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 }