Changeset 106197 in webkit for trunk/Source/JavaScriptCore/runtime/Completion.cpp

Timestamp:

Jan 28, 2012, 7:47:13 PM (13 years ago)

Author:

[email protected]

Message:

Implement a JIT-code aware sampling profiler for JSC
​https://bugs.webkit.org/show_bug.cgi?id=76855

Reviewed by Oliver Hunt.

To enable the profiler, set the JSC_CODE_PROFILING environment variable to
1 (no tracing the C stack), 2 (trace one level of C code) or 3 (recursively
trace all samples).

The profiler requires -fomit-frame-pointer to be removed from the build flags.

• JavaScriptCore.exp:
  • Removed an export.
• JavaScriptCore.xcodeproj/project.pbxproj:
  • Added new files
• bytecode/CodeBlock.cpp:
  • For baseline codeblocks, cache the result of canCompileWithDFG.
• bytecode/CodeBlock.h:
  • For baseline codeblocks, cache the result of canCompileWithDFG.
• jit/ExecutableAllocator.cpp:

(JSC::ExecutableAllocator::initializeAllocator):

• Notify the profiler when the allocator is created.

(JSC::ExecutableAllocator::allocate):

• Inform the allocated of the ownerUID.

• jit/ExecutableAllocatorFixedVMPool.cpp:

(JSC::ExecutableAllocator::initializeAllocator):

• Notify the profiler when the allocator is created.

(JSC::ExecutableAllocator::allocate):

• Inform the allocated of the ownerUID.

• jit/JITStubs.cpp:
  • If profiling, don't mask the return address in JIT code. (We do so to provide nicer backtraces in debug builds).
• runtime/Completion.cpp:

(JSC::evaluate):

• Notify the profiler of script evaluations.

• tools: Added.
• tools/CodeProfile.cpp: Added.

(JSC::symbolName):

• Helper function to get the name of a symbol in the framework.

(JSC::truncateTrace):

• Helper to truncate traces into methods know to have uninformatively deep stacks.

(JSC::CodeProfile::sample):

• Record a stack trace classifying samples.

(JSC::CodeProfile::report):

• {Print profiler output.

• tools/CodeProfile.h: Added.
  • new class, captures a set of samples associated with an evaluated script, and nested to record samples from subscripts.
• tools/CodeProfiling.cpp: Added.

(JSC::CodeProfiling::profilingTimer):

• callback fired then a timer event occurs.

(JSC::CodeProfiling::notifyAllocator):

• called when the executable allocator is constructed.

(JSC::CodeProfiling::getOwnerUIDForPC):

• helper to lookup the codeblock from an address in JIT code

(JSC::CodeProfiling::begin):

• enter a profiling scope.

(JSC::CodeProfiling::end):

• exit a profiling scope.

• tools/CodeProfiling.h: Added.
  • new class, instantialed from Completion to define a profiling scope.
• tools/ProfileTreeNode.h: Added.
  • new class, used to construct a tree of samples.
• tools/TieredMMapArray.h: Added.
  • new class, a malloc-free vector (can be used while the main thread is suspended, possibly holding the malloc heap lock).
• wtf/MetaAllocator.cpp:

(WTF::MetaAllocatorHandle::MetaAllocatorHandle):
(WTF::MetaAllocator::allocate):

• Allow allocation handles to track information about their owner.

• wtf/MetaAllocator.h:

(MetaAllocator):

• Allow allocation handles to track information about their owner.

• wtf/MetaAllocatorHandle.h:

(MetaAllocatorHandle):
(WTF::MetaAllocatorHandle::ownerUID):

• Allow allocation handles to track information about their owner.

• wtf/OSAllocator.h:

(WTF::OSAllocator::reallocateCommitted):

• reallocate an existing, committed memory allocation.

File:

• trunk/Source/JavaScriptCore/runtime/Completion.cpp (modified) (2 diffs)

trunk/Source/JavaScriptCore/runtime/Completion.cpp

@@ -25 +25 @@
 
 #include "CallFrame.h"
+#include "CodeProfiling.h"
 #include "JSGlobalObject.h"
 #include "JSLock.h"
@@ -56 +57 @@
     ASSERT(exec->globalData().identifierTable == wtfThreadData().currentIdentifierTable());
 
+    CodeProfiling profile(source);
+
     ProgramExecutable* program = ProgramExecutable::create(exec, source);
     if (!program) {