1 files changed, 163 insertions, 0 deletions
diff --git a/Source/JavaScriptCore/tools/CodeProfiling.cpp b/Source/JavaScriptCore/tools/CodeProfiling.cpp
new file mode 100644
index 000000000..f236484c9
--- /dev/null
+++ b/Source/JavaScriptCore/tools/CodeProfiling.cpp
@@ -0,0 +1,163 @@
+/*
+ * Copyright (C) 2012 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#include "config.h"
+#include "CodeProfiling.h"
+
+#include "CodeProfile.h"
+#include "MetaAllocator.h"
+#include "signal.h"
+
+namespace JSC {
+
+volatile CodeProfile* CodeProfiling::s_profileStack = 0;
+CodeProfiling::Mode CodeProfiling::s_mode = CodeProfiling::Disabled;
+WTF::MetaAllocatorTracker* CodeProfiling::s_tracker = 0;
+
+#if COMPILER(CLANG)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wmissing-noreturn"
+#endif
+
+#if PLATFORM(MAC) && CPU(X86_64)
+// Helper function to start & stop the timer.
+// Presently we're using the wall-clock timer, since this seems to give the best results.
+static void setProfileTimer(unsigned usec)
+{
+    itimerval timer;
+    timer.it_value.tv_sec = 0;
+    timer.it_value.tv_usec = usec;
+    timer.it_interval.tv_sec = 0;
+    timer.it_interval.tv_usec = usec;
+    setitimer(ITIMER_REAL, &timer, 0);
+}
+#endif
+
+#if COMPILER(CLANG)
+#pragma clang diagnostic pop
+#endif
+
+#if PLATFORM(MAC) && CPU(X86_64)
+static void profilingTimer(int, siginfo_t*, void* uap)
+{
+    mcontext_t context = static_cast<ucontext_t*>(uap)->uc_mcontext;
+    CodeProfiling::sample(reinterpret_cast<void*>(context->__ss.__rip),
+                          reinterpret_cast<void**>(context->__ss.__rbp));
+}
+#endif
+
+// Callback triggered when the timer is fired.
+void CodeProfiling::sample(void* pc, void** framePointer)
+{
+    CodeProfile* profileStack = const_cast<CodeProfile*>(s_profileStack);
+    if (profileStack)
+        profileStack->sample(pc, framePointer);
+}
+
+void CodeProfiling::notifyAllocator(WTF::MetaAllocator* allocator)
+{
+    // Check for JSC_CODE_PROFILING.
+    const char* codeProfilingMode = getenv("JSC_CODE_PROFILING");
+    if (!codeProfilingMode)
+        return;
+
+    // Check for a valid mode, currently "1", "2", or "3".
+    if (!codeProfilingMode[0] || codeProfilingMode[1])
+        return;
+    switch (*codeProfilingMode) {
+    case '1':
+        s_mode = Enabled;
+        break;
+    case '2':
+        s_mode = Verbose;
+        break;
+    case '3':
+        s_mode = VeryVerbose;
+        break;
+    default:
+        return;
+    }
+
+    ASSERT(enabled());
+    ASSERT(!s_tracker);
+    s_tracker = new WTF::MetaAllocatorTracker();
+    allocator->trackAllocations(s_tracker);
+}
+
+void* CodeProfiling::getOwnerUIDForPC(void* address)
+{
+    if (!s_tracker)
+        return 0;
+    WTF::MetaAllocatorHandle* handle = s_tracker->find(address);
+    if (!handle)
+        return 0;
+    return handle->ownerUID();
+}
+
+void CodeProfiling::begin(const SourceCode& source)
+{
+    // Push a new CodeProfile onto the stack for each script encountered.
+    CodeProfile* profileStack = const_cast<CodeProfile*>(s_profileStack);
+    bool alreadyProfiling = profileStack;
+    s_profileStack = profileStack = new CodeProfile(source, profileStack);
+
+    // Is the profiler already running - if so, the timer will already be set up.
+    if (alreadyProfiling)
+        return;
+
+#if PLATFORM(MAC) && CPU(X86_64)
+    // Regsiter a signal handler & itimer.
+    struct sigaction action;
+    action.sa_sigaction = reinterpret_cast<void (*)(int, struct __siginfo *, void *)>(profilingTimer);
+    sigfillset(&action.sa_mask);
+    action.sa_flags = SA_SIGINFO;
+    sigaction(SIGALRM, &action, 0);
+    setProfileTimer(100);
+#endif
+}
+
+void CodeProfiling::end()
+{
+    // Pop the current profiler off the stack.
+    CodeProfile* current = const_cast<CodeProfile*>(s_profileStack);
+    ASSERT(current);
+    s_profileStack = current->parent();
+
+    // Is this the outermost script being profiled? - if not, just return.
+    // We perform all output of profiles recursively from the outermost script,
+    // to minimize profiling overhead from skewing results.
+    if (s_profileStack)
+        return;
+
+#if PLATFORM(MAC) && CPU(X86_64)
+    // Stop profiling
+    setProfileTimer(0);
+#endif
+
+    current->report();
+    delete current;
+}
+
+}