Bug 1399921 - Register zone allocator independently, and delay jemalloc initialization on mac. r=njn

In bug 1361258, we unified the initialization sequence on mac, and
chose to make the zone registration happen after jemalloc
initialization.

The order between jemalloc init and zone registration shouldn't actually
matter, because jemalloc initializes the first time the allocator is
actually used.

On the other hand, in some build setups (e.g. with light optimization),
the initialization of the thread_arena thread local variable can happen
after the forced jemalloc initialization because of the order the
corresponding static initializers run. In some levels of optimization,
the thread_arena initializer resets the value the jemalloc
initialization has set, which subsequently makes choose_arena() return
a bogus value (or hit an assertion in ThreadLocal.h on debug builds).

So instead of initializing jemalloc from a static initializer, which
then registers the zone, we instead register the zone and let jemalloc
initialize itself when used, which increases the chances of the
thread_arena initializer running first.

--HG--
extra : rebase_source : 4d9a5340d097ac8528dc4aaaf0c05bbef40b59bb

memory/build/mozjemalloc.cpp

@@ -4375,7 +4375,7 @@ huge_dalloc(void *ptr)
  * implementation has to take pains to avoid infinite recursion during
  * initialization.
  */
-#if (defined(XP_WIN) || defined(XP_DARWIN))
+#if defined(XP_WIN)
 #define	malloc_init() false
 #else
 static inline bool
@@ -4389,10 +4389,6 @@ malloc_init(void)
 }
 #endif
 
-#if defined(XP_DARWIN)
-extern "C" void register_zone(void);
-#endif
-
 static size_t
 GetKernelPageSize()
 {
@@ -4657,10 +4653,6 @@ MALLOC_OUT:
   pthread_atfork(_malloc_prefork, _malloc_postfork_parent, _malloc_postfork_child);
 #endif
 
-#if defined(XP_DARWIN)
-  register_zone();
-#endif
-
 #ifndef XP_WIN
   malloc_mutex_unlock(&init_lock);
 #endif
@@ -5450,18 +5442,6 @@ replace_malloc_init_funcs()
 #  include <dlfcn.h>
 #endif
 
-#if defined(XP_DARWIN)
-
-__attribute__((constructor))
-void
-jemalloc_darwin_init(void)
-{
-	if (malloc_init_hard())
-		MOZ_CRASH();
-}
-
-#endif
-
 #if defined(__GLIBC__) && !defined(__UCLIBC__)
 /*
  * glibc provides the RTLD_DEEPBIND flag for dlopen which can make it possible

memory/build/zone.c

@@ -345,7 +345,8 @@ static malloc_zone_t *get_default_zone()
 }
 
 
-void
+ __attribute__((constructor))
+static void
 register_zone(void)
 {
   malloc_zone_t *default_zone = get_default_zone();