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/*
* 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 <wtf/MetaAllocator.h>
#if HAVE(SIGNAL_H)
#include <signal.h>
#endif
#if OS(LINUX) || OS(DARWIN)
#include <sys/time.h>
#endif
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 (OS(DARWIN) && !PLATFORM(GTK) && CPU(X86_64)) || (OS(LINUX) && CPU(X86))
// 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 OS(DARWIN) && !PLATFORM(GTK) && 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));
}
#elif OS(LINUX) && CPU(X86)
static void profilingTimer(int, siginfo_t*, void* uap)
{
mcontext_t context = static_cast<ucontext_t*>(uap)->uc_mcontext;
CodeProfiling::sample(reinterpret_cast<void*>(context.gregs[REG_EIP]),
reinterpret_cast<void**>(context.gregs[REG_EBP]));
}
#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 (OS(DARWIN) && !PLATFORM(GTK) && CPU(X86_64)) || (OS(LINUX) && CPU(X86))
// Regsiter a signal handler & itimer.
struct sigaction action;
action.sa_sigaction = reinterpret_cast<void (*)(int, siginfo_t *, 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 (OS(DARWIN) && !PLATFORM(GTK) && CPU(X86_64)) || (OS(LINUX) && CPU(X86))
// Stop profiling
setProfileTimer(0);
#endif
current->report();
delete current;
}
}
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