??????
/**?@file?dining_philosophers_solve.c
??*?@note?HangZhou?Hikvision?Digital?Technology?Co.?Ltd.?All?Right?Reserved.
??*?@brief????哲學家就餐問題
??*?
??*?@author???liuboyf1
??*?@date?????2012-9-17
??*?@version??V1.0.0
??*?
??*?@note?///Description?here?
??*?@note?History:????
??*?@note???????????????
??*?@note??
??*?@warning??
??*/

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

#define?PHILOSOPHER_NUM?5
#define?THINKING?1
#define?HUNGRY?2
#define?DINING?3


sem_t?semph[PHILOSOPHER_NUM];???//?每個叉子有一個信號量
pthread_mutex_t?mutex;??????????//?Mutex?for?printing?


/**?@brief????描述哲學家行為函數
??*?@param[in]??代表哲學家的id
??*?@param[out]??
??*?@return??
??*/
void*?philosopher（void*?param）;?

int?main（int?argc?char*?argv[]）?
{?
????int?i;?
????srand（getpid（））;?
????pthread_t?PhilosopherThread[PHILOSOPHER_NUM];?//定義線程數組
????int?phId[PHILOSOPHER_NUM];?
????pthread_mutex_init（&mutex?NULL）;?
????for?（i=0;?i????{?
????????phId[i]?=?i;?
		//對每個叉子信號量進行初始化為當前進程的局部信號量
????????sem_init（&semph[i]?0?1）;
		//以philosopher為原型創建PHILOSOPHER_NUM個線程
????????pthread_create（&PhilosopherThread[i]?NULL?philosopher?（void*）（&phId[i]））;?
????????usleep（5000）;?
????}?
????sleep（30）;?
????return?0;?
}?

/**?@brief????描述哲學家行為函數
??*?@param[in]??代表哲學家的id
??*?@param[out]??
??*?@return??
??*/

void*?philosopher（void*?param）?
{?
????int?myid;?
????char?stateStr[128];?
????char?mystate;?
????int?ret;?
????unsigned?int?leftFork;?
????unsigned?int?rightFork;?
????myid?=?*（（int*）（param））;?
	printf（“philosopher?%d?begin?....\n“?myid）;
????usleep（1000000）;?//把進程掛起一段時間，?單位是微秒（百萬分之一秒）；

????//?初始狀態為THINKING
????mystate?=?THINKING;?
????leftFork?=?（myid）?%?PHILOSOPHER_NUM;?
????rightFork?=?（myid?+?1）?%?PHILOSOPHER_NUM;?
????while?（1）?
????{?
????????switch（mystate）?
????????{?
????????case?THINKING:
????????????//?改變狀態
????????????mystate?=?HUNGRY;?
????????????strcpy（stateStr?“HUNGRY“）;?
????????????break;?
????????case?HUNGRY:?
????????????strcpy（stateStr?“HUNGRY“）;?
????????????//?先測試左邊叉子
????????????ret?=?sem_trywait（&semph[leftFork]）;?
????????????if?（ret?==?0）?
????????????{
????????????????//?左叉子可用?拿起來?然后測試右邊叉子?...?
????????????????ret?=?sem_trywait（&semph[rightFork]）;?
????????????????if?（ret?==?0）?
????????????????{?
????????????????????//?右邊叉子也可用?!?改變我的狀態?
????????????????????mystate?=?DINING;?
????????????????????strcpy（stateStr?“DINING“）;?
????????????????}?
????????????????else?
????????????????{?
????????????????????//?右邊叉子被別人使用?放下左邊叉子.
????????????????????sem_post（&semph[leftFork]）;?
????????????????}?
????????????}?
????????????break;?
????????case?DINING:?
????????????//?放下左邊和右邊叉子
????????????sem_post（&semph[leftFork]）;?
????????????sem_post（&semph[rightFork]）;?
????????????//?改變我的狀態
????????????mystate?=?THINKING;?
?????????

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2012-09-18?05:38??劉博yf1+多線程作業\
?????目錄???????????0??2012-09-18?05:37??劉博yf1+多線程作業\homework\
?????文件????????3586??2012-09-18?05:31??劉博yf1+多線程作業\homework\dining_philosophers_solve.c
?????文件????????1345??2012-09-18?05:35??劉博yf1+多線程作業\homework\Makefile
?????文件???????41474??2012-09-18?05:36??劉博yf1+多線程作業\homework\Pic-20120917-143650.png
?????文件????????6874??2012-09-18?05:36??劉博yf1+多線程作業\homework\dining_philosophers_solve