minix/tests/test52.c

   1 #include <unistd.h>
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <sys/types.h>
   5 #include <sys/wait.h>
   6 #include <signal.h>
   7 #include <math.h>
   8
   9 #define ROUNDS 20
  10 #define SWAPS 40
  11 int max_error = 5;
  12 #include "common.h"
  13
  14
  15
  16 int pipefdc[2];
  17 int pipefdp[2];
  18 int subtest = 0;
  19 int child_is_dead = 0;
  20
  21 void dead_child(int n);
  22 void do_child(void);
  23 void do_parent(void);
  24 void do_calcs(void);
  25 void err(int n);
  26 void quit(void);
  27
  28 void err(int n)
  29 {
  30   e(n);
  31 }
  32
  33 void do_calcs(void)
  34 {
  35   float a, b, c, d, e;
  36   float foo, bar;
  37   int i;
  38   subtest = 3;
  39
  40   a = 1.1;
  41   b = 2.2;
  42   c = 3.3;
  43   d = 4.4;
  44   e = 5.5;
  45
  46   foo = a * b; /* 2.42 */
  47   bar = c * d; /* 14.52 */
  48
  49   i = 0;
  50   while(i < ROUNDS) {
  51         foo += c; /* 5.72 */
  52         foo *= d; /* 25.168 */
  53         foo /= e; /* 4.5760 */
  54         bar -= a; /* 13.42 */
  55         bar *= b; /* 29.524 */
  56         bar /= e; /* 5.3680 */
  57
  58         /* Undo */
  59         foo *= e;
  60         foo /= d;
  61         foo -= c;
  62
  63         bar *= e;
  64         bar /= b;
  65         bar += a;
  66
  67         i++;
  68   }
  69
  70   if (fabs(foo - (a * b)) > 0.0001) err(1);
  71   if (fabs(bar - (c * d)) > 0.0001) err(2);
  72 }
  73
  74 void dead_child(int n)
  75 {
  76   int status;
  77   subtest = 4;
  78
  79   (void) n; /* Avoid warning about unused parameter */
  80
  81   if (wait(&status) == -1) err(1);
  82
  83   if (!WIFEXITED(status)) {
  84         err(2);
  85         quit();
  86   } else {
  87         errct += WEXITSTATUS(status);
  88         child_is_dead = 1;
  89   }
  90 }
  91
  92 void do_child(void)
  93 {
  94   char buf[2];
  95   int s;
  96
  97   s = 0;
  98   close(pipefdp[0]);
  99   close(pipefdc[1]);
 100
 101   while(s < SWAPS) {
 102         do_calcs();
 103
 104         /* Wake up parent */
 105         write(pipefdp[1], buf, 1);
 106
 107         /* Wait for parent to wake me up */
 108         read(pipefdc[0], buf, 1);
 109
 110         s++;
 111   }
 112   exit(0);
 113 }
 114
 115 void do_parent(void)
 116 {
 117   int s;
 118   char buf[2];
 119   struct sigaction sa;
 120   subtest = 2;
 121
 122   sa.sa_handler = dead_child;
 123   sa.sa_flags = 0;
 124   if (sigaction(SIGCHLD, &sa, NULL) == -1) err(1);
 125
 126   s = 0;
 127   close(pipefdp[1]);
 128   close(pipefdc[0]);
 129
 130   while(s < SWAPS) {
 131         /* Wait for child to wake me up */
 132         read(pipefdp[0], buf, 1);
 133
 134         do_calcs();
 135
 136         /* Wake up child */
 137         write(pipefdc[1], buf, 1);
 138         s++;
 139   }
 140
 141   while(child_is_dead == 0) { fflush(stdout); } /* Busy wait */
 142
 143   quit();
 144 }
 145
 146 int main(void)
 147 {
 148   pid_t r;
 149   subtest = 1;
 150
 151   start(52);
 152
 153   if (pipe(pipefdc) == -1) err(1);
 154   if (pipe(pipefdp) == -1) err(2);
 155
 156   r = fork();
 157   if(r < 0) {
 158         err(3);
 159   } else if(r == 0) {
 160         /* Child */
 161         do_child();
 162   } else {
 163         /* Parent */
 164         do_parent();
 165   }
 166
 167   return(0); /* Never reached */
 168
 169 }
 170