openmp/runtime/test/misc_bugs/stack-propagate.c

   1 // RUN: %libomp-compile-and-run
   2
   3 // https://bugs.llvm.org/show_bug.cgi?id=26540 requested
   4 // stack size to be propagated from master to workers.
   5 // Library implements propagation of not too big stack
   6 // for Linux x86_64 platform (skipped Windows for now).
   7 //
   8 // The test checks that workers can use more than 4MB
   9 // of stack (4MB - was historical default for
  10 // stack size of worker thread in runtime library).
  11
  12 #include <stdio.h>
  13 #include <omp.h>
  14 #if !defined(_WIN32)
  15 #include <sys/resource.h> // getrlimit
  16 #endif
  17
  18 #define STK 4800000
  19
  20 double foo(int n, int th)
  21 {
  22   double arr[n];
  23   int i;
  24   double res = 0.0;
  25   for (i = 0; i < n; ++i) {
  26     arr[i] = (double)i / (n + 2);
  27   }
  28   for (i = 0; i < n; ++i) {
  29     res += arr[i] / n;
  30   }
  31   return res;
  32 }
  33
  34 int main(int argc, char *argv[])
  35 {
  36 #if defined(_WIN32)
  37   // don't test Windows
  38   printf("stack propagation not implemented, skipping test...\n");
  39   return 0;
  40 #else
  41   int status;
  42   double val = 0.0;
  43   int m = STK / 8; // > 4800000 bytes per thread
  44   // read stack size of calling thread, save it as default
  45   struct rlimit rlim;
  46   status = getrlimit(RLIMIT_STACK, &rlim);
  47   if (sizeof(void *) > 4 &&                 // do not test 32-bit systems,
  48       status == 0 && rlim.rlim_cur > STK) { // or small initial stack size
  49 #pragma omp parallel reduction(+:val)
  50     {
  51       val += foo(m, omp_get_thread_num());
  52     }
  53   } else {
  54     printf("too small stack size limit (needs about 8MB), skipping test...\n");
  55     return 0;
  56   }
  57   if (val > 0.1) {
  58     printf("passed\n");
  59     return 0;
  60   } else {
  61     printf("failed, val = %f\n", val);
  62     return 1;
  63   }
  64 #endif // _WIN32
  65 }