csci4061/lab08-code/em_server.c
Michael Zhang 041f660ccd
f
2018-01-29 17:28:37 -06:00

101 lines
3.4 KiB
C

// Server code which contains a name/email pairs and will fulfill
// requests from a client through FIFOs.
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/select.h>
#include <string.h>
#include <time.h>
#include <sys/types.h>
#include <signal.h>
#include <errno.h>
// data the server has and clients want: pairings of name and email
char *data[][2] = {
{"Chris Kauffman" ,"kauffman@umn.edu"},
{"Christopher Jonathan" ,"jonat003@umn.edu"},
{"Amy Larson" ,"larson@cs.umn.edu"},
{"Chris Dovolis" ,"dovolis@cs.umn.edu"},
{"Dan Knights" ,"knights@cs.umn.edu"},
{"George Karypis" ,"karypis@cs.umn.edu"},
{"Steven Jensen" ,"sjensen@cs.umn.edu"},
{"Daniel Keefe" ,"dfk@umn.edu"},
{"Michael W. Whalen" ,"whalen@cs.umn.edu"},
{"Catherine Qi Zhao" ,"qzhao@umn.edu"},
{"Dan Challou" ,"challou@cs.umn.edu"},
{"Steven Wu" ,"zsw@umn.edu"},
{"Michael Steinbach" ,"steinbac@cs.umn.edu"},
{"Jon Weissman" ,"jon@cs.umn.edu"},
{"Victoria Interrante" ,"interran@cs.umn.edu"},
{"Shana Watters" ,"watt0087@umn.edu"},
{"James Parker" ,"jparker@cs.umn.edu"},
{"James Moen" ,"moen0017@cs.umn.edu"},
{"Daniel Giesel" ,"giese138@umn.edu"},
{"Jon Read" ,"readx028@umn.edu"},
{"Sara Stokowski" ,"stoko004@umn.edu"},
{NULL , NULL},
};
// structure to store a lookup_t. client fills in with name, server
// fills in email if found in
typedef struct {
int pid;
char name[256];
char email[256];
} lookup_t;
int main() {
setvbuf(stdout, NULL, _IONBF, 0);
printf("starting server\n");
remove("requests.fifo");
remove("completions.fifo");
remove("data.fifo");
printf("SERVER: removed old fifos\n");
mkfifo("requests.fifo", S_IRUSR | S_IWUSR);
mkfifo("completions.fifo", S_IRUSR | S_IWUSR);
mkfifo("data.fifo", S_IRUSR | S_IWUSR);
printf("SERVER: created new fifos\n");
int requests_fd = open("requests.fifo", O_RDWR); // open read/write in case server hasn't started
int completions_fd = open("completions.fifo", O_RDWR); // open read or write only may cause hangs if the
int data_fd = open("data.fifo", O_RDWR); // other end of the pipe has not be openened
printf("SERVER: opened FIFOs, listening\n");
while(1){
lookup_t request;
read(requests_fd, &request, sizeof(lookup_t));
printf("%d B SERVER: received request {pid=%d name=\"%s\" }\n",
request.pid, request.pid, request.name);
char *name = request.name;
int found = 0;
for(int i=0; data[i][0] != NULL; i++){
if(strcmp(name, data[i][0]) == 0){
strcpy(request.email, data[i][1]);
found = 1;
}
}
if(!found){
strcpy(request.email, "NOT FOUND");
}
printf("%d B SERVER: filling request {pid=%d name=\"%s\" email=\"%s\" }\n",
request.pid,request.pid, request.name, request.email);
write(data_fd, &request, sizeof(request));
printf("%d B SERVER: signaling pid %d\n",
request.pid, request.pid);
kill(request.pid, SIGCONT);
int done_pid = -1;
read(completions_fd, &done_pid, sizeof(int));
printf("%d E SERVER: %d completion\n",done_pid,done_pid);
if(request.pid != done_pid){
printf("Server Problems: PID %d vs %d",
request.pid, done_pid);
}
}
exit(0);
}