Upgrade V8 to version 4.9.385.28
https://chromium.googlesource.com/v8/v8/+/4.9.385.28
FPIIM-449
Change-Id: I4b2e74289d4bf3667f2f3dc8aa2e541f63e26eb4
diff --git a/src/profiler/sampler.cc b/src/profiler/sampler.cc
new file mode 100644
index 0000000..dc4c4c4
--- /dev/null
+++ b/src/profiler/sampler.cc
@@ -0,0 +1,861 @@
+// Copyright 2013 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/profiler/sampler.h"
+
+#if V8_OS_POSIX && !V8_OS_CYGWIN
+
+#define USE_SIGNALS
+
+#include <errno.h>
+#include <pthread.h>
+#include <signal.h>
+#include <sys/time.h>
+
+#if !V8_OS_QNX && !V8_OS_NACL && !V8_OS_AIX
+#include <sys/syscall.h> // NOLINT
+#endif
+
+#if V8_OS_MACOSX
+#include <mach/mach.h>
+// OpenBSD doesn't have <ucontext.h>. ucontext_t lives in <signal.h>
+// and is a typedef for struct sigcontext. There is no uc_mcontext.
+#elif(!V8_OS_ANDROID || defined(__BIONIC_HAVE_UCONTEXT_T)) && \
+ !V8_OS_OPENBSD && !V8_OS_NACL
+#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 V8_OS_ANDROID && !defined(__BIONIC_HAVE_UCONTEXT_T) && \
+ (defined(__arm__) || defined(__aarch64__)) && \
+ !defined(__BIONIC_HAVE_STRUCT_SIGCONTEXT)
+#include <asm/sigcontext.h> // NOLINT
+#endif
+
+#elif V8_OS_WIN || V8_OS_CYGWIN
+
+#include "src/base/win32-headers.h"
+
+#endif
+
+#include "src/base/platform/platform.h"
+#include "src/flags.h"
+#include "src/frames-inl.h"
+#include "src/log.h"
+#include "src/profiler/cpu-profiler-inl.h"
+#include "src/simulator.h"
+#include "src/v8threads.h"
+#include "src/vm-state-inl.h"
+
+
+#if V8_OS_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(__aarch64__)
+
+typedef struct sigcontext mcontext_t;
+
+typedef struct ucontext {
+ uint64_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 };
+
+#elif defined(__x86_64__)
+// x64 version for Android.
+typedef struct {
+ uint64_t gregs[23];
+ void* fpregs;
+ uint64_t __reserved1[8];
+} mcontext_t;
+
+typedef struct ucontext {
+ uint64_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_RBP = 10, REG_RSP = 15, REG_RIP = 16 };
+#endif
+
+#endif // V8_OS_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_;
+};
+
+
+bool IsSamePage(byte* ptr1, byte* ptr2) {
+ const uint32_t kPageSize = 4096;
+ uintptr_t mask = ~static_cast<uintptr_t>(kPageSize - 1);
+ return (reinterpret_cast<uintptr_t>(ptr1) & mask) ==
+ (reinterpret_cast<uintptr_t>(ptr2) & mask);
+}
+
+
+// Check if the code at specified address could potentially be a
+// frame setup code.
+bool IsNoFrameRegion(Address address) {
+ struct Pattern {
+ int bytes_count;
+ byte bytes[8];
+ int offsets[4];
+ };
+ byte* pc = reinterpret_cast<byte*>(address);
+ static Pattern patterns[] = {
+#if V8_HOST_ARCH_IA32
+ // push %ebp
+ // mov %esp,%ebp
+ {3, {0x55, 0x89, 0xe5}, {0, 1, -1}},
+ // pop %ebp
+ // ret N
+ {2, {0x5d, 0xc2}, {0, 1, -1}},
+ // pop %ebp
+ // ret
+ {2, {0x5d, 0xc3}, {0, 1, -1}},
+#elif V8_HOST_ARCH_X64
+ // pushq %rbp
+ // movq %rsp,%rbp
+ {4, {0x55, 0x48, 0x89, 0xe5}, {0, 1, -1}},
+ // popq %rbp
+ // ret N
+ {2, {0x5d, 0xc2}, {0, 1, -1}},
+ // popq %rbp
+ // ret
+ {2, {0x5d, 0xc3}, {0, 1, -1}},
+#endif
+ {0, {}, {}}
+ };
+ for (Pattern* pattern = patterns; pattern->bytes_count; ++pattern) {
+ for (int* offset_ptr = pattern->offsets; *offset_ptr != -1; ++offset_ptr) {
+ int offset = *offset_ptr;
+ if (!offset || IsSamePage(pc, pc - offset)) {
+ MSAN_MEMORY_IS_INITIALIZED(pc - offset, pattern->bytes_count);
+ if (!memcmp(pc - offset, pattern->bytes, pattern->bytes_count))
+ return true;
+ } else {
+ // It is not safe to examine bytes on another page as it might not be
+ // allocated thus causing a SEGFAULT.
+ // Check the pattern part that's on the same page and
+ // pessimistically assume it could be the entire pattern match.
+ MSAN_MEMORY_IS_INITIALIZED(pc, pattern->bytes_count - offset);
+ if (!memcmp(pc, pattern->bytes + offset, pattern->bytes_count - offset))
+ return true;
+ }
+ }
+ }
+ return false;
+}
+
+} // 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 V8_OS_WIN || V8_OS_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(Isolate* isolate) {
+ simulator_ = isolate->thread_local_top()->simulator_;
+ // Check if there is active simulator.
+ return simulator_ != NULL;
+ }
+
+ inline void FillRegisters(v8::RegisterState* state) {
+#if V8_TARGET_ARCH_ARM
+ if (!simulator_->has_bad_pc()) {
+ state->pc = reinterpret_cast<Address>(simulator_->get_pc());
+ }
+ state->sp = reinterpret_cast<Address>(simulator_->get_register(
+ Simulator::sp));
+ state->fp = reinterpret_cast<Address>(simulator_->get_register(
+ Simulator::r11));
+#elif V8_TARGET_ARCH_ARM64
+ if (simulator_->sp() == 0 || simulator_->fp() == 0) {
+ // It's possible that the simulator is interrupted while it is updating
+ // the sp or fp register. ARM64 simulator does this in two steps:
+ // first setting it to zero and then setting it to a new value.
+ // Bailout if sp/fp doesn't contain the new value.
+ //
+ // FIXME: The above doesn't really solve the issue.
+ // If a 64-bit target is executed on a 32-bit host even the final
+ // write is non-atomic, so it might obtain a half of the result.
+ // Moreover as long as the register set code uses memcpy (as of now),
+ // it is not guaranteed to be atomic even when both host and target
+ // are of same bitness.
+ return;
+ }
+ state->pc = reinterpret_cast<Address>(simulator_->pc());
+ state->sp = reinterpret_cast<Address>(simulator_->sp());
+ state->fp = reinterpret_cast<Address>(simulator_->fp());
+#elif V8_TARGET_ARCH_MIPS || V8_TARGET_ARCH_MIPS64
+ if (!simulator_->has_bad_pc()) {
+ state->pc = reinterpret_cast<Address>(simulator_->get_pc());
+ }
+ state->sp = reinterpret_cast<Address>(simulator_->get_register(
+ Simulator::sp));
+ state->fp = reinterpret_cast<Address>(simulator_->get_register(
+ Simulator::fp));
+#elif V8_TARGET_ARCH_PPC
+ if (!simulator_->has_bad_pc()) {
+ state->pc = reinterpret_cast<Address>(simulator_->get_pc());
+ }
+ state->sp =
+ reinterpret_cast<Address>(simulator_->get_register(Simulator::sp));
+ 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 void SetUp() { if (!mutex_) mutex_ = new base::Mutex(); }
+ static void TearDown() { delete mutex_; mutex_ = NULL; }
+
+ static void IncreaseSamplerCount() {
+ base::LockGuard<base::Mutex> lock_guard(mutex_);
+ if (++client_count_ == 1) Install();
+ }
+
+ static void DecreaseSamplerCount() {
+ base::LockGuard<base::Mutex> lock_guard(mutex_);
+ if (--client_count_ == 0) Restore();
+ }
+
+ static bool Installed() {
+ return signal_handler_installed_;
+ }
+
+ private:
+ static void Install() {
+#if !V8_OS_NACL
+ struct sigaction sa;
+ sa.sa_sigaction = &HandleProfilerSignal;
+ sigemptyset(&sa.sa_mask);
+#if V8_OS_QNX
+ sa.sa_flags = SA_SIGINFO;
+#else
+ sa.sa_flags = SA_RESTART | SA_SIGINFO;
+#endif
+ signal_handler_installed_ =
+ (sigaction(SIGPROF, &sa, &old_signal_handler_) == 0);
+#endif
+ }
+
+ static void Restore() {
+#if !V8_OS_NACL
+ if (signal_handler_installed_) {
+ sigaction(SIGPROF, &old_signal_handler_, 0);
+ signal_handler_installed_ = false;
+ }
+#endif
+ }
+
+#if !V8_OS_NACL
+ static void HandleProfilerSignal(int signal, siginfo_t* info, void* context);
+#endif
+ // Protects the process wide state below.
+ static base::Mutex* mutex_;
+ static int client_count_;
+ static bool signal_handler_installed_;
+ static struct sigaction old_signal_handler_;
+};
+
+
+base::Mutex* SignalHandler::mutex_ = NULL;
+int SignalHandler::client_count_ = 0;
+struct sigaction SignalHandler::old_signal_handler_;
+bool SignalHandler::signal_handler_installed_ = false;
+
+
+// As Native Client does not support signal handling, profiling is disabled.
+#if !V8_OS_NACL
+void SignalHandler::HandleProfilerSignal(int signal, siginfo_t* info,
+ void* context) {
+ USE(info);
+ if (signal != SIGPROF) return;
+ Isolate* isolate = Isolate::UnsafeCurrent();
+ if (isolate == NULL || !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) return;
+
+ v8::RegisterState state;
+
+#if defined(USE_SIMULATOR)
+ SimulatorHelper helper;
+ if (!helper.Init(isolate)) return;
+ helper.FillRegisters(&state);
+ // It possible that the simulator is interrupted while it is updating
+ // the sp or fp register. ARM64 simulator does this in two steps:
+ // first setting it to zero and then setting it to the new value.
+ // Bailout if sp/fp doesn't contain the new value.
+ if (state.sp == 0 || state.fp == 0) return;
+#else
+ // Extracting the sample from the context is extremely machine dependent.
+ ucontext_t* ucontext = reinterpret_cast<ucontext_t*>(context);
+#if !(V8_OS_OPENBSD || (V8_OS_LINUX && V8_HOST_ARCH_PPC))
+ mcontext_t& mcontext = ucontext->uc_mcontext;
+#endif
+#if V8_OS_LINUX
+#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 V8_LIBC_GLIBC && !V8_GLIBC_PREREQ(2, 4)
+ // 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 // V8_LIBC_GLIBC && !V8_GLIBC_PREREQ(2, 4)
+#elif V8_HOST_ARCH_ARM64
+ state.pc = reinterpret_cast<Address>(mcontext.pc);
+ state.sp = reinterpret_cast<Address>(mcontext.sp);
+ // FP is an alias for x29.
+ state.fp = reinterpret_cast<Address>(mcontext.regs[29]);
+#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]);
+#elif V8_HOST_ARCH_MIPS64
+ state.pc = reinterpret_cast<Address>(mcontext.pc);
+ state.sp = reinterpret_cast<Address>(mcontext.gregs[29]);
+ state.fp = reinterpret_cast<Address>(mcontext.gregs[30]);
+#elif V8_HOST_ARCH_PPC
+ state.pc = reinterpret_cast<Address>(ucontext->uc_mcontext.regs->nip);
+ state.sp = reinterpret_cast<Address>(ucontext->uc_mcontext.regs->gpr[PT_R1]);
+ state.fp = reinterpret_cast<Address>(ucontext->uc_mcontext.regs->gpr[PT_R31]);
+#endif // V8_HOST_ARCH_*
+#elif V8_OS_MACOSX
+#if V8_HOST_ARCH_X64
+#if __DARWIN_UNIX03
+ state.pc = reinterpret_cast<Address>(mcontext->__ss.__rip);
+ state.sp = reinterpret_cast<Address>(mcontext->__ss.__rsp);
+ state.fp = reinterpret_cast<Address>(mcontext->__ss.__rbp);
+#else // !__DARWIN_UNIX03
+ state.pc = reinterpret_cast<Address>(mcontext->ss.rip);
+ state.sp = reinterpret_cast<Address>(mcontext->ss.rsp);
+ state.fp = reinterpret_cast<Address>(mcontext->ss.rbp);
+#endif // __DARWIN_UNIX03
+#elif V8_HOST_ARCH_IA32
+#if __DARWIN_UNIX03
+ state.pc = reinterpret_cast<Address>(mcontext->__ss.__eip);
+ state.sp = reinterpret_cast<Address>(mcontext->__ss.__esp);
+ state.fp = reinterpret_cast<Address>(mcontext->__ss.__ebp);
+#else // !__DARWIN_UNIX03
+ state.pc = reinterpret_cast<Address>(mcontext->ss.eip);
+ state.sp = reinterpret_cast<Address>(mcontext->ss.esp);
+ state.fp = reinterpret_cast<Address>(mcontext->ss.ebp);
+#endif // __DARWIN_UNIX03
+#endif // V8_HOST_ARCH_IA32
+#elif V8_OS_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 V8_OS_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 V8_OS_OPENBSD
+#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 V8_OS_SOLARIS
+ 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]);
+#elif V8_OS_QNX
+#if V8_HOST_ARCH_IA32
+ state.pc = reinterpret_cast<Address>(mcontext.cpu.eip);
+ state.sp = reinterpret_cast<Address>(mcontext.cpu.esp);
+ state.fp = reinterpret_cast<Address>(mcontext.cpu.ebp);
+#elif V8_HOST_ARCH_ARM
+ state.pc = reinterpret_cast<Address>(mcontext.cpu.gpr[ARM_REG_PC]);
+ state.sp = reinterpret_cast<Address>(mcontext.cpu.gpr[ARM_REG_SP]);
+ state.fp = reinterpret_cast<Address>(mcontext.cpu.gpr[ARM_REG_FP]);
+#endif // V8_HOST_ARCH_*
+#elif V8_OS_AIX
+ state.pc = reinterpret_cast<Address>(mcontext.jmp_context.iar);
+ state.sp = reinterpret_cast<Address>(mcontext.jmp_context.gpr[1]);
+ state.fp = reinterpret_cast<Address>(mcontext.jmp_context.gpr[31]);
+#endif // V8_OS_AIX
+#endif // USE_SIMULATOR
+ sampler->SampleStack(state);
+}
+#endif // V8_OS_NACL
+
+#endif
+
+
+class SamplerThread : public base::Thread {
+ public:
+ static const int kSamplerThreadStackSize = 64 * KB;
+
+ explicit SamplerThread(int interval)
+ : Thread(base::Thread::Options("SamplerThread", kSamplerThreadStackSize)),
+ interval_(interval) {}
+
+ static void SetUp() { if (!mutex_) mutex_ = new base::Mutex(); }
+ static void TearDown() { delete mutex_; mutex_ = NULL; }
+
+ static void AddActiveSampler(Sampler* sampler) {
+ bool need_to_start = false;
+ base::LockGuard<base::Mutex> lock_guard(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;
+ }
+
+ DCHECK(sampler->IsActive());
+ DCHECK(!instance_->active_samplers_.Contains(sampler));
+ DCHECK(instance_->interval_ == sampler->interval());
+ instance_->active_samplers_.Add(sampler);
+
+ if (need_to_start) instance_->StartSynchronously();
+ }
+
+ static void RemoveActiveSampler(Sampler* sampler) {
+ SamplerThread* instance_to_remove = NULL;
+ {
+ base::LockGuard<base::Mutex> lock_guard(mutex_);
+
+ DCHECK(sampler->IsActive());
+ bool removed = instance_->active_samplers_.RemoveElement(sampler);
+ DCHECK(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 (!instance_to_remove) return;
+ instance_to_remove->Join();
+ delete instance_to_remove;
+ }
+
+ // Implement Thread::Run().
+ virtual void Run() {
+ while (true) {
+ {
+ base::LockGuard<base::Mutex> lock_guard(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->IsProfiling()) continue;
+ sampler->DoSample();
+ }
+ }
+ base::OS::Sleep(base::TimeDelta::FromMilliseconds(interval_));
+ }
+ }
+
+ private:
+ // Protects the process wide state below.
+ static base::Mutex* mutex_;
+ static SamplerThread* instance_;
+
+ const int interval_;
+ List<Sampler*> active_samplers_;
+
+ DISALLOW_COPY_AND_ASSIGN(SamplerThread);
+};
+
+
+base::Mutex* SamplerThread::mutex_ = NULL;
+SamplerThread* SamplerThread::instance_ = NULL;
+
+
+//
+// StackTracer implementation
+//
+DISABLE_ASAN void TickSample::Init(Isolate* isolate,
+ const v8::RegisterState& regs,
+ RecordCEntryFrame record_c_entry_frame) {
+ timestamp = base::TimeTicks::HighResolutionNow();
+ pc = reinterpret_cast<Address>(regs.pc);
+ state = isolate->current_vm_state();
+
+ // Avoid collecting traces while doing GC.
+ if (state == GC) return;
+
+ Address js_entry_sp = isolate->js_entry_sp();
+ if (js_entry_sp == 0) return; // Not executing JS now.
+
+ if (pc && IsNoFrameRegion(pc)) {
+ pc = 0;
+ 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 {
+ // sp register may point at an arbitrary place in memory, make
+ // sure MSAN doesn't complain about it.
+ MSAN_MEMORY_IS_INITIALIZED(regs.sp, sizeof(Address));
+ // Sample potential return address value for frameless invocation of
+ // stubs (we'll figure out later, if this value makes sense).
+ tos = Memory::Address_at(reinterpret_cast<Address>(regs.sp));
+ has_external_callback = false;
+ }
+
+ SafeStackFrameIterator it(isolate, reinterpret_cast<Address>(regs.fp),
+ reinterpret_cast<Address>(regs.sp), js_entry_sp);
+ top_frame_type = it.top_frame_type();
+
+ SampleInfo info;
+ GetStackSample(isolate, regs, record_c_entry_frame,
+ reinterpret_cast<void**>(&stack[0]), kMaxFramesCount, &info);
+ frames_count = static_cast<unsigned>(info.frames_count);
+}
+
+
+void TickSample::GetStackSample(Isolate* isolate, const v8::RegisterState& regs,
+ RecordCEntryFrame record_c_entry_frame,
+ void** frames, size_t frames_limit,
+ v8::SampleInfo* sample_info) {
+ sample_info->frames_count = 0;
+ sample_info->vm_state = isolate->current_vm_state();
+ if (sample_info->vm_state == GC) return;
+
+ Address js_entry_sp = isolate->js_entry_sp();
+ if (js_entry_sp == 0) return; // Not executing JS now.
+
+ SafeStackFrameIterator it(isolate, reinterpret_cast<Address>(regs.fp),
+ reinterpret_cast<Address>(regs.sp), js_entry_sp);
+ size_t i = 0;
+ if (record_c_entry_frame == kIncludeCEntryFrame && !it.done() &&
+ it.top_frame_type() == StackFrame::EXIT) {
+ frames[i++] = isolate->c_function();
+ }
+ while (!it.done() && i < frames_limit) {
+ frames[i++] = it.frame()->pc();
+ it.Advance();
+ }
+ sample_info->frames_count = i;
+}
+
+
+void Sampler::SetUp() {
+#if defined(USE_SIGNALS)
+ SignalHandler::SetUp();
+#endif
+ SamplerThread::SetUp();
+}
+
+
+void Sampler::TearDown() {
+ SamplerThread::TearDown();
+#if defined(USE_SIGNALS)
+ SignalHandler::TearDown();
+#endif
+}
+
+
+Sampler::Sampler(Isolate* isolate, int interval)
+ : isolate_(isolate),
+ interval_(interval),
+ profiling_(false),
+ has_processing_thread_(false),
+ active_(false),
+ is_counting_samples_(false),
+ js_and_external_sample_count_(0) {
+ data_ = new PlatformData;
+}
+
+
+Sampler::~Sampler() {
+ DCHECK(!IsActive());
+ delete data_;
+}
+
+
+void Sampler::Start() {
+ DCHECK(!IsActive());
+ SetActive(true);
+ SamplerThread::AddActiveSampler(this);
+}
+
+
+void Sampler::Stop() {
+ DCHECK(IsActive());
+ SamplerThread::RemoveActiveSampler(this);
+ SetActive(false);
+}
+
+
+void Sampler::IncreaseProfilingDepth() {
+ base::NoBarrier_AtomicIncrement(&profiling_, 1);
+#if defined(USE_SIGNALS)
+ SignalHandler::IncreaseSamplerCount();
+#endif
+}
+
+
+void Sampler::DecreaseProfilingDepth() {
+#if defined(USE_SIGNALS)
+ SignalHandler::DecreaseSamplerCount();
+#endif
+ base::NoBarrier_AtomicIncrement(&profiling_, -1);
+}
+
+
+void Sampler::SampleStack(const v8::RegisterState& state) {
+ TickSample* sample = isolate_->cpu_profiler()->StartTickSample();
+ TickSample sample_obj;
+ if (sample == NULL) sample = &sample_obj;
+ sample->Init(isolate_, state, TickSample::kIncludeCEntryFrame);
+ if (is_counting_samples_) {
+ if (sample->state == JS || sample->state == EXTERNAL) {
+ ++js_and_external_sample_count_;
+ }
+ }
+ Tick(sample);
+ if (sample != &sample_obj) {
+ isolate_->cpu_profiler()->FinishTickSample();
+ }
+}
+
+
+#if defined(USE_SIGNALS)
+
+void Sampler::DoSample() {
+ if (!SignalHandler::Installed()) return;
+ pthread_kill(platform_data()->vm_tid(), SIGPROF);
+}
+
+#elif V8_OS_WIN || V8_OS_CYGWIN
+
+void Sampler::DoSample() {
+ HANDLE profiled_thread = platform_data()->profiled_thread();
+ if (profiled_thread == NULL) return;
+
+#if defined(USE_SIMULATOR)
+ SimulatorHelper helper;
+ if (!helper.Init(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) {
+ v8::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
+ SampleStack(state);
+ }
+ ResumeThread(profiled_thread);
+}
+
+#endif // USE_SIGNALS
+
+
+} // namespace internal
+} // namespace v8