root/user/forktest.c

DEFINITIONS

1. print
2. forktest
3. main

   1 // Test that fork fails gracefully.
   2 // Tiny executable so that the limit can be filling the proc table.
   3 
   4 #include "kernel/types.h"
   5 #include "kernel/stat.h"
   6 #include "user/user.h"
   7 
   8 #define N  1000
   9 
  10 void
  11 print(const char *s)
  12 {
  13   write(1, s, strlen(s));
  14 }
  15 
  16 void
  17 forktest(void)
  18 {
  19   int n, pid;
  20 
  21   print("fork test\n");
  22 
  23   for(n=0; n<N; n++){
  24     pid = fork();
  25     if(pid < 0)
  26       break;
  27     if(pid == 0)
  28       exit(0);
  29   }
  30 
  31   if(n == N){
  32     print("fork claimed to work N times!\n");
  33     exit(1);
  34   }
  35 
  36   for(; n > 0; n--){
  37     if(wait(0) < 0){
  38       print("wait stopped early\n");
  39       exit(1);
  40     }
  41   }
  42 
  43   if(wait(0) != -1){
  44     print("wait got too many\n");
  45     exit(1);
  46   }
  47 
  48   print("fork test OK\n");
  49 }
  50 
  51 int
  52 main(void)
  53 {
  54   forktest();
  55   exit(0);
  56 }