1 // Copyright 2014 the V8 project authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef V8_EXECUTION_H_ 6 #define V8_EXECUTION_H_ 7 8 #include "src/handles.h" 9 10 namespace v8 { 11 namespace internal { 12 13 class Execution FINAL : public AllStatic { 14 public: 15 // Call a function, the caller supplies a receiver and an array 16 // of arguments. Arguments are Object* type. After function returns, 17 // pointers in 'args' might be invalid. 18 // 19 // *pending_exception tells whether the invoke resulted in 20 // a pending exception. 21 // 22 // When convert_receiver is set, and the receiver is not an object, 23 // and the function called is not in strict mode, receiver is converted to 24 // an object. 25 // 26 MUST_USE_RESULT static MaybeHandle<Object> Call( 27 Isolate* isolate, 28 Handle<Object> callable, 29 Handle<Object> receiver, 30 int argc, 31 Handle<Object> argv[], 32 bool convert_receiver = false); 33 34 // Construct object from function, the caller supplies an array of 35 // arguments. Arguments are Object* type. After function returns, 36 // pointers in 'args' might be invalid. 37 // 38 // *pending_exception tells whether the invoke resulted in 39 // a pending exception. 40 // 41 MUST_USE_RESULT static MaybeHandle<Object> New(Handle<JSFunction> func, 42 int argc, 43 Handle<Object> argv[]); 44 45 // Call a function, just like Call(), but make sure to silently catch 46 // any thrown exceptions. The return value is either the result of 47 // calling the function (if caught exception is false) or the exception 48 // that occurred (if caught exception is true). 49 // In the exception case, exception_out holds the caught exceptions, unless 50 // it is a termination exception. 51 static MaybeHandle<Object> TryCall(Handle<JSFunction> func, 52 Handle<Object> receiver, int argc, 53 Handle<Object> argv[], 54 MaybeHandle<Object>* exception_out = NULL); 55 56 // ECMA-262 9.3 57 MUST_USE_RESULT static MaybeHandle<Object> ToNumber( 58 Isolate* isolate, Handle<Object> obj); 59 60 // ECMA-262 9.4 61 MUST_USE_RESULT static MaybeHandle<Object> ToInteger( 62 Isolate* isolate, Handle<Object> obj); 63 64 // ECMA-262 9.5 65 MUST_USE_RESULT static MaybeHandle<Object> ToInt32( 66 Isolate* isolate, Handle<Object> obj); 67 68 // ECMA-262 9.6 69 MUST_USE_RESULT static MaybeHandle<Object> ToUint32( 70 Isolate* isolate, Handle<Object> obj); 71 72 // ECMA-262 9.8 73 MUST_USE_RESULT static MaybeHandle<Object> ToString( 74 Isolate* isolate, Handle<Object> obj); 75 76 // ECMA-262 9.8 77 MUST_USE_RESULT static MaybeHandle<Object> ToDetailString( 78 Isolate* isolate, Handle<Object> obj); 79 80 // ECMA-262 9.9 81 MUST_USE_RESULT static MaybeHandle<Object> ToObject( 82 Isolate* isolate, Handle<Object> obj); 83 84 // Create a new date object from 'time'. 85 MUST_USE_RESULT static MaybeHandle<Object> NewDate( 86 Isolate* isolate, double time); 87 88 // Create a new regular expression object from 'pattern' and 'flags'. 89 MUST_USE_RESULT static MaybeHandle<JSRegExp> NewJSRegExp( 90 Handle<String> pattern, Handle<String> flags); 91 92 // Used to implement [] notation on strings (calls JS code) 93 static Handle<Object> CharAt(Handle<String> str, uint32_t index); 94 95 static Handle<Object> GetFunctionFor(); 96 MUST_USE_RESULT static MaybeHandle<JSFunction> InstantiateFunction( 97 Handle<FunctionTemplateInfo> data); 98 MUST_USE_RESULT static MaybeHandle<JSObject> InstantiateObject( 99 Handle<ObjectTemplateInfo> data); 100 MUST_USE_RESULT static MaybeHandle<Object> ConfigureInstance( 101 Isolate* isolate, Handle<Object> instance, Handle<Object> data); 102 static Handle<String> GetStackTraceLine(Handle<Object> recv, 103 Handle<JSFunction> fun, 104 Handle<Object> pos, 105 Handle<Object> is_global); 106 107 // Get a function delegate (or undefined) for the given non-function 108 // object. Used for support calling objects as functions. 109 static Handle<Object> GetFunctionDelegate(Isolate* isolate, 110 Handle<Object> object); 111 MUST_USE_RESULT static MaybeHandle<Object> TryGetFunctionDelegate( 112 Isolate* isolate, 113 Handle<Object> object); 114 115 // Get a function delegate (or undefined) for the given non-function 116 // object. Used for support calling objects as constructors. 117 static Handle<Object> GetConstructorDelegate(Isolate* isolate, 118 Handle<Object> object); 119 static MaybeHandle<Object> TryGetConstructorDelegate(Isolate* isolate, 120 Handle<Object> object); 121 }; 122 123 124 class ExecutionAccess; 125 class PostponeInterruptsScope; 126 127 128 // StackGuard contains the handling of the limits that are used to limit the 129 // number of nested invocations of JavaScript and the stack size used in each 130 // invocation. 131 class StackGuard FINAL { 132 public: 133 // Pass the address beyond which the stack should not grow. The stack 134 // is assumed to grow downwards. 135 void SetStackLimit(uintptr_t limit); 136 137 // Threading support. 138 char* ArchiveStackGuard(char* to); 139 char* RestoreStackGuard(char* from); 140 static int ArchiveSpacePerThread() { return sizeof(ThreadLocal); } 141 void FreeThreadResources(); 142 // Sets up the default stack guard for this thread if it has not 143 // already been set up. 144 void InitThread(const ExecutionAccess& lock); 145 // Clears the stack guard for this thread so it does not look as if 146 // it has been set up. 147 void ClearThread(const ExecutionAccess& lock); 148 149 #define INTERRUPT_LIST(V) \ 150 V(DEBUGBREAK, DebugBreak, 0) \ 151 V(DEBUGCOMMAND, DebugCommand, 1) \ 152 V(TERMINATE_EXECUTION, TerminateExecution, 2) \ 153 V(GC_REQUEST, GC, 3) \ 154 V(INSTALL_CODE, InstallCode, 4) \ 155 V(API_INTERRUPT, ApiInterrupt, 5) \ 156 V(DEOPT_MARKED_ALLOCATION_SITES, DeoptMarkedAllocationSites, 6) 157 158 #define V(NAME, Name, id) \ 159 inline bool Check##Name() { return CheckInterrupt(NAME); } \ 160 inline void Request##Name() { RequestInterrupt(NAME); } \ 161 inline void Clear##Name() { ClearInterrupt(NAME); } 162 INTERRUPT_LIST(V) 163 #undef V 164 165 // Flag used to set the interrupt causes. 166 enum InterruptFlag { 167 #define V(NAME, Name, id) NAME = (1 << id), 168 INTERRUPT_LIST(V) 169 #undef V 170 #define V(NAME, Name, id) NAME | 171 ALL_INTERRUPTS = INTERRUPT_LIST(V) 0 172 #undef V 173 }; 174 175 // This provides an asynchronous read of the stack limits for the current 176 // thread. There are no locks protecting this, but it is assumed that you 177 // have the global V8 lock if you are using multiple V8 threads. 178 uintptr_t climit() { 179 return thread_local_.climit_; 180 } 181 uintptr_t real_climit() { 182 return thread_local_.real_climit_; 183 } 184 uintptr_t jslimit() { 185 return thread_local_.jslimit_; 186 } 187 uintptr_t real_jslimit() { 188 return thread_local_.real_jslimit_; 189 } 190 Address address_of_jslimit() { 191 return reinterpret_cast<Address>(&thread_local_.jslimit_); 192 } 193 Address address_of_real_jslimit() { 194 return reinterpret_cast<Address>(&thread_local_.real_jslimit_); 195 } 196 197 // If the stack guard is triggered, but it is not an actual 198 // stack overflow, then handle the interruption accordingly. 199 Object* HandleInterrupts(); 200 201 private: 202 StackGuard(); 203 204 bool CheckInterrupt(InterruptFlag flag); 205 void RequestInterrupt(InterruptFlag flag); 206 void ClearInterrupt(InterruptFlag flag); 207 bool CheckAndClearInterrupt(InterruptFlag flag); 208 209 // You should hold the ExecutionAccess lock when calling this method. 210 bool has_pending_interrupts(const ExecutionAccess& lock) { 211 return thread_local_.interrupt_flags_ != 0; 212 } 213 214 // You should hold the ExecutionAccess lock when calling this method. 215 inline void set_interrupt_limits(const ExecutionAccess& lock); 216 217 // Reset limits to actual values. For example after handling interrupt. 218 // You should hold the ExecutionAccess lock when calling this method. 219 inline void reset_limits(const ExecutionAccess& lock); 220 221 // Enable or disable interrupts. 222 void EnableInterrupts(); 223 void DisableInterrupts(); 224 225 #if V8_TARGET_ARCH_64_BIT 226 static const uintptr_t kInterruptLimit = V8_UINT64_C(0xfffffffffffffffe); 227 static const uintptr_t kIllegalLimit = V8_UINT64_C(0xfffffffffffffff8); 228 #else 229 static const uintptr_t kInterruptLimit = 0xfffffffe; 230 static const uintptr_t kIllegalLimit = 0xfffffff8; 231 #endif 232 233 void PushPostponeInterruptsScope(PostponeInterruptsScope* scope); 234 void PopPostponeInterruptsScope(); 235 236 class ThreadLocal FINAL { 237 public: 238 ThreadLocal() { Clear(); } 239 // You should hold the ExecutionAccess lock when you call Initialize or 240 // Clear. 241 void Clear(); 242 243 // Returns true if the heap's stack limits should be set, false if not. 244 bool Initialize(Isolate* isolate); 245 246 // The stack limit is split into a JavaScript and a C++ stack limit. These 247 // two are the same except when running on a simulator where the C++ and 248 // JavaScript stacks are separate. Each of the two stack limits have two 249 // values. The one eith the real_ prefix is the actual stack limit 250 // set for the VM. The one without the real_ prefix has the same value as 251 // the actual stack limit except when there is an interruption (e.g. debug 252 // break or preemption) in which case it is lowered to make stack checks 253 // fail. Both the generated code and the runtime system check against the 254 // one without the real_ prefix. 255 uintptr_t real_jslimit_; // Actual JavaScript stack limit set for the VM. 256 uintptr_t jslimit_; 257 uintptr_t real_climit_; // Actual C++ stack limit set for the VM. 258 uintptr_t climit_; 259 260 PostponeInterruptsScope* postpone_interrupts_; 261 int interrupt_flags_; 262 }; 263 264 // TODO(isolates): Technically this could be calculated directly from a 265 // pointer to StackGuard. 266 Isolate* isolate_; 267 ThreadLocal thread_local_; 268 269 friend class Isolate; 270 friend class StackLimitCheck; 271 friend class PostponeInterruptsScope; 272 273 DISALLOW_COPY_AND_ASSIGN(StackGuard); 274 }; 275 276 } } // namespace v8::internal 277 278 #endif // V8_EXECUTION_H_ 279
