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POprocess sync using sigusr1 and sigusr2
 

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  1. POprocess sync using sigusr1 and sigusr2
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    <p>i am writing a producer process to write a block of data to a file, and a consumer process to read the same block, but the below code gets stuck in an infinite loop, now from my side i think i am having a problem in the consumer process implementation!!</p> <pre><code>void wakeup() { ; }; unsigned int sleep ( unsigned int timer ) { if (sigset(SIGALRM, wakeup)==-1) { perror("sigset"); return 1; } (void)alarm( timer ); (void)pause(); return 0; } int main(void) { int fd, n, i, SomeInt, DataRead; pid_t pid, ppid; char buf[4]; char *buf2; int x=0; if((fd=open("/tmp/data_file", O_APPEND|O_CREAT, 0640)) &lt;0) exit(1); sigset(SIGTERM,SIG_IGN);/* signal */ ; sigset(SIGINT,SIG_IGN); /* signal */ pid=fork(); switch (pid) { case -1: { perror("FORK"); exit(1); } break; case 0: /* child process - Producer */ sigset(SIGUSR1,wakeup); sighold(SIGUSR1); /* block / hold signals SIGUSR1 until sigpause*/ FILE *file = fopen ("binary.txt", "r"); while (!feof(file)) { n = (int)(getpid()%256); srand((unsigned)n); sleep(rand() %5); for( x=0; x&lt;=4;x++) fscanf (file, "", buf[x]); write(fd, buf,sizeof(buf)); ppid=getppid(); kill(ppid, SIGUSR2); sigpause(SIGUSR1); } fclose(file); fflush(stdin); break; default: /* -parent code - Consumer */ sigset(SIGUSR2,wakeup); sighold(SIGUSR2); /* block / hold signals SIGUSR2 until sigpause*/ for (i=0; i&lt;=100; i++) { /* sleep a random amount of time */ n = (int)(getpid()%256); srand((unsigned)n); sleep(rand() %5); sigpause(SIGUSR2); /* pause(); */ /* reads a character from file */ read(fd, buf,sizeof(buf)); fprintf(stderr,"Consumer PID=%d value=%d\n",getpid(),atoi(buf)); kill(pid, SIGUSR1) ; } break; } exit(0); } </code></pre>
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    1. USThair Abdalla
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    1. COplease,please,please fix the indentation
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      1. USAShelly
    2. COwhat is wrong with it??
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      1. POprocess sync using sigusr1 and sigusr2
      1. USThair Abdalla
    3. COSee https://en.wikipedia.org/wiki/Indent_style#K.26R_style. Pick one of the top 3. and use it. Then people will be able to read your code, and might help.
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      1. USAShelly
 

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