Source/JavaScriptCore/dfg/DFGWorklist.h

/*
 * Copyright (C) 2013-2020 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``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 APPLE INC. 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
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 */

#pragma once

#include "DFGPlan.h"
#include "DFGThreadData.h"
#include <wtf/AutomaticThread.h>
#include <wtf/Condition.h>
#include <wtf/Deque.h>
#include <wtf/HashMap.h>
#include <wtf/Lock.h>

namespace JSC {

class SlotVisitor;

namespace DFG {

#if ENABLE(DFG_JIT)

class Worklist : public RefCounted<Worklist> {
public:
    enum State { NotKnown, Compiling, Compiled };

    ~Worklist();
    
    static Ref<Worklist> create(CString&& tierName, unsigned numberOfThreads, int relativePriority = 0);
    
    void enqueue(Ref<Plan>&&);
    
    // This is equivalent to:
    // worklist->waitUntilAllPlansForVMAreReady(vm);
    // worklist->completeAllReadyPlansForVM(vm);
    void completeAllPlansForVM(VM&);

    template<typename Func>
    void iterateCodeBlocksForGC(VM&, const Func&);

    void waitUntilAllPlansForVMAreReady(VM&);
    State completeAllReadyPlansForVM(VM&, CompilationKey = CompilationKey());
    void removeAllReadyPlansForVM(VM&);
    
    State compilationState(CompilationKey);
    
    size_t queueLength();
    
    void suspendAllThreads();
    void resumeAllThreads();
    
    bool isActiveForVM(VM&) const;
    
    // Only called on the main thread after suspending all threads.
    void visitWeakReferences(SlotVisitor&);
    void removeDeadPlans(VM&);
    
    void removeNonCompilingPlansForVM(VM&);
    
    void dump(PrintStream&) const;
    unsigned setNumberOfThreads(unsigned, int);
    
private:
    Worklist(CString&& tierName);
    void finishCreation(unsigned numberOfThreads, int);
    void createNewThread(const AbstractLocker&, int);
    
    class ThreadBody;
    friend class ThreadBody;
    
    void runThread(ThreadData*);
    static void threadFunction(void* argument);
    
    void removeAllReadyPlansForVM(VM&, Vector<RefPtr<Plan>, 8>&);

    void dump(const AbstractLocker&, PrintStream&) const;
    
    unsigned m_numberOfActiveThreads { 0 };
    CString m_threadName;
    Vector<std::unique_ptr<ThreadData>> m_threads;
    
    // Used to inform the thread about what work there is left to do.
    Deque<RefPtr<Plan>> m_queue;
    
    // Used to answer questions about the current state of a code block. This
    // is particularly great for the cti_optimize OSR slow path, which wants
    // to know: did I get here because a better version of me just got
    // compiled?
    typedef HashMap<CompilationKey, RefPtr<Plan>> PlanMap;
    PlanMap m_plans;
    
    // Used to quickly find which plans have been compiled and are ready to
    // be completed.
    Vector<RefPtr<Plan>, 16> m_readyPlans;
    Ref<AutomaticThreadCondition> m_planEnqueued;
    Condition m_planCompiled;

    Lock m_suspensionLock;
    Box<Lock> m_lock;
};

JS_EXPORT_PRIVATE unsigned setNumberOfDFGCompilerThreads(unsigned);
JS_EXPORT_PRIVATE unsigned setNumberOfFTLCompilerThreads(unsigned);

// For DFGMode compilations.
JS_EXPORT_PRIVATE Worklist& ensureGlobalDFGWorklist();
JS_EXPORT_PRIVATE Worklist* existingGlobalDFGWorklistOrNull();

// For FTLMode and FTLForOSREntryMode compilations.
JS_EXPORT_PRIVATE Worklist& ensureGlobalFTLWorklist();
JS_EXPORT_PRIVATE Worklist* existingGlobalFTLWorklistOrNull();

Worklist& ensureGlobalWorklistFor(CompilationMode);

// Simplify doing things for all worklists.
unsigned numberOfWorklists();
Worklist& ensureWorklistForIndex(unsigned index);
Worklist* existingWorklistForIndexOrNull(unsigned index);
Worklist& existingWorklistForIndex(unsigned index);

#endif // ENABLE(DFG_JIT)

void completeAllPlansForVM(VM&);

template<typename Func>
void iterateCodeBlocksForGC(VM&, const Func&);

} } // namespace JSC::DFG