X-Git-Url: http://wien.tomnetworks.com/gitweb/?a=blobdiff_plain;ds=sidebyside;f=mono%2Futils%2Fmach-support-x86.c;h=76d2b06beef149fdee73ddc7c1977bc6c2f40d42;hb=2e34a838d380715565ada6d447a06d03d6874136;hp=e65fe6bdeefe05a40f603c9d482fedbb2baa8b04;hpb=4df4b7a47a07d924d7bfcfc53f43bd2319b54266;p=mono.git

diff --git a/mono/utils/mach-support-x86.c b/mono/utils/mach-support-x86.c
index e65fe6bdeef..76d2b06beef 100644
--- a/mono/utils/mach-support-x86.c
+++ b/mono/utils/mach-support-x86.c
@@ -16,6 +16,14 @@
 #include "utils/mono-sigcontext.h"
 #include "mach-support.h"
 
+/* Known offsets used for TLS storage*/
+
+/* All OSX versions up to 10.8 */
+#define TLS_VECTOR_OFFSET_CATS 0x48
+#define TLS_VECTOR_OFFSET_10_9 0xb0
+
+static int tls_vector_offset;
+
 void *
 mono_mach_arch_get_ip (thread_state_t state)
 {
@@ -85,11 +93,11 @@ void *
 mono_mach_get_tls_address_from_thread (pthread_t thread, pthread_key_t key)
 {
 	/* OSX stores TLS values in a hidden array inside the pthread_t structure
-	 * They are keyed off a giant array offset 0x48 into the pointer.  This value
+	 * They are keyed off a giant array from a known offset into the pointer.  This value
 	 * is baked into their pthread_getspecific implementation
 	 */
 	intptr_t *p = (intptr_t *) thread;
-	intptr_t **tsd = (intptr_t **) ((char*)p + 0x48);
+	intptr_t **tsd = (intptr_t **) ((char*)p + tls_vector_offset);
 
 	return (void *) &tsd [key];	
 }
@@ -100,5 +108,29 @@ mono_mach_arch_get_tls_value_from_thread (pthread_t thread, guint32 key)
 	return *(void**)mono_mach_get_tls_address_from_thread (thread, key);
 }
 
+void
+mono_mach_init (pthread_key_t key)
+{
+	void *old_value = pthread_getspecific (key);
+	void *canary = (void*)0xDEADBEEFu;
+
+	pthread_key_create (&key, NULL);
+	g_assert (old_value != canary);
+
+	pthread_setspecific (key, canary);
+
+	/*First we probe for cats*/
+	tls_vector_offset = TLS_VECTOR_OFFSET_CATS;
+	if (mono_mach_arch_get_tls_value_from_thread (pthread_self (), key) == canary)
+		goto ok;
+
+	tls_vector_offset = TLS_VECTOR_OFFSET_10_9;
+	if (mono_mach_arch_get_tls_value_from_thread (pthread_self (), key) == canary)
+		goto ok;
+
+	g_error ("could not discover the mach TLS offset");
+ok:
+	pthread_setspecific (key, old_value);
+}
 
 #endif