// Copyright 2012 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.
#include "src/debug/debug.h"
#include "src/api.h"
#include "src/arguments.h"
#include "src/bootstrapper.h"
#include "src/code-stubs.h"
#include "src/codegen.h"
#include "src/compilation-cache.h"
#include "src/compiler.h"
#include "src/deoptimizer.h"
#include "src/execution.h"
#include "src/frames-inl.h"
#include "src/full-codegen/full-codegen.h"
#include "src/global-handles.h"
#include "src/isolate-inl.h"
#include "src/list.h"
#include "src/log.h"
#include "src/messages.h"
#include "src/snapshot/natives.h"
#include "include/v8-debug.h"
namespace v8 {
namespace internal {
Debug::Debug(Isolate* isolate)
: debug_context_(Handle<Context>()),
event_listener_(Handle<Object>()),
event_listener_data_(Handle<Object>()),
message_handler_(NULL),
command_received_(0),
command_queue_(isolate->logger(), kQueueInitialSize),
is_active_(false),
is_suppressed_(false),
live_edit_enabled_(true), // TODO(yangguo): set to false by default.
break_disabled_(false),
break_points_active_(true),
in_debug_event_listener_(false),
break_on_exception_(false),
break_on_uncaught_exception_(false),
debug_info_list_(NULL),
feature_tracker_(isolate),
isolate_(isolate) {
ThreadInit();
}
static v8::Local<v8::Context> GetDebugEventContext(Isolate* isolate) {
Handle<Context> context = isolate->debug()->debugger_entry()->GetContext();
// Isolate::context() may have been NULL when "script collected" event
// occured.
if (context.is_null()) return v8::Local<v8::Context>();
Handle<Context> native_context(context->native_context());
return v8::Utils::ToLocal(native_context);
}
BreakLocation::BreakLocation(Handle<DebugInfo> debug_info, RelocInfo* rinfo,
int position, int statement_position)
: debug_info_(debug_info),
pc_offset_(static_cast<int>(rinfo->pc() - debug_info->code()->entry())),
rmode_(rinfo->rmode()),
data_(rinfo->data()),
position_(position),
statement_position_(statement_position) {}
BreakLocation::Iterator::Iterator(Handle<DebugInfo> debug_info,
BreakLocatorType type)
: debug_info_(debug_info),
reloc_iterator_(debug_info->code(), GetModeMask(type)),
break_index_(-1),
position_(1),
statement_position_(1) {
if (!Done()) Next();
}
int BreakLocation::Iterator::GetModeMask(BreakLocatorType type) {
int mask = 0;
mask |= RelocInfo::ModeMask(RelocInfo::POSITION);
mask |= RelocInfo::ModeMask(RelocInfo::STATEMENT_POSITION);
mask |= RelocInfo::ModeMask(RelocInfo::DEBUG_BREAK_SLOT_AT_RETURN);
mask |= RelocInfo::ModeMask(RelocInfo::DEBUG_BREAK_SLOT_AT_CALL);
if (type == ALL_BREAK_LOCATIONS) {
mask |= RelocInfo::ModeMask(RelocInfo::DEBUG_BREAK_SLOT_AT_POSITION);
mask |= RelocInfo::ModeMask(RelocInfo::DEBUGGER_STATEMENT);
}
return mask;
}
void BreakLocation::Iterator::Next() {
DisallowHeapAllocation no_gc;
DCHECK(!Done());
// Iterate through reloc info for code and original code stopping at each
// breakable code target.
bool first = break_index_ == -1;
while (!Done()) {
if (!first) reloc_iterator_.next();
first = false;
if (Done()) return;
// Whenever a statement position or (plain) position is passed update the
// current value of these.
if (RelocInfo::IsPosition(rmode())) {
if (RelocInfo::IsStatementPosition(rmode())) {
statement_position_ = static_cast<int>(
rinfo()->data() - debug_info_->shared()->start_position());
}
// Always update the position as we don't want that to be before the
// statement position.
position_ = static_cast<int>(rinfo()->data() -
debug_info_->shared()->start_position());
DCHECK(position_ >= 0);
DCHECK(statement_position_ >= 0);
continue;
}
DCHECK(RelocInfo::IsDebugBreakSlot(rmode()) ||
RelocInfo::IsDebuggerStatement(rmode()));
if (RelocInfo::IsDebugBreakSlotAtReturn(rmode())) {
// Set the positions to the end of the function.
if (debug_info_->shared()->HasSourceCode()) {
position_ = debug_info_->shared()->end_position() -
debug_info_->shared()->start_position() - 1;
} else {
position_ = 0;
}
statement_position_ = position_;
}
break;
}
break_index_++;
}
// Find the break point at the supplied address, or the closest one before
// the address.
BreakLocation BreakLocation::FromAddress(Handle<DebugInfo> debug_info,
Address pc) {
Iterator it(debug_info, ALL_BREAK_LOCATIONS);
it.SkipTo(BreakIndexFromAddress(debug_info, pc));
return it.GetBreakLocation();
}
// Find the break point at the supplied address, or the closest one before
// the address.
void BreakLocation::FromAddressSameStatement(Handle<DebugInfo> debug_info,
Address pc,
List<BreakLocation>* result_out) {
int break_index = BreakIndexFromAddress(debug_info, pc);
Iterator it(debug_info, ALL_BREAK_LOCATIONS);
it.SkipTo(break_index);
int statement_position = it.statement_position();
while (!it.Done() && it.statement_position() == statement_position) {
result_out->Add(it.GetBreakLocation());
it.Next();
}
}
int BreakLocation::BreakIndexFromAddress(Handle<DebugInfo> debug_info,
Address pc) {
// Run through all break points to locate the one closest to the address.
int closest_break = 0;
int distance = kMaxInt;
for (Iterator it(debug_info, ALL_BREAK_LOCATIONS); !it.Done(); it.Next()) {
// Check if this break point is closer that what was previously found.
if (it.pc() <= pc && pc - it.pc() < distance) {
closest_break = it.break_index();
distance = static_cast<int>(pc - it.pc());
// Check whether we can't get any closer.
if (distance == 0) break;
}
}
return closest_break;
}
BreakLocation BreakLocation::FromPosition(Handle<DebugInfo> debug_info,
int position,
BreakPositionAlignment alignment) {
// Run through all break points to locate the one closest to the source
// position.
int closest_break = 0;
int distance = kMaxInt;
for (Iterator it(debug_info, ALL_BREAK_LOCATIONS); !it.Done(); it.Next()) {
int next_position;
if (alignment == STATEMENT_ALIGNED) {
next_position = it.statement_position();
} else {
DCHECK(alignment == BREAK_POSITION_ALIGNED);
next_position = it.position();
}
if (position <= next_position && next_position - position < distance) {
closest_break = it.break_index();
distance = next_position - position;
// Check whether we can't get any closer.
if (distance == 0) break;
}
}
Iterator it(debug_info, ALL_BREAK_LOCATIONS);
it.SkipTo(closest_break);
return it.GetBreakLocation();
}
void BreakLocation::SetBreakPoint(Handle<Object> break_point_object) {
// If there is not already a real break point here patch code with debug
// break.
if (!HasBreakPoint()) SetDebugBreak();
DCHECK(IsDebugBreak() || IsDebuggerStatement());
// Set the break point information.
DebugInfo::SetBreakPoint(debug_info_, pc_offset_, position_,
statement_position_, break_point_object);
}
void BreakLocation::ClearBreakPoint(Handle<Object> break_point_object) {
// Clear the break point information.
DebugInfo::ClearBreakPoint(debug_info_, pc_offset_, break_point_object);
// If there are no more break points here remove the debug break.
if (!HasBreakPoint()) {
ClearDebugBreak();
DCHECK(!IsDebugBreak());
}
}
void BreakLocation::SetOneShot() {
// Debugger statement always calls debugger. No need to modify it.
if (IsDebuggerStatement()) return;
// If there is a real break point here no more to do.
if (HasBreakPoint()) {
DCHECK(IsDebugBreak());
return;
}
// Patch code with debug break.
SetDebugBreak();
}
void BreakLocation::ClearOneShot() {
// Debugger statement always calls debugger. No need to modify it.
if (IsDebuggerStatement()) return;
// If there is a real break point here no more to do.
if (HasBreakPoint()) {
DCHECK(IsDebugBreak());
return;
}
// Patch code removing debug break.
ClearDebugBreak();
DCHECK(!IsDebugBreak());
}
void BreakLocation::SetDebugBreak() {
// Debugger statement always calls debugger. No need to modify it.
if (IsDebuggerStatement()) return;
// If there is already a break point here just return. This might happen if
// the same code is flooded with break points twice. Flooding the same
// function twice might happen when stepping in a function with an exception
// handler as the handler and the function is the same.
if (IsDebugBreak()) return;
DCHECK(IsDebugBreakSlot());
Isolate* isolate = debug_info_->GetIsolate();
Builtins* builtins = isolate->builtins();
Handle<Code> target =
IsReturn() ? builtins->Return_DebugBreak() : builtins->Slot_DebugBreak();
DebugCodegen::PatchDebugBreakSlot(isolate, pc(), target);
DCHECK(IsDebugBreak());
}
void BreakLocation::ClearDebugBreak() {
// Debugger statement always calls debugger. No need to modify it.
if (IsDebuggerStatement()) return;
DCHECK(IsDebugBreakSlot());
DebugCodegen::ClearDebugBreakSlot(debug_info_->GetIsolate(), pc());
DCHECK(!IsDebugBreak());
}
bool BreakLocation::IsDebugBreak() const {
if (IsDebuggerStatement()) return false;
DCHECK(IsDebugBreakSlot());
return rinfo().IsPatchedDebugBreakSlotSequence();
}
Handle<Object> BreakLocation::BreakPointObjects() const {
return debug_info_->GetBreakPointObjects(pc_offset_);
}
void DebugFeatureTracker::Track(DebugFeatureTracker::Feature feature) {
uint32_t mask = 1 << feature;
// Only count one sample per feature and isolate.
if (bitfield_ & mask) return;
isolate_->counters()->debug_feature_usage()->AddSample(feature);
bitfield_ |= mask;
}
// Threading support.
void Debug::ThreadInit() {
thread_local_.break_count_ = 0;
thread_local_.break_id_ = 0;
thread_local_.break_frame_id_ = StackFrame::NO_ID;
thread_local_.last_step_action_ = StepNone;
thread_local_.last_statement_position_ = RelocInfo::kNoPosition;
thread_local_.last_fp_ = 0;
thread_local_.target_fp_ = 0;
thread_local_.step_in_enabled_ = false;
// TODO(isolates): frames_are_dropped_?
base::NoBarrier_Store(&thread_local_.current_debug_scope_,
static_cast<base::AtomicWord>(0));
}
char* Debug::ArchiveDebug(char* storage) {
char* to = storage;
MemCopy(to, reinterpret_cast<char*>(&thread_local_), sizeof(ThreadLocal));
ThreadInit();
return storage + ArchiveSpacePerThread();
}
char* Debug::RestoreDebug(char* storage) {
char* from = storage;
MemCopy(reinterpret_cast<char*>(&thread_local_), from, sizeof(ThreadLocal));
return storage + ArchiveSpacePerThread();
}
int Debug::ArchiveSpacePerThread() {
return sizeof(ThreadLocal);
}
DebugInfoListNode::DebugInfoListNode(DebugInfo* debug_info): next_(NULL) {
// Globalize the request debug info object and make it weak.
GlobalHandles* global_handles = debug_info->GetIsolate()->global_handles();
debug_info_ =
Handle<DebugInfo>::cast(global_handles->Create(debug_info)).location();
}
DebugInfoListNode::~DebugInfoListNode() {
if (debug_info_ == nullptr) return;
GlobalHandles::Destroy(reinterpret_cast<Object**>(debug_info_));
debug_info_ = nullptr;
}
bool Debug::Load() {
// Return if debugger is already loaded.
if (is_loaded()) return true;
// Bail out if we're already in the process of compiling the native
// JavaScript source code for the debugger.
if (is_suppressed_) return false;
SuppressDebug while_loading(this);
// Disable breakpoints and interrupts while compiling and running the
// debugger scripts including the context creation code.
DisableBreak disable(this, true);
PostponeInterruptsScope postpone(isolate_);
// Create the debugger context.
HandleScope scope(isolate_);
ExtensionConfiguration no_extensions;
Handle<Context> context = isolate_->bootstrapper()->CreateEnvironment(
MaybeHandle<JSGlobalProxy>(), v8::Local<ObjectTemplate>(), &no_extensions,
DEBUG_CONTEXT);
// Fail if no context could be created.
if (context.is_null()) return false;
debug_context_ = Handle<Context>::cast(
isolate_->global_handles()->Create(*context));
feature_tracker()->Track(DebugFeatureTracker::kActive);
return true;
}
void Debug::Unload() {
ClearAllBreakPoints();
ClearStepping();
// Return debugger is not loaded.
if (!is_loaded()) return;
// Clear debugger context global handle.
GlobalHandles::Destroy(Handle<Object>::cast(debug_context_).location());
debug_context_ = Handle<Context>();
}
void Debug::Break(Arguments args, JavaScriptFrame* frame) {
HandleScope scope(isolate_);
DCHECK(args.length() == 0);
// Initialize LiveEdit.
LiveEdit::InitializeThreadLocal(this);
// Just continue if breaks are disabled or debugger cannot be loaded.
if (break_disabled()) return;
// Enter the debugger.
DebugScope debug_scope(this);
if (debug_scope.failed()) return;
// Postpone interrupt during breakpoint processing.
PostponeInterruptsScope postpone(isolate_);
// Get the debug info (create it if it does not exist).
Handle<JSFunction> function(frame->function());
Handle<SharedFunctionInfo> shared(function->shared());
if (!EnsureDebugInfo(shared, function)) {
// Return if we failed to retrieve the debug info.
return;
}
Handle<DebugInfo> debug_info(shared->GetDebugInfo());
// Find the break location where execution has stopped.
// PC points to the instruction after the current one, possibly a break
// location as well. So the "- 1" to exclude it from the search.
Address call_pc = frame->pc() - 1;
BreakLocation location = BreakLocation::FromAddress(debug_info, call_pc);
// Find actual break points, if any, and trigger debug break event.
if (break_points_active_ && location.HasBreakPoint()) {
Handle<Object> break_point_objects = location.BreakPointObjects();
Handle<Object> break_points_hit = CheckBreakPoints(break_point_objects);
if (!break_points_hit->IsUndefined()) {
// Clear all current stepping setup.
ClearStepping();
// Notify the debug event listeners.
OnDebugBreak(break_points_hit, false);
return;
}
}
// No break point. Check for stepping.
StepAction step_action = last_step_action();
Address current_fp = frame->UnpaddedFP();
Address target_fp = thread_local_.target_fp_;
Address last_fp = thread_local_.last_fp_;
bool step_break = true;
switch (step_action) {
case StepNone:
return;
case StepOut:
// Step out has not reached the target frame yet.
if (current_fp < target_fp) return;
break;
case StepNext:
// Step next should not break in a deeper frame.
if (current_fp < target_fp) return;
// Fall through.
case StepIn:
step_break = location.IsReturn() || (current_fp != last_fp) ||
(thread_local_.last_statement_position_ !=
location.code()->SourceStatementPosition(frame->pc()));
break;
case StepFrame:
step_break = current_fp != last_fp;
break;
}
// Clear all current stepping setup.
ClearStepping();
if (step_break) {
// Notify the debug event listeners.
OnDebugBreak(isolate_->factory()->undefined_value(), false);
} else {
// Re-prepare to continue.
PrepareStep(step_action);
}
}
// Check the break point objects for whether one or more are actually
// triggered. This function returns a JSArray with the break point objects
// which is triggered.
Handle<Object> Debug::CheckBreakPoints(Handle<Object> break_point_objects) {
Factory* factory = isolate_->factory();
// Count the number of break points hit. If there are multiple break points
// they are in a FixedArray.
Handle<FixedArray> break_points_hit;
int break_points_hit_count = 0;
DCHECK(!break_point_objects->IsUndefined());
if (break_point_objects->IsFixedArray()) {
Handle<FixedArray> array(FixedArray::cast(*break_point_objects));
break_points_hit = factory->NewFixedArray(array->length());
for (int i = 0; i < array->length(); i++) {
Handle<Object> o(array->get(i), isolate_);
if (CheckBreakPoint(o)) {
break_points_hit->set(break_points_hit_count++, *o);
}
}
} else {
break_points_hit = factory->NewFixedArray(1);
if (CheckBreakPoint(break_point_objects)) {
break_points_hit->set(break_points_hit_count++, *break_point_objects);
}
}
// Return undefined if no break points were triggered.
if (break_points_hit_count == 0) {
return factory->undefined_value();
}
// Return break points hit as a JSArray.
Handle<JSArray> result = factory->NewJSArrayWithElements(break_points_hit);
result->set_length(Smi::FromInt(break_points_hit_count));
return result;
}
MaybeHandle<Object> Debug::CallFunction(const char* name, int argc,
Handle<Object> args[]) {
PostponeInterruptsScope no_interrupts(isolate_);
AssertDebugContext();
Handle<Object> holder = isolate_->natives_utils_object();
Handle<JSFunction> fun = Handle<JSFunction>::cast(
Object::GetProperty(isolate_, holder, name, STRICT).ToHandleChecked());
Handle<Object> undefined = isolate_->factory()->undefined_value();
return Execution::TryCall(isolate_, fun, undefined, argc, args);
}
// Check whether a single break point object is triggered.
bool Debug::CheckBreakPoint(Handle<Object> break_point_object) {
Factory* factory = isolate_->factory();
HandleScope scope(isolate_);
// Ignore check if break point object is not a JSObject.
if (!break_point_object->IsJSObject()) return true;
// Get the break id as an object.
Handle<Object> break_id = factory->NewNumberFromInt(Debug::break_id());
// Call IsBreakPointTriggered.
Handle<Object> argv[] = { break_id, break_point_object };
Handle<Object> result;
if (!CallFunction("IsBreakPointTriggered", arraysize(argv), argv)
.ToHandle(&result)) {
return false;
}
// Return whether the break point is triggered.
return result->IsTrue();
}
bool Debug::SetBreakPoint(Handle<JSFunction> function,
Handle<Object> break_point_object,
int* source_position) {
HandleScope scope(isolate_);
// Make sure the function is compiled and has set up the debug info.
Handle<SharedFunctionInfo> shared(function->shared());
if (!EnsureDebugInfo(shared, function)) {
// Return if retrieving debug info failed.
return true;
}
Handle<DebugInfo> debug_info(shared->GetDebugInfo());
// Source positions starts with zero.
DCHECK(*source_position >= 0);
// Find the break point and change it.
BreakLocation location = BreakLocation::FromPosition(
debug_info, *source_position, STATEMENT_ALIGNED);
*source_position = location.statement_position();
location.SetBreakPoint(break_point_object);
feature_tracker()->Track(DebugFeatureTracker::kBreakPoint);
// At least one active break point now.
return debug_info->GetBreakPointCount() > 0;
}
bool Debug::SetBreakPointForScript(Handle<Script> script,
Handle<Object> break_point_object,
int* source_position,
BreakPositionAlignment alignment) {
HandleScope scope(isolate_);
// Obtain shared function info for the function.
Handle<Object> result =
FindSharedFunctionInfoInScript(script, *source_position);
if (result->IsUndefined()) return false;
// Make sure the function has set up the debug info.
Handle<SharedFunctionInfo> shared = Handle<SharedFunctionInfo>::cast(result);
if (!EnsureDebugInfo(shared, Handle<JSFunction>::null())) {
// Return if retrieving debug info failed.
return false;
}
// Find position within function. The script position might be before the
// source position of the first function.
int position;
if (shared->start_position() > *source_position) {
position = 0;
} else {
position = *source_position - shared->start_position();
}
Handle<DebugInfo> debug_info(shared->GetDebugInfo());
// Source positions starts with zero.
DCHECK(position >= 0);
// Find the break point and change it.
BreakLocation location =
BreakLocation::FromPosition(debug_info, position, alignment);
location.SetBreakPoint(break_point_object);
feature_tracker()->Track(DebugFeatureTracker::kBreakPoint);
position = (alignment == STATEMENT_ALIGNED) ? location.statement_position()
: location.position();
*source_position = position + shared->start_position();
// At least one active break point now.
DCHECK(debug_info->GetBreakPointCount() > 0);
return true;
}
void Debug::ClearBreakPoint(Handle<Object> break_point_object) {
HandleScope scope(isolate_);
DebugInfoListNode* node = debug_info_list_;
while (node != NULL) {
Handle<Object> result =
DebugInfo::FindBreakPointInfo(node->debug_info(), break_point_object);
if (!result->IsUndefined()) {
// Get information in the break point.
Handle<BreakPointInfo> break_point_info =
Handle<BreakPointInfo>::cast(result);
Handle<DebugInfo> debug_info = node->debug_info();
// Find the break point and clear it.
Address pc =
debug_info->code()->entry() + break_point_info->code_position();
BreakLocation location = BreakLocation::FromAddress(debug_info, pc);
location.ClearBreakPoint(break_point_object);
// If there are no more break points left remove the debug info for this
// function.
if (debug_info->GetBreakPointCount() == 0) {
RemoveDebugInfoAndClearFromShared(debug_info);
}
return;
}
node = node->next();
}
}
// Clear out all the debug break code. This is ONLY supposed to be used when
// shutting down the debugger as it will leave the break point information in
// DebugInfo even though the code is patched back to the non break point state.
void Debug::ClearAllBreakPoints() {
for (DebugInfoListNode* node = debug_info_list_; node != NULL;
node = node->next()) {
for (BreakLocation::Iterator it(node->debug_info(), ALL_BREAK_LOCATIONS);
!it.Done(); it.Next()) {
it.GetBreakLocation().ClearDebugBreak();
}
}
// Remove all debug info.
while (debug_info_list_ != NULL) {
RemoveDebugInfoAndClearFromShared(debug_info_list_->debug_info());
}
}
void Debug::FloodWithOneShot(Handle<JSFunction> function,
BreakLocatorType type) {
// Debug utility functions are not subject to debugging.
if (function->native_context() == *debug_context()) return;
if (!function->shared()->IsSubjectToDebugging()) {
// Builtin functions are not subject to stepping, but need to be
// deoptimized, because optimized code does not check for debug
// step in at call sites.
Deoptimizer::DeoptimizeFunction(*function);
return;
}
// Make sure the function is compiled and has set up the debug info.
Handle<SharedFunctionInfo> shared(function->shared());
if (!EnsureDebugInfo(shared, function)) {
// Return if we failed to retrieve the debug info.
return;
}
// Flood the function with break points.
Handle<DebugInfo> debug_info(shared->GetDebugInfo());
for (BreakLocation::Iterator it(debug_info, type); !it.Done(); it.Next()) {
it.GetBreakLocation().SetOneShot();
}
}
void Debug::ChangeBreakOnException(ExceptionBreakType type, bool enable) {
if (type == BreakUncaughtException) {
break_on_uncaught_exception_ = enable;
} else {
break_on_exception_ = enable;
}
}
bool Debug::IsBreakOnException(ExceptionBreakType type) {
if (type == BreakUncaughtException) {
return break_on_uncaught_exception_;
} else {
return break_on_exception_;
}
}
FrameSummary GetFirstFrameSummary(JavaScriptFrame* frame) {
List<FrameSummary> frames(FLAG_max_inlining_levels + 1);
frame->Summarize(&frames);
return frames.first();
}
void Debug::PrepareStepIn(Handle<JSFunction> function) {
if (!is_active()) return;
if (last_step_action() < StepIn) return;
if (in_debug_scope()) return;
if (thread_local_.step_in_enabled_) {
FloodWithOneShot(function);
}
}
void Debug::PrepareStepOnThrow() {
if (!is_active()) return;
if (last_step_action() == StepNone) return;
if (in_debug_scope()) return;
ClearOneShot();
// Iterate through the JavaScript stack looking for handlers.
JavaScriptFrameIterator it(isolate_);
while (!it.done()) {
JavaScriptFrame* frame = it.frame();
int stack_slots = 0; // The computed stack slot count is not used.
if (frame->LookupExceptionHandlerInTable(&stack_slots, NULL) > 0) break;
it.Advance();
}
// Find the closest Javascript frame we can flood with one-shots.
while (!it.done() &&
!it.frame()->function()->shared()->IsSubjectToDebugging()) {
it.Advance();
}
if (it.done()) return; // No suitable Javascript catch handler.
FloodWithOneShot(Handle<JSFunction>(it.frame()->function()));
}
void Debug::PrepareStep(StepAction step_action) {
HandleScope scope(isolate_);
DCHECK(in_debug_scope());
// Get the frame where the execution has stopped and skip the debug frame if
// any. The debug frame will only be present if execution was stopped due to
// hitting a break point. In other situations (e.g. unhandled exception) the
// debug frame is not present.
StackFrame::Id frame_id = break_frame_id();
// If there is no JavaScript stack don't do anything.
if (frame_id == StackFrame::NO_ID) return;
JavaScriptFrameIterator frames_it(isolate_, frame_id);
JavaScriptFrame* frame = frames_it.frame();
feature_tracker()->Track(DebugFeatureTracker::kStepping);
// Remember this step action and count.
thread_local_.last_step_action_ = step_action;
STATIC_ASSERT(StepFrame > StepIn);
thread_local_.step_in_enabled_ = (step_action >= StepIn);
// If the function on the top frame is unresolved perform step out. This will
// be the case when calling unknown function and having the debugger stopped
// in an unhandled exception.
if (!frame->function()->IsJSFunction()) {
// Step out: Find the calling JavaScript frame and flood it with
// breakpoints.
frames_it.Advance();
// Fill the function to return to with one-shot break points.
JSFunction* function = frames_it.frame()->function();
FloodWithOneShot(Handle<JSFunction>(function));
return;
}
// Get the debug info (create it if it does not exist).
FrameSummary summary = GetFirstFrameSummary(frame);
Handle<JSFunction> function(summary.function());
Handle<SharedFunctionInfo> shared(function->shared());
if (!EnsureDebugInfo(shared, function)) {
// Return if ensuring debug info failed.
return;
}
Handle<DebugInfo> debug_info(shared->GetDebugInfo());
// Refresh frame summary if the code has been recompiled for debugging.
if (shared->code() != *summary.code()) summary = GetFirstFrameSummary(frame);
// PC points to the instruction after the current one, possibly a break
// location as well. So the "- 1" to exclude it from the search.
Address call_pc = summary.pc() - 1;
BreakLocation location = BreakLocation::FromAddress(debug_info, call_pc);
// At a return statement we will step out either way.
if (location.IsReturn()) step_action = StepOut;
thread_local_.last_statement_position_ =
debug_info->code()->SourceStatementPosition(summary.pc());
thread_local_.last_fp_ = frame->UnpaddedFP();
switch (step_action) {
case StepNone:
UNREACHABLE();
break;
case StepOut:
// Advance to caller frame.
frames_it.Advance();
// Skip native and extension functions on the stack.
while (!frames_it.done() &&
!frames_it.frame()->function()->shared()->IsSubjectToDebugging()) {
// Builtin functions are not subject to stepping, but need to be
// deoptimized to include checks for step-in at call sites.
Deoptimizer::DeoptimizeFunction(frames_it.frame()->function());
frames_it.Advance();
}
if (frames_it.done()) {
// Stepping out to the embedder. Disable step-in to avoid stepping into
// the next (unrelated) call that the embedder makes.
thread_local_.step_in_enabled_ = false;
} else {
// Fill the caller function to return to with one-shot break points.
Handle<JSFunction> caller_function(frames_it.frame()->function());
FloodWithOneShot(caller_function);
thread_local_.target_fp_ = frames_it.frame()->UnpaddedFP();
}
// Clear last position info. For stepping out it does not matter.
thread_local_.last_statement_position_ = RelocInfo::kNoPosition;
thread_local_.last_fp_ = 0;
break;
case StepNext:
thread_local_.target_fp_ = frame->UnpaddedFP();
FloodWithOneShot(function);
break;
case StepIn:
FloodWithOneShot(function);
break;
case StepFrame:
// No point in setting one-shot breaks at places where we are not about
// to leave the current frame.
FloodWithOneShot(function, CALLS_AND_RETURNS);
break;
}
}
// Simple function for returning the source positions for active break points.
Handle<Object> Debug::GetSourceBreakLocations(
Handle<SharedFunctionInfo> shared,
BreakPositionAlignment position_alignment) {
Isolate* isolate = shared->GetIsolate();
Heap* heap = isolate->heap();
if (!shared->HasDebugInfo()) {
return Handle<Object>(heap->undefined_value(), isolate);
}
Handle<DebugInfo> debug_info(shared->GetDebugInfo());
if (debug_info->GetBreakPointCount() == 0) {
return Handle<Object>(heap->undefined_value(), isolate);
}
Handle<FixedArray> locations =
isolate->factory()->NewFixedArray(debug_info->GetBreakPointCount());
int count = 0;
for (int i = 0; i < debug_info->break_points()->length(); ++i) {
if (!debug_info->break_points()->get(i)->IsUndefined()) {
BreakPointInfo* break_point_info =
BreakPointInfo::cast(debug_info->break_points()->get(i));
int break_points = break_point_info->GetBreakPointCount();
if (break_points == 0) continue;
Smi* position = NULL;
switch (position_alignment) {
case STATEMENT_ALIGNED:
position = Smi::FromInt(break_point_info->statement_position());
break;
case BREAK_POSITION_ALIGNED:
position = Smi::FromInt(break_point_info->source_position());
break;
}
for (int j = 0; j < break_points; ++j) locations->set(count++, position);
}
}
return locations;
}
void Debug::ClearStepping() {
// Clear the various stepping setup.
ClearOneShot();
thread_local_.last_step_action_ = StepNone;
thread_local_.step_in_enabled_ = false;
thread_local_.last_statement_position_ = RelocInfo::kNoPosition;
thread_local_.last_fp_ = 0;
thread_local_.target_fp_ = 0;
}
// Clears all the one-shot break points that are currently set. Normally this
// function is called each time a break point is hit as one shot break points
// are used to support stepping.
void Debug::ClearOneShot() {
// The current implementation just runs through all the breakpoints. When the
// last break point for a function is removed that function is automatically
// removed from the list.
for (DebugInfoListNode* node = debug_info_list_; node != NULL;
node = node->next()) {
for (BreakLocation::Iterator it(node->debug_info(), ALL_BREAK_LOCATIONS);
!it.Done(); it.Next()) {
it.GetBreakLocation().ClearOneShot();
}
}
}
void Debug::EnableStepIn() {
STATIC_ASSERT(StepFrame > StepIn);
thread_local_.step_in_enabled_ = (last_step_action() >= StepIn);
}
bool MatchingCodeTargets(Code* target1, Code* target2) {
if (target1 == target2) return true;
if (target1->kind() != target2->kind()) return false;
return target1->is_handler() || target1->is_inline_cache_stub();
}
// Count the number of calls before the current frame PC to find the
// corresponding PC in the newly recompiled code.
static Address ComputeNewPcForRedirect(Code* new_code, Code* old_code,
Address old_pc) {
DCHECK_EQ(old_code->kind(), Code::FUNCTION);
DCHECK_EQ(new_code->kind(), Code::FUNCTION);
DCHECK(new_code->has_debug_break_slots());
static const int mask = RelocInfo::kCodeTargetMask;
// Find the target of the current call.
Code* target = NULL;
intptr_t delta = 0;
for (RelocIterator it(old_code, mask); !it.done(); it.next()) {
RelocInfo* rinfo = it.rinfo();
Address current_pc = rinfo->pc();
// The frame PC is behind the call instruction by the call instruction size.
if (current_pc > old_pc) break;
delta = old_pc - current_pc;
target = Code::GetCodeFromTargetAddress(rinfo->target_address());
}
// Count the number of calls to the same target before the current call.
int index = 0;
for (RelocIterator it(old_code, mask); !it.done(); it.next()) {
RelocInfo* rinfo = it.rinfo();
Address current_pc = rinfo->pc();
if (current_pc > old_pc) break;
Code* current = Code::GetCodeFromTargetAddress(rinfo->target_address());
if (MatchingCodeTargets(target, current)) index++;
}
DCHECK(index > 0);
// Repeat the count on the new code to find corresponding call.
for (RelocIterator it(new_code, mask); !it.done(); it.next()) {
RelocInfo* rinfo = it.rinfo();
Code* current = Code::GetCodeFromTargetAddress(rinfo->target_address());
if (MatchingCodeTargets(target, current)) index--;
if (index == 0) return rinfo->pc() + delta;
}
UNREACHABLE();
return NULL;
}
// Count the number of continuations at which the current pc offset is at.
static int ComputeContinuationIndexFromPcOffset(Code* code, int pc_offset) {
DCHECK_EQ(code->kind(), Code::FUNCTION);
Address pc = code->instruction_start() + pc_offset;
int mask = RelocInfo::ModeMask(RelocInfo::GENERATOR_CONTINUATION);
int index = 0;
for (RelocIterator it(code, mask); !it.done(); it.next()) {
index++;
RelocInfo* rinfo = it.rinfo();
Address current_pc = rinfo->pc();
if (current_pc == pc) break;
DCHECK(current_pc < pc);
}
return index;
}
// Find the pc offset for the given continuation index.
static int ComputePcOffsetFromContinuationIndex(Code* code, int index) {
DCHECK_EQ(code->kind(), Code::FUNCTION);
DCHECK(code->has_debug_break_slots());
int mask = RelocInfo::ModeMask(RelocInfo::GENERATOR_CONTINUATION);
RelocIterator it(code, mask);
for (int i = 1; i < index; i++) it.next();
return static_cast<int>(it.rinfo()->pc() - code->instruction_start());
}
class RedirectActiveFunctions : public ThreadVisitor {
public:
explicit RedirectActiveFunctions(SharedFunctionInfo* shared)
: shared_(shared) {
DCHECK(shared->HasDebugCode());
}
void VisitThread(Isolate* isolate, ThreadLocalTop* top) {
for (JavaScriptFrameIterator it(isolate, top); !it.done(); it.Advance()) {
JavaScriptFrame* frame = it.frame();
JSFunction* function = frame->function();
if (frame->is_optimized()) continue;
if (!function->Inlines(shared_)) continue;
Code* frame_code = frame->LookupCode();
DCHECK(frame_code->kind() == Code::FUNCTION);
if (frame_code->has_debug_break_slots()) continue;
Code* new_code = function->shared()->code();
Address old_pc = frame->pc();
Address new_pc = ComputeNewPcForRedirect(new_code, frame_code, old_pc);
if (FLAG_trace_deopt) {
PrintF("Replacing pc for debugging: %08" V8PRIxPTR " => %08" V8PRIxPTR
"\n",
reinterpret_cast<intptr_t>(old_pc),
reinterpret_cast<intptr_t>(new_pc));
}
if (FLAG_enable_embedded_constant_pool) {
// Update constant pool pointer for new code.
frame->set_constant_pool(new_code->constant_pool());
}
// Patch the return address to return into the code with
// debug break slots.
frame->set_pc(new_pc);
}
}
private:
SharedFunctionInfo* shared_;
DisallowHeapAllocation no_gc_;
};
bool Debug::PrepareFunctionForBreakPoints(Handle<SharedFunctionInfo> shared) {
DCHECK(shared->is_compiled());
if (isolate_->concurrent_recompilation_enabled()) {
isolate_->optimizing_compile_dispatcher()->Flush();
}
List<Handle<JSFunction> > functions;
List<Handle<JSGeneratorObject> > suspended_generators;
// Flush all optimized code maps. Note that the below heap iteration does not
// cover this, because the given function might have been inlined into code
// for which no JSFunction exists.
{
SharedFunctionInfo::Iterator iterator(isolate_);
while (SharedFunctionInfo* shared = iterator.Next()) {
if (!shared->OptimizedCodeMapIsCleared()) {
shared->ClearOptimizedCodeMap();
}
}
}
// Make sure we abort incremental marking.
isolate_->heap()->CollectAllGarbage(Heap::kMakeHeapIterableMask,
"prepare for break points");
{
HeapIterator iterator(isolate_->heap());
HeapObject* obj;
bool include_generators = shared->is_generator();
while ((obj = iterator.next())) {
if (obj->IsJSFunction()) {
JSFunction* function = JSFunction::cast(obj);
if (!function->Inlines(*shared)) continue;
if (function->code()->kind() == Code::OPTIMIZED_FUNCTION) {
Deoptimizer::DeoptimizeFunction(function);
}
if (function->shared() == *shared) functions.Add(handle(function));
} else if (include_generators && obj->IsJSGeneratorObject()) {
JSGeneratorObject* generator_obj = JSGeneratorObject::cast(obj);
if (!generator_obj->is_suspended()) continue;
JSFunction* function = generator_obj->function();
if (!function->Inlines(*shared)) continue;
int pc_offset = generator_obj->continuation();
int index =
ComputeContinuationIndexFromPcOffset(function->code(), pc_offset);
generator_obj->set_continuation(index);
suspended_generators.Add(handle(generator_obj));
}
}
}
if (!shared->HasDebugCode()) {
DCHECK(functions.length() > 0);
if (!Compiler::CompileDebugCode(functions.first())) return false;
}
for (Handle<JSFunction> const function : functions) {
function->ReplaceCode(shared->code());
}
for (Handle<JSGeneratorObject> const generator_obj : suspended_generators) {
int index = generator_obj->continuation();
int pc_offset = ComputePcOffsetFromContinuationIndex(shared->code(), index);
generator_obj->set_continuation(pc_offset);
}
// Update PCs on the stack to point to recompiled code.
RedirectActiveFunctions redirect_visitor(*shared);
redirect_visitor.VisitThread(isolate_, isolate_->thread_local_top());
isolate_->thread_manager()->IterateArchivedThreads(&redirect_visitor);
return true;
}
class SharedFunctionInfoFinder {
public:
explicit SharedFunctionInfoFinder(int target_position)
: current_candidate_(NULL),
current_candidate_closure_(NULL),
current_start_position_(RelocInfo::kNoPosition),
target_position_(target_position) {}
void NewCandidate(SharedFunctionInfo* shared, JSFunction* closure = NULL) {
if (!shared->IsSubjectToDebugging()) return;
int start_position = shared->function_token_position();
if (start_position == RelocInfo::kNoPosition) {
start_position = shared->start_position();
}
if (start_position > target_position_) return;
if (target_position_ > shared->end_position()) return;
if (current_candidate_ != NULL) {
if (current_start_position_ == start_position &&
shared->end_position() == current_candidate_->end_position()) {
// If we already have a matching closure, do not throw it away.
if (current_candidate_closure_ != NULL && closure == NULL) return;
// If a top-level function contains only one function
// declaration the source for the top-level and the function
// is the same. In that case prefer the non top-level function.
if (!current_candidate_->is_toplevel() && shared->is_toplevel()) return;
} else if (start_position < current_start_position_ ||
current_candidate_->end_position() < shared->end_position()) {
return;
}
}
current_start_position_ = start_position;
current_candidate_ = shared;
current_candidate_closure_ = closure;
}
SharedFunctionInfo* Result() { return current_candidate_; }
JSFunction* ResultClosure() { return current_candidate_closure_; }
private:
SharedFunctionInfo* current_candidate_;
JSFunction* current_candidate_closure_;
int current_start_position_;
int target_position_;
DisallowHeapAllocation no_gc_;
};
// We need to find a SFI for a literal that may not yet have been compiled yet,
// and there may not be a JSFunction referencing it. Find the SFI closest to
// the given position, compile it to reveal possible inner SFIs and repeat.
// While we are at this, also ensure code with debug break slots so that we do
// not have to compile a SFI without JSFunction, which is paifu for those that
// cannot be compiled without context (need to find outer compilable SFI etc.)
Handle<Object> Debug::FindSharedFunctionInfoInScript(Handle<Script> script,
int position) {
for (int iteration = 0;; iteration++) {
// Go through all shared function infos associated with this script to
// find the inner most function containing this position.
// If there is no shared function info for this script at all, there is
// no point in looking for it by walking the heap.
if (!script->shared_function_infos()->IsWeakFixedArray()) break;
SharedFunctionInfo* shared;
{
SharedFunctionInfoFinder finder(position);
WeakFixedArray::Iterator iterator(script->shared_function_infos());
SharedFunctionInfo* candidate;
while ((candidate = iterator.Next<SharedFunctionInfo>())) {
finder.NewCandidate(candidate);
}
shared = finder.Result();
if (shared == NULL) break;
// We found it if it's already compiled and has debug code.
if (shared->HasDebugCode()) {
Handle<SharedFunctionInfo> shared_handle(shared);
// If the iteration count is larger than 1, we had to compile the outer
// function in order to create this shared function info. So there can
// be no JSFunction referencing it. We can anticipate creating a debug
// info while bypassing PrepareFunctionForBreakpoints.
if (iteration > 1) {
AllowHeapAllocation allow_before_return;
CreateDebugInfo(shared_handle);
}
return shared_handle;
}
}
// If not, compile to reveal inner functions, if possible.
if (shared->allows_lazy_compilation_without_context()) {
HandleScope scope(isolate_);
if (!Compiler::CompileDebugCode(handle(shared))) break;
continue;
}
// If not possible, comb the heap for the best suitable compile target.
JSFunction* closure;
{
HeapIterator it(isolate_->heap());
SharedFunctionInfoFinder finder(position);
while (HeapObject* object = it.next()) {
JSFunction* candidate_closure = NULL;
SharedFunctionInfo* candidate = NULL;
if (object->IsJSFunction()) {
candidate_closure = JSFunction::cast(object);
candidate = candidate_closure->shared();
} else if (object->IsSharedFunctionInfo()) {
candidate = SharedFunctionInfo::cast(object);
if (!candidate->allows_lazy_compilation_without_context()) continue;
} else {
continue;
}
if (candidate->script() == *script) {
finder.NewCandidate(candidate, candidate_closure);
}
}
closure = finder.ResultClosure();
shared = finder.Result();
}
if (shared == NULL) break;
HandleScope scope(isolate_);
if (closure == NULL) {
if (!Compiler::CompileDebugCode(handle(shared))) break;
} else {
if (!Compiler::CompileDebugCode(handle(closure))) break;
}
}
return isolate_->factory()->undefined_value();
}
// Ensures the debug information is present for shared.
bool Debug::EnsureDebugInfo(Handle<SharedFunctionInfo> shared,
Handle<JSFunction> function) {
if (!shared->IsSubjectToDebugging()) return false;
// Return if we already have the debug info for shared.
if (shared->HasDebugInfo()) return true;
if (function.is_null()) {
DCHECK(shared->HasDebugCode());
} else if (!Compiler::Compile(function, CLEAR_EXCEPTION)) {
return false;
}
if (!PrepareFunctionForBreakPoints(shared)) return false;
CreateDebugInfo(shared);
return true;
}
void Debug::CreateDebugInfo(Handle<SharedFunctionInfo> shared) {
// Create the debug info object.
DCHECK(shared->HasDebugCode());
Handle<DebugInfo> debug_info = isolate_->factory()->NewDebugInfo(shared);
// Add debug info to the list.
DebugInfoListNode* node = new DebugInfoListNode(*debug_info);
node->set_next(debug_info_list_);
debug_info_list_ = node;
}
void Debug::RemoveDebugInfoAndClearFromShared(Handle<DebugInfo> debug_info) {
HandleScope scope(isolate_);
Handle<SharedFunctionInfo> shared(debug_info->shared());
DCHECK_NOT_NULL(debug_info_list_);
// Run through the debug info objects to find this one and remove it.
DebugInfoListNode* prev = NULL;
DebugInfoListNode* current = debug_info_list_;
while (current != NULL) {
if (current->debug_info().is_identical_to(debug_info)) {
// Unlink from list. If prev is NULL we are looking at the first element.
if (prev == NULL) {
debug_info_list_ = current->next();
} else {
prev->set_next(current->next());
}
delete current;
shared->set_debug_info(isolate_->heap()->undefined_value());
return;
}
// Move to next in list.
prev = current;
current = current->next();
}
UNREACHABLE();
}
void Debug::SetAfterBreakTarget(JavaScriptFrame* frame) {
after_break_target_ = NULL;
if (LiveEdit::SetAfterBreakTarget(this)) return; // LiveEdit did the job.
// Continue just after the slot.
after_break_target_ = frame->pc();
}
bool Debug::IsBreakAtReturn(JavaScriptFrame* frame) {
HandleScope scope(isolate_);
// Get the executing function in which the debug break occurred.
Handle<JSFunction> function(JSFunction::cast(frame->function()));
Handle<SharedFunctionInfo> shared(function->shared());
// With no debug info there are no break points, so we can't be at a return.
if (!shared->HasDebugInfo()) return false;
Handle<DebugInfo> debug_info(shared->GetDebugInfo());
Handle<Code> code(debug_info->code());
#ifdef DEBUG
// Get the code which is actually executing.
Handle<Code> frame_code(frame->LookupCode());
DCHECK(frame_code.is_identical_to(code));
#endif
// Find the reloc info matching the start of the debug break slot.
Address slot_pc = frame->pc() - Assembler::kDebugBreakSlotLength;
int mask = RelocInfo::ModeMask(RelocInfo::DEBUG_BREAK_SLOT_AT_RETURN);
for (RelocIterator it(*code, mask); !it.done(); it.next()) {
if (it.rinfo()->pc() == slot_pc) return true;
}
return false;
}
void Debug::FramesHaveBeenDropped(StackFrame::Id new_break_frame_id,
LiveEdit::FrameDropMode mode) {
if (mode != LiveEdit::CURRENTLY_SET_MODE) {
thread_local_.frame_drop_mode_ = mode;
}
thread_local_.break_frame_id_ = new_break_frame_id;
}
bool Debug::IsDebugGlobal(JSGlobalObject* global) {
return is_loaded() && global == debug_context()->global_object();
}
void Debug::ClearMirrorCache() {
PostponeInterruptsScope postpone(isolate_);
HandleScope scope(isolate_);
CallFunction("ClearMirrorCache", 0, NULL);
}
Handle<FixedArray> Debug::GetLoadedScripts() {
isolate_->heap()->CollectAllGarbage();
Factory* factory = isolate_->factory();
if (!factory->script_list()->IsWeakFixedArray()) {
return factory->empty_fixed_array();
}
Handle<WeakFixedArray> array =
Handle<WeakFixedArray>::cast(factory->script_list());
Handle<FixedArray> results = factory->NewFixedArray(array->Length());
int length = 0;
{
Script::Iterator iterator(isolate_);
Script* script;
while ((script = iterator.Next())) {
if (script->HasValidSource()) results->set(length++, script);
}
}
results->Shrink(length);
return results;
}
void Debug::GetStepinPositions(JavaScriptFrame* frame, StackFrame::Id frame_id,
List<int>* results_out) {
FrameSummary summary = GetFirstFrameSummary(frame);
Handle<JSFunction> fun = Handle<JSFunction>(summary.function());
Handle<SharedFunctionInfo> shared = Handle<SharedFunctionInfo>(fun->shared());
if (!EnsureDebugInfo(shared, fun)) return;
Handle<DebugInfo> debug_info(shared->GetDebugInfo());
// Refresh frame summary if the code has been recompiled for debugging.
if (shared->code() != *summary.code()) summary = GetFirstFrameSummary(frame);
// Find range of break points starting from the break point where execution
// has stopped.
Address call_pc = summary.pc() - 1;
List<BreakLocation> locations;
BreakLocation::FromAddressSameStatement(debug_info, call_pc, &locations);
for (BreakLocation location : locations) {
if (location.pc() <= summary.pc()) {
// The break point is near our pc. Could be a step-in possibility,
// that is currently taken by active debugger call.
if (break_frame_id() == StackFrame::NO_ID) {
continue; // We are not stepping.
} else {
JavaScriptFrameIterator frame_it(isolate_, break_frame_id());
// If our frame is a top frame and we are stepping, we can do step-in
// at this place.
if (frame_it.frame()->id() != frame_id) continue;
}
}
if (location.IsCall()) results_out->Add(location.position());
}
}
void Debug::RecordEvalCaller(Handle<Script> script) {
script->set_compilation_type(Script::COMPILATION_TYPE_EVAL);
// For eval scripts add information on the function from which eval was
// called.
StackTraceFrameIterator it(script->GetIsolate());
if (!it.done()) {
script->set_eval_from_shared(it.frame()->function()->shared());
Code* code = it.frame()->LookupCode();
int offset = static_cast<int>(
it.frame()->pc() - code->instruction_start());
script->set_eval_from_instructions_offset(offset);
}
}
MaybeHandle<Object> Debug::MakeExecutionState() {
// Create the execution state object.
Handle<Object> argv[] = { isolate_->factory()->NewNumberFromInt(break_id()) };
return CallFunction("MakeExecutionState", arraysize(argv), argv);
}
MaybeHandle<Object> Debug::MakeBreakEvent(Handle<Object> break_points_hit) {
// Create the new break event object.
Handle<Object> argv[] = { isolate_->factory()->NewNumberFromInt(break_id()),
break_points_hit };
return CallFunction("MakeBreakEvent", arraysize(argv), argv);
}
MaybeHandle<Object> Debug::MakeExceptionEvent(Handle<Object> exception,
bool uncaught,
Handle<Object> promise) {
// Create the new exception event object.
Handle<Object> argv[] = { isolate_->factory()->NewNumberFromInt(break_id()),
exception,
isolate_->factory()->ToBoolean(uncaught),
promise };
return CallFunction("MakeExceptionEvent", arraysize(argv), argv);
}
MaybeHandle<Object> Debug::MakeCompileEvent(Handle<Script> script,
v8::DebugEvent type) {
// Create the compile event object.
Handle<Object> script_wrapper = Script::GetWrapper(script);
Handle<Object> argv[] = { script_wrapper,
isolate_->factory()->NewNumberFromInt(type) };
return CallFunction("MakeCompileEvent", arraysize(argv), argv);
}
MaybeHandle<Object> Debug::MakePromiseEvent(Handle<JSObject> event_data) {
// Create the promise event object.
Handle<Object> argv[] = { event_data };
return CallFunction("MakePromiseEvent", arraysize(argv), argv);
}
MaybeHandle<Object> Debug::MakeAsyncTaskEvent(Handle<JSObject> task_event) {
// Create the async task event object.
Handle<Object> argv[] = { task_event };
return CallFunction("MakeAsyncTaskEvent", arraysize(argv), argv);
}
void Debug::OnThrow(Handle<Object> exception) {
if (in_debug_scope() || ignore_events()) return;
PrepareStepOnThrow();
// Temporarily clear any scheduled_exception to allow evaluating
// JavaScript from the debug event handler.
HandleScope scope(isolate_);
Handle<Object> scheduled_exception;
if (isolate_->has_scheduled_exception()) {
scheduled_exception = handle(isolate_->scheduled_exception(), isolate_);
isolate_->clear_scheduled_exception();
}
OnException(exception, isolate_->GetPromiseOnStackOnThrow());
if (!scheduled_exception.is_null()) {
isolate_->thread_local_top()->scheduled_exception_ = *scheduled_exception;
}
}
void Debug::OnPromiseReject(Handle<JSObject> promise, Handle<Object> value) {
if (in_debug_scope() || ignore_events()) return;
HandleScope scope(isolate_);
// Check whether the promise has been marked as having triggered a message.
Handle<Symbol> key = isolate_->factory()->promise_debug_marker_symbol();
if (JSReceiver::GetDataProperty(promise, key)->IsUndefined()) {
OnException(value, promise);
}
}
MaybeHandle<Object> Debug::PromiseHasUserDefinedRejectHandler(
Handle<JSObject> promise) {
Handle<JSFunction> fun = isolate_->promise_has_user_defined_reject_handler();
return Execution::Call(isolate_, fun, promise, 0, NULL);
}
void Debug::OnException(Handle<Object> exception, Handle<Object> promise) {
// In our prediction, try-finally is not considered to catch.
Isolate::CatchType catch_type = isolate_->PredictExceptionCatcher();
bool uncaught = (catch_type == Isolate::NOT_CAUGHT);
if (promise->IsJSObject()) {
Handle<JSObject> jspromise = Handle<JSObject>::cast(promise);
// Mark the promise as already having triggered a message.
Handle<Symbol> key = isolate_->factory()->promise_debug_marker_symbol();
JSObject::SetProperty(jspromise, key, key, STRICT).Assert();
// Check whether the promise reject is considered an uncaught exception.
Handle<Object> has_reject_handler;
ASSIGN_RETURN_ON_EXCEPTION_VALUE(
isolate_, has_reject_handler,
PromiseHasUserDefinedRejectHandler(jspromise), /* void */);
uncaught = has_reject_handler->IsFalse();
}
// Bail out if exception breaks are not active
if (uncaught) {
// Uncaught exceptions are reported by either flags.
if (!(break_on_uncaught_exception_ || break_on_exception_)) return;
} else {
// Caught exceptions are reported is activated.
if (!break_on_exception_) return;
}
DebugScope debug_scope(this);
if (debug_scope.failed()) return;
// Create the event data object.
Handle<Object> event_data;
// Bail out and don't call debugger if exception.
if (!MakeExceptionEvent(
exception, uncaught, promise).ToHandle(&event_data)) {
return;
}
// Process debug event.
ProcessDebugEvent(v8::Exception, Handle<JSObject>::cast(event_data), false);
// Return to continue execution from where the exception was thrown.
}
void Debug::OnDebugBreak(Handle<Object> break_points_hit,
bool auto_continue) {
// The caller provided for DebugScope.
AssertDebugContext();
// Bail out if there is no listener for this event
if (ignore_events()) return;
HandleScope scope(isolate_);
// Create the event data object.
Handle<Object> event_data;
// Bail out and don't call debugger if exception.
if (!MakeBreakEvent(break_points_hit).ToHandle(&event_data)) return;
// Process debug event.
ProcessDebugEvent(v8::Break,
Handle<JSObject>::cast(event_data),
auto_continue);
}
void Debug::OnCompileError(Handle<Script> script) {
ProcessCompileEvent(v8::CompileError, script);
}
void Debug::OnBeforeCompile(Handle<Script> script) {
ProcessCompileEvent(v8::BeforeCompile, script);
}
// Handle debugger actions when a new script is compiled.
void Debug::OnAfterCompile(Handle<Script> script) {
ProcessCompileEvent(v8::AfterCompile, script);
}
void Debug::OnPromiseEvent(Handle<JSObject> data) {
if (in_debug_scope() || ignore_events()) return;
HandleScope scope(isolate_);
DebugScope debug_scope(this);
if (debug_scope.failed()) return;
// Create the script collected state object.
Handle<Object> event_data;
// Bail out and don't call debugger if exception.
if (!MakePromiseEvent(data).ToHandle(&event_data)) return;
// Process debug event.
ProcessDebugEvent(v8::PromiseEvent,
Handle<JSObject>::cast(event_data),
true);
}
void Debug::OnAsyncTaskEvent(Handle<JSObject> data) {
if (in_debug_scope() || ignore_events()) return;
HandleScope scope(isolate_);
DebugScope debug_scope(this);
if (debug_scope.failed()) return;
// Create the script collected state object.
Handle<Object> event_data;
// Bail out and don't call debugger if exception.
if (!MakeAsyncTaskEvent(data).ToHandle(&event_data)) return;
// Process debug event.
ProcessDebugEvent(v8::AsyncTaskEvent,
Handle<JSObject>::cast(event_data),
true);
}
void Debug::ProcessDebugEvent(v8::DebugEvent event,
Handle<JSObject> event_data,
bool auto_continue) {
HandleScope scope(isolate_);
// Create the execution state.
Handle<Object> exec_state;
// Bail out and don't call debugger if exception.
if (!MakeExecutionState().ToHandle(&exec_state)) return;
// First notify the message handler if any.
if (message_handler_ != NULL) {
NotifyMessageHandler(event,
Handle<JSObject>::cast(exec_state),
event_data,
auto_continue);
}
// Notify registered debug event listener. This can be either a C or
// a JavaScript function. Don't call event listener for v8::Break
// here, if it's only a debug command -- they will be processed later.
if ((event != v8::Break || !auto_continue) && !event_listener_.is_null()) {
CallEventCallback(event, exec_state, event_data, NULL);
}
}
void Debug::CallEventCallback(v8::DebugEvent event,
Handle<Object> exec_state,
Handle<Object> event_data,
v8::Debug::ClientData* client_data) {
// Prevent other interrupts from triggering, for example API callbacks,
// while dispatching event listners.
PostponeInterruptsScope postpone(isolate_);
bool previous = in_debug_event_listener_;
in_debug_event_listener_ = true;
if (event_listener_->IsForeign()) {
// Invoke the C debug event listener.
v8::Debug::EventCallback callback =
FUNCTION_CAST<v8::Debug::EventCallback>(
Handle<Foreign>::cast(event_listener_)->foreign_address());
EventDetailsImpl event_details(event,
Handle<JSObject>::cast(exec_state),
Handle<JSObject>::cast(event_data),
event_listener_data_,
client_data);
callback(event_details);
DCHECK(!isolate_->has_scheduled_exception());
} else {
// Invoke the JavaScript debug event listener.
DCHECK(event_listener_->IsJSFunction());
Handle<Object> argv[] = { Handle<Object>(Smi::FromInt(event), isolate_),
exec_state,
event_data,
event_listener_data_ };
Handle<JSReceiver> global(isolate_->global_proxy());
Execution::TryCall(isolate_, Handle<JSFunction>::cast(event_listener_),
global, arraysize(argv), argv);
}
in_debug_event_listener_ = previous;
}
void Debug::ProcessCompileEvent(v8::DebugEvent event, Handle<Script> script) {
if (ignore_events()) return;
SuppressDebug while_processing(this);
bool in_nested_debug_scope = in_debug_scope();
HandleScope scope(isolate_);
DebugScope debug_scope(this);
if (debug_scope.failed()) return;
if (event == v8::AfterCompile) {
// If debugging there might be script break points registered for this
// script. Make sure that these break points are set.
Handle<Object> argv[] = {Script::GetWrapper(script)};
if (CallFunction("UpdateScriptBreakPoints", arraysize(argv), argv)
.is_null()) {
return;
}
}
// Create the compile state object.
Handle<Object> event_data;
// Bail out and don't call debugger if exception.
if (!MakeCompileEvent(script, event).ToHandle(&event_data)) return;
// Don't call NotifyMessageHandler if already in debug scope to avoid running
// nested command loop.
if (in_nested_debug_scope) {
if (event_listener_.is_null()) return;
// Create the execution state.
Handle<Object> exec_state;
// Bail out and don't call debugger if exception.
if (!MakeExecutionState().ToHandle(&exec_state)) return;
CallEventCallback(event, exec_state, event_data, NULL);
} else {
// Process debug event.
ProcessDebugEvent(event, Handle<JSObject>::cast(event_data), true);
}
}
Handle<Context> Debug::GetDebugContext() {
if (!is_loaded()) return Handle<Context>();
DebugScope debug_scope(this);
if (debug_scope.failed()) return Handle<Context>();
// The global handle may be destroyed soon after. Return it reboxed.
return handle(*debug_context(), isolate_);
}
void Debug::NotifyMessageHandler(v8::DebugEvent event,
Handle<JSObject> exec_state,
Handle<JSObject> event_data,
bool auto_continue) {
// Prevent other interrupts from triggering, for example API callbacks,
// while dispatching message handler callbacks.
PostponeInterruptsScope no_interrupts(isolate_);
DCHECK(is_active_);
HandleScope scope(isolate_);
// Process the individual events.
bool sendEventMessage = false;
switch (event) {
case v8::Break:
sendEventMessage = !auto_continue;
break;
case v8::NewFunction:
case v8::BeforeCompile:
case v8::CompileError:
case v8::PromiseEvent:
case v8::AsyncTaskEvent:
break;
case v8::Exception:
case v8::AfterCompile:
sendEventMessage = true;
break;
}
// The debug command interrupt flag might have been set when the command was
// added. It should be enough to clear the flag only once while we are in the
// debugger.
DCHECK(in_debug_scope());
isolate_->stack_guard()->ClearDebugCommand();
// Notify the debugger that a debug event has occurred unless auto continue is
// active in which case no event is send.
if (sendEventMessage) {
MessageImpl message = MessageImpl::NewEvent(
event,
auto_continue,
Handle<JSObject>::cast(exec_state),
Handle<JSObject>::cast(event_data));
InvokeMessageHandler(message);
}
// If auto continue don't make the event cause a break, but process messages
// in the queue if any. For script collected events don't even process
// messages in the queue as the execution state might not be what is expected
// by the client.
if (auto_continue && !has_commands()) return;
// DebugCommandProcessor goes here.
bool running = auto_continue;
Handle<Object> cmd_processor_ctor = Object::GetProperty(
isolate_, exec_state, "debugCommandProcessor").ToHandleChecked();
Handle<Object> ctor_args[] = { isolate_->factory()->ToBoolean(running) };
Handle<Object> cmd_processor = Execution::Call(
isolate_, cmd_processor_ctor, exec_state, 1, ctor_args).ToHandleChecked();
Handle<JSFunction> process_debug_request = Handle<JSFunction>::cast(
Object::GetProperty(
isolate_, cmd_processor, "processDebugRequest").ToHandleChecked());
Handle<Object> is_running = Object::GetProperty(
isolate_, cmd_processor, "isRunning").ToHandleChecked();
// Process requests from the debugger.
do {
// Wait for new command in the queue.
command_received_.Wait();
// Get the command from the queue.
CommandMessage command = command_queue_.Get();
isolate_->logger()->DebugTag(
"Got request from command queue, in interactive loop.");
if (!is_active()) {
// Delete command text and user data.
command.Dispose();
return;
}
Vector<const uc16> command_text(
const_cast<const uc16*>(command.text().start()),
command.text().length());
Handle<String> request_text = isolate_->factory()->NewStringFromTwoByte(
command_text).ToHandleChecked();
Handle<Object> request_args[] = { request_text };
Handle<Object> answer_value;
Handle<String> answer;
MaybeHandle<Object> maybe_exception;
MaybeHandle<Object> maybe_result =
Execution::TryCall(isolate_, process_debug_request, cmd_processor, 1,
request_args, &maybe_exception);
if (maybe_result.ToHandle(&answer_value)) {
if (answer_value->IsUndefined()) {
answer = isolate_->factory()->empty_string();
} else {
answer = Handle<String>::cast(answer_value);
}
// Log the JSON request/response.
if (FLAG_trace_debug_json) {
PrintF("%s\n", request_text->ToCString().get());
PrintF("%s\n", answer->ToCString().get());
}
Handle<Object> is_running_args[] = { answer };
maybe_result = Execution::Call(
isolate_, is_running, cmd_processor, 1, is_running_args);
Handle<Object> result;
if (!maybe_result.ToHandle(&result)) break;
running = result->IsTrue();
} else {
Handle<Object> exception;
if (!maybe_exception.ToHandle(&exception)) break;
Handle<Object> result;
if (!Object::ToString(isolate_, exception).ToHandle(&result)) break;
answer = Handle<String>::cast(result);
}
// Return the result.
MessageImpl message = MessageImpl::NewResponse(
event, running, exec_state, event_data, answer, command.client_data());
InvokeMessageHandler(message);
command.Dispose();
// Return from debug event processing if either the VM is put into the
// running state (through a continue command) or auto continue is active
// and there are no more commands queued.
} while (!running || has_commands());
command_queue_.Clear();
}
void Debug::SetEventListener(Handle<Object> callback,
Handle<Object> data) {
GlobalHandles* global_handles = isolate_->global_handles();
// Remove existing entry.
GlobalHandles::Destroy(event_listener_.location());
event_listener_ = Handle<Object>();
GlobalHandles::Destroy(event_listener_data_.location());
event_listener_data_ = Handle<Object>();
// Set new entry.
if (!callback->IsUndefined() && !callback->IsNull()) {
event_listener_ = global_handles->Create(*callback);
if (data.is_null()) data = isolate_->factory()->undefined_value();
event_listener_data_ = global_handles->Create(*data);
}
UpdateState();
}
void Debug::SetMessageHandler(v8::Debug::MessageHandler handler) {
message_handler_ = handler;
UpdateState();
if (handler == NULL && in_debug_scope()) {
// Send an empty command to the debugger if in a break to make JavaScript
// run again if the debugger is closed.
EnqueueCommandMessage(Vector<const uint16_t>::empty());
}
}
void Debug::UpdateState() {
bool is_active = message_handler_ != NULL || !event_listener_.is_null();
if (is_active || in_debug_scope()) {
// Note that the debug context could have already been loaded to
// bootstrap test cases.
isolate_->compilation_cache()->Disable();
is_active = Load();
} else if (is_loaded()) {
isolate_->compilation_cache()->Enable();
Unload();
}
is_active_ = is_active;
}
// Calls the registered debug message handler. This callback is part of the
// public API.
void Debug::InvokeMessageHandler(MessageImpl message) {
if (message_handler_ != NULL) message_handler_(message);
}
// Puts a command coming from the public API on the queue. Creates
// a copy of the command string managed by the debugger. Up to this
// point, the command data was managed by the API client. Called
// by the API client thread.
void Debug::EnqueueCommandMessage(Vector<const uint16_t> command,
v8::Debug::ClientData* client_data) {
// Need to cast away const.
CommandMessage message = CommandMessage::New(
Vector<uint16_t>(const_cast<uint16_t*>(command.start()),
command.length()),
client_data);
isolate_->logger()->DebugTag("Put command on command_queue.");
command_queue_.Put(message);
command_received_.Signal();
// Set the debug command break flag to have the command processed.
if (!in_debug_scope()) isolate_->stack_guard()->RequestDebugCommand();
}
MaybeHandle<Object> Debug::Call(Handle<Object> fun, Handle<Object> data) {
DebugScope debug_scope(this);
if (debug_scope.failed()) return isolate_->factory()->undefined_value();
// Create the execution state.
Handle<Object> exec_state;
if (!MakeExecutionState().ToHandle(&exec_state)) {
return isolate_->factory()->undefined_value();
}
Handle<Object> argv[] = { exec_state, data };
return Execution::Call(
isolate_,
fun,
Handle<Object>(debug_context()->global_proxy(), isolate_),
arraysize(argv),
argv);
}
void Debug::HandleDebugBreak() {
// Ignore debug break during bootstrapping.
if (isolate_->bootstrapper()->IsActive()) return;
// Just continue if breaks are disabled.
if (break_disabled()) return;
// Ignore debug break if debugger is not active.
if (!is_active()) return;
StackLimitCheck check(isolate_);
if (check.HasOverflowed()) return;
{ JavaScriptFrameIterator it(isolate_);
DCHECK(!it.done());
Object* fun = it.frame()->function();
if (fun && fun->IsJSFunction()) {
// Don't stop in builtin functions.
if (!JSFunction::cast(fun)->shared()->IsSubjectToDebugging()) return;
JSGlobalObject* global =
JSFunction::cast(fun)->context()->global_object();
// Don't stop in debugger functions.
if (IsDebugGlobal(global)) return;
}
}
// Collect the break state before clearing the flags.
bool debug_command_only = isolate_->stack_guard()->CheckDebugCommand() &&
!isolate_->stack_guard()->CheckDebugBreak();
isolate_->stack_guard()->ClearDebugBreak();
// Clear stepping to avoid duplicate breaks.
ClearStepping();
ProcessDebugMessages(debug_command_only);
}
void Debug::ProcessDebugMessages(bool debug_command_only) {
isolate_->stack_guard()->ClearDebugCommand();
StackLimitCheck check(isolate_);
if (check.HasOverflowed()) return;
HandleScope scope(isolate_);
DebugScope debug_scope(this);
if (debug_scope.failed()) return;
// Notify the debug event listeners. Indicate auto continue if the break was
// a debug command break.
OnDebugBreak(isolate_->factory()->undefined_value(), debug_command_only);
}
DebugScope::DebugScope(Debug* debug)
: debug_(debug),
prev_(debug->debugger_entry()),
save_(debug_->isolate_),
no_termination_exceptons_(debug_->isolate_,
StackGuard::TERMINATE_EXECUTION) {
// Link recursive debugger entry.
base::NoBarrier_Store(&debug_->thread_local_.current_debug_scope_,
reinterpret_cast<base::AtomicWord>(this));
// Store the previous break id and frame id.
break_id_ = debug_->break_id();
break_frame_id_ = debug_->break_frame_id();
// Create the new break info. If there is no JavaScript frames there is no
// break frame id.
JavaScriptFrameIterator it(isolate());
bool has_js_frames = !it.done();
debug_->thread_local_.break_frame_id_ = has_js_frames ? it.frame()->id()
: StackFrame::NO_ID;
debug_->SetNextBreakId();
debug_->UpdateState();
// Make sure that debugger is loaded and enter the debugger context.
// The previous context is kept in save_.
failed_ = !debug_->is_loaded();
if (!failed_) isolate()->set_context(*debug->debug_context());
}
DebugScope::~DebugScope() {
if (!failed_ && prev_ == NULL) {
// Clear mirror cache when leaving the debugger. Skip this if there is a
// pending exception as clearing the mirror cache calls back into
// JavaScript. This can happen if the v8::Debug::Call is used in which
// case the exception should end up in the calling code.
if (!isolate()->has_pending_exception()) debug_->ClearMirrorCache();
// If there are commands in the queue when leaving the debugger request
// that these commands are processed.
if (debug_->has_commands()) isolate()->stack_guard()->RequestDebugCommand();
}
// Leaving this debugger entry.
base::NoBarrier_Store(&debug_->thread_local_.current_debug_scope_,
reinterpret_cast<base::AtomicWord>(prev_));
// Restore to the previous break state.
debug_->thread_local_.break_frame_id_ = break_frame_id_;
debug_->thread_local_.break_id_ = break_id_;
debug_->UpdateState();
}
MessageImpl MessageImpl::NewEvent(DebugEvent event,
bool running,
Handle<JSObject> exec_state,
Handle<JSObject> event_data) {
MessageImpl message(true, event, running,
exec_state, event_data, Handle<String>(), NULL);
return message;
}
MessageImpl MessageImpl::NewResponse(DebugEvent event,
bool running,
Handle<JSObject> exec_state,
Handle<JSObject> event_data,
Handle<String> response_json,
v8::Debug::ClientData* client_data) {
MessageImpl message(false, event, running,
exec_state, event_data, response_json, client_data);
return message;
}
MessageImpl::MessageImpl(bool is_event,
DebugEvent event,
bool running,
Handle<JSObject> exec_state,
Handle<JSObject> event_data,
Handle<String> response_json,
v8::Debug::ClientData* client_data)
: is_event_(is_event),
event_(event),
running_(running),
exec_state_(exec_state),
event_data_(event_data),
response_json_(response_json),
client_data_(client_data) {}
bool MessageImpl::IsEvent() const {
return is_event_;
}
bool MessageImpl::IsResponse() const {
return !is_event_;
}
DebugEvent MessageImpl::GetEvent() const {
return event_;
}
bool MessageImpl::WillStartRunning() const {
return running_;
}
v8::Local<v8::Object> MessageImpl::GetExecutionState() const {
return v8::Utils::ToLocal(exec_state_);
}
v8::Isolate* MessageImpl::GetIsolate() const {
return reinterpret_cast<v8::Isolate*>(exec_state_->GetIsolate());
}
v8::Local<v8::Object> MessageImpl::GetEventData() const {
return v8::Utils::ToLocal(event_data_);
}
v8::Local<v8::String> MessageImpl::GetJSON() const {
Isolate* isolate = event_data_->GetIsolate();
v8::EscapableHandleScope scope(reinterpret_cast<v8::Isolate*>(isolate));
if (IsEvent()) {
// Call toJSONProtocol on the debug event object.
Handle<Object> fun = Object::GetProperty(
isolate, event_data_, "toJSONProtocol").ToHandleChecked();
if (!fun->IsJSFunction()) {
return v8::Local<v8::String>();
}
MaybeHandle<Object> maybe_json =
Execution::TryCall(isolate, fun, event_data_, 0, NULL);
Handle<Object> json;
if (!maybe_json.ToHandle(&json) || !json->IsString()) {
return v8::Local<v8::String>();
}
return scope.Escape(v8::Utils::ToLocal(Handle<String>::cast(json)));
} else {
return v8::Utils::ToLocal(response_json_);
}
}
v8::Local<v8::Context> MessageImpl::GetEventContext() const {
Isolate* isolate = event_data_->GetIsolate();
v8::Local<v8::Context> context = GetDebugEventContext(isolate);
// Isolate::context() may be NULL when "script collected" event occurs.
DCHECK(!context.IsEmpty());
return context;
}
v8::Debug::ClientData* MessageImpl::GetClientData() const {
return client_data_;
}
EventDetailsImpl::EventDetailsImpl(DebugEvent event,
Handle<JSObject> exec_state,
Handle<JSObject> event_data,
Handle<Object> callback_data,
v8::Debug::ClientData* client_data)
: event_(event),
exec_state_(exec_state),
event_data_(event_data),
callback_data_(callback_data),
client_data_(client_data) {}
DebugEvent EventDetailsImpl::GetEvent() const {
return event_;
}
v8::Local<v8::Object> EventDetailsImpl::GetExecutionState() const {
return v8::Utils::ToLocal(exec_state_);
}
v8::Local<v8::Object> EventDetailsImpl::GetEventData() const {
return v8::Utils::ToLocal(event_data_);
}
v8::Local<v8::Context> EventDetailsImpl::GetEventContext() const {
return GetDebugEventContext(exec_state_->GetIsolate());
}
v8::Local<v8::Value> EventDetailsImpl::GetCallbackData() const {
return v8::Utils::ToLocal(callback_data_);
}
v8::Debug::ClientData* EventDetailsImpl::GetClientData() const {
return client_data_;
}
CommandMessage::CommandMessage() : text_(Vector<uint16_t>::empty()),
client_data_(NULL) {
}
CommandMessage::CommandMessage(const Vector<uint16_t>& text,
v8::Debug::ClientData* data)
: text_(text),
client_data_(data) {
}
void CommandMessage::Dispose() {
text_.Dispose();
delete client_data_;
client_data_ = NULL;
}
CommandMessage CommandMessage::New(const Vector<uint16_t>& command,
v8::Debug::ClientData* data) {
return CommandMessage(command.Clone(), data);
}
CommandMessageQueue::CommandMessageQueue(int size) : start_(0), end_(0),
size_(size) {
messages_ = NewArray<CommandMessage>(size);
}
CommandMessageQueue::~CommandMessageQueue() {
while (!IsEmpty()) Get().Dispose();
DeleteArray(messages_);
}
CommandMessage CommandMessageQueue::Get() {
DCHECK(!IsEmpty());
int result = start_;
start_ = (start_ + 1) % size_;
return messages_[result];
}
void CommandMessageQueue::Put(const CommandMessage& message) {
if ((end_ + 1) % size_ == start_) {
Expand();
}
messages_[end_] = message;
end_ = (end_ + 1) % size_;
}
void CommandMessageQueue::Expand() {
CommandMessageQueue new_queue(size_ * 2);
while (!IsEmpty()) {
new_queue.Put(Get());
}
CommandMessage* array_to_free = messages_;
*this = new_queue;
new_queue.messages_ = array_to_free;
// Make the new_queue empty so that it doesn't call Dispose on any messages.
new_queue.start_ = new_queue.end_;
// Automatic destructor called on new_queue, freeing array_to_free.
}
LockingCommandMessageQueue::LockingCommandMessageQueue(Logger* logger, int size)
: logger_(logger), queue_(size) {}
bool LockingCommandMessageQueue::IsEmpty() const {
base::LockGuard<base::Mutex> lock_guard(&mutex_);
return queue_.IsEmpty();
}
CommandMessage LockingCommandMessageQueue::Get() {
base::LockGuard<base::Mutex> lock_guard(&mutex_);
CommandMessage result = queue_.Get();
logger_->DebugEvent("Get", result.text());
return result;
}
void LockingCommandMessageQueue::Put(const CommandMessage& message) {
base::LockGuard<base::Mutex> lock_guard(&mutex_);
queue_.Put(message);
logger_->DebugEvent("Put", message.text());
}
void LockingCommandMessageQueue::Clear() {
base::LockGuard<base::Mutex> lock_guard(&mutex_);
queue_.Clear();
}
} // namespace internal
} // namespace v8