From 03f02a76c6e1b5786c8afa4e95d8d72e2a91a915 Mon Sep 17 00:00:00 2001
From: root <root>
Date: Wed, 9 Apr 2008 22:07:50 +0000
Subject: *** empty log message ***

---
 Changes |  7 +++++--
 ev.c    | 19 +++++++++++++++++--
 ev.pod  | 15 +++++++++------
 3 files changed, 31 insertions(+), 10 deletions(-)

diff --git a/Changes b/Changes
index eb03147..7ae2943 100644
--- a/Changes
+++ b/Changes
@@ -1,5 +1,7 @@
 Revision history for libev, a high-performance and full-featured event loop.
 
+        - event_base_loopexit should return 0 on success
+          (W.C.A. Wijngaards).
 	- added linux eventfd support.
         - try to autodetect epoll and inotify support
           by libc header version if not using autoconf.
@@ -7,8 +9,9 @@ Revision history for libev, a high-performance and full-featured event loop.
         - declare functions defined in ev.h as inline if
           C99 or gcc are available.
         - enable inlining with gcc versions 2 and 3.
-        - event_base_loopexit should return 0 on success
-          (W.C.A. Wijngaards).
+        - work around a bug in realloc on openbsd and darwin,
+          also makes the errornous valgrind complaints
+          go away (noted by various people).
 
 3.2  Wed Apr  2 17:11:19 CEST 2008
 	- fix a 64 bit overflow issue in the select backend,
diff --git a/ev.c b/ev.c
index 68adb7e..51a070e 100644
--- a/ev.c
+++ b/ev.c
@@ -362,7 +362,22 @@ syserr (const char *msg)
     }
 }
 
-static void *(*alloc)(void *ptr, long size);
+static void *
+ev_realloc_emul (void *ptr, long size)
+{
+  /* some systems, notably openbsd and darwin, fail to properly
+   * implement realloc (x, 0) (as required by both ansi c-98 and
+   * the single unix specification, so work around them here.
+   */
+
+  if (size)
+    return realloc (ptr, size);
+
+  free (ptr);
+  return 0;
+}
+
+static void *(*alloc)(void *ptr, long size) = ev_realloc_emul;
 
 void
 ev_set_allocator (void *(*cb)(void *ptr, long size))
@@ -373,7 +388,7 @@ ev_set_allocator (void *(*cb)(void *ptr, long size))
 inline_speed void *
 ev_realloc (void *ptr, long size)
 {
-  ptr = alloc ? alloc (ptr, size) : realloc (ptr, size);
+  ptr = alloc (ptr, size);
 
   if (!ptr && size)
     {
diff --git a/ev.pod b/ev.pod
index fb837c0..2d60895 100644
--- a/ev.pod
+++ b/ev.pod
@@ -198,18 +198,21 @@ See the description of C<ev_embed> watchers for more info.
 =item ev_set_allocator (void *(*cb)(void *ptr, long size))
 
 Sets the allocation function to use (the prototype is similar - the
-semantics is identical - to the realloc C function). It is used to
-allocate and free memory (no surprises here). If it returns zero when
-memory needs to be allocated, the library might abort or take some
-potentially destructive action. The default is your system realloc
-function.
+semantics are identical to the C<realloc> C89/SuS/POSIX function). It is
+used to allocate and free memory (no surprises here). If it returns zero
+when memory needs to be allocated (C<size != 0>), the library might abort
+or take some potentially destructive action.
+
+Since some systems (at least OpenBSD and Darwin) fail to implement
+correct C<realloc> semantics, libev will use a wrapper around the system
+C<realloc> and C<free> functions by default.
 
 You could override this function in high-availability programs to, say,
 free some memory if it cannot allocate memory, to use a special allocator,
 or even to sleep a while and retry until some memory is available.
 
 Example: Replace the libev allocator with one that waits a bit and then
-retries).
+retries (example requires a standards-compliant C<realloc>).
 
    static void *
    persistent_realloc (void *ptr, size_t size)
-- 
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