sleepfunctionerror（AdvancedProgrammingintheUNIXEnvironmentThirdEditionNo.374）

#include
#include
#include
#include "apue.h"static void sig_alrm(int signo)
{/* nothing to do, just returning wakes up sigsuspend */
}static void sig_usr1(int signo)
{}//static void sig_alrm_test(int signo)
//{
// err_msg("left an alrm");
//}

unsigned int sleep(unsigned int seconds)
{struct sigaction newact, oldact;sigset_t newmask, oldmask, suspmask;unsigned int unslept;timespec ts; // &＃43;&＃43;ts.tv_sec &＃61; 25; // &＃43;&＃43;ts.tv_nsec &＃61; 0; // &＃43;&＃43;/* set our handler, save previous information */newact.sa_handler &＃61; sig_alrm;sigemptyset(&newact.sa_mask);newact.sa_flags &＃61; 0;sigaction(SIGALRM, &newact, &oldact);/* block SIGALRM and save current signal mask */sigemptyset(&newmask);sigaddset(&newmask, SIGALRM);sigprocmask(SIG_BLOCK, &newmask, &oldmask);alarm(seconds);suspmask &＃61; oldmask;/* make sure SIGALRM isn&＃39;t block */sigdelset(&suspmask, SIGALRM);/* wait for any signal to be caught */sigsuspend(&suspmask);nanosleep(&ts, NULL); // &＃43;&＃43;/* some signal has been caught, SIGALRM is now blocked */unslept &＃61; alarm(0);/* reset previous action */sigaction(SIGALRM, &oldact, NULL);/* reset signal mask, which unblocks SIGALRM */sigprocmask(SIG_SETMASK, &oldmask, NULL);return unslept;
}int main(int argc, char *argv[])
{struct sigaction useract;struct sigaction alrmact;useract.sa_handler &＃61; sig_usr1;sigemptyset(&useract.sa_mask);useract.sa_flags &＃61; 0;if (sigaction(SIGUSR1, &useract, NULL) <0)err_sys("SIG SUR1 error");// alrmact.sa_handler &＃61; sig_alrm_test;
// sigemptyset(&alrmact.sa_mask);
// alrmact.sa_flags &＃61; 0;
// if (sigaction(SIGALRM, &alrmact, NULL) <0)
// err_sys("SIG ALRM error");
sleep(20);return 0;
}