js/public/ProfilingFrameIterator.h
author Masayuki Nakano <masayuki@d-toybox.com>
Fri, 19 May 2017 17:49:41 +0900
changeset 359318 b75c111837a802ceb953dba50a3c5a193d53ca22
parent 348922 39cc35b68133a2e59069fc9aa3b5aee97294755f
child 362481 2688b23e8e9a09b738450679a172332e4cb532e0
permissions -rw-r--r--
Bug 1339543 part 4 Change nsIWidget::ExecuteNativeKeyBinding() to nsIWidget::GetEditCommands() which just retrieves edit commands for the type r=smaug Now, nsIWidget::ExecuteNativeKeyBinding() isn't used by anybody for executing edit commands. Instead, they need array of edit commands for the key combination. So, the method should be renamed to GetEditCommands() and just return edit commands as an array. MozReview-Commit-ID: 4G0B1lJ8Lbe

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 * vim: set ts=8 sts=4 et sw=4 tw=99:
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef js_ProfilingFrameIterator_h
#define js_ProfilingFrameIterator_h

#include "mozilla/Attributes.h"
#include "mozilla/Maybe.h"

#include "jsbytecode.h"
#include "js/GCAPI.h"
#include "js/TypeDecls.h"
#include "js/Utility.h"

struct JSContext;
struct JSRuntime;
class JSScript;

namespace js {
    class Activation;
    namespace jit {
        class JitActivation;
        class JitProfilingFrameIterator;
        class JitcodeGlobalEntry;
    } // namespace jit
    namespace wasm {
        class ProfilingFrameIterator;
    } // namespace wasm
} // namespace js

namespace JS {

struct ForEachTrackedOptimizationAttemptOp;
struct ForEachTrackedOptimizationTypeInfoOp;

// This iterator can be used to walk the stack of a thread suspended at an
// arbitrary pc. To provide acurate results, profiling must have been enabled
// (via EnableRuntimeProfilingStack) before executing the callstack being
// unwound.
//
// Note that the caller must not do anything that could cause GC to happen while
// the iterator is alive, since this could invalidate Ion code and cause its
// contents to become out of date.
class MOZ_NON_PARAM JS_PUBLIC_API(ProfilingFrameIterator)
{
    JSContext* cx_;
    uint32_t sampleBufferGen_;
    js::Activation* activation_;

    // When moving past a JitActivation, we need to save the prevJitTop
    // from it to use as the exit-frame pointer when the next caller jit
    // activation (if any) comes around.
    void* savedPrevJitTop_;

    static const unsigned StorageSpace = 8 * sizeof(void*);
    alignas(void*) unsigned char storage_[StorageSpace];

    void* storage() { return storage_; }
    const void* storage() const { return storage_; }

    js::wasm::ProfilingFrameIterator& wasmIter() {
        MOZ_ASSERT(!done());
        MOZ_ASSERT(isWasm());
        return *static_cast<js::wasm::ProfilingFrameIterator*>(storage());
    }
    const js::wasm::ProfilingFrameIterator& wasmIter() const {
        MOZ_ASSERT(!done());
        MOZ_ASSERT(isWasm());
        return *static_cast<const js::wasm::ProfilingFrameIterator*>(storage());
    }

    js::jit::JitProfilingFrameIterator& jitIter() {
        MOZ_ASSERT(!done());
        MOZ_ASSERT(isJit());
        return *static_cast<js::jit::JitProfilingFrameIterator*>(storage());
    }

    const js::jit::JitProfilingFrameIterator& jitIter() const {
        MOZ_ASSERT(!done());
        MOZ_ASSERT(isJit());
        return *static_cast<const js::jit::JitProfilingFrameIterator*>(storage());
    }

    void settle();

    bool hasSampleBufferGen() const {
        return sampleBufferGen_ != UINT32_MAX;
    }

  public:
    struct RegisterState
    {
        RegisterState() : pc(nullptr), sp(nullptr), fp(nullptr), lr(nullptr) {}
        void* pc;
        void* sp;
        void* fp;
        void* lr;
    };

    ProfilingFrameIterator(JSContext* cx, const RegisterState& state,
                           uint32_t sampleBufferGen = UINT32_MAX);
    ~ProfilingFrameIterator();
    void operator++();
    bool done() const { return !activation_; }

    // Assuming the stack grows down (we do), the return value:
    //  - always points into the stack
    //  - is weakly monotonically increasing (may be equal for successive frames)
    //  - will compare greater than newer native and psuedo-stack frame addresses
    //    and less than older native and psuedo-stack frame addresses
    void* stackAddress() const;

    enum FrameKind
    {
      Frame_Baseline,
      Frame_Ion,
      Frame_Wasm
    };

    struct Frame
    {
        FrameKind kind;
        void* stackAddress;
        void* returnAddress;
        void* activation;
        const char* label;
    } JS_HAZ_GC_INVALIDATED;

    bool isWasm() const;
    bool isJit() const;

    uint32_t extractStack(Frame* frames, uint32_t offset, uint32_t end) const;

    mozilla::Maybe<Frame> getPhysicalFrameWithoutLabel() const;

  private:
    mozilla::Maybe<Frame> getPhysicalFrameAndEntry(js::jit::JitcodeGlobalEntry* entry) const;

    void iteratorConstruct(const RegisterState& state);
    void iteratorConstruct();
    void iteratorDestroy();
    bool iteratorDone();
} JS_HAZ_GC_INVALIDATED;

JS_FRIEND_API(bool)
IsProfilingEnabledForContext(JSContext* cx);

/**
 * After each sample run, this method should be called with the latest sample
 * buffer generation, and the lapCount.  It will update corresponding fields on
 * JSRuntime.
 *
 * See fields |profilerSampleBufferGen|, |profilerSampleBufferLapCount| on
 * JSRuntime for documentation about what these values are used for.
 */
JS_FRIEND_API(void)
UpdateJSContextProfilerSampleBufferGen(JSContext* cx, uint32_t generation,
                                       uint32_t lapCount);

struct ForEachProfiledFrameOp
{
    // A handle to the underlying JitcodeGlobalEntry, so as to avoid repeated
    // lookups on JitcodeGlobalTable.
    class MOZ_STACK_CLASS FrameHandle
    {
        friend JS_PUBLIC_API(void) ForEachProfiledFrame(JSContext* cx, void* addr,
                                                        ForEachProfiledFrameOp& op);

        JSRuntime* rt_;
        js::jit::JitcodeGlobalEntry& entry_;
        void* addr_;
        void* canonicalAddr_;
        const char* label_;
        uint32_t depth_;
        mozilla::Maybe<uint8_t> optsIndex_;

        FrameHandle(JSRuntime* rt, js::jit::JitcodeGlobalEntry& entry, void* addr,
                    const char* label, uint32_t depth);

        void updateHasTrackedOptimizations();

      public:
        const char* label() const { return label_; }
        uint32_t depth() const { return depth_; }
        bool hasTrackedOptimizations() const { return optsIndex_.isSome(); }
        void* canonicalAddress() const { return canonicalAddr_; }

        JS_PUBLIC_API(ProfilingFrameIterator::FrameKind) frameKind() const;
        JS_PUBLIC_API(void) forEachOptimizationAttempt(ForEachTrackedOptimizationAttemptOp& op,
                                                       JSScript** scriptOut,
                                                       jsbytecode** pcOut) const;

        JS_PUBLIC_API(void)
        forEachOptimizationTypeInfo(ForEachTrackedOptimizationTypeInfoOp& op) const;
    };

    // Called once per frame.
    virtual void operator()(const FrameHandle& frame) = 0;
};

JS_PUBLIC_API(void)
ForEachProfiledFrame(JSContext* cx, void* addr, ForEachProfiledFrameOp& op);

} // namespace JS

#endif  /* js_ProfilingFrameIterator_h */