Changeset 19245 in webkit for trunk/JavaScriptCore/wtf/TCSpinLock.h

Timestamp:

Jan 29, 2007, 9:07:25 PM (18 years ago)

Author:

ggaren

Message:

JavaScriptCore:

Reviewed by Maciej Stachowiak.

Fixed <rdar://problem/4485644> REGRESSION: JavaScriptCore has init routines

The TCMalloc module now initializes, if needed, inside GetCache() and
fastMallocSetIsMultiThreaded(). We leverage the same synchronization
technique used for enabling / disabling the single-threaded optimization
to synchronize initialization of the library without requiring a lock
for every malloc.

1,251 runs of tcmalloc_unittest, 2 runs of a custom, massively multi-threaded
tcmalloc_unittest, and my custom version of the PLT show no regressions.
Super-accurate JS iBench reports a .24% regression, which is right at the
limit of its error range, so I'm declaring victory.

• wtf/FastMalloc.cpp: (WTF::fastMallocSetIsMultiThreaded): Initialize, if needed. (InitModule() checks the "if needed" part.) (WTF::TCMalloc_ThreadCache::GetCache): Restored original TCMalloc code inside #ifdef, for posterity. Added new initialization logic. (WTF::TCMalloc_ThreadCache::InitModule): Call InitTSD(), since we don't have a static initializer to call it for us, now. This means that fastMalloc is not usable as a general libc allocator, but it never was, and if it were the general libc allocator, we wouldn't be here in the first place, so whatever. (WTF::TCMalloc_ThreadCache::InitTSD): Don't try to take the pageheap_lock, since InitModule already has it.

WebKitTools:

Reviewed by Maciej Stachowiak.

Fixed <rdar://problem/4485644> REGRESSION: JavaScriptCore has init routines

No more mollycoddling for you, FastMalloc.o!

• Scripts/check-for-global-initializers:

File:

• trunk/JavaScriptCore/wtf/TCSpinLock.h (modified) (1 diff)

trunk/JavaScriptCore/wtf/TCSpinLock.h

@@ -95 +95 @@
 #endif
   }
+
+#ifdef WTF_CHANGES  
+  inline bool IsLocked() {
+    return private_lockword_ != 0;
+  }
+#endif
 };