v8/src/v8.cc

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// Copyright 2011 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 "v8.h"
#include "isolate.h"
#include "elements.h"
#include "bootstrapper.h"
#include "debug.h"
#include "deoptimizer.h"
#include "heap-profiler.h"
#include "hydrogen.h"
#include "lithium-allocator.h"
#include "log.h"
#include "runtime-profiler.h"
#include "serialize.h"
#include "store-buffer.h"
namespace v8 {
namespace internal {
static Mutex* init_once_mutex = OS::CreateMutex();
static bool init_once_called = false;
bool V8::is_running_ = false;
bool V8::has_been_setup_ = false;
bool V8::has_been_disposed_ = false;
bool V8::has_fatal_error_ = false;
bool V8::use_crankshaft_ = true;
List<CallCompletedCallback>* V8::call_completed_callbacks_ = NULL;
static Mutex* entropy_mutex = OS::CreateMutex();
static EntropySource entropy_source;
bool V8::Initialize(Deserializer* des) {
FlagList::EnforceFlagImplications();
InitializeOncePerProcess();
// The current thread may not yet had entered an isolate to run.
// Note the Isolate::Current() may be non-null because for various
// initialization purposes an initializing thread may be assigned an isolate
// but not actually enter it.
if (i::Isolate::CurrentPerIsolateThreadData() == NULL) {
i::Isolate::EnterDefaultIsolate();
}
ASSERT(i::Isolate::CurrentPerIsolateThreadData() != NULL);
ASSERT(i::Isolate::CurrentPerIsolateThreadData()->thread_id().Equals(
i::ThreadId::Current()));
ASSERT(i::Isolate::CurrentPerIsolateThreadData()->isolate() ==
i::Isolate::Current());
if (IsDead()) return false;
Isolate* isolate = Isolate::Current();
if (isolate->IsInitialized()) return true;
is_running_ = true;
has_been_setup_ = true;
has_fatal_error_ = false;
has_been_disposed_ = false;
return isolate->Init(des);
}
void V8::SetFatalError() {
is_running_ = false;
has_fatal_error_ = true;
}
void V8::TearDown() {
Isolate* isolate = Isolate::Current();
ASSERT(isolate->IsDefaultIsolate());
if (!has_been_setup_ || has_been_disposed_) return;
isolate->TearDown();
is_running_ = false;
has_been_disposed_ = true;
delete call_completed_callbacks_;
call_completed_callbacks_ = NULL;
}
static void seed_random(uint32_t* state) {
for (int i = 0; i < 2; ++i) {
if (FLAG_random_seed != 0) {
state[i] = FLAG_random_seed;
} else if (entropy_source != NULL) {
uint32_t val;
ScopedLock lock(entropy_mutex);
entropy_source(reinterpret_cast<unsigned char*>(&val), sizeof(uint32_t));
state[i] = val;
} else {
state[i] = random();
}
}
}
// Random number generator using George Marsaglia's MWC algorithm.
static uint32_t random_base(uint32_t* state) {
// Initialize seed using the system random().
// No non-zero seed will ever become zero again.
if (state[0] == 0) seed_random(state);
// Mix the bits. Never replaces state[i] with 0 if it is nonzero.
state[0] = 18273 * (state[0] & 0xFFFF) + (state[0] >> 16);
state[1] = 36969 * (state[1] & 0xFFFF) + (state[1] >> 16);
return (state[0] << 14) + (state[1] & 0x3FFFF);
}
void V8::SetEntropySource(EntropySource source) {
entropy_source = source;
}
// Used by JavaScript APIs
uint32_t V8::Random(Context* context) {
ASSERT(context->IsGlobalContext());
ByteArray* seed = context->random_seed();
return random_base(reinterpret_cast<uint32_t*>(seed->GetDataStartAddress()));
}
// Used internally by the JIT and memory allocator for security
// purposes. So, we keep a different state to prevent informations
// leaks that could be used in an exploit.
uint32_t V8::RandomPrivate(Isolate* isolate) {
ASSERT(isolate == Isolate::Current());
return random_base(isolate->private_random_seed());
}
bool V8::IdleNotification(int hint) {
// Returning true tells the caller that there is no need to call
// IdleNotification again.
if (!FLAG_use_idle_notification) return true;
// Tell the heap that it may want to adjust.
return HEAP->IdleNotification(hint);
}
void V8::AddCallCompletedCallback(CallCompletedCallback callback) {
if (call_completed_callbacks_ == NULL) { // Lazy init.
call_completed_callbacks_ = new List<CallCompletedCallback>();
}
for (int i = 0; i < call_completed_callbacks_->length(); i++) {
if (callback == call_completed_callbacks_->at(i)) return;
}
call_completed_callbacks_->Add(callback);
}
void V8::RemoveCallCompletedCallback(CallCompletedCallback callback) {
if (call_completed_callbacks_ == NULL) return;
for (int i = 0; i < call_completed_callbacks_->length(); i++) {
if (callback == call_completed_callbacks_->at(i)) {
call_completed_callbacks_->Remove(i);
}
}
}
void V8::FireCallCompletedCallback(Isolate* isolate) {
if (call_completed_callbacks_ == NULL) return;
HandleScopeImplementer* handle_scope_implementer =
isolate->handle_scope_implementer();
if (!handle_scope_implementer->CallDepthIsZero()) return;
// Fire callbacks. Increase call depth to prevent recursive callbacks.
handle_scope_implementer->IncrementCallDepth();
for (int i = 0; i < call_completed_callbacks_->length(); i++) {
call_completed_callbacks_->at(i)();
}
handle_scope_implementer->DecrementCallDepth();
}
// Use a union type to avoid type-aliasing optimizations in GCC.
typedef union {
double double_value;
uint64_t uint64_t_value;
} double_int_union;
Object* V8::FillHeapNumberWithRandom(Object* heap_number,
Context* context) {
uint64_t random_bits = Random(context);
// Make a double* from address (heap_number + sizeof(double)).
double_int_union* r = reinterpret_cast<double_int_union*>(
reinterpret_cast<char*>(heap_number) +
HeapNumber::kValueOffset - kHeapObjectTag);
// Convert 32 random bits to 0.(32 random bits) in a double
// by computing:
// ( 1.(20 0s)(32 random bits) x 2^20 ) - (1.0 x 2^20)).
const double binary_million = 1048576.0;
r->double_value = binary_million;
r->uint64_t_value |= random_bits;
r->double_value -= binary_million;
return heap_number;
}
void V8::InitializeOncePerProcess() {
ScopedLock lock(init_once_mutex);
if (init_once_called) return;
init_once_called = true;
// Setup the platform OS support.
OS::Setup();
use_crankshaft_ = FLAG_crankshaft;
if (Serializer::enabled()) {
use_crankshaft_ = false;
}
CPU::Setup();
if (!CPU::SupportsCrankshaft()) {
use_crankshaft_ = false;
}
RuntimeProfiler::GlobalSetup();
// Peephole optimization might interfere with deoptimization.
FLAG_peephole_optimization = !use_crankshaft_;
ElementsAccessor::InitializeOncePerProcess();
if (FLAG_stress_compaction) {
FLAG_force_marking_deque_overflows = true;
FLAG_gc_global = true;
FLAG_max_new_space_size = (1 << (kPageSizeBits - 10)) * 2;
}
}
} } // namespace v8::internal