Changeset 1653 for zzufTweet

Timestamp:

Jan 12, 2007, 12:30:29 AM (14 years ago)

Author:

Sam Hocevar

Message:

• Got rid of malloc() for each file opened. Now we only start calling malloc() after the 32th file descriptor.

File:

• zzuf/trunk/src/fd.c (modified) (7 diffs)

zzuf/trunk/src/fd.c

@@ -27 +27 @@
 #include <stdlib.h>
 #include <regex.h>
+#include <string.h>
 
 #include "libzzuf.h"
@@ -35 +36 @@
 static int has_include = 0, has_exclude = 0;
 
-/* File descriptor stuff */
-/* TODO: split this into a static table of around 32 file descriptors, for
- * most common uses, and a dynamic table for optional additional fds. */
+/* File descriptor stuff. When program is launched, we use the static array of
+ * 32 structures, which ought to be enough for most programs. If it happens
+ * not to be the case, ie. if the process opens more than 32 file descriptors
+ * at the same time, a bigger array is malloc()ed and replaces the static one.
+ */
+#define STATIC_FILES 32
 static struct files
 {
@@ -46 +50 @@
     struct fuzz fuzz;
 }
-*files;
-static int *fds;
+*files, static_files[STATIC_FILES];
+static int *fds, static_fds[STATIC_FILES];
 static int maxfd, nfiles;
 
@@ -67 +71 @@
      * calls to malloc() that we do, so we get better chances that memory
      * corruption errors are reproducible */
-    files = malloc(32 * sizeof(*files));
+    files = static_files;
     for(nfiles = 0; nfiles < 32; nfiles++)
         files[nfiles].managed = 0;
 
-    fds = malloc(32 * sizeof(int));
+    fds = static_fds;
     for(maxfd = 0; maxfd < 32; maxfd++)
         fds[maxfd] = -1;
@@ -89 +93 @@
     }
 
-    free(files);
-    free(fds);
+    if(files != static_files)
+       free(files);
+    if(fds != static_fds)
+        free(fds);
 }
 
@@ -119 +125 @@
         return;
 
+    /* If filedescriptor is outside our bounds */
     while(fd >= maxfd)
     {
-        fds = realloc(fds, 2 * maxfd * sizeof(int));
+        if(fds == static_fds)
+        {
+            fds = malloc(2 * maxfd * sizeof(*fds));
+            memcpy(fds, static_fds, maxfd * sizeof(*fds));
+        }
+        else
+            fds = realloc(fds, 2 * maxfd * sizeof(*fds));
         for(i = maxfd; i < maxfd * 2; i++)
             fds[i] = -1;
@@ -136 +149 @@
     {
         nfiles++;
-        files = realloc(files, nfiles * sizeof(struct files));
+        if(files == static_files)
+        {
+            files = malloc(nfiles * sizeof(*files));
+            memcpy(files, static_files, nfiles * sizeof(*files));
+        }
+        else
+            files = realloc(files, nfiles * sizeof(*files));
     }