#include #include #include “scheduler.h” #include #include #include #include int sysclk = 0; // system clock int policy = 0; // 0: FCFS, 1: RR int time_quota = 0; // time quota for RR FILE* out; std::vector jobs; // print the usage void usage() { printf(“Usage: FCFS
“); printf(” RR
“); } // fork and run the job int run(Job& job, int timeslice = 100 /* s */) { if(job.pid == -100) job.pid = fork(); if(job.pid 0) // in father process { if(job.end >= 0) { kill(job.pid, SIGCONT); fprintf(out, “%d sec: Job %d continued
“, (int)(time(0)-sysclk), job.id); } else { fprintf(out, “%d sec: Job %d run
“, (int)(time(0)-sysclk), job.id); } timeslice *= 1000; // ms int delta = (timeslice>=100) ? 100 : timeslice; if(job.duration 0) { //printf(“sleep %dms for pid(%d).
“, delta, job.pid); usleep(delta*1000); // sleep for a while job.duration -= delta; job.end = (int)time(0) – sysclk; if(job.duration =100) ? 100 : timeslice; int status; pid_t ret = waitpid(job.pid, &status, WNOHANG); if(ret < 0) // no such a child { job.duration = 0; fprintf(out, "%d sec: Job %d terminated
", (int)(time(0)-sysclk), job.id); return -1; } if(ret == 0) continue; // test if child exited if (WIFEXITED(status)) { kill(job.pid, SIGKILL); job.duration = 0; fprintf(out, "%d sec: Job %d terminated
", (int)(time(0)-sysclk), job.id); //printf("%d exited(%d).
", job.pid, WEXITSTATUS(status)); return 0; } } // if the timeslice is exhaused kill(job.pid, SIGSTOP); fprintf(out, "%d sec: Job %d suspended
", (int)(time(0)-sysclk), job.id); return 0; } else if (job.pid == 0) // in child process { execvp(job.cmds0, job.cmds.data()); exit(-1); // if execvp failed } } // get next word std::string next(const char*& p) { // ignore white char while(*p==' ' || *p==' ' || *p=='
' || *p=='
') p++; if(!*p) return std::string(); const char* q = p; while(*p && *p!=' ' && *p!=' ' && *p!='
' && *p!='
') p++; return std::string(q, (unsigned long)p-(unsigned long)q); } int read(const char* path) { FILE* f = fopen(path, "r"); if(!f) { printf("ERROR: failed to open '%s'.
", path); return -1; } char buf1024; std::vector args; while(fgets(buf, 1024, f)) { args.clear(); const char* p = buf; bool first = true; for(;;) { std::string s = next(p); if(s.length() = 3) { Job j; j.cmdbuf.reserve(1024); j.start = atoi(args0.c_str()); j.duration = atoi(argsn-1.c_str())*1000; for(int i=1; i
