connect_test.cpp
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00001 /*
00002  * Copyright (c) 2011, Willow Garage, Inc.
00003  * All rights reserved.
00004  *
00005  * Redistribution and use in source and binary forms, with or without
00006  * modification, are permitted provided that the following conditions are met:
00007  *
00008  *     * Redistributions of source code must retain the above copyright
00009  *       notice, this list of conditions and the following disclaimer.
00010  *     * Redistributions in binary form must reproduce the above copyright
00011  *       notice, this list of conditions and the following disclaimer in the
00012  *       documentation and/or other materials provided with the distribution.
00013  *     * Neither the name of the Willow Garage, Inc. nor the names of its
00014  *       contributors may be used to endorse or promote products derived from
00015  *       this software without specific prior written permission.
00016  *
00017  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
00018  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
00019  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
00020  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
00021  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
00022  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
00023  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
00024  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
00025  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
00026  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
00027  * POSSIBILITY OF SUCH DAMAGE.
00028  */
00029 
00030 #include <stdio.h>
00031 #include <sys/time.h>
00032 
00033 // This is a simple speed test to compare suppressing a signal/slot
00034 // emission by one of two methods:
00035 //
00036 // 1) disconnect and reconnect the signal/slot.
00037 //
00038 // 2) define a bool suppress_ member which makes the slot do nothing.
00039 //
00040 // Results for Qt 4.6 are that disconnect/reconnect takes about 11
00041 // times as long as boolean suppressor.
00042 
00043 #include "connect_test.h"
00044 
00045 double now()
00046 {
00047   struct timeval tv;
00048   gettimeofday( &tv, NULL );
00049   return double(tv.tv_sec) + double(tv.tv_usec) / 1000000.0;
00050 }
00051 
00052 int main( int argc, char **argv )
00053 {
00054   MyObject* obj = new MyObject;
00055   obj->enableChanges();
00056 
00057   QObject::connect( obj, SIGNAL( changed() ), obj, SLOT( onChanged() ));
00058   obj->emitChanged();
00059 
00060   double start, end;
00061   int count = 1000000;
00062 
00063   start = now();
00064   for( int i = 0; i < count; i++ )
00065   {
00066     QObject::disconnect( obj, SIGNAL( changed() ), obj, SLOT( onChanged() ));
00067     obj->emitChanged();
00068     QObject::connect( obj, SIGNAL( changed() ), obj, SLOT( onChanged() ));
00069   }
00070   end = now();
00071   printf("disconnect/emit/connect %d times took %lf seconds.\n", count, end - start );
00072 
00073   obj->emitChanged();
00074 
00075   start = now();
00076   for( int i = 0; i < count; i++ )
00077   {
00078     obj->suppressChanges();
00079     obj->emitChanged();
00080     obj->enableChanges();
00081   }
00082   end = now();
00083   printf("suppress/emit/enable %d times took %lf seconds.\n", count, end - start );
00084 
00085   return 0;
00086 }


rviz_qt
Author(s): Dave Hershberger
autogenerated on Fri Dec 6 2013 20:56:52