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Fix fast TLS support on Mac.

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Review URL: http://codereview.chromium.org/6706018

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7488 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This commit is contained in:
vitalyr@chromium.org 2011-04-04 05:46:51 +00:00
parent 20bdf9a07d
commit d37b5750d1
2 changed files with 76 additions and 7 deletions
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71
src/platform-macos.cc
View File

@ -48,8 +48,10 @@
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/types.h>
#include <sys/sysctl.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#undef MAP_TYPE
@ -507,12 +509,79 @@ void Thread::Join() {
}
#ifdef V8_FAST_TLS_SUPPORTED
static Atomic32 tls_base_offset_initialized = 0;
intptr_t kMacTlsBaseOffset = 0;
// It's safe to do the initialization more that once, but it has to be
// done at least once.
static void InitializeTlsBaseOffset() {
const size_t kBufferSize = 128;
char buffer[kBufferSize];
size_t buffer_size = kBufferSize;
int ctl_name[] = { CTL_KERN , KERN_OSRELEASE };
if (sysctl(ctl_name, 2, buffer, &buffer_size, NULL, 0) != 0) {
V8_Fatal(__FILE__, __LINE__, "V8 failed to get kernel version");
}
// The buffer now contains a string of the form XX.YY.ZZ, where
// XX is the major kernel version component.
// Make sure the buffer is 0-terminated.
buffer[kBufferSize - 1] = '\0';
char* period_pos = strchr(buffer, '.');
*period_pos = '\0';
int kernel_version_major =
static_cast<int>(strtol(buffer, NULL, 10)); // NOLINT
// The constants below are taken from pthreads.s from the XNU kernel
// sources archive at www.opensource.apple.com.
if (kernel_version_major < 11) {
// 8.x.x (Tiger), 9.x.x (Leopard), 10.x.x (Snow Leopard) have the
// same offsets.
#if defined(V8_HOST_ARCH_IA32)
kMacTlsBaseOffset = 0x48;
#else
kMacTlsBaseOffset = 0x60;
#endif
} else {
// 11.x.x (Lion) changed the offset.
kMacTlsBaseOffset = 0;
}
Release_Store(&tls_base_offset_initialized, 1);
}
static void CheckFastTls(Thread::LocalStorageKey key) {
void* expected = reinterpret_cast<void*>(0x1234CAFE);
Thread::SetThreadLocal(key, expected);
void* actual = Thread::GetExistingThreadLocal(key);
if (expected != actual) {
V8_Fatal(__FILE__, __LINE__,
"V8 failed to initialize fast TLS on current kernel");
}
Thread::SetThreadLocal(key, NULL);
}
#endif // V8_FAST_TLS_SUPPORTED
Thread::LocalStorageKey Thread::CreateThreadLocalKey() {
#ifdef V8_FAST_TLS_SUPPORTED
bool check_fast_tls = false;
if (tls_base_offset_initialized == 0) {
check_fast_tls = true;
InitializeTlsBaseOffset();
}
#endif
pthread_key_t key;
int result = pthread_key_create(&key, NULL);
USE(result);
ASSERT(result == 0);
return static_cast<LocalStorageKey>(key);
LocalStorageKey typed_key = static_cast<LocalStorageKey>(key);
#ifdef V8_FAST_TLS_SUPPORTED
// If we just initialized fast TLS support, make sure it works.
if (check_fast_tls) CheckFastTls(typed_key);
#endif
return typed_key;
}

12
src/platform-tls-mac.h
View File

@ -37,20 +37,20 @@ namespace internal {
#define V8_FAST_TLS_SUPPORTED 1
extern intptr_t kMacTlsBaseOffset;
INLINE(intptr_t InternalGetExistingThreadLocal(intptr_t index));
inline intptr_t InternalGetExistingThreadLocal(intptr_t index) {
// The constants below are taken from pthreads.s from the XNU kernel
// sources archive at www.opensource.apple.com.
intptr_t result;
#if defined(V8_HOST_ARCH_IA32)
asm("movl %%gs:0x48(,%1,4), %0;"
asm("movl %%gs:(%1,%2,4), %0;"
:"=r"(result) // Output must be a writable register.
:"0"(index)); // Input is the same as output.
:"r"(kMacTlsBaseOffset), "r"(index));
#else
asm("movq %%gs:0x60(,%1,8), %0;"
asm("movq %%gs:(%1,%2,8), %0;"
:"=r"(result)
:"0"(index));
:"r"(kMacTlsBaseOffset), "r"(index));
#endif
return result;
}