WorkerScriptController.cpp   [plain text]

/*
 * Copyright (C) 2008 Apple Inc. All Rights Reserved.
 * Copyright (C) 2011, 2012 Google Inc. All Rights Reserved.
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#include "config.h"
#include "WorkerScriptController.h"

#include "JSDOMBinding.h"
#include "JSDedicatedWorkerGlobalScope.h"
#include "ScriptSourceCode.h"
#include "WebCoreJSClientData.h"
#include "WorkerGlobalScope.h"
#include "WorkerObjectProxy.h"
#include "WorkerScriptDebugServer.h"
#include "WorkerThread.h"
#include <bindings/ScriptValue.h>
#include <heap/StrongInlines.h>
#include <interpreter/Interpreter.h>
#include <runtime/Completion.h>
#include <runtime/Exception.h>
#include <runtime/ExceptionHelpers.h>
#include <runtime/Error.h>
#include <runtime/JSLock.h>

using namespace JSC;

namespace WebCore {

WorkerScriptController::WorkerScriptController(WorkerGlobalScope* workerGlobalScope)
    : m_vm(VM::create())
    , m_workerGlobalScope(workerGlobalScope)
    , m_workerGlobalScopeWrapper(*m_vm)
    , m_executionForbidden(false)
{
    initNormalWorldClientData(m_vm.get());
}

WorkerScriptController::~WorkerScriptController()
{
    JSLockHolder lock(vm());
    m_workerGlobalScopeWrapper.clear();
    m_vm = nullptr;
}

void WorkerScriptController::initScript()
{
    ASSERT(!m_workerGlobalScopeWrapper);

    JSLockHolder lock(m_vm.get());

    // Explicitly protect the global object's prototype so it isn't collected
    // when we allocate the global object. (Once the global object is fully
    // constructed, it can mark its own prototype.)
    Structure* workerGlobalScopePrototypeStructure = JSWorkerGlobalScopePrototype::createStructure(*m_vm, 0, jsNull());
    Strong<JSWorkerGlobalScopePrototype> workerGlobalScopePrototype(*m_vm, JSWorkerGlobalScopePrototype::create(*m_vm, 0, workerGlobalScopePrototypeStructure));

    if (m_workerGlobalScope->isDedicatedWorkerGlobalScope()) {
        Structure* dedicatedContextPrototypeStructure = JSDedicatedWorkerGlobalScopePrototype::createStructure(*m_vm, 0, workerGlobalScopePrototype.get());
        Strong<JSDedicatedWorkerGlobalScopePrototype> dedicatedContextPrototype(*m_vm, JSDedicatedWorkerGlobalScopePrototype::create(*m_vm, 0, dedicatedContextPrototypeStructure));
        Structure* structure = JSDedicatedWorkerGlobalScope::createStructure(*m_vm, 0, dedicatedContextPrototype.get());

        m_workerGlobalScopeWrapper.set(*m_vm, JSDedicatedWorkerGlobalScope::create(*m_vm, structure, static_cast<DedicatedWorkerGlobalScope&>(*m_workerGlobalScope)));
        workerGlobalScopePrototypeStructure->setGlobalObject(*m_vm, m_workerGlobalScopeWrapper.get());
        dedicatedContextPrototypeStructure->setGlobalObject(*m_vm, m_workerGlobalScopeWrapper.get());
        ASSERT(structure->globalObject() == m_workerGlobalScopeWrapper);
        ASSERT(m_workerGlobalScopeWrapper->structure()->globalObject() == m_workerGlobalScopeWrapper);
        workerGlobalScopePrototype->structure()->setGlobalObject(*m_vm, m_workerGlobalScopeWrapper.get());
        dedicatedContextPrototype->structure()->setGlobalObject(*m_vm, m_workerGlobalScopeWrapper.get());
    }
    ASSERT(m_workerGlobalScopeWrapper->globalObject() == m_workerGlobalScopeWrapper);
    ASSERT(asObject(m_workerGlobalScopeWrapper->prototype())->globalObject() == m_workerGlobalScopeWrapper);
}

void WorkerScriptController::evaluate(const ScriptSourceCode& sourceCode)
{
    if (isExecutionForbidden())
        return;

    NakedPtr<Exception> exception;
    evaluate(sourceCode, exception);
    if (exception) {
        JSLockHolder lock(vm());
        reportException(m_workerGlobalScopeWrapper->globalExec(), exception);
    }
}

void WorkerScriptController::evaluate(const ScriptSourceCode& sourceCode, NakedPtr<JSC::Exception>& returnedException)
{
    if (isExecutionForbidden())
        return;

    initScriptIfNeeded();

    ExecState* exec = m_workerGlobalScopeWrapper->globalExec();
    JSLockHolder lock(exec);

    JSC::evaluate(exec, sourceCode.jsSourceCode(), m_workerGlobalScopeWrapper->globalThis(), returnedException);

    VM& vm = exec->vm();
    if ((returnedException && isTerminatedExecutionException(returnedException))
        || (vm.watchdog && vm.watchdog->didFire())) {
        forbidExecution();
        return;
    }

    if (returnedException) {
        String errorMessage;
        int lineNumber = 0;
        int columnNumber = 0;
        String sourceURL = sourceCode.url().string();
        if (m_workerGlobalScope->sanitizeScriptError(errorMessage, lineNumber, columnNumber, sourceURL, sourceCode.cachedScript())) {
            vm.throwException(exec, createError(exec, errorMessage.impl()));
            returnedException = vm.exception();
            vm.clearException();
        }
    }
}

void WorkerScriptController::setException(JSC::Exception* exception)
{
    JSC::ExecState* exec = m_workerGlobalScopeWrapper->globalExec();
    exec->vm().throwException(exec, exception);
}

void WorkerScriptController::scheduleExecutionTermination()
{
    // The mutex provides a memory barrier to ensure that once
    // termination is scheduled, isExecutionTerminating will
    // accurately reflect that state when called from another thread.
    MutexLocker locker(m_scheduledTerminationMutex);
    if (m_vm->watchdog)
        m_vm->watchdog->fire();
}

bool WorkerScriptController::isExecutionTerminating() const
{
    // See comments in scheduleExecutionTermination regarding mutex usage.
    MutexLocker locker(m_scheduledTerminationMutex);
    if (m_vm->watchdog)
        return m_vm->watchdog->didFire();
    return false;
}

void WorkerScriptController::forbidExecution()
{
    ASSERT(m_workerGlobalScope->isContextThread());
    m_executionForbidden = true;
}

bool WorkerScriptController::isExecutionForbidden() const
{
    ASSERT(m_workerGlobalScope->isContextThread());
    return m_executionForbidden;
}

void WorkerScriptController::disableEval(const String& errorMessage)
{
    initScriptIfNeeded();
    JSLockHolder lock(vm());

    m_workerGlobalScopeWrapper->setEvalEnabled(false, errorMessage);
}

void WorkerScriptController::attachDebugger(JSC::Debugger* debugger)
{
    initScriptIfNeeded();
    debugger->attach(m_workerGlobalScopeWrapper->globalObject());
}

void WorkerScriptController::detachDebugger(JSC::Debugger* debugger)
{
    debugger->detach(m_workerGlobalScopeWrapper->globalObject(), JSC::Debugger::TerminatingDebuggingSession);
}

} // namespace WebCore