貼一個學習OpenMP過程中的程序
??1#include?<stdio.h>
??2#include?<tchar.h>
??3#include?<omp.h>
??4int?_tmain(int?argc,?_TCHAR*?argv[])
??5{????
??6????Timer?tm;
??7//????omp_set_num_threads(2),設定活動線程數為2
??8????omp_set_num_threads(3);
??9//????omp_get_num_procs()
?10????int?procs=omp_get_num_procs();
?11????printf("There?are?%d?processor(s)?available!\n",procs);
?12//??omp_get_thread_num(),返回當前線程號;
?13????int?Threadid=omp_get_thread_num();
?14????printf("當前線程號為:%d\n",Threadid);
?15//????omp_get_num_threads(),返回當前線程總數;
?16????int?Threadnum?=?omp_get_num_threads();
?17????printf("當前活動線程數為:%d\n",Threadnum);
?18
?19//?并行化編譯指導語句
?20????printf("下面開始測試并行化編譯指導語句!!\n\n");
?21//?1.parallel
?22????printf("------------------華麗無比的分隔線--------------------\n");
?23????printf("#pragma?omp?parallel\n\n");
?24
?25#pragma?omp?parallel
?26
?27????printf("This?is?Thread?%d?say?hello?to?you!\n",omp_get_thread_num());
?28
?29//?2.parallel?for
?30????printf("------------------華麗無比的分隔線--------------------\n");
?31????printf("#pragma?omp?parallel?for\n\n");
?32
?33#pragma?omp?parallel?for
?34????for?(int?i=0;i<4;i++)
?35????{
?36????????printf("Thread?%d?is?active?when?i?=?%d\n",omp_get_thread_num(),i);
?37????}
?38????int?i,j=0;
?39//?3.parallel?for?private
?40????printf("------------------華麗無比的分隔線--------------------\n");
?41????printf("#pragma?omp?parallel?for?private(j)\n\n");
?42
?43????printf("使用private子句\n");
?44#pragma?omp?parallel?for?private(j)
?45????for?(i=0;i<2;i++)
?46????????for(j=5;j<7;j++)
?47????????????printf("Thread?%d?is?active?when?i?=?%d,and?j=?%d\n",omp_get_thread_num(),i,j);
?48????printf("不使用private子句\n");
?49#pragma?omp?parallel?for?
?50????for?(i=0;i<2;i++)
?51//#pragma?omp?parallel?for
?52????????for(j=5;j<7;j++)
?53????????????printf("Thread?%d?is?active?when?i?=?%d,and?j=?%d\n",omp_get_thread_num(),i,j);
?54//?4.parallel?for?firstprivate()?and?lastprivate()
?55????printf("------------------華麗無比的分隔線--------------------\n");
?56????printf("#pragma?omp?parallel?for?firstprivate?and?lastprivate\n\n");
?57
?58????int?ai=10;
?59????int?bi=0;
?60????printf("Before?\"parallel?for?\",?ai?=?10?,and?bi?=?0?!\n\n");
?61#pragma?omp?parallel?for?firstprivate(ai)?lastprivate(bi)?
?62????????for?(int?i=1;i<4;i++)
?63????????{????????
?64????????????bi=ai;
?65????????????ai=0;
?66????????}
?67????printf("After?\"parallel?for?\"?bi?equal?to?%d?!\n\n",bi);
?68????printf("After?\"parallel?for?\"?ai?still?equal?to?%d?!\n\n",ai);
?69//?5.critical?臨界區
?70????printf("------------------華麗無比的分隔線--------------------\n");
?71????printf("#pragma?omp?critical?\n\n");
?72
?73????int?n=100000;
?74????int?ver?=?0;
?75????tm.start();
?76#pragma?omp?parallel?for?
?77????for?(int?i=1;i<=n;i++)
?78????{
?79????????//for?(j=0;j<1000000;j+=2){;}
?80#pragma?omp?critical
?81????????ver+=i;
?82????????//printf("Thread?%d?is?active?when?i?=?%d\n",omp_get_thread_num(),i);
?83????}
?84????printf("ver?=?%d\n",ver);
?85????tm.stop();
?86????printf("%f\n",tm.elapsedSeconds());
?87
?88//?6.reduction(<op>:<variable>)
?89????printf("------------------華麗無比的分隔線--------------------\n");
?90????printf("#pragma?omp?reduction?\n\n");
?91????
?92????int?ver2?=?0;
?93????tm.start();
?94#pragma?omp?parallel?for?reduction(+:ver2)
?95????for(int?i=0;i<=n;i++)
?96????{
?97????????//for?(j=0;j<1000000;j+=2){;}
?98????????ver2+=i;
?99????}
100
101????printf("ver2?=?%d\n",ver2);
102????tm.stop();
103????printf("%f\n",tm.elapsedSeconds());
104
105//?7.#pragma?omp?for
106????printf("------------------華麗無比的分隔線--------------------\n");
107????printf("#pragma?omp?for?\n\n");
108//將內層for循環并行化
109#pragma?omp?parallel?
110????for?(int?i=0;i<2;i++)
111????{
112#pragma?omp?for
113????????for?(int?j=0;j<2;j++)
114????????{
115????????????printf("Thread?%d?is?active?when?i=%d,and?j=%d\n",omp_get_thread_num(),i,j);
116????????}
117????}
118//?8.threadprivate?and?copyin
119????printf("------------------華麗無比的分隔線--------------------\n");
120????printf("#pragma?omp?threadprivate?and?copyin?\n\n");
121
122????int?global=10;
123//#pragma?omp?threadprivate(global)
124//#pragma?omp?parallel
125????for?(int?i=0;i<100;i++)
126????{
127????????global++;
128????}
129
130????printf("Global?is?equal?to?%d\n",global);
131
132
133//?9.功能并行#prgama?omp?parallel?sections?
134????printf("------------------華麗無比的分隔線--------------------\n");
135????printf("#pragma?omp?parallel?sections?\n\n");
136
137#pragma?omp?parallel?sections
138????{
139#pragma?omp?section
140????????printf("Section?1?'s?thread?is?NO.%d\n",omp_get_thread_num());
141#pragma?omp?section
142????????printf("Section?2?'s?thread?is?NO.%d\n",omp_get_thread_num());
143#pragma?omp?section
144????????printf("Section?3?'s?thread?is?NO.%d\n",omp_get_thread_num());
145????}
146
147//?10.同步編譯指導語句?
148//????1).同步屏障
149#pragma?omp?parallel
150????{
151????????int?initialization=0;
152#pragma?omp?barrier
153????????int?process=1;
154????}
155
156//????2.互斥鎖機制(庫函數)
157#ifdef?LOCKLOCK
158#define?LOCKLOCK
159????omp_lock_t?lock;
160//普通鎖
161????omp_init_lock(&lock);
162????omp_destroy_lock(&lock);
163????omp_set_lock(&lock);
164????omp_unset_lock(&lock);
165????omp_test_lock(&lock);
166//嵌套鎖
167????omp_init_nest_lock(&lock);
168????omp_destroy_nest_lock(&lock);
169????omp_set_nest_lock(&lock);
170????omp_unset_nest_lock(&lock);
171????omp_test_nest_lock(&lock);
172#endif
173//其他的OpenMP編譯指導語句請參考OpenMP手冊;
174
175
176
177????return?0;
178}

轉載于:https://www.cnblogs.com/lyq105/archive/2008/12/19/1358727.html

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