linux作业调度C程序

#include <stdio.h> #include <unistd.h> #include <sys/types.h> #include <sys/stat.h> #include <sys/time.h> #include <sys/wait.h> #include <string.h> #include <signal.h> #include <fcntl.h> #include <time.h> #include "job.h" void sig_handler(int sig, siginfo_t *info,void *notused); void schedule(); int allocjid(); void do_enq(struct jobinfo *newjob,struct jobcmd enqcmd); void do_deq(struct jobcmd deqcmd); void do_stat(struct jobcmd statcmd); void updateall(); struct waitqueue* jobselect(); void jobswitch(); int jobid=0; int siginfo=1; int fifo; int globalfd; struct waitqueue *head=NULL; struct waitqueue *next=NULL,*current=NULL; int main() { struct timeval interval; struct itimerval new,old; struct stat statbuf;//??? struct sigaction newact,oldact1,oldact2; if(stat("/tmp/server",&statbuf) == 0) {//?????? if(remove("/tmp/server") < 0) printf("remove failed"); } if(mkfifo("/tmp/server",0666) < 0) printf("mkfifo failed"); if((fifo=open("/tmp/server",O_RDONLY|O_NONBLOCK)) < 0) printf("open fifo failed"); if((globalfd=open("/dev/null",O_WRONLY)) < 0)//????? printf("open global file failed"); newact.sa_sigaction=sig_handler; sigemptyset(&newact.sa_mask); newact.sa_flags=SA_SIGINFO; sigaction(SIGCHLD,&newact,&oldact1); sigaction(SIGVTALRM,&newact,&oldact2); interval.tv_sec=0; interval.tv_usec=100; new.it_interval=interval; new.it_value=interval; setitimer(ITIMER_VIRTUAL,&new,&old); while(siginfo == 1) ; close(fifo); close(globalfd); return 0; } void sig_handler(int sig, siginfo_t *info,void *notused) { int status; int ret; switch(sig){ case SIGVTALRM: schedule(); return; case SIGCHLD: ret=waitpid(-1,&status,WNOHANG); if(ret == 0) return ; if(WIFEXITED(status)){//???????????? current->job->state=DONE; printf("normal termation,exit status=%d\n",WEXITSTATUS(status)); }else if(WIFSIGNALED(status)){ printf("abnormal termation,signal number=%d\n",WEXITSTATUS(status)); }else if(WIFSTOPPED(status)){ printf("child stopped,signal number=%d\n",WSTOPSIG(status)); } return; default: return; } } void schedule() { struct jobinfo *newjob=NULL; struct jobcmd cmd; int count=0; bzero(&cmd,DATALEN); if((count=read(fifo,&cmd,DATALEN)) < 0) printf("read fifo failed"); #ifdef DEBUG//?????????/ if(count){ printf("cmd cmdtype\t%d\n" "cmd defpri\t%d\n" "cmd data\t%s\n", cmd.type,cmd.defpri,cmd.data); }else printf("no data read\n"); #endif switch(cmd.type){ case ENQ: do_enq(newjob,cmd); break; case DEQ: do_deq(cmd); break; case STAT: do_stat(cmd); break; default: break; } updateall(); next=jobselect(); jobswitch(); } void do_enq(struct jobinfo *newjob,struct jobcmd enqcmd) { struct waitqueue *newnode,*p; int i=0,pid; char *offset,*argvec,*q; char **arglist; sigset_t zeromask; sigemptyset(&zeromask); newjob=(struct jobinfo*)malloc(sizeof(struct jobinfo)); newjob->jid=allocjid(); newjob->defpri=enqcmd.defpri; newjob->curpri=enqcmd.defpri; newjob->ownerid=enqcmd.owner; newjob->state=READY; newjob->create_time=time(NULL);//???? newjob->wait_time=0; newjob->run_time=0; arglist=(char**)malloc(sizeof(char*)*(enqcmd.argnum+1)); newjob->cmdarg=arglist; offset=enqcmd.data; argvec=enqcmd.data; while(i < enqcmd.argnum){ if(*offset == ':'){ *offset++='\0'; q=(char*)malloc(offset-argvec); strcpy(q,argvec); arglist[i++]=q; argvec=offset; }else offset++; } arglist[i]=NULL; #ifdef DEBUG printf("enqcmd argnum %d\n",enqcmd.argnum); for(i=0; i < enqcmd.argnum; i++) printf("parse enqcmd:%s\n",arglist[i]); #endif newnode=(struct waitqueue*)malloc(sizeof(struct waitqueue)); newnode->next=NULL; newnode->job=newjob; if(head){ for(p=head;p->next != NULL; p=p->next) ; p->next=newnode; }else head=newnode; if((pid=fork()) < 0) printf("enq fork failed"); if(pid == 0){ newjob->pid=getpid(); raise(SIGSTOP); #ifdef DEBUG printf("begin running\n"); for(i=0;arglist[i] != NULL; i++) printf("arglist %s\n",arglist[i]); #endif dup2(globalfd,1); if(execv(arglist[0],arglist) < 0) printf("exec failed\n"); exit(1); }else{ newjob->pid=pid; } } int allocjid() { return ++jobid; } void do_deq(struct jobcmd deqcmd) { int deqid,i; struct waitqueue *p,*prev,*select,*selectprev; deqid=atoi(deqcmd.data); #ifdef DEBUG printf("deq jid %d\n",deqid); #endif if(current && current->job->jid == deqid){ printf("terminate current job\n"); kill(SIGKILL,current->job->pid); for(i=0; (current->job->cmdarg)[i] != NULL; i++) free((current->job->cmdarg)[i]); free(current->job->cmdarg); free(current->job); free(current); current=NULL; }else{ select=NULL; selectprev=NULL; for(prev=NULL,p=head; p != NULL; prev=p,p=p->next) if(p->job->jid == deqid) break; if(p != NULL){ if(prev == NULL) head=NULL; else prev->next=p->next; for(i=0; (p->job->cmdarg)[i] != NULL; i++) free((p->job->cmdarg)[i]); free(p->job->cmdarg); free(p->job); free(p); p=NULL; } } } void do_stat(struct jobcmd statcmd) { struct waitqueue *p; char timebuf[BUFLEN]; printf("JOBID\tPID\tOWNER\tRUNTIME\tWAITTIME\tCREATTIME\tSTATE\n"); if(current){ strcpy(timebuf,ctime(&(current->job->create_time))); timebuf[strlen(timebuf) - 1]='\0'; printf("%d\t%d\t%d\t%d\t%d\t%s\t%s\n", current->job->jid, current->job->pid, current->job->ownerid, current->job->run_time, current->job->wait_time, timebuf, "RUNNING"); } for(p=head; p != NULL; p=p->next){ strcpy(timebuf,ctime(&(p->job->create_time))); timebuf[strlen(timebuf) - 1]='\0'; printf("%d\t%d\t%d\t%d\t%d\t%s\t%s\n", current->job->jid, current->job->pid, current->job->ownerid, current->job->run_time, current->job->wait_time, timebuf, "READY"); } } void updateall() { struct waitqueue *p; if(current) current->job->run_time += 1; for(p=head; p != NULL; p=p->next){ p->job->wait_time += 100; if(p->job->wait_time >= 1000 && p->job->curpri < 3) p->job->curpri++; } } struct waitqueue* jobselect() { struct waitqueue *p,*prev,*select,*selectprev; int highest=-1; select=NULL; selectprev=NULL; for(prev=NULL,p=head; p != NULL; prev=p,p=p->next) if(p->job->curpri > highest){ select=p; selectprev=prev; highest=p->job->curpri; } if(select != NULL){ if(selectprev != NULL) selectprev->next=select->next; else head=NULL; } return select; } void jobswitch() { struct waitqueue *p; int i; if(current != NULL && current->job->state == DONE){ for(i=0; (current->job->cmdarg)[i] != NULL; i++) free((current->job->cmdarg)[i]); free(current->job->cmdarg); free(current->job); free(current); current=NULL; } if(next == NULL && current == NULL) return ; else if(next != NULL && current == NULL){ printf("begin start new job\n"); current=next; next=NULL; current->job->state=RUNNING; kill(current->job->pid,SIGCONT); return ; }else if(next != NULL && current != NULL){ printf("begin switch\n"); kill(current->job->pid,SIGSTOP); current->job->curpri=current->job->defpri; current->job->wait_time=0; current->job->state=READY; if(head != NULL){ for(p=head; p->next != NULL; p=p->next) ; p->next=current; }else head=current; current=next; next=NULL; current->job->state=RUNNING; kill(current->job->pid,SIGCONT); return ; }else return; }