v8/src/sampler.cc

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// Copyright 2013 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * 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.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "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 THE COPYRIGHT
// OWNER 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 "sampler.h"
#if defined(__linux__) || defined(__FreeBSD__) || defined(__OpenBSD__) \
|| defined(__NetBSD__) || defined(__sun) || defined(__ANDROID__) \
|| defined(__native_client__)
#define USE_SIGNALS
#include <errno.h>
#include <pthread.h>
#include <signal.h>
#include <sys/time.h>
#include <sys/syscall.h>
#if !defined(__ANDROID__) || defined(__BIONIC_HAVE_UCONTEXT_T)
#include <ucontext.h>
#endif
#include <unistd.h>
// GLibc on ARM defines mcontext_t has a typedef for 'struct sigcontext'.
// Old versions of the C library <signal.h> didn't define the type.
#if defined(__ANDROID__) && !defined(__BIONIC_HAVE_UCONTEXT_T) && \
defined(__arm__) && !defined(__BIONIC_HAVE_STRUCT_SIGCONTEXT)
#include <asm/sigcontext.h>
#endif
#elif defined(__MACH__)
#include <mach/mach.h>
#elif defined(_WIN32) || defined(_WIN64) || defined(__CYGWIN__)
#include "win32-headers.h"
#endif
#include "v8.h"
#include "cpu-profiler.h"
#include "flags.h"
#include "frames-inl.h"
#include "log.h"
#include "platform.h"
#include "simulator.h"
#include "v8threads.h"
#include "vm-state-inl.h"
#if defined(__ANDROID__) && !defined(__BIONIC_HAVE_UCONTEXT_T)
// Not all versions of Android's C library provide ucontext_t.
// Detect this and provide custom but compatible definitions. Note that these
// follow the GLibc naming convention to access register values from
// mcontext_t.
//
// See http://code.google.com/p/android/issues/detail?id=34784
#if defined(__arm__)
typedef struct sigcontext mcontext_t;
typedef struct ucontext {
uint32_t uc_flags;
struct ucontext* uc_link;
stack_t uc_stack;
mcontext_t uc_mcontext;
// Other fields are not used by V8, don't define them here.
} ucontext_t;
#elif defined(__mips__)
// MIPS version of sigcontext, for Android bionic.
typedef struct {
uint32_t regmask;
uint32_t status;
uint64_t pc;
uint64_t gregs[32];
uint64_t fpregs[32];
uint32_t acx;
uint32_t fpc_csr;
uint32_t fpc_eir;
uint32_t used_math;
uint32_t dsp;
uint64_t mdhi;
uint64_t mdlo;
uint32_t hi1;
uint32_t lo1;
uint32_t hi2;
uint32_t lo2;
uint32_t hi3;
uint32_t lo3;
} mcontext_t;
typedef struct ucontext {
uint32_t uc_flags;
struct ucontext* uc_link;
stack_t uc_stack;
mcontext_t uc_mcontext;
// Other fields are not used by V8, don't define them here.
} ucontext_t;
#elif defined(__i386__)
// x86 version for Android.
typedef struct {
uint32_t gregs[19];
void* fpregs;
uint32_t oldmask;
uint32_t cr2;
} mcontext_t;
typedef uint32_t kernel_sigset_t[2]; // x86 kernel uses 64-bit signal masks
typedef struct ucontext {
uint32_t uc_flags;
struct ucontext* uc_link;
stack_t uc_stack;
mcontext_t uc_mcontext;
// Other fields are not used by V8, don't define them here.
} ucontext_t;
enum { REG_EBP = 6, REG_ESP = 7, REG_EIP = 14 };
#endif
#endif // __ANDROID__ && !defined(__BIONIC_HAVE_UCONTEXT_T)
namespace v8 {
namespace internal {
namespace {
class PlatformDataCommon : public Malloced {
public:
PlatformDataCommon() : profiled_thread_id_(ThreadId::Current()) {}
ThreadId profiled_thread_id() { return profiled_thread_id_; }
protected:
~PlatformDataCommon() {}
private:
ThreadId profiled_thread_id_;
};
} // namespace
#if defined(USE_SIGNALS)
class Sampler::PlatformData : public PlatformDataCommon {
public:
PlatformData() : vm_tid_(pthread_self()) {}
pthread_t vm_tid() const { return vm_tid_; }
private:
pthread_t vm_tid_;
};
#elif defined(__MACH__)
class Sampler::PlatformData : public PlatformDataCommon {
public:
PlatformData() : profiled_thread_(mach_thread_self()) {}
~PlatformData() {
// Deallocate Mach port for thread.
mach_port_deallocate(mach_task_self(), profiled_thread_);
}
thread_act_t profiled_thread() { return profiled_thread_; }
private:
// Note: for profiled_thread_ Mach primitives are used instead of PThread's
// because the latter doesn't provide thread manipulation primitives required.
// For details, consult "Mac OS X Internals" book, Section 7.3.
thread_act_t profiled_thread_;
};
#elif defined(_WIN32) || defined(_WIN64) || defined(__CYGWIN__)
// ----------------------------------------------------------------------------
// Win32 profiler support. On Cygwin we use the same sampler implementation as
// on Win32.
class Sampler::PlatformData : public PlatformDataCommon {
public:
// Get a handle to the calling thread. This is the thread that we are
// going to profile. We need to make a copy of the handle because we are
// going to use it in the sampler thread. Using GetThreadHandle() will
// not work in this case. We're using OpenThread because DuplicateHandle
// for some reason doesn't work in Chrome's sandbox.
PlatformData()
: profiled_thread_(OpenThread(THREAD_GET_CONTEXT |
THREAD_SUSPEND_RESUME |
THREAD_QUERY_INFORMATION,
false,
GetCurrentThreadId())) {}
~PlatformData() {
if (profiled_thread_ != NULL) {
CloseHandle(profiled_thread_);
profiled_thread_ = NULL;
}
}
HANDLE profiled_thread() { return profiled_thread_; }
private:
HANDLE profiled_thread_;
};
#endif
#if defined(USE_SIMULATOR)
class SimulatorHelper {
public:
inline bool Init(Sampler* sampler, Isolate* isolate) {
ThreadId thread_id = sampler->platform_data()->profiled_thread_id();
Isolate::PerIsolateThreadData* per_thread_data = isolate->
FindPerThreadDataForThread(thread_id);
if (!per_thread_data) return false;
simulator_ = per_thread_data->simulator();
// Check if there is active simulator.
return simulator_ != NULL;
}
inline void FillRegisters(RegisterState* state) {
state->pc = reinterpret_cast<Address>(simulator_->get_pc());
state->sp = reinterpret_cast<Address>(simulator_->get_register(
Simulator::sp));
#if V8_TARGET_ARCH_ARM
state->fp = reinterpret_cast<Address>(simulator_->get_register(
Simulator::r11));
#elif V8_TARGET_ARCH_MIPS
state->fp = reinterpret_cast<Address>(simulator_->get_register(
Simulator::fp));
#endif
}
private:
Simulator* simulator_;
};
#endif // USE_SIMULATOR
#if defined(USE_SIGNALS)
class SignalHandler : public AllStatic {
public:
static inline void EnsureInstalled() {
if (signal_handler_installed_) return;
struct sigaction sa;
sa.sa_sigaction = &HandleProfilerSignal;
sigemptyset(&sa.sa_mask);
sa.sa_flags = SA_RESTART | SA_SIGINFO;
signal_handler_installed_ =
(sigaction(SIGPROF, &sa, &old_signal_handler_) == 0);
}
static inline void Restore() {
if (signal_handler_installed_) {
sigaction(SIGPROF, &old_signal_handler_, 0);
signal_handler_installed_ = false;
}
}
static inline bool Installed() {
return signal_handler_installed_;
}
private:
static void HandleProfilerSignal(int signal, siginfo_t* info, void* context);
static bool signal_handler_installed_;
static struct sigaction old_signal_handler_;
};
struct sigaction SignalHandler::old_signal_handler_;
bool SignalHandler::signal_handler_installed_ = false;
void SignalHandler::HandleProfilerSignal(int signal, siginfo_t* info,
void* context) {
#if defined(__native_client__)
// As Native Client does not support signal handling, profiling
// is disabled.
return;
#else
USE(info);
if (signal != SIGPROF) return;
Isolate* isolate = Isolate::UncheckedCurrent();
if (isolate == NULL || !isolate->IsInitialized() || !isolate->IsInUse()) {
// We require a fully initialized and entered isolate.
return;
}
if (v8::Locker::IsActive() &&
!isolate->thread_manager()->IsLockedByCurrentThread()) {
return;
}
Sampler* sampler = isolate->logger()->sampler();
if (sampler == NULL || !sampler->IsActive()) return;
RegisterState state;
#if defined(USE_SIMULATOR)
SimulatorHelper helper;
if (!helper.Init(sampler, isolate)) return;
helper.FillRegisters(&state);
#else
// Extracting the sample from the context is extremely machine dependent.
ucontext_t* ucontext = reinterpret_cast<ucontext_t*>(context);
mcontext_t& mcontext = ucontext->uc_mcontext;
#if defined(__linux__) || defined(__ANDROID__)
#if V8_HOST_ARCH_IA32
state.pc = reinterpret_cast<Address>(mcontext.gregs[REG_EIP]);
state.sp = reinterpret_cast<Address>(mcontext.gregs[REG_ESP]);
state.fp = reinterpret_cast<Address>(mcontext.gregs[REG_EBP]);
#elif V8_HOST_ARCH_X64
state.pc = reinterpret_cast<Address>(mcontext.gregs[REG_RIP]);
state.sp = reinterpret_cast<Address>(mcontext.gregs[REG_RSP]);
state.fp = reinterpret_cast<Address>(mcontext.gregs[REG_RBP]);
#elif V8_HOST_ARCH_ARM
#if defined(__GLIBC__) && !defined(__UCLIBC__) && \
(__GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ <= 3))
// Old GLibc ARM versions used a gregs[] array to access the register
// values from mcontext_t.
state.pc = reinterpret_cast<Address>(mcontext.gregs[R15]);
state.sp = reinterpret_cast<Address>(mcontext.gregs[R13]);
state.fp = reinterpret_cast<Address>(mcontext.gregs[R11]);
#else
state.pc = reinterpret_cast<Address>(mcontext.arm_pc);
state.sp = reinterpret_cast<Address>(mcontext.arm_sp);
state.fp = reinterpret_cast<Address>(mcontext.arm_fp);
#endif // defined(__GLIBC__) && !defined(__UCLIBC__) &&
// (__GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ <= 3))
#elif V8_HOST_ARCH_MIPS
state.pc = reinterpret_cast<Address>(mcontext.pc);
state.sp = reinterpret_cast<Address>(mcontext.gregs[29]);
state.fp = reinterpret_cast<Address>(mcontext.gregs[30]);
#endif // V8_HOST_ARCH_*
#elif defined(__FreeBSD__)
#if V8_HOST_ARCH_IA32
state.pc = reinterpret_cast<Address>(mcontext.mc_eip);
state.sp = reinterpret_cast<Address>(mcontext.mc_esp);
state.fp = reinterpret_cast<Address>(mcontext.mc_ebp);
#elif V8_HOST_ARCH_X64
state.pc = reinterpret_cast<Address>(mcontext.mc_rip);
state.sp = reinterpret_cast<Address>(mcontext.mc_rsp);
state.fp = reinterpret_cast<Address>(mcontext.mc_rbp);
#elif V8_HOST_ARCH_ARM
state.pc = reinterpret_cast<Address>(mcontext.mc_r15);
state.sp = reinterpret_cast<Address>(mcontext.mc_r13);
state.fp = reinterpret_cast<Address>(mcontext.mc_r11);
#endif // V8_HOST_ARCH_*
#elif defined(__NetBSD__)
#if V8_HOST_ARCH_IA32
state.pc = reinterpret_cast<Address>(mcontext.__gregs[_REG_EIP]);
state.sp = reinterpret_cast<Address>(mcontext.__gregs[_REG_ESP]);
state.fp = reinterpret_cast<Address>(mcontext.__gregs[_REG_EBP]);
#elif V8_HOST_ARCH_X64
state.pc = reinterpret_cast<Address>(mcontext.__gregs[_REG_RIP]);
state.sp = reinterpret_cast<Address>(mcontext.__gregs[_REG_RSP]);
state.fp = reinterpret_cast<Address>(mcontext.__gregs[_REG_RBP]);
#endif // V8_HOST_ARCH_*
#elif defined(__OpenBSD__)
USE(mcontext);
#if V8_HOST_ARCH_IA32
state.pc = reinterpret_cast<Address>(ucontext->sc_eip);
state.sp = reinterpret_cast<Address>(ucontext->sc_esp);
state.fp = reinterpret_cast<Address>(ucontext->sc_ebp);
#elif V8_HOST_ARCH_X64
state.pc = reinterpret_cast<Address>(ucontext->sc_rip);
state.sp = reinterpret_cast<Address>(ucontext->sc_rsp);
state.fp = reinterpret_cast<Address>(ucontext->sc_rbp);
#endif // V8_HOST_ARCH_*
#elif defined(__sun)
state.pc = reinterpret_cast<Address>(mcontext.gregs[REG_PC]);
state.sp = reinterpret_cast<Address>(mcontext.gregs[REG_SP]);
state.fp = reinterpret_cast<Address>(mcontext.gregs[REG_FP]);
#endif // __sun
#endif // USE_SIMULATOR
sampler->SampleStack(state);
#endif // __native_client__
}
#endif
class SamplerThread : public Thread {
public:
static const int kSamplerThreadStackSize = 64 * KB;
explicit SamplerThread(int interval)
: Thread(Thread::Options("SamplerThread", kSamplerThreadStackSize)),
interval_(interval) {}
static void SetUp() { if (!mutex_) mutex_ = OS::CreateMutex(); }
static void TearDown() { delete mutex_; }
static void AddActiveSampler(Sampler* sampler) {
bool need_to_start = false;
ScopedLock lock(mutex_);
if (instance_ == NULL) {
// Start a thread that will send SIGPROF signal to VM threads,
// when CPU profiling will be enabled.
instance_ = new SamplerThread(sampler->interval());
need_to_start = true;
}
ASSERT(sampler->IsActive());
ASSERT(!instance_->active_samplers_.Contains(sampler));
ASSERT(instance_->interval_ == sampler->interval());
instance_->active_samplers_.Add(sampler);
#if defined(USE_SIGNALS)
SignalHandler::EnsureInstalled();
#endif
if (need_to_start) instance_->StartSynchronously();
}
static void RemoveActiveSampler(Sampler* sampler) {
SamplerThread* instance_to_remove = NULL;
{
ScopedLock lock(mutex_);
ASSERT(sampler->IsActive());
bool removed = instance_->active_samplers_.RemoveElement(sampler);
ASSERT(removed);
USE(removed);
// We cannot delete the instance immediately as we need to Join() the
// thread but we are holding mutex_ and the thread may try to acquire it.
if (instance_->active_samplers_.is_empty()) {
instance_to_remove = instance_;
instance_ = NULL;
#if defined(USE_SIGNALS)
SignalHandler::Restore();
#endif
}
}
if (!instance_to_remove) return;
instance_to_remove->Join();
delete instance_to_remove;
}
// Implement Thread::Run().
virtual void Run() {
while (true) {
{
ScopedLock lock(mutex_);
if (active_samplers_.is_empty()) break;
// When CPU profiling is enabled both JavaScript and C++ code is
// profiled. We must not suspend.
for (int i = 0; i < active_samplers_.length(); ++i) {
Sampler* sampler = active_samplers_.at(i);
if (!sampler->isolate()->IsInitialized()) continue;
if (!sampler->IsProfiling()) continue;
SampleContext(sampler);
}
}
OS::Sleep(interval_);
}
}
private:
#if defined(USE_SIGNALS)
void SampleContext(Sampler* sampler) {
if (!SignalHandler::Installed()) return;
pthread_t tid = sampler->platform_data()->vm_tid();
pthread_kill(tid, SIGPROF);
}
#elif defined(__MACH__)
void SampleContext(Sampler* sampler) {
thread_act_t profiled_thread = sampler->platform_data()->profiled_thread();
#if defined(USE_SIMULATOR)
SimulatorHelper helper;
Isolate* isolate = sampler->isolate();
if (!helper.Init(sampler, isolate)) return;
#endif
if (KERN_SUCCESS != thread_suspend(profiled_thread)) return;
#if V8_HOST_ARCH_X64
thread_state_flavor_t flavor = x86_THREAD_STATE64;
x86_thread_state64_t thread_state;
mach_msg_type_number_t count = x86_THREAD_STATE64_COUNT;
#if __DARWIN_UNIX03
#define REGISTER_FIELD(name) __r ## name
#else
#define REGISTER_FIELD(name) r ## name
#endif // __DARWIN_UNIX03
#elif V8_HOST_ARCH_IA32
thread_state_flavor_t flavor = i386_THREAD_STATE;
i386_thread_state_t thread_state;
mach_msg_type_number_t count = i386_THREAD_STATE_COUNT;
#if __DARWIN_UNIX03
#define REGISTER_FIELD(name) __e ## name
#else
#define REGISTER_FIELD(name) e ## name
#endif // __DARWIN_UNIX03
#else
#error Unsupported Mac OS X host architecture.
#endif // V8_HOST_ARCH
if (thread_get_state(profiled_thread,
flavor,
reinterpret_cast<natural_t*>(&thread_state),
&count) == KERN_SUCCESS) {
RegisterState state;
#if defined(USE_SIMULATOR)
helper.FillRegisters(&state);
#else
state.pc = reinterpret_cast<Address>(thread_state.REGISTER_FIELD(ip));
state.sp = reinterpret_cast<Address>(thread_state.REGISTER_FIELD(sp));
state.fp = reinterpret_cast<Address>(thread_state.REGISTER_FIELD(bp));
#endif // USE_SIMULATOR
#undef REGISTER_FIELD
sampler->SampleStack(state);
}
thread_resume(profiled_thread);
}
#elif defined(_WIN32) || defined(_WIN64) || defined(__CYGWIN__)
void SampleContext(Sampler* sampler) {
HANDLE profiled_thread = sampler->platform_data()->profiled_thread();
if (profiled_thread == NULL) return;
Isolate* isolate = sampler->isolate();
#if defined(USE_SIMULATOR)
SimulatorHelper helper;
if (!helper.Init(sampler, isolate)) return;
#endif
const DWORD kSuspendFailed = static_cast<DWORD>(-1);
if (SuspendThread(profiled_thread) == kSuspendFailed) return;
// Context used for sampling the register state of the profiled thread.
CONTEXT context;
memset(&context, 0, sizeof(context));
context.ContextFlags = CONTEXT_FULL;
if (GetThreadContext(profiled_thread, &context) != 0) {
RegisterState state;
#if defined(USE_SIMULATOR)
helper.FillRegisters(&state);
#else
#if V8_HOST_ARCH_X64
state.pc = reinterpret_cast<Address>(context.Rip);
state.sp = reinterpret_cast<Address>(context.Rsp);
state.fp = reinterpret_cast<Address>(context.Rbp);
#else
state.pc = reinterpret_cast<Address>(context.Eip);
state.sp = reinterpret_cast<Address>(context.Esp);
state.fp = reinterpret_cast<Address>(context.Ebp);
#endif
#endif // USE_SIMULATOR
sampler->SampleStack(state);
}
ResumeThread(profiled_thread);
}
#endif // USE_SIGNALS
// Protects the process wide state below.
static Mutex* mutex_;
static SamplerThread* instance_;
const int interval_;
List<Sampler*> active_samplers_;
DISALLOW_COPY_AND_ASSIGN(SamplerThread);
};
Mutex* SamplerThread::mutex_ = NULL;
SamplerThread* SamplerThread::instance_ = NULL;
//
// StackTracer implementation
//
DISABLE_ASAN void TickSample::Init(Isolate* isolate,
const RegisterState& regs) {
ASSERT(isolate->IsInitialized());
pc = regs.pc;
state = isolate->current_vm_state();
// Avoid collecting traces while doing GC.
if (state == GC) return;
const Address js_entry_sp =
Isolate::js_entry_sp(isolate->thread_local_top());
if (js_entry_sp == 0) {
// Not executing JS now.
return;
}
ExternalCallbackScope* scope = isolate->external_callback_scope();
Address handler = Isolate::handler(isolate->thread_local_top());
// If there is a handler on top of the external callback scope then
// we have already entrered JavaScript again and the external callback
// is not the top function.
if (scope && scope->scope_address() < handler) {
external_callback = scope->callback();
has_external_callback = true;
} else {
// Sample potential return address value for frameless invocation of
// stubs (we'll figure out later, if this value makes sense).
tos = Memory::Address_at(regs.sp);
has_external_callback = false;
}
SafeStackFrameIterator it(isolate, regs.fp, regs.sp, js_entry_sp);
top_frame_type = it.top_frame_type();
int i = 0;
while (!it.done() && i < TickSample::kMaxFramesCount) {
stack[i++] = it.frame()->pc();
it.Advance();
}
frames_count = i;
}
void Sampler::SetUp() {
SamplerThread::SetUp();
}
void Sampler::TearDown() {
SamplerThread::TearDown();
}
Sampler::Sampler(Isolate* isolate, int interval)
: isolate_(isolate),
interval_(interval),
profiling_(false),
active_(false),
is_counting_samples_(false),
js_and_external_sample_count_(0) {
data_ = new PlatformData;
}
Sampler::~Sampler() {
ASSERT(!IsActive());
delete data_;
}
void Sampler::Start() {
ASSERT(!IsActive());
SetActive(true);
SamplerThread::AddActiveSampler(this);
}
void Sampler::Stop() {
ASSERT(IsActive());
SamplerThread::RemoveActiveSampler(this);
SetActive(false);
}
void Sampler::SampleStack(const RegisterState& state) {
TickSample* sample = isolate_->cpu_profiler()->TickSampleEvent();
TickSample sample_obj;
if (sample == NULL) sample = &sample_obj;
sample->Init(isolate_, state);
if (is_counting_samples_) {
if (sample->state == JS || sample->state == EXTERNAL) {
++js_and_external_sample_count_;
}
}
Tick(sample);
}
} } // namespace v8::internal