, add debug 
output to C_mutate on m-stack resize, grow m-stack at higher rate

---
 runtime.c |   25 +++++++++++++++----------
 1 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/runtime.c b/runtime.c
index 05bf39c..5e4f755 100644
--- a/runtime.c
+++ b/runtime.c
@@ -156,7 +156,6 @@ extern void _C_do_apply_hack(void *proc, C_word *args, int 
count) C_noret;
 #define TEMPORARY_STACK_SIZE          2048
 #define STRING_BUFFER_SIZE             4096
 #define DEFAULT_MUTATION_STACK_SIZE    1024
-#define MUTATION_STACK_GROWTH          1024
 
 #define FILE_INFO_SIZE                 7
 
@@ -2605,7 +2604,7 @@ C_word C_h_structure(int n, ...)
 
 C_regparm C_word C_fcall C_mutate(C_word *slot, C_word val)
 {
-  int mssize;
+  unsigned int mssize, newmssize, bytes;
 
   if(!C_immediatep(val)) {
 #ifdef C_GC_HOOKS
@@ -2615,14 +2614,19 @@ C_regparm C_word C_fcall C_mutate(C_word *slot, C_word 
val)
     if(mutation_stack_top >= mutation_stack_limit) {
       assert(mutation_stack_top == mutation_stack_limit);
       mssize = mutation_stack_top - mutation_stack_bottom;
-      mutation_stack_bottom =
-          (C_word **)realloc(mutation_stack_bottom,
-                             (mssize + MUTATION_STACK_GROWTH) * sizeof(C_word 
*));
+      newmssize = mssize * 2;
+      bytes = newmssize * sizeof(C_word *);
+
+      if(debug_mode) 
+       C_dbg(C_text("debug"), C_text("resizing mutation-stack from " 
UWORD_COUNT_FORMAT_STRING "k to " UWORD_COUNT_FORMAT_STRING "k ...\n"), 
+             (mssize * sizeof(C_word *)) / 1024, bytes / 1024);
+
+      mutation_stack_bottom = (C_word **)realloc(mutation_stack_bottom, bytes);
 
       if(mutation_stack_bottom == NULL)
        panic(C_text("out of memory - cannot re-allocate mutation stack"));
 
-      mutation_stack_limit = mutation_stack_bottom + mssize + 
MUTATION_STACK_GROWTH;
+      mutation_stack_limit = mutation_stack_bottom + newmssize;
       mutation_stack_top = mutation_stack_bottom + mssize;
     }
 
@@ -2666,7 +2670,7 @@ static void mark(C_word *x) { \
 
 C_regparm void C_fcall C_reclaim(void *trampoline, void *proc)
 {
-  int i, j, n, fcount, weakn;
+  int i, j, n, fcount, weakn = 0;
   C_uword count, bytes;
   C_word *p, **msp, bucket, last, item, container;
   C_header h;
@@ -2675,7 +2679,7 @@ C_regparm void C_fcall C_reclaim(void *trampoline, void 
*proc)
   C_SCHEME_BLOCK *bp;
   C_GC_ROOT *gcrp;
   WEAK_TABLE_ENTRY *wep;
-  double tgc;
+  double tgc = 0;
   C_SYMBOL_TABLE *stp;
   volatile int finalizers_checked;
   FINALIZER_NODE *flist;
@@ -2694,9 +2698,10 @@ C_regparm void C_fcall C_reclaim(void *trampoline, void 
*proc)
   C_restart_address = proc;
   heap_scan_top = (C_byte *)C_align((C_uword)C_fromspace_top);
   gc_mode = GC_MINOR;
+  start = C_fromspace_top;
 
   /* Entry point for second-level GC (on explicit request or because of full 
fromspace): */
-  if(C_setjmp(gc_restart) || (start = C_fromspace_top) >= C_fromspace_limit) {
+  if(C_setjmp(gc_restart) || start >= C_fromspace_limit) {
     if(gc_bell) {
       C_putchar(7);
       C_fflush(stdout);
@@ -3173,7 +3178,7 @@ C_regparm void C_fcall C_rereclaim2(C_uword size, int 
double_plus)
 
   if(debug_mode) 
     C_dbg(C_text("debug"), C_text("resizing heap dynamically from " 
UWORD_COUNT_FORMAT_STRING "k to " UWORD_COUNT_FORMAT_STRING "k ...\n"), 
-         (C_uword)heap_size / 1000, size / 1000);
+         (C_uword)heap_size / 1024, size / 1024);
 
   if(gc_report_flag) {
     C_dbg(C_text("GC"), C_text("(old) fromspace: \tstart=" UWORD_FORMAT_STRING 
-- 
1.6.0.4