Use OSSpinLock*() for locking on OS X.

pthread_mutex_lock() can call malloc() on OS X (!!!), which causes
deadlock.  Work around this by using spinlocks that are built of more
primitive stuff.

jemalloc/configure.ac

@@ -792,6 +792,21 @@ if test "x${osatomic}" = "xyes" ; then
   AC_DEFINE([JEMALLOC_OSATOMIC])
 fi
 
+dnl ============================================================================
+dnl Check for spinlock(3) operations as provided on Darwin.
+
+JE_COMPILABLE([Darwin OSSpin*()], [
+#include <libkern/OSAtomic.h>
+#include <inttypes.h>
+], [
+	OSSpinLock lock = 0;
+	OSSpinLockLock(&lock);
+	OSSpinLockUnlock(&lock);
+], [osspin])
+if test "x${osspin}" = "xyes" ; then
+  AC_DEFINE([JEMALLOC_OSSPIN])
+fi
+
 dnl ============================================================================
 dnl Check for allocator-related functions that should be wrapped.
 

jemalloc/include/jemalloc/internal/atomic.h

@@ -13,13 +13,19 @@
 #define	atomic_read_uint32(p)	atomic_add_uint32(p, 0)
 
 #if (LG_SIZEOF_PTR == 3)
-#  define atomic_read_z(p) atomic_add_uint64(p, 0)
-#  define atomic_add_z(p, x) atomic_add_uint64(p, x)
-#  define atomic_sub_z(p, x) atomic_sub_uint64(p, x)
+#  define atomic_read_z(p)						\
+    (size_t)atomic_add_uint64((uint64_t *)p, (uint64_t)0)
+#  define atomic_add_z(p, x)						\
+    (size_t)atomic_add_uint64((uint64_t *)p, (uint64_t)x)
+#  define atomic_sub_z(p, x)						\
+    (size_t)atomic_sub_uint64((uint64_t *)p, (uint64_t)x)
 #elif (LG_SIZEOF_PTR == 2)
-#  define atomic_read_z(p) atomic_add_uint32(p, 0)
-#  define atomic_add_z(p, x) atomic_add_uint32(p, x)
-#  define atomic_sub_z(p, x) atomic_sub_uint32(p, x)
+#  define atomic_read_z(p)						\
+    (size_t)atomic_add_uint32((uint32_t *)p, (uint32_t)0)
+#  define atomic_add_z(p, x)						\
+    (size_t)atomic_add_uint32((uint32_t *)p, (uint32_t)x)
+#  define atomic_sub_z(p, x)						\
+    (size_t)atomic_sub_uint32((uint32_t *)p, (uint32_t)x)
 #endif
 
 #endif /* JEMALLOC_H_EXTERNS */

jemalloc/include/jemalloc/internal/jemalloc_internal.h.in

@@ -33,7 +33,7 @@
 #define	JEMALLOC_MANGLE
 #include "../jemalloc@install_suffix@.h"
 
-#ifdef JEMALLOC_OSATOMIC
+#if (defined(JEMALLOC_OSATOMIC) || defined(JEMALLOC_OSSPIN))
 #include <libkern/OSAtomic.h>
 #endif
 

jemalloc/include/jemalloc/internal/mutex.h

@@ -1,7 +1,11 @@
 /******************************************************************************/
 #ifdef JEMALLOC_H_TYPES
 
+#ifdef JEMALLOC_OSSPIN
+typedef OSSpinLock malloc_mutex_t;
+#else
 typedef pthread_mutex_t malloc_mutex_t;
+#endif
 
 #ifdef PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP
 #  define MALLOC_MUTEX_INITIALIZER PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP
@@ -41,17 +45,26 @@ JEMALLOC_INLINE void
 malloc_mutex_lock(malloc_mutex_t *mutex)
 {
 
-	if (isthreaded)
+	if (isthreaded) {
+#ifdef JEMALLOC_OSSPIN
+		OSSpinLockLock(mutex);
+#else
 		pthread_mutex_lock(mutex);
+#endif
+	}
 }
 
 JEMALLOC_INLINE bool
 malloc_mutex_trylock(malloc_mutex_t *mutex)
 {
 
-	if (isthreaded)
+	if (isthreaded) {
+#ifdef JEMALLOC_OSSPIN
+		return (OSSpinLockTry(mutex) == false);
+#else
 		return (pthread_mutex_trylock(mutex) != 0);
-	else
+#endif
+	} else
 		return (false);
 }
 
@@ -59,8 +72,13 @@ JEMALLOC_INLINE void
 malloc_mutex_unlock(malloc_mutex_t *mutex)
 {
 
-	if (isthreaded)
+	if (isthreaded) {
+#ifdef JEMALLOC_OSSPIN
+		OSSpinLockUnlock(mutex);
+#else
 		pthread_mutex_unlock(mutex);
+#endif
+	}
 }
 #endif
 

jemalloc/include/jemalloc/jemalloc_defs.h.in

@@ -30,6 +30,12 @@
  */
 #undef JEMALLOC_OSATOMIC
 
+/*
+ * Defined if OSSpin*() functions are available, as provided by Darwin, and
+ * documented in the spinlock(3) manual page.
+ */
+#undef JEMALLOC_OSSPIN
+
 /* Defined if __attribute__((...)) syntax is supported. */
 #undef JEMALLOC_HAVE_ATTR
 #ifdef JEMALLOC_HAVE_ATTR

jemalloc/src/jemalloc.c

@@ -28,7 +28,13 @@ static bool		malloc_initialized = false;
 static pthread_t	malloc_initializer = (unsigned long)0;
 
 /* Used to avoid initialization races. */
-static malloc_mutex_t	init_lock = MALLOC_MUTEX_INITIALIZER;
+static malloc_mutex_t	init_lock =
+#ifdef JEMALLOC_OSSPIN
+    0
+#else
+    MALLOC_MUTEX_INITIALIZER
+#endif
+    ;
 
 #ifdef DYNAMIC_PAGE_SHIFT
 size_t		pagesize;

jemalloc/src/mutex.c

@@ -55,6 +55,9 @@ pthread_create(pthread_t *__restrict thread,
 bool
 malloc_mutex_init(malloc_mutex_t *mutex)
 {
+#ifdef JEMALLOC_OSSPIN
+	*mutex = 0;
+#else
 	pthread_mutexattr_t attr;
 
 	if (pthread_mutexattr_init(&attr) != 0)
@@ -70,6 +73,7 @@ malloc_mutex_init(malloc_mutex_t *mutex)
 	}
 	pthread_mutexattr_destroy(&attr);
 
+#endif
 	return (false);
 }
 
@@ -77,8 +81,10 @@ void
 malloc_mutex_destroy(malloc_mutex_t *mutex)
 {
 
+#ifndef JEMALLOC_OSSPIN
 	if (pthread_mutex_destroy(mutex) != 0) {
 		malloc_write("<jemalloc>: Error in pthread_mutex_destroy()\n");
 		abort();
 	}
+#endif
 }