webkitgtk-2.16.5HEADwebkitgtk-2.16.5master

1 files changed, 30 insertions, 41 deletions

diff --git a/Source/JavaScriptCore/runtime/VMEntryScope.cpp b/Source/JavaScriptCore/runtime/VMEntryScope.cpp
index 47782ce3b..e1e708ce0 100644
--- a/Source/JavaScriptCore/runtime/VMEntryScope.cpp
+++ b/Source/JavaScriptCore/runtime/VMEntryScope.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2013-2015 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -26,70 +26,59 @@
 #include "config.h"
 #include "VMEntryScope.h"
 
-#include "Debugger.h"
+#include "Options.h"
+#include "SamplingProfiler.h"
 #include "VM.h"
+#include "Watchdog.h"
 #include <wtf/StackBounds.h>
+#include <wtf/SystemTracing.h>
 
 namespace JSC {
 
 VMEntryScope::VMEntryScope(VM& vm, JSGlobalObject* globalObject)
     : m_vm(vm)
-    , m_stack(wtfThreadData().stack())
     , m_globalObject(globalObject)
-    , m_prev(vm.entryScope)
-    , m_prevStackLimit(vm.stackLimit())
-    , m_recompilationNeeded(false)
 {
+    ASSERT(wtfThreadData().stack().isGrowingDownward());
     if (!vm.entryScope) {
-#if ENABLE(ASSEMBLER)
-        if (ExecutableAllocator::underMemoryPressure())
-            vm.heap.deleteAllCompiledCode();
-#endif
         vm.entryScope = this;
 
         // Reset the date cache between JS invocations to force the VM to
-        // observe time xone changes.
+        // observe time zone changes.
         vm.resetDateCache();
+
+        if (vm.watchdog())
+            vm.watchdog()->enteredVM();
+
+#if ENABLE(SAMPLING_PROFILER)
+        if (SamplingProfiler* samplingProfiler = vm.samplingProfiler())
+            samplingProfiler->noticeVMEntry();
+#endif
+        TracePoint(VMEntryScopeStart);
     }
-    // Clear the exception stack between entries
-    vm.clearExceptionStack();
 
-    void* limit = m_stack.recursionLimit(requiredCapacity());
-    vm.setStackLimit(limit);
+    vm.clearLastException();
 }
 
-VMEntryScope::~VMEntryScope()
+void VMEntryScope::addDidPopListener(std::function<void ()> listener)
 {
-    m_vm.entryScope = m_prev;
-    m_vm.setStackLimit(m_prevStackLimit);
-
-    if (m_recompilationNeeded) {
-        if (m_vm.entryScope)
-            m_vm.entryScope->setRecompilationNeeded(true);
-        else {
-            if (Debugger* debugger = m_globalObject->debugger())
-                debugger->recompileAllJSFunctions(&m_vm);
-        }
-    }
+    m_didPopListeners.append(listener);
 }
 
-size_t VMEntryScope::requiredCapacity() const
+VMEntryScope::~VMEntryScope()
 {
-    Interpreter* interpreter = m_vm.interpreter;
+    if (m_vm.entryScope != this)
+        return;
+
+    TracePoint(VMEntryScopeEnd);
+
+    if (m_vm.watchdog())
+        m_vm.watchdog()->exitedVM();
 
-    // We require a smaller stack budget for the error stack. This is to allow
-    // some minimal JS execution to proceed and do the work of throwing a stack
-    // overflow error if needed. In contrast, arbitrary JS code will require the
-    // more generous stack budget in order to proceed.
-    //
-    // These sizes were derived from the stack usage of a number of sites when
-    // layout occurs when we've already consumed most of the C stack.
-    const size_t requiredStack = 128 * KB;
-    const size_t errorModeRequiredStack = 64 * KB;
+    m_vm.entryScope = nullptr;
 
-    size_t requiredCapacity = interpreter->isInErrorHandlingMode() ? errorModeRequiredStack : requiredStack;
-    RELEASE_ASSERT(m_stack.size() >= requiredCapacity);
-    return requiredCapacity;
+    for (auto& listener : m_didPopListeners)
+        listener();
 }
 
 } // namespace JSC