src/compiler-rt/test/profile/Inputs/instrprof-file_ex.c

   1 /* This is a test case where the parent process forks 10
   2  * children which contend to write to the same file. With
   3  * file locking support, the data from each child should not
   4  * be lost.
   5  */
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <unistd.h>
   9 #include <sys/wait.h>
  10
  11 extern FILE *lprofOpenFileEx(const char *);
  12 int main(int argc, char *argv[]) {
  13   pid_t tid;
  14   FILE *F;
  15   const char *FN;
  16   int child[10];
  17   int c;
  18   int i;
  19
  20   if (argc < 2) {
  21     fprintf(stderr, "Requires one argument \n");
  22     exit(1);
  23   }
  24   FN = argv[1];
  25   truncate(FN, 0);
  26
  27   for (i = 0; i < 10; i++) {
  28     c = fork();
  29     // in child:
  30     if (c == 0) {
  31       FILE *F = lprofOpenFileEx(FN);
  32       if (!F) {
  33         fprintf(stderr, "Can not open file %s from child\n", FN);
  34         exit(1);
  35       }
  36       fseek(F, 0, SEEK_END);
  37       fprintf(F, "Dump from Child %d\n", i);
  38       fclose(F);
  39       exit(0);
  40     } else {
  41       child[i] = c;
  42     }
  43   }
  44
  45   // In parent
  46   for (i = 0; i < 10; i++) {
  47     int child_status;
  48     if ((tid = waitpid(child[i], &child_status, 0)) == -1)
  49       break;
  50   }
  51   F = lprofOpenFileEx(FN);
  52   if (!F) {
  53     fprintf(stderr, "Can not open file %s from parent\n", FN);
  54     exit(1);
  55   }
  56   fseek(F, 0, SEEK_END);
  57   fprintf(F, "Dump from parent %d\n", i);
  58   return 0;
  59 }