perf.h

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/*
 * perf.h
 *
 * Copyright (C) 2006,2007,2010  Thomas A. Vaughan
 * All rights reserved.
 *
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * 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.
 *     * Neither the name of the <organization> nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THOMAS A. VAUGHAN ''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 THOMAS A. VAUGHAN 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 PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *
 * Performance timers for (duh) timing.  Should be threadsafe!
 */

#ifndef WAVEPACKET_PERF_H__
#define WAVEPACKET_PERF_H__

// includes --------------------------------------------------------------------
#include "common/common.h"

#ifdef WIN32
#include <winsock2.h>
int gettimeofday(OUT struct timeval * tv, OUT struct timezone * tz);
#endif  // WIN32


namespace perf {


/// \ingroup general
/*@{*/


////////////////////////////////////////////////////////////////////////////////
///
/// \defgroup perf Performance Timers API
///
/// A set of simple timers (and time objects) used to quickly generate
/// information about how the code is performing.
///
////////////////////////////////////////////////////////////////////////////////
/*@{*/

/// yes, my own time_t for convenience in the perf library
struct time_t {
        // constructor, manipulators
        time_t(IN long in_sec, IN long in_usec) throw() {
                        this->set(in_sec, in_usec);
                }
        time_t(void) throw() { this->clear(); }

        void increment(IN const time_t& t) throw() {
                        // increment uSeconds, and account for rollover
                        useconds += t.useconds;
                        int nSecs = useconds / 1000000;
                        useconds = useconds % 1000000;

                        // now increment seconds
                        seconds += nSecs;
                        seconds += t.seconds;
                }

        void decrement(IN const time_t& t) throw() {

                        // DPRINTF("Have: %ld sec  %ld usec", seconds, useconds);
                        // DPRINTF("  dec %ld sec  %ld usec", t.seconds, t.useconds);

                        // decrement uSeconds, borrow if necessary
                        if (t.useconds > useconds) {
                                useconds += 1000000;
                                --seconds;
                        }

                        useconds -= t.useconds;
                        seconds -= t.seconds;

                        ASSERT(useconds >= 0 && useconds < 1000000,
                            "Bad microseconds: %ld", useconds);
                        if (seconds < 0) {
                                DPRINTF("Negative seconds!");
                                DPRINTF("Input: seconds=%ld  useconds=%ld",
                                    t.seconds, t.useconds);
                                DPRINTF("Local: seconds=%ld  useconds=%ld",
                                    seconds, useconds);
                                // ASSERT(false, "Input > Local?");

                                // this happens when someone resets the system
                                //   clock while we're timing.  Just use zero
                                seconds = 0;
                                useconds = 0;
                        }
                        // DPRINTF("  now %ld sec  %ld usec", seconds, useconds);
                }

        bool isGreaterThan(IN const time_t& t) const throw() {
                        if (seconds > t.seconds)
                                return true;
                        if (seconds < t.seconds)
                                return false;
                        return (useconds > t.useconds);
                }

        double getSeconds(void) const throw() {
                        return (1.0 * seconds) + (1.0e-6 * useconds);
                }

        long getMicroseconds(void) const throw() {
                        return useconds;
                }

        void clear(void) throw() {
                        seconds = useconds = 0;
                }

        void set(IN long in_sec, IN long in_usec) throw() {
                        ASSERT(in_sec >= 0, "Invalid seconds: %ld", in_sec);
                        ASSERT(in_usec >= 0 && in_usec < 1000000,
                            "Invalid microseconds: %ld", in_usec);

                        seconds = in_sec;
                        useconds = in_usec;
                }

private:
        // data fields
        long    seconds;
        long    useconds;
};



////////////////////////////////////////////////////////////////////////////////
///
///     Timer class -- just throw one of these on the stack with a unique name
///
///     When the timer destructs, it will register the time.  At the end of
///     program execution (actually, at any time!) you can call
///     getTimingSummary() and retrieve the list of all timers encountered and
///     basic statistics.
///
/// Example:
/// \code
///     void myFunction(void) {
///             perf::Timer timer("myFunction");
///             dosomething();
///             dosomething_else();
///             {
///                     perf::Timer timer("myFunction--expensive");
///                     dosomething_expensive();
//              }
///     }
/// \endcode
////////////////////////////////////////////////////////////////////////////////

class Timer {
public:
        Timer(const char * name);
        ~Timer(void);

private:
        // disallowed operations
        Timer(const Timer&);
        const Timer& operator = (const Timer&);

        // private data
        time_t          m_start_time;
        void           *m_context;
};



////////////////////////////////////////////////////////////////////////////////
//
//      DebugTimer -- prints to stderr on destruction
//
////////////////////////////////////////////////////////////////////////////////

class DebugTimer {
public:
        DebugTimer(IN const char * msg);
        ~DebugTimer(void) throw();

private:
        DebugTimer(const DebugTimer&);
        const DebugTimer& operator = (const DebugTimer&);

        // data
        time_t          m_start_time;
        std::string     m_msg;
};



////////////////////////////////////////////////////////////////////////////////
//
//      Other public APIs (reporting mostly)
//
////////////////////////////////////////////////////////////////////////////////

/// return time_t object containing current time
time_t getNow(void) throw();

/// you can disable the timing system
/// it is better to remove verbose timers, however!
///
/// TODO: remove this function altogether?
void enableTimers(IN bool enabled) throw();     // enabled by default


/// return a string containing (human-readable) formatted timing information
void getTimingSummary(OUT std::string&);

/// dumps timing summary to the given stream
void dumpTimingSummary(IO std::ostream&);

};      // perf namespace


/*@}*/  // end documentation block


#endif  // WAVEPACKET_PERF_H__