src/hotspot/share/prims/jni.cpp

*** 3809,3821 ****
    // but __sync_lock_test_and_set is not guaranteed to do what we want
    // on all architectures.  So we check it works before relying on it.
  #if defined(ZERO) && defined(ASSERT)
    {
      jint a = 0xcafebabe;
!     jint b = Atomic::xchg((jint) 0xdeadbeef, &a);
      void *c = &a;
!     void *d = Atomic::xchg(&b, &c);
      assert(a == (jint) 0xdeadbeef && b == (jint) 0xcafebabe, "Atomic::xchg() works");
      assert(c == &b && d == &a, "Atomic::xchg() works");
    }
  #endif // ZERO && ASSERT
  
--- 3809,3821 ----
    // but __sync_lock_test_and_set is not guaranteed to do what we want
    // on all architectures.  So we check it works before relying on it.
  #if defined(ZERO) && defined(ASSERT)
    {
      jint a = 0xcafebabe;
!     jint b = Atomic::xchg(&a, (jint) 0xdeadbeef);
      void *c = &a;
!     void *d = Atomic::xchg(&c, &b);
      assert(a == (jint) 0xdeadbeef && b == (jint) 0xcafebabe, "Atomic::xchg() works");
      assert(c == &b && d == &a, "Atomic::xchg() works");
    }
  #endif // ZERO && ASSERT
  
*** 3827,3840 ****
    // one thread can call this method at a time
  
    // We use Atomic::xchg rather than Atomic::add/dec since on some platforms
    // the add/dec implementations are dependent on whether we are running
    // on a multiprocessor Atomic::xchg does not have this problem.
!   if (Atomic::xchg(1, &vm_created) == 1) {
      return JNI_EEXIST;   // already created, or create attempt in progress
    }
!   if (Atomic::xchg(0, &safe_to_recreate_vm) == 0) {
      return JNI_ERR;  // someone tried and failed and retry not allowed.
    }
  
    assert(vm_created == 1, "vm_created is true during the creation");
  
--- 3827,3840 ----
    // one thread can call this method at a time
  
    // We use Atomic::xchg rather than Atomic::add/dec since on some platforms
    // the add/dec implementations are dependent on whether we are running
    // on a multiprocessor Atomic::xchg does not have this problem.
!   if (Atomic::xchg(&vm_created, 1) == 1) {
      return JNI_EEXIST;   // already created, or create attempt in progress
    }
!   if (Atomic::xchg(&safe_to_recreate_vm, 0) == 0) {
      return JNI_ERR;  // someone tried and failed and retry not allowed.
    }
  
    assert(vm_created == 1, "vm_created is true during the creation");