1 // Copyright 2011 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 "bootstrapper.h"
32 #include "debug.h"
33 #include "deoptimizer.h"
34 #include "heap-profiler.h"
35 #include "hydrogen.h"
36 #include "lithium-allocator.h"
37 #include "log.h"
38 #include "runtime-profiler.h"
39 #include "serialize.h"
40
41 namespace v8 {
42 namespace internal {
43
44 static Mutex* init_once_mutex = OS::CreateMutex();
45 static bool init_once_called = false;
46
47 bool V8::is_running_ = false;
48 bool V8::has_been_setup_ = false;
49 bool V8::has_been_disposed_ = false;
50 bool V8::has_fatal_error_ = false;
51 bool V8::use_crankshaft_ = true;
52
53
Initialize(Deserializer * des)54 bool V8::Initialize(Deserializer* des) {
55 InitializeOncePerProcess();
56
57 // The current thread may not yet had entered an isolate to run.
58 // Note the Isolate::Current() may be non-null because for various
59 // initialization purposes an initializing thread may be assigned an isolate
60 // but not actually enter it.
61 if (i::Isolate::CurrentPerIsolateThreadData() == NULL) {
62 i::Isolate::EnterDefaultIsolate();
63 }
64
65 ASSERT(i::Isolate::CurrentPerIsolateThreadData() != NULL);
66 ASSERT(i::Isolate::CurrentPerIsolateThreadData()->thread_id().Equals(
67 i::ThreadId::Current()));
68 ASSERT(i::Isolate::CurrentPerIsolateThreadData()->isolate() ==
69 i::Isolate::Current());
70
71 if (IsDead()) return false;
72
73 Isolate* isolate = Isolate::Current();
74 if (isolate->IsInitialized()) return true;
75
76 is_running_ = true;
77 has_been_setup_ = true;
78 has_fatal_error_ = false;
79 has_been_disposed_ = false;
80
81 return isolate->Init(des);
82 }
83
84
SetFatalError()85 void V8::SetFatalError() {
86 is_running_ = false;
87 has_fatal_error_ = true;
88 }
89
90
TearDown()91 void V8::TearDown() {
92 Isolate* isolate = Isolate::Current();
93 ASSERT(isolate->IsDefaultIsolate());
94
95 if (!has_been_setup_ || has_been_disposed_) return;
96 isolate->TearDown();
97
98 is_running_ = false;
99 has_been_disposed_ = true;
100 }
101
102
random_seed()103 static uint32_t random_seed() {
104 if (FLAG_random_seed == 0) {
105 return random();
106 }
107 return FLAG_random_seed;
108 }
109
110
111 typedef struct {
112 uint32_t hi;
113 uint32_t lo;
114 } random_state;
115
116
117 // Random number generator using George Marsaglia's MWC algorithm.
random_base(random_state * state)118 static uint32_t random_base(random_state *state) {
119 // Initialize seed using the system random(). If one of the seeds
120 // should ever become zero again, or if random() returns zero, we
121 // avoid getting stuck with zero bits in hi or lo by re-initializing
122 // them on demand.
123 if (state->hi == 0) state->hi = random_seed();
124 if (state->lo == 0) state->lo = random_seed();
125
126 // Mix the bits.
127 state->hi = 36969 * (state->hi & 0xFFFF) + (state->hi >> 16);
128 state->lo = 18273 * (state->lo & 0xFFFF) + (state->lo >> 16);
129 return (state->hi << 16) + (state->lo & 0xFFFF);
130 }
131
132
133 // Used by JavaScript APIs
Random(Isolate * isolate)134 uint32_t V8::Random(Isolate* isolate) {
135 ASSERT(isolate == Isolate::Current());
136 // TODO(isolates): move lo and hi to isolate
137 static random_state state = {0, 0};
138 return random_base(&state);
139 }
140
141
142 // Used internally by the JIT and memory allocator for security
143 // purposes. So, we keep a different state to prevent informations
144 // leaks that could be used in an exploit.
RandomPrivate(Isolate * isolate)145 uint32_t V8::RandomPrivate(Isolate* isolate) {
146 ASSERT(isolate == Isolate::Current());
147 // TODO(isolates): move lo and hi to isolate
148 static random_state state = {0, 0};
149 return random_base(&state);
150 }
151
152
IdleNotification()153 bool V8::IdleNotification() {
154 // Returning true tells the caller that there is no need to call
155 // IdleNotification again.
156 if (!FLAG_use_idle_notification) return true;
157
158 // Tell the heap that it may want to adjust.
159 return HEAP->IdleNotification();
160 }
161
162
163 // Use a union type to avoid type-aliasing optimizations in GCC.
164 typedef union {
165 double double_value;
166 uint64_t uint64_t_value;
167 } double_int_union;
168
169
FillHeapNumberWithRandom(Object * heap_number,Isolate * isolate)170 Object* V8::FillHeapNumberWithRandom(Object* heap_number, Isolate* isolate) {
171 uint64_t random_bits = Random(isolate);
172 // Make a double* from address (heap_number + sizeof(double)).
173 double_int_union* r = reinterpret_cast<double_int_union*>(
174 reinterpret_cast<char*>(heap_number) +
175 HeapNumber::kValueOffset - kHeapObjectTag);
176 // Convert 32 random bits to 0.(32 random bits) in a double
177 // by computing:
178 // ( 1.(20 0s)(32 random bits) x 2^20 ) - (1.0 x 2^20)).
179 const double binary_million = 1048576.0;
180 r->double_value = binary_million;
181 r->uint64_t_value |= random_bits;
182 r->double_value -= binary_million;
183
184 return heap_number;
185 }
186
187
InitializeOncePerProcess()188 void V8::InitializeOncePerProcess() {
189 ScopedLock lock(init_once_mutex);
190 if (init_once_called) return;
191 init_once_called = true;
192
193 // Setup the platform OS support.
194 OS::Setup();
195
196 use_crankshaft_ = FLAG_crankshaft;
197
198 if (Serializer::enabled()) {
199 use_crankshaft_ = false;
200 }
201
202 CPU::Setup();
203 if (!CPU::SupportsCrankshaft()) {
204 use_crankshaft_ = false;
205 }
206
207 RuntimeProfiler::GlobalSetup();
208
209 // Peephole optimization might interfere with deoptimization.
210 FLAG_peephole_optimization = !use_crankshaft_;
211 }
212
213 } } // namespace v8::internal
214