// Copyright 2006-2008 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.
#ifndef V8_EXECUTION_H_
#define V8_EXECUTION_H_
namespace v8 {
namespace internal {
// Flag used to set the interrupt causes.
enum InterruptFlag {
INTERRUPT = 1 << 0,
DEBUGBREAK = 1 << 1,
DEBUGCOMMAND = 1 << 2,
PREEMPT = 1 << 3,
TERMINATE = 1 << 4,
RUNTIME_PROFILER_TICK = 1 << 5
};
class Execution : 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.
//
static Handle<Object> Call(Handle<JSFunction> func,
Handle<Object> receiver,
int argc,
Object*** args,
bool* pending_exception);
// 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.
//
static Handle<Object> New(Handle<JSFunction> func,
int argc,
Object*** args,
bool* pending_exception);
// 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).
static Handle<Object> TryCall(Handle<JSFunction> func,
Handle<Object> receiver,
int argc,
Object*** args,
bool* caught_exception);
// ECMA-262 9.2
static Handle<Object> ToBoolean(Handle<Object> obj);
// ECMA-262 9.3
static Handle<Object> ToNumber(Handle<Object> obj, bool* exc);
// ECMA-262 9.4
static Handle<Object> ToInteger(Handle<Object> obj, bool* exc);
// ECMA-262 9.5
static Handle<Object> ToInt32(Handle<Object> obj, bool* exc);
// ECMA-262 9.6
static Handle<Object> ToUint32(Handle<Object> obj, bool* exc);
// ECMA-262 9.8
static Handle<Object> ToString(Handle<Object> obj, bool* exc);
// ECMA-262 9.8
static Handle<Object> ToDetailString(Handle<Object> obj, bool* exc);
// ECMA-262 9.9
static Handle<Object> ToObject(Handle<Object> obj, bool* exc);
// Create a new date object from 'time'.
static Handle<Object> NewDate(double time, bool* exc);
// Create a new regular expression object from 'pattern' and 'flags'.
static Handle<JSRegExp> NewJSRegExp(Handle<String> pattern,
Handle<String> flags,
bool* exc);
// Used to implement [] notation on strings (calls JS code)
static Handle<Object> CharAt(Handle<String> str, uint32_t index);
static Handle<Object> GetFunctionFor();
static Handle<JSFunction> InstantiateFunction(
Handle<FunctionTemplateInfo> data, bool* exc);
static Handle<JSObject> InstantiateObject(Handle<ObjectTemplateInfo> data,
bool* exc);
static void ConfigureInstance(Handle<Object> instance,
Handle<Object> data,
bool* exc);
static Handle<String> GetStackTraceLine(Handle<Object> recv,
Handle<JSFunction> fun,
Handle<Object> pos,
Handle<Object> is_global);
#ifdef ENABLE_DEBUGGER_SUPPORT
static Object* DebugBreakHelper();
static void ProcessDebugMesssages(bool debug_command_only);
#endif
// If the stack guard is triggered, but it is not an actual
// stack overflow, then handle the interruption accordingly.
MUST_USE_RESULT static MaybeObject* HandleStackGuardInterrupt();
// Get a function delegate (or undefined) for the given non-function
// object. Used for support calling objects as functions.
static Handle<Object> GetFunctionDelegate(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(Handle<Object> object);
};
class ExecutionAccess;
class Isolate;
// 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 {
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);
bool IsStackOverflow();
bool IsPreempted();
void Preempt();
bool IsInterrupted();
void Interrupt();
bool IsTerminateExecution();
void TerminateExecution();
bool IsRuntimeProfilerTick();
void RequestRuntimeProfilerTick();
#ifdef ENABLE_DEBUGGER_SUPPORT
bool IsDebugBreak();
void DebugBreak();
bool IsDebugCommand();
void DebugCommand();
#endif
void Continue(InterruptFlag after_what);
// 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_);
}
private:
StackGuard();
// You should hold the ExecutionAccess lock when calling this method.
bool has_pending_interrupts(const ExecutionAccess& lock) {
// Sanity check: We shouldn't be asking about pending interrupts
// unless we're not postponing them anymore.
ASSERT(!should_postpone_interrupts(lock));
return thread_local_.interrupt_flags_ != 0;
}
// You should hold the ExecutionAccess lock when calling this method.
bool should_postpone_interrupts(const ExecutionAccess& lock) {
return thread_local_.postpone_interrupts_nesting_ > 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();
#ifdef V8_TARGET_ARCH_X64
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
class ThreadLocal {
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();
// 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_;
int nesting_;
int postpone_interrupts_nesting_;
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_