perfEvents.h

/*
 * Copyright 2017 Andrei Pangin
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef _PERFEVENTS_H
#define _PERFEVENTS_H

#ifdef __linux__

#include <signal.h>
#include "arch.h"
#include "engine.h"

class PerfEvent;
class PerfEventType;
class StackContext;

class PerfEvents : public Engine {
  private:
    static volatile bool _enabled;
    static int _max_events;
    static PerfEvent* _events;
    static PerfEventType* _event_type;
    static long _interval;
    static Ring _ring;
    static CStack _cstack;
    static bool _use_mmap_page;

    // cppcheck-suppress unusedPrivateFunction
    static u64 readCounter(siginfo_t* siginfo, void* ucontext);
    // cppcheck-suppress unusedPrivateFunction
    static void signalHandler(int signo, siginfo_t* siginfo, void* ucontext);

  public:
    Error check(Arguments& args);
    Error start(Arguments& args);
    void stop();


    virtual int registerThread(int tid);
    virtual void unregisterThread(int tid);
    long interval() const {
        return _interval;
    }

    const char* name() {
      return "PerfEvents";
    }

    static int walkKernel(int tid, const void** callchain, int max_depth, StackContext* java_ctx);

    static void resetBuffer(int tid);

    static const char* getEventName(int event_id);

    inline void enableEvents(bool enabled) {
      _enabled = enabled;
    }
};

#else

#include "engine.h"

class StackContext;

class PerfEvents : public Engine {
  public:
    Error check(Arguments& args) {
        return Error("PerfEvents are unsupported on this platform");
    }

    Error start(Arguments& args) {
        return Error("PerfEvents are unsupported on this platform");
    }

    static int walkKernel(int tid, const void** callchain, int max_depth, StackContext* java_ctx) {
        return 0;
    }

    inline void enableEvents(bool enabled) {}

    static void resetBuffer(int tid) {
    }

    static const char* getEventName(int event_id) {
        return NULL;
    }

    virtual int registerThread(int tid) {
        return -1;
    }
    virtual void unregisterThread(int tid) {}

    long interval() const {
        return -1;
    }
};

#endif // __linux__

#endif // _PERFEVENTS_H