libstdc++-v3/testsuite/30_threads/try_lock/5.cc

   1 // { dg-do run }
   2 // { dg-additional-options "-pthread" { target pthread } }
   3 // { dg-require-effective-target c++11 }
   4 // { dg-require-gthreads "" }
   5
   6 #include <mutex>
   7 #include <testsuite_hooks.h>
   8
   9 struct Lockable
  10 {
  11   static int tries;
  12
  13   void lock() { }
  14   void unlock() { }
  15   bool try_lock() { return ++tries != 2; }
  16 };
  17
  18 int Lockable::tries = 0;
  19
  20 void test01()
  21 {
  22   Lockable l1, l2, l3;
  23   std::mutex m1, m2;
  24
  25   VERIFY( std::try_lock(l1, l2, l3) == 1 );
  26   VERIFY( Lockable::tries == 2 );
  27
  28   Lockable::tries = 0;
  29   VERIFY( std::try_lock(m1, l1, l2, l3) == 2 );
  30   VERIFY( Lockable::tries == 2 );
  31
  32   Lockable::tries = 0;
  33   VERIFY( std::try_lock(l1, l2, l3, m1) == 1 );
  34   VERIFY( Lockable::tries == 2 );
  35
  36   Lockable::tries = 0;
  37   VERIFY( std::try_lock(m1, l1, l2, l3, m2) == 2 );
  38   VERIFY( Lockable::tries == 2 );
  39 }
  40
  41 int main()
  42 {
  43   test01();
  44 }