// Copyright 2014 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.
#ifndef V8_EXECUTION_H_
#define V8_EXECUTION_H_
#include "src/handles.h"
namespace v8 {
namespace internal {
class Execution FINAL : public AllStatic {
public:
// Call a function, the caller supplies a receiver and an array
// of arguments. Arguments are Object* type. After function returns,
// pointers in 'args' might be invalid.
//
// *pending_exception tells whether the invoke resulted in
// a pending exception.
//
// When convert_receiver is set, and the receiver is not an object,
// and the function called is not in strict mode, receiver is converted to
// an object.
//
MUST_USE_RESULT static MaybeHandle<Object> Call(
Isolate* isolate,
Handle<Object> callable,
Handle<Object> receiver,
int argc,
Handle<Object> argv[],
bool convert_receiver = false);
// Construct object from function, the caller supplies an array of
// arguments. Arguments are Object* type. After function returns,
// pointers in 'args' might be invalid.
//
// *pending_exception tells whether the invoke resulted in
// a pending exception.
//
MUST_USE_RESULT static MaybeHandle<Object> New(Handle<JSFunction> func,
int argc,
Handle<Object> argv[]);
// Call a function, just like Call(), but make sure to silently catch
// any thrown exceptions. The return value is either the result of
// calling the function (if caught exception is false) or the exception
// that occurred (if caught exception is true).
// In the exception case, exception_out holds the caught exceptions, unless
// it is a termination exception.
static MaybeHandle<Object> TryCall(Handle<JSFunction> func,
Handle<Object> receiver, int argc,
Handle<Object> argv[],
MaybeHandle<Object>* exception_out = NULL);
// ECMA-262 9.3
MUST_USE_RESULT static MaybeHandle<Object> ToNumber(
Isolate* isolate, Handle<Object> obj);
// ECMA-262 9.4
MUST_USE_RESULT static MaybeHandle<Object> ToInteger(
Isolate* isolate, Handle<Object> obj);
// ECMA-262 9.5
MUST_USE_RESULT static MaybeHandle<Object> ToInt32(
Isolate* isolate, Handle<Object> obj);
// ECMA-262 9.6
MUST_USE_RESULT static MaybeHandle<Object> ToUint32(
Isolate* isolate, Handle<Object> obj);
// ECMA-262 9.8
MUST_USE_RESULT static MaybeHandle<Object> ToString(
Isolate* isolate, Handle<Object> obj);
// ECMA-262 9.8
MUST_USE_RESULT static MaybeHandle<Object> ToDetailString(
Isolate* isolate, Handle<Object> obj);
// ECMA-262 9.9
MUST_USE_RESULT static MaybeHandle<Object> ToObject(
Isolate* isolate, Handle<Object> obj);
// Create a new date object from 'time'.
MUST_USE_RESULT static MaybeHandle<Object> NewDate(
Isolate* isolate, double time);
// Create a new regular expression object from 'pattern' and 'flags'.
MUST_USE_RESULT static MaybeHandle<JSRegExp> NewJSRegExp(
Handle<String> pattern, Handle<String> flags);
// Used to implement [] notation on strings (calls JS code)
static Handle<Object> CharAt(Handle<String> str, uint32_t index);
static Handle<Object> GetFunctionFor();
MUST_USE_RESULT static MaybeHandle<JSFunction> InstantiateFunction(
Handle<FunctionTemplateInfo> data);
MUST_USE_RESULT static MaybeHandle<JSObject> InstantiateObject(
Handle<ObjectTemplateInfo> data);
MUST_USE_RESULT static MaybeHandle<Object> ConfigureInstance(
Isolate* isolate, Handle<Object> instance, Handle<Object> data);
static Handle<String> GetStackTraceLine(Handle<Object> recv,
Handle<JSFunction> fun,
Handle<Object> pos,
Handle<Object> is_global);
// Get a function delegate (or undefined) for the given non-function
// object. Used for support calling objects as functions.
static Handle<Object> GetFunctionDelegate(Isolate* isolate,
Handle<Object> object);
MUST_USE_RESULT static MaybeHandle<Object> TryGetFunctionDelegate(
Isolate* isolate,
Handle<Object> object);
// Get a function delegate (or undefined) for the given non-function
// object. Used for support calling objects as constructors.
static Handle<Object> GetConstructorDelegate(Isolate* isolate,
Handle<Object> object);
static MaybeHandle<Object> TryGetConstructorDelegate(Isolate* isolate,
Handle<Object> object);
};
class ExecutionAccess;
class PostponeInterruptsScope;
// StackGuard contains the handling of the limits that are used to limit the
// number of nested invocations of JavaScript and the stack size used in each
// invocation.
class StackGuard FINAL {
public:
// Pass the address beyond which the stack should not grow. The stack
// is assumed to grow downwards.
void SetStackLimit(uintptr_t limit);
// Threading support.
char* ArchiveStackGuard(char* to);
char* RestoreStackGuard(char* from);
static int ArchiveSpacePerThread() { return sizeof(ThreadLocal); }
void FreeThreadResources();
// Sets up the default stack guard for this thread if it has not
// already been set up.
void InitThread(const ExecutionAccess& lock);
// Clears the stack guard for this thread so it does not look as if
// it has been set up.
void ClearThread(const ExecutionAccess& lock);
#define INTERRUPT_LIST(V) \
V(DEBUGBREAK, DebugBreak, 0) \
V(DEBUGCOMMAND, DebugCommand, 1) \
V(TERMINATE_EXECUTION, TerminateExecution, 2) \
V(GC_REQUEST, GC, 3) \
V(INSTALL_CODE, InstallCode, 4) \
V(API_INTERRUPT, ApiInterrupt, 5) \
V(DEOPT_MARKED_ALLOCATION_SITES, DeoptMarkedAllocationSites, 6)
#define V(NAME, Name, id) \
inline bool Check##Name() { return CheckInterrupt(NAME); } \
inline void Request##Name() { RequestInterrupt(NAME); } \
inline void Clear##Name() { ClearInterrupt(NAME); }
INTERRUPT_LIST(V)
#undef V
// Flag used to set the interrupt causes.
enum InterruptFlag {
#define V(NAME, Name, id) NAME = (1 << id),
INTERRUPT_LIST(V)
#undef V
#define V(NAME, Name, id) NAME |
ALL_INTERRUPTS = INTERRUPT_LIST(V) 0
#undef V
};
// This provides an asynchronous read of the stack limits for the current
// thread. There are no locks protecting this, but it is assumed that you
// have the global V8 lock if you are using multiple V8 threads.
uintptr_t climit() {
return thread_local_.climit_;
}
uintptr_t real_climit() {
return thread_local_.real_climit_;
}
uintptr_t jslimit() {
return thread_local_.jslimit_;
}
uintptr_t real_jslimit() {
return thread_local_.real_jslimit_;
}
Address address_of_jslimit() {
return reinterpret_cast<Address>(&thread_local_.jslimit_);
}
Address address_of_real_jslimit() {
return reinterpret_cast<Address>(&thread_local_.real_jslimit_);
}
// If the stack guard is triggered, but it is not an actual
// stack overflow, then handle the interruption accordingly.
Object* HandleInterrupts();
private:
StackGuard();
bool CheckInterrupt(InterruptFlag flag);
void RequestInterrupt(InterruptFlag flag);
void ClearInterrupt(InterruptFlag flag);
bool CheckAndClearInterrupt(InterruptFlag flag);
// You should hold the ExecutionAccess lock when calling this method.
bool has_pending_interrupts(const ExecutionAccess& lock) {
return thread_local_.interrupt_flags_ != 0;
}
// You should hold the ExecutionAccess lock when calling this method.
inline void set_interrupt_limits(const ExecutionAccess& lock);
// Reset limits to actual values. For example after handling interrupt.
// You should hold the ExecutionAccess lock when calling this method.
inline void reset_limits(const ExecutionAccess& lock);
// Enable or disable interrupts.
void EnableInterrupts();
void DisableInterrupts();
#if V8_TARGET_ARCH_64_BIT
static const uintptr_t kInterruptLimit = V8_UINT64_C(0xfffffffffffffffe);
static const uintptr_t kIllegalLimit = V8_UINT64_C(0xfffffffffffffff8);
#else
static const uintptr_t kInterruptLimit = 0xfffffffe;
static const uintptr_t kIllegalLimit = 0xfffffff8;
#endif
void PushPostponeInterruptsScope(PostponeInterruptsScope* scope);
void PopPostponeInterruptsScope();
class ThreadLocal FINAL {
public:
ThreadLocal() { Clear(); }
// You should hold the ExecutionAccess lock when you call Initialize or
// Clear.
void Clear();
// Returns true if the heap's stack limits should be set, false if not.
bool Initialize(Isolate* isolate);
// The stack limit is split into a JavaScript and a C++ stack limit. These
// two are the same except when running on a simulator where the C++ and
// JavaScript stacks are separate. Each of the two stack limits have two
// values. The one eith the real_ prefix is the actual stack limit
// set for the VM. The one without the real_ prefix has the same value as
// the actual stack limit except when there is an interruption (e.g. debug
// break or preemption) in which case it is lowered to make stack checks
// fail. Both the generated code and the runtime system check against the
// one without the real_ prefix.
uintptr_t real_jslimit_; // Actual JavaScript stack limit set for the VM.
uintptr_t jslimit_;
uintptr_t real_climit_; // Actual C++ stack limit set for the VM.
uintptr_t climit_;
PostponeInterruptsScope* postpone_interrupts_;
int interrupt_flags_;
};
// TODO(isolates): Technically this could be calculated directly from a
// pointer to StackGuard.
Isolate* isolate_;
ThreadLocal thread_local_;
friend class Isolate;
friend class StackLimitCheck;
friend class PostponeInterruptsScope;
DISALLOW_COPY_AND_ASSIGN(StackGuard);
};
} } // namespace v8::internal
#endif // V8_EXECUTION_H_