android_frameworks_base/libs/common_time/utils.h

/*
 * Copyright (C) 2012 The Android Open Source Project
 *
 * 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 __UTILS_H__
#define __UTILS_H__

#include <stdint.h>
#include <unistd.h>

#include <utils/String8.h>
#include <utils/threads.h>
#include <utils/Timers.h>

namespace android {

class Timeout {
  public:
    Timeout() : mSystemEndTime(0) { }

    // Set a timeout which should occur msec milliseconds from now.
    // Negative values will cancel any current timeout;
    void setTimeout(int msec);

    // Return the number of milliseconds until the timeout occurs, or -1 if
    // no timeout is scheduled.
    int msecTillTimeout(nsecs_t nowTime);
    int msecTillTimeout() { return msecTillTimeout(systemTime()); }

  private:
    // The systemTime() at which the timeout will be complete, or 0 if no
    // timeout is currently scheduled.
    nsecs_t mSystemEndTime;
};

class LogRing {
  public:
    LogRing(const char* header, size_t entries);
    ~LogRing();

    // Send a log message to logcat as well as storing it in the ring buffer.
    void log(int prio, const char* tag, const char* fmt, ...);

    // Add a log message the ring buffer, do not send the message to logcat.
    void log(const char* fmt, ...);

    // Dump the log to an fd (dumpsys style)
    void dumpLog(int fd);

  private:
    class Entry {
      public:
        uint32_t count;
        struct timeval first_ts;
        struct timeval last_ts;
        String8 s;
    };

    Mutex  mLock;
    Entry* mRingBuffer;
    size_t mSize;
    size_t mWr;
    bool   mIsFull;
    const char* mHeader;

    void internalLog(int prio, const char* tag, const char* fmt, va_list va);
};

}  // namespace android

#endif  // __UTILS_H__