1// Copyright 2012 the V8 project authors. All rights reserved.
2// Redistribution and use in source and binary forms, with or without
3// modification, are permitted provided that the following conditions are
4// met:
5//
6//     * Redistributions of source code must retain the above copyright
7//       notice, this list of conditions and the following disclaimer.
8//     * Redistributions in binary form must reproduce the above
9//       copyright notice, this list of conditions and the following
10//       disclaimer in the documentation and/or other materials provided
11//       with the distribution.
12//     * Neither the name of Google Inc. nor the names of its
13//       contributors may be used to endorse or promote products derived
14//       from this software without specific prior written permission.
15//
16// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27
28#include "v8.h"
29
30#include "isolate.h"
31#include "elements.h"
32#include "bootstrapper.h"
33#include "debug.h"
34#include "deoptimizer.h"
35#include "heap-profiler.h"
36#include "hydrogen.h"
37#include "lithium-allocator.h"
38#include "log.h"
39#include "once.h"
40#include "platform.h"
41#include "runtime-profiler.h"
42#include "serialize.h"
43#include "store-buffer.h"
44
45namespace v8 {
46namespace internal {
47
48V8_DECLARE_ONCE(init_once);
49
50bool V8::is_running_ = false;
51bool V8::has_been_set_up_ = false;
52bool V8::has_been_disposed_ = false;
53bool V8::has_fatal_error_ = false;
54bool V8::use_crankshaft_ = true;
55List<CallCompletedCallback>* V8::call_completed_callbacks_ = NULL;
56
57static LazyMutex entropy_mutex = LAZY_MUTEX_INITIALIZER;
58
59static EntropySource entropy_source;
60
61
62bool V8::Initialize(Deserializer* des) {
63  FlagList::EnforceFlagImplications();
64
65  InitializeOncePerProcess();
66
67  // The current thread may not yet had entered an isolate to run.
68  // Note the Isolate::Current() may be non-null because for various
69  // initialization purposes an initializing thread may be assigned an isolate
70  // but not actually enter it.
71  if (i::Isolate::CurrentPerIsolateThreadData() == NULL) {
72    i::Isolate::EnterDefaultIsolate();
73  }
74
75  ASSERT(i::Isolate::CurrentPerIsolateThreadData() != NULL);
76  ASSERT(i::Isolate::CurrentPerIsolateThreadData()->thread_id().Equals(
77           i::ThreadId::Current()));
78  ASSERT(i::Isolate::CurrentPerIsolateThreadData()->isolate() ==
79         i::Isolate::Current());
80
81  if (IsDead()) return false;
82
83  Isolate* isolate = Isolate::Current();
84  if (isolate->IsInitialized()) return true;
85
86  is_running_ = true;
87  has_been_set_up_ = true;
88  has_fatal_error_ = false;
89  has_been_disposed_ = false;
90
91  return isolate->Init(des);
92}
93
94
95void V8::SetFatalError() {
96  is_running_ = false;
97  has_fatal_error_ = true;
98}
99
100
101void V8::TearDown() {
102  Isolate* isolate = Isolate::Current();
103  ASSERT(isolate->IsDefaultIsolate());
104
105  if (!has_been_set_up_ || has_been_disposed_) return;
106  isolate->TearDown();
107
108  is_running_ = false;
109  has_been_disposed_ = true;
110
111  delete call_completed_callbacks_;
112  call_completed_callbacks_ = NULL;
113}
114
115
116static void seed_random(uint32_t* state) {
117  for (int i = 0; i < 2; ++i) {
118    if (FLAG_random_seed != 0) {
119      state[i] = FLAG_random_seed;
120    } else if (entropy_source != NULL) {
121      uint32_t val;
122      ScopedLock lock(entropy_mutex.Pointer());
123      entropy_source(reinterpret_cast<unsigned char*>(&val), sizeof(uint32_t));
124      state[i] = val;
125    } else {
126      state[i] = random();
127    }
128  }
129}
130
131
132// Random number generator using George Marsaglia's MWC algorithm.
133static uint32_t random_base(uint32_t* state) {
134  // Initialize seed using the system random().
135  // No non-zero seed will ever become zero again.
136  if (state[0] == 0) seed_random(state);
137
138  // Mix the bits.  Never replaces state[i] with 0 if it is nonzero.
139  state[0] = 18273 * (state[0] & 0xFFFF) + (state[0] >> 16);
140  state[1] = 36969 * (state[1] & 0xFFFF) + (state[1] >> 16);
141
142  return (state[0] << 14) + (state[1] & 0x3FFFF);
143}
144
145
146void V8::SetEntropySource(EntropySource source) {
147  entropy_source = source;
148}
149
150
151void V8::SetReturnAddressLocationResolver(
152      ReturnAddressLocationResolver resolver) {
153  StackFrame::SetReturnAddressLocationResolver(resolver);
154}
155
156
157// Used by JavaScript APIs
158uint32_t V8::Random(Context* context) {
159  ASSERT(context->IsGlobalContext());
160  ByteArray* seed = context->random_seed();
161  return random_base(reinterpret_cast<uint32_t*>(seed->GetDataStartAddress()));
162}
163
164
165// Used internally by the JIT and memory allocator for security
166// purposes. So, we keep a different state to prevent informations
167// leaks that could be used in an exploit.
168uint32_t V8::RandomPrivate(Isolate* isolate) {
169  ASSERT(isolate == Isolate::Current());
170  return random_base(isolate->private_random_seed());
171}
172
173
174bool V8::IdleNotification(int hint) {
175  // Returning true tells the caller that there is no need to call
176  // IdleNotification again.
177  if (!FLAG_use_idle_notification) return true;
178
179  // Tell the heap that it may want to adjust.
180  return HEAP->IdleNotification(hint);
181}
182
183
184void V8::AddCallCompletedCallback(CallCompletedCallback callback) {
185  if (call_completed_callbacks_ == NULL) {  // Lazy init.
186    call_completed_callbacks_ = new List<CallCompletedCallback>();
187  }
188  for (int i = 0; i < call_completed_callbacks_->length(); i++) {
189    if (callback == call_completed_callbacks_->at(i)) return;
190  }
191  call_completed_callbacks_->Add(callback);
192}
193
194
195void V8::RemoveCallCompletedCallback(CallCompletedCallback callback) {
196  if (call_completed_callbacks_ == NULL) return;
197  for (int i = 0; i < call_completed_callbacks_->length(); i++) {
198    if (callback == call_completed_callbacks_->at(i)) {
199      call_completed_callbacks_->Remove(i);
200    }
201  }
202}
203
204
205void V8::FireCallCompletedCallback(Isolate* isolate) {
206  if (call_completed_callbacks_ == NULL) return;
207  HandleScopeImplementer* handle_scope_implementer =
208      isolate->handle_scope_implementer();
209  if (!handle_scope_implementer->CallDepthIsZero()) return;
210  // Fire callbacks.  Increase call depth to prevent recursive callbacks.
211  handle_scope_implementer->IncrementCallDepth();
212  for (int i = 0; i < call_completed_callbacks_->length(); i++) {
213    call_completed_callbacks_->at(i)();
214  }
215  handle_scope_implementer->DecrementCallDepth();
216}
217
218
219// Use a union type to avoid type-aliasing optimizations in GCC.
220typedef union {
221  double double_value;
222  uint64_t uint64_t_value;
223} double_int_union;
224
225
226Object* V8::FillHeapNumberWithRandom(Object* heap_number,
227                                     Context* context) {
228  double_int_union r;
229  uint64_t random_bits = Random(context);
230  // Convert 32 random bits to 0.(32 random bits) in a double
231  // by computing:
232  // ( 1.(20 0s)(32 random bits) x 2^20 ) - (1.0 x 2^20)).
233  static const double binary_million = 1048576.0;
234  r.double_value = binary_million;
235  r.uint64_t_value |= random_bits;
236  r.double_value -= binary_million;
237
238  HeapNumber::cast(heap_number)->set_value(r.double_value);
239  return heap_number;
240}
241
242void V8::InitializeOncePerProcessImpl() {
243  // Set up the platform OS support.
244  OS::SetUp();
245
246  use_crankshaft_ = FLAG_crankshaft;
247
248  if (Serializer::enabled()) {
249    use_crankshaft_ = false;
250  }
251
252  CPU::SetUp();
253  if (!CPU::SupportsCrankshaft()) {
254    use_crankshaft_ = false;
255  }
256
257  OS::PostSetUp();
258
259  RuntimeProfiler::GlobalSetup();
260
261  ElementsAccessor::InitializeOncePerProcess();
262
263  if (FLAG_stress_compaction) {
264    FLAG_force_marking_deque_overflows = true;
265    FLAG_gc_global = true;
266    FLAG_max_new_space_size = (1 << (kPageSizeBits - 10)) * 2;
267  }
268
269  LOperand::SetUpCaches();
270}
271
272void V8::InitializeOncePerProcess() {
273  CallOnce(&init_once, &InitializeOncePerProcessImpl);
274}
275
276} }  // namespace v8::internal
277