From 12a9a6e512e0f5b3f6ec574bd84f045aa973897c Mon Sep 17 00:00:00 2001
From: mdw <mdw>
Date: Sun, 21 Nov 1999 22:14:19 +0000
Subject: [PATCH] Fix bug.  Improve diagnostic capabilities.

---
 mparena.c | 94 ++++++++++++++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 81 insertions(+), 13 deletions(-)

diff --git a/mparena.c b/mparena.c
index 4e02454..e40a6a6 100644
--- a/mparena.c
+++ b/mparena.c
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: mparena.c,v 1.1 1999/11/17 18:02:16 mdw Exp $
+ * $Id: mparena.c,v 1.2 1999/11/21 22:14:19 mdw Exp $
  *
  * Allocation and freeing of MP buffers
  *
@@ -30,6 +30,9 @@
 /*----- Revision history --------------------------------------------------* 
  *
  * $Log: mparena.c,v $
+ * Revision 1.2  1999/11/21 22:14:19  mdw
+ * Fix bug.  Improve diagnostic capabilities.
+ *
  * Revision 1.1  1999/11/17 18:02:16  mdw
  * New multiprecision integer arithmetic suite.
  *
@@ -46,6 +49,12 @@
 
 #include "mparena.h"
 
+/*----- Tweakables --------------------------------------------------------*/
+
+/* #define MPARENA_TRIVIAL */
+
+/* #define MPARENA_DEBUG "mparena.out" */
+
 /*----- Default allocator -------------------------------------------------*/
 
 static void *defalloc(mparena *a, size_t sz) { return xmalloc(sz); }
@@ -55,6 +64,20 @@ mparena_ops mparena_defops = { defalloc, deffree };
 
 /*----- Static variables --------------------------------------------------*/
 
+#ifdef MPARENA_DEBUG
+  static FILE *debugfp = 0;
+
+#  define MPARENA_OPENFILE do {						\
+    if (!debugfp) {							\
+      if ((debugfp = fopen(MPARENA_DEBUG, "w")) == 0) {			\
+	fprintf(stderr, "couldn't open debug output file\n");		\
+	exit(EXIT_FAILURE);						\
+      }									\
+    }									\
+  } while (0)
+
+#endif
+
 static mparena arena = { 0, &mparena_defops };
 
 #define MPARENA_RESOLVE(a) do {						\
@@ -73,19 +96,23 @@ static mparena arena = { 0, &mparena_defops };
  * Use:		Recursively dumps out the allocation tree.
  */
 
+#ifdef MPARENA_DEBUG
+
 static void tdump(mparena_node *n)
 {
   if (!n)
-    putchar('*');
+    putc('*', debugfp);
   else {
-    putchar('(');
+    putc('(', debugfp);
     tdump(n->left);
-    printf(", %u, ", n->v[0]);
+    fprintf(debugfp, ", %u, ", n->v[0]);
     tdump(n->right);
-    putchar(')');
+    putc(')', debugfp);
   }
 }
 
+#endif
+
 /* --- @mparena_create@ --- *
  *
  * Arguments:	@mparena *a@ = pointer to arena block
@@ -160,6 +187,16 @@ void mparena_destroy(mparena *a)
  *		digits.
  */
 
+#ifdef MPARENA_TRIVIAL
+
+mpw *mpalloc(mparena *a, size_t sz)
+{
+  MPARENA_RESOLVE(a);
+  return (a->ops->alloc(a, MPWS(sz)));
+}
+
+#else
+
 mpw *mpalloc(mparena *a, size_t sz)
 {
   mparena_node **nn, *n;
@@ -168,9 +205,12 @@ mpw *mpalloc(mparena *a, size_t sz)
   MPARENA_RESOLVE(a);
   nn = &a->root;
 
-#ifdef notdef
-  printf("*** alloc %u\n", sz);
-  tdump(a->root); putchar('\n');
+#ifdef MPARENA_DEBUG
+  MPARENA_OPENFILE;
+  fprintf(debugfp, "alloc %u\n  before: ", sz);
+  tdump(a->root); putc('\n', debugfp);
+  if (sz == 0)
+    asm("nop");
 #endif
 
   /* --- First, find a block which is big enough --- */
@@ -178,6 +218,9 @@ mpw *mpalloc(mparena *a, size_t sz)
 again:
   n = *nn;
   if (!n) {
+#ifdef MPARENA_DEBUG
+    fputs("  failed\n", debugfp);
+#endif
     v = a->ops->alloc(a, MPWS(sz + 1));
     v[0] = sz;
     return (v + 1);
@@ -196,7 +239,7 @@ again:
 
   /* --- If the block we've got is still too large, start digging --- */
 
-  if (n->v[0] >= sz * 2) {
+  if (n->v[0] > sz * 2) {
     nn = &n->left;
     goto again;
   }
@@ -219,12 +262,19 @@ again:
     p->left = left;
   }
 
+#ifdef MPARENA_DEBUG
+  fputs("  after: ", debugfp);
+  tdump(a->root); putc('\n', debugfp);
+#endif
+
   /* --- Get rid of this node now --- */
 
   DESTROY(n);
   return (v + 1);
 }
 
+#endif
+
 /* --- @mpfree@ --- *
  *
  * Arguments:	@mparena *a@ = pointer to arena block
@@ -236,14 +286,30 @@ again:
  *		returned to the arena from which it was allocated.
  */
 
+#ifdef MPARENA_TRIVIAL
+
+void mpfree(mparena *a, mpw *v)
+{
+  MPARENA_RESOLVE(a);
+  a->ops->free(a, v);
+}
+
+#else
+
 void mpfree(mparena *a, mpw *v)
 {
   mparena_node **nn, *n;
   size_t sz = *--v;
 
   MPARENA_RESOLVE(a);
-  nn = &a->root;
 
+#ifdef MPARENA_DEBUG
+  MPARENA_OPENFILE;
+  fprintf(debugfp, "free %u\n  before: ", sz);
+  tdump(a->root); putc('\n', debugfp);
+#endif
+
+  nn = &a->root;
   while (*nn) {
     n = *nn;
     if (n->v[0] > sz)
@@ -257,10 +323,12 @@ void mpfree(mparena *a, mpw *v)
   n->v = v;
   *nn = n;
 
-#ifdef notdef
-  printf("*** free %u\n", sz);
-  tdump(a->root); putchar('\n');
+#ifdef MPARENA_DEBUG
+  fputs("  after: ", debugfp);
+  tdump(a->root); putc('\n', debugfp);
 #endif
 }
 
+#endif
+
 /*----- That's all, folks -------------------------------------------------*/
-- 
2.11.0