drd/tests/sem_wait.cpp

   1 #include <iostream>
   2 #include <cerrno>
   3 #include <cstring>
   4 #include <pthread.h>
   5 #include <semaphore.h>
   6
   7 struct FailedOn
   8 {
   9   FailedOn(const char *f, int e) : func(f), eno(e) {}
  10   std::string func;
  11   int eno;
  12 };
  13
  14 int main(void)
  15 {
  16   try {
  17     sem_t mySemaphore;
  18     if (sem_init(&mySemaphore, 0, 0) != 0)
  19       throw FailedOn("sem_init", errno);
  20
  21     std::cerr << "Calling sem_trywait\n";
  22     if (sem_trywait(&mySemaphore) != 0) {
  23       if (errno != EAGAIN)
  24         throw FailedOn("sem_trywait", errno);
  25
  26       std::cerr << "Wait would have blocked" << std::endl;
  27     } else {
  28       std::cerr << "Wait succeeded" << std::endl;
  29     }
  30
  31     if (sem_destroy(&mySemaphore) != 0)
  32       throw FailedOn("sem_destroy", errno);
  33
  34     return 0;
  35   } catch (FailedOn &e) {
  36     std::cerr << e.func << " failed: " << strerror(e.eno) << std::endl;
  37   } catch (...) {
  38     std::cerr << "Unknown exception" << std::endl;
  39   }
  40
  41   return -1;
  42 }