#include?
#include?
#include?
#include?
#include?

#define?max_threads?512

double?local_res[max_threads];
int?num_threads?num_per_thread?N;

void?*compute_pi（void?*id）?{
	int?index?=?*（（int?*）id）;
	int?begin?=?index?*?num_per_thread;
	int?end;
	if（index?==?num_threads?-?1）
		end?=?N;
	else
		end?=?begin?+?num_per_thread?-?1;
	int?i;
	double?lc?=?0.0;
	for（i?=?begin;i?<=?end;i++）{
		double?tmp?=?（i?+?0.5）?/?N;
		tmp?=?tmp?*?tmp?+?1;
		tmp?=?4?/?（N?*?tmp）;
		lc?+=?tmp;
	}
	local_res[index]?=?lc;
}

int?main（int?argcchar?*argv[]）?{
	pthread_t?p_threads[max_threads];
	double?result?=?0.0;
	int?i;
	int?*tmp;
	struct?timeval?tv;
	double?time_start?time_end;

	num_threads?=?atoi（argv[1]）;
	N?=?atoi（argv[2]）;
	num_per_thread?=?N?/?num_threads;?
	
	gettimeofday（&tv?NULL）;
	time_start?=?（double）tv.tv_sec?+?（double）tv.tv_usec?/?1000000.0;

	for（i?=?0;i?		tmp?=?（int?*）malloc（sizeof（int））;
		*tmp?=?i;
		pthread_create（&p_threads[i]?NULL?compute_pi?（void?*）tmp）;
	}
	for（i=?0;i?		pthread_join（p_threads[i]?NULL）;
		result?+=?local_res[i];
	}
	
	gettimeofday（&tv?NULL）;
	time_end?=?（double）tv.tv_sec?+?（double）tv.tv_usec?/?1000000.0;

	printf（“Computed?PI?=?%lf\n“?result）;
	printf（“Time?Consuming:?%lf\n“?time_end?-?time_start）;
	return?0;
}

?屬性????????????大小?????日期????時間???名稱
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?????文件???????1389??2009-12-12?23:10??線程ipc\pi.c

?????文件??????22528??2009-12-12?22:59??線程ipc\res.xls

?????目錄??????????0??2009-12-12?21:00??線程ipc

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????????????????23917????????????????????3