unchecked_malloc() for Skia on OSX.

base/process_util_mac.mm

Index: base/process_util_mac.mm
diff --git a/base/process_util_mac.mm b/base/process_util_mac.mm
index b257021401726975aa33eb3fc7cc96b140964141..ba5490336cb7a755da234ea334674ad34e154e76 100644
--- a/base/process_util_mac.mm
+++ b/base/process_util_mac.mm
@@ -13,7 +13,6 @@
 #include <mach/mach_vm.h>
 #include <mach/shared_region.h>
 #include <mach/task.h>
-#include <mach-o/dyld.h>
 #include <mach-o/nlist.h>
 #include <malloc/malloc.h>
 #import <objc/runtime.h>
@@ -36,8 +35,6 @@
 #include "base/mac/mac_util.h"
 #include "base/string_util.h"
 #include "base/sys_info.h"
-#include "base/sys_string_conversions.h"
-#include "base/time.h"
 #include "third_party/apple_apsl/CFBase.h"
 #include "third_party/apple_apsl/malloc.h"
 #include "third_party/mach_override/mach_override.h"
@@ -572,11 +569,11 @@ void CrMallocErrorBreak() {
   // Out of memory is certainly not heap corruption, and not necessarily
   // something for which the process should be terminated. Leave that decision
   // to the OOM killer.
-  if (errno == ENOMEM)
+  if (errno == ENOMEM || errno == EBADF)

[Mark Mentovai, 2012/09/18 00:18:22]

I don’t think this is cool. Can you be more surgical?

[Scott Hess - ex-Googler, 2012/09/18 01:55:26]

I don't really think it's cool, either, but ... I also have no idea what the
alternative is.  Tomorrow I'll review the malloc code to see if there are any
other likely errno-setting operations which can lead here, but that's obviously
a failure waiting to happen.  Presumably there wouldn't be a ton of
file-descriptor accesses in the malloc library, outside of logging and debugging
code.

We could hook szone_error() to pre-empt the problem.  That's terrifying in its
own way, but it would have the side benefit of allowing us to suppress the
logging currently done on NULL pointer return.  [I'm away from my Libc checkout
right now, so that logging may only happen on debug.]

I'm waiting for a rsesek response, though.  This started out as "Oh, yeah, we
could just <x>", but it's quickly building momentum...

     return;
 
   // A unit test checks this error message, so it needs to be in release builds.
-  LOG(ERROR) <<
+  PLOG(ERROR) <<
       "Terminating process due to a potential for future heap corruption";
   int* volatile death_ptr = NULL;
   *death_ptr = 0xf00bad;
@@ -836,16 +833,12 @@ id oom_killer_allocWithZone(id self, SEL _cmd, NSZone* zone)
 
 }  // namespace
 
-malloc_zone_t* GetPurgeableZone() {
-  // malloc_default_purgeable_zone only exists on >= 10.6. Use dlsym to grab it
-  // at runtime because it may not be present in the SDK used for compilation.
-  typedef malloc_zone_t* (*malloc_default_purgeable_zone_t)(void);
-  malloc_default_purgeable_zone_t malloc_purgeable_zone =
-      reinterpret_cast<malloc_default_purgeable_zone_t>(
-          dlsym(RTLD_DEFAULT, "malloc_default_purgeable_zone"));
-  if (malloc_purgeable_zone)
-    return malloc_purgeable_zone();
-  return NULL;
+void* UncheckedMalloc(size_t size) {
+  if (g_old_malloc) {
+    ScopedClearErrno clear_errno;
+    return g_old_malloc(malloc_default_zone(), size);
+  }
+  return malloc(size);
 }
 
 void EnableTerminationOnOutOfMemory() {
@@ -880,7 +873,7 @@ void EnableTerminationOnOutOfMemory() {
   ChromeMallocZone* default_zone =
       reinterpret_cast<ChromeMallocZone*>(malloc_default_zone());
   ChromeMallocZone* purgeable_zone =
-      reinterpret_cast<ChromeMallocZone*>(GetPurgeableZone());
+      reinterpret_cast<ChromeMallocZone*>(malloc_default_purgeable_zone());
 
   vm_address_t page_start_default = 0;
   vm_address_t page_start_purgeable = 0;