/* This program consists of 12 functions named, philosopher(), setPhilosopher(),
* take_Forks(), put_Forks(), downPhilosopher(), writeFile(), thinking(), test(), setState(),
* readFile(), eating(),argNo, and main(). It allows a philosopher to think using the function
* thinking, take forks using take_fork function, eat using the eating function, then
* put forks using put_forks when done eating.
* philosopher: the function calls thinking(),take_fork(),eating(),and put_forks() functions.
* setphilosopher: this function sets the status of the philosopher whether he is thinking
* or eating.
* take_forks: this functions checks whether the left and right forks are available.
* put_fork: this function it allows the philosopher to put down the forks when done eating.
* downPhilospher: this function allows the philosopher to "sleep".
* writeFile: this function writes a number to file.
* thinking: this function allows the philosopher to think.
* test: this function tests if the left and right forks are available.
* setState: this function sets the state of the philosopher.
* readFile: this function reads numbers from a file. eating: this function allows the philosophers to eat.
*/
#include<stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <string.h>
#include <sys/types.h>
#define N 5
#define REPETITIONS 10
#define EATTIME 3000000
#define THINKTIME EATTIME * 3
#define LEFT (i+N-1)%N
#define RIGHT (i+1)%N
#define HUNGRY 1
#define EATING 2
#define THINKING 0
#define mutex "mutex"
#define mutexLock "mutex.lock"
#define Output "output"
#define states "states"
#define statesLock "states.lock"
#define binarySemaphore "semaphore"
#define binarySemaphoreLock "semaphore.lock"
#define up(lock) unlink(lock)
#define down(lock1,lock2) while(link(lock1,lock2)== -1);
void readFile(int numberFromFile[],char *file);
void writeFile(int numberToFile[],char *file);
void setPhilosopher(int i,int number);
void take_Forks(int i);
void downPhilosopher(int i);
void thinking(int j);
void setState(int i,int number);
void test(int i);
void philosopher(int i);
void eating(int j);
void put_Forks(int i);
int argNo(char *argv);
void main(int args,char *argv[]){
int i;
i = argNo(argv[1]);
if((i < 0) || (i >= N))
{
fprintf(stderr,"Input not valid\n");
}
else
{
if((i < N) && (i >= 0))
philosopher(i);
}
}
int argNo(char *argv){
int number;
sscanf(argv,"%d",&number);
return number;
}
void philosopher(int i){
int j;
for(j = 0; j < REPETITIONS; j++)
{
thinking(i);
take_Forks(i);
eating(i);
put_Forks(i);
}
}
void thinking(int j){
int i,pid;
FILE *fp = fopen(Output,"a+");
pid = getpid();
for(i = 0;i < THINKTIME ; i++);
fclose(fp);
}
void take_Forks(int i){
down(mutex,mutexLock);
setState(i,HUNGRY);
test(i);
up(mutexLock);
downPhilosopher(i);
}
void eating(int j){
int i, pid = getpid();
FILE *fp = fopen(Output,"a+");
fprintf(fp,"%d %d eating\n",pid,j);
fprintf(stdout,"%d %d eating\n",pid,j);
fflush(fp);
for(i = 0; i < EATTIME; i++);
fprintf(fp,"%d %d done eating\n",pid,j);
fprintf(stdout,"%d %d done eating\n",pid,j); fflush(fp);
fclose(fp);
}
void put_Forks(int i){
down(mutex,mutexLock);
setState(i,THINKING);
test(LEFT);
test(RIGHT);
up(mutexLock);
}
void downPhilosopher(int i){
int semaphores[N];
do
{
readFile(semaphores,binarySemaphore);
}while(semaphores[i] == 0);
setPhilosopher(i,0);
}
void setState(int i,int number){
int theStates[N];
down(states,statesLock);
readFile(theStates,states);
theStates[i] = number;
writeFile(theStates,states);
up(statesLock);
}
void test(int i){
int theStates[N];
down(states,statesLock);
readFile(theStates,states);
up(statesLock);
if(theStates[i] == HUNGRY && theStates[LEFT] != EATING &&
theStates[RIGHT] != EATING)
{
setState(i,EATING);
setPhilosopher(i,1);
}
}
void setPhilosopher(int i,int number){
int semaphores[N];
down(binarySemaphore,binarySemaphoreLock);
readFile(semaphores,binarySemaphore);
semaphores[i] = number;
writeFile(semaphores,binarySemaphore);
up(binarySemaphoreLock);
}
void readFile(int numberFromFile[],char *file){
FILE *fp = fopen(file,"r");
int i;
for(i = 0; i< N; i++)
fscanf(fp,"%d",&numberFromFile[i]);
fclose(fp);
}
void writeFile(int numberToFile[],char *file){
FILE *fp = fopen(file,"w");
int i;
for(i = 0; i< N; i++)
fprintf(fp,"%d\n",numberToFile[i])
fclose(fp);
}
问问题
558 次
2 回答
3
您可能会考虑安装图形调试器而不是在 stackoverflow 上发布错误（Nemiver 是 linux 上最好的）
于 2012-10-14T23:57:09.703 回答
0
您正在尝试访问未分配给您的内存的某个地方。查看您的代码，以查找循环中您正在遍历数组的位置，并且您越过了该数组的边界。或者您可能正在测试您无权访问的东西的地方。既然你正在研究餐饮哲学家的问题，这可能是家庭作业，我建议你仔细看看你的设计，并注意每件事都应该做什么。如果您不想使用调试器（例如，如果您使用的是 OS161，我不怪您），但可以放入一些打印语句以找出您的程序在哪里给您 seg 错误。
于 2012-10-15T08:20:43.983 回答