新手求助：高手请进(页 1) - C/C++ (STL/boost) - Linux伊甸园论坛

yzli840324 发表于 2006-10-23 18:48

新手求助：高手请进

[font=宋体][font=宋体]新手求助：[/font][/font]
[font=宋体][font=宋体]c语言程序[/font][/font]@$w uzx#r V4k&R
[font=宋体][font=宋体][/font][/font][font=宋体][font=宋体][font=宋体]“利用pthread编写一个多线程程序来模拟两个人使用两个自动取款机来访问同一个共享帐号的情况。“[/font]~v(`5|Ymc
[/font][/font]

sof_ljh 发表于 2006-10-24 19:47

这有什么难的，你phtread_create创造两个线程，设置一个pthread_mutex就行了，每一个线程进去phtread_lock(mutex),就行阿。.G;R2u"u4q%N)z5a/E%G}w
其余的自己给上边贴代码就行阿

yzli840324 发表于 2006-10-29 20:26

我的代码为什么不行？CsAo {;Pe;~4oJ-V
出现错误：W!V(ej1O%Bu G
Abort : A memory image file is created as "core"

#include"pthread.h"-n g&V)F^3Vh$eq-l2J
#include"stdio.h"
#include"stdlib.h"*O8e6R.v__
pthread_mutex_t mutex;
void *function();#K'g)dYz7rF
double balance=500.0;?5IT8uB4g[
int main()K3T?rh
{&H^D})?:j*[7y'Q8J
int i,num_threads=2,a[2];
pthread_t p_threads[2]; ?z5r-B^0y#{
pthread_attr_t attr;
pthread_init(); w$t1X k_
pthread_mutex_init(&mutex,NULL);
pthread_attr_init(&attr);(dqK7aa A
pthread_attr_setscope(&attr,PTHREAD_SCOPE_SYSTEM);0lLS(`8e9` }
for(i=0;i<num_threads;i++)_1nI,S(x@b
if(pthread_create(&p_threads[i],NULL,function,NULL)!=0)4{:|7K5`&cH+l
perror("Pthread_create fails");wVp#cu{a
_5vq;b1c.G1]q
(Te#l LeU6}h1S
for(i=0;i<num_threads;i++)Y}s9u#m n Vf
{if ( pthread_join (p_threads[i], NULL ) )8UK p*~i3WwZ
perror("error joining thread.");
abort();
}S7glp9J9X
exit(0);L%ane~ Eo[
}2c'G3i#d$bPc
_ {*_T$TR E
void *function()
{
char c;
double amount1,amount2;}lc+Y&g3m
pthread_mutex_lock(&mutex);
printf("choose your service:\n");;cY @(Kb0[\
printf(" enter 1 deposit :\n");\J-bi)c r
printf(" enter 2 withdraw: \n");
scanf("%c",&c);oH(ZKvsJ-w|] W.B
switch(c)
{
case '1':II9^+M&o([~
printf(" enter the amount deposit:\n");
scanf("%lf",&amount1);
if(amount1<0)
printf("error:deposit amount is invalidate");,Q;UtG3zZ
else{
balance=balance+amount1;
}AQ7ow3a/]r6E
printf("Available: %lf\n",balance);
break;:@7}laJw:U
case '2':`n#R _|3[
printf("enter the amount withdraw:\n");
scanf("%lf",&amount2);)x`/}2S/[+`ilX
if(amount2<0)
printf("error: withdraw amount is invalidate");9{AP7V:]*h|
else{Ibv t X1r8ZJ"u
if(amount2>balance){
printf("error:insufficient funds");
}
else{
balance=balance-amount2;M8IB o$xq
}
6Siq9R8Agke [.O
}Y~!~[t.U1@R5U
printf("Available: %lf\n",balance);
}U/w_PV']0a
pthread_mutex_unlock(&mutex);
return;FC.M"g+K-m
}

sof_ljh 发表于 2006-11-2 17:17

perror不是可重入函数！你在编写多线程时不能判断是非正常结束的！

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