/**
* validates the following
*
* writer is excluded while another thread holds the rwmutex for read
* once reader exits writer can enter
*/
TEST(RWMutex, WritersExcludedTest)
{
SupportThreadInfo *info;
omrthread_entrypoint_t functionsToRun[2];
functionsToRun[0] = (omrthread_entrypoint_t) &enter_rwmutex_write;
functionsToRun[1] = (omrthread_entrypoint_t) &exit_rwmutex_write;
info = createSupportThreadInfo(functionsToRun, 2);
/* first enter the mutex for read */
ASSERT_TRUE(0 == info->writeCounter);
omrthread_rwmutex_enter_read(info->handle);
/* start the concurrent thread that will try to enter for write and
* check that it is blocked
*/
startConcurrentThread(info);
ASSERT_TRUE(0 == info->writeCounter);
/* now release the rwmutex and validate that the thread enters it */
omrthread_monitor_enter(info->synchronization);
omrthread_rwmutex_exit_read(info->handle);
omrthread_monitor_wait_interruptable(info->synchronization, MILLI_TIMEOUT, NANO_TIMEOUT);
omrthread_monitor_exit(info->synchronization);
ASSERT_TRUE(1 == info->writeCounter);
/* done now so ask thread to release and clean up */
triggerNextStepDone(info);
ASSERT_TRUE(0 == info->writeCounter);
freeSupportThreadInfo(info);
}
/**
* This step enters the rwmutex in the SupporThreadInfo for read
* @param info the SupporThreadInfo which can be used by the step
*/
static intptr_t J9THREAD_PROC
enter_rwmutex_read(SupportThreadInfo *info)
{
omrthread_rwmutex_enter_read(info->handle);
info->readCounter++;
return 0;
}
/**
* Validate that we can enter/exit a RWMutex for read
*/
TEST(RWMutex, RWReadEnterExitTest)
{
intptr_t result;
omrthread_rwmutex_t handle;
uintptr_t flags = 0;
const char *mutexName = "test_mutex";
result = omrthread_rwmutex_init(&handle, flags, mutexName);
ASSERT_TRUE(0 == result);
result = omrthread_rwmutex_enter_read(handle);
ASSERT_TRUE(0 == result);
result = omrthread_rwmutex_exit_read(handle);
ASSERT_TRUE(0 == result);
/* clean up */
result = omrthread_rwmutex_destroy(handle);
ASSERT_TRUE(0 == result);
}
TEST(RWMutex, MultipleReadersTest)
{
SupportThreadInfo *info;
omrthread_entrypoint_t functionsToRun[2];
functionsToRun[0] = (omrthread_entrypoint_t) &enter_rwmutex_read;
functionsToRun[1] = (omrthread_entrypoint_t) &exit_rwmutex_read;
info = createSupportThreadInfo(functionsToRun, 2);
startConcurrentThread(info);
/* now the concurrent thread should have acquired the rwmutex
* so validate that we can acquire it as well
*/
ASSERT_TRUE(1 == info->readCounter);
omrthread_rwmutex_enter_read(info->handle);
ASSERT_TRUE(1 == info->readCounter);
omrthread_rwmutex_exit_read(info->handle);
/* ok we were not blocked by the other thread holding the mutex for read
* so ask it to release the mutex
*/
triggerNextStepDone(info);
ASSERT_TRUE(0 == info->readCounter);
freeSupportThreadInfo(info);
}
/**
* Validate that is_writelocked return true in writing state
*/
TEST(RWMutex, IsWriteLockedTest)
{
intptr_t result;
omrthread_rwmutex_t handle;
uintptr_t flags = 0;
BOOLEAN ret;
const char *mutexName = "test_mutex";
result = omrthread_rwmutex_init(&handle, flags, mutexName);
ASSERT_TRUE(0 == result);
ret = omrthread_rwmutex_is_writelocked(handle);
ASSERT_TRUE(FALSE == ret);
result = omrthread_rwmutex_enter_read(handle);
ASSERT_TRUE(0 == result);
ret = omrthread_rwmutex_is_writelocked(handle);
ASSERT_TRUE(FALSE == ret);
result = omrthread_rwmutex_exit_read(handle);
ASSERT_TRUE(0 == result);
result = omrthread_rwmutex_enter_write(handle);
ASSERT_TRUE(0 == result);
ret = omrthread_rwmutex_is_writelocked(handle);
ASSERT_TRUE(TRUE == ret);
result = omrthread_rwmutex_exit_write(handle);
ASSERT_TRUE(0 == result);
/* clean up */
result = omrthread_rwmutex_destroy(handle);
ASSERT_TRUE(0 == result);
}
/* validates the following
*
* reader can enter rwmutex even if write is pending (waiting on another reader)
* 2nd reader to enter rwmutex continues to block write after first thread exits
*/
TEST(RWMutex, SecondReaderExcludesWrite)
{
omrthread_rwmutex_t saveHandle;
SupportThreadInfo *info;
SupportThreadInfo *infoReader;
omrthread_entrypoint_t functionsToRun[2];
omrthread_entrypoint_t functionsToRunReader[2];
/* set up the steps for the 2 concurrent threads */
functionsToRun[0] = (omrthread_entrypoint_t) &enter_rwmutex_write;
functionsToRun[1] = (omrthread_entrypoint_t) &exit_rwmutex_write;
functionsToRunReader[0] = (omrthread_entrypoint_t) &enter_rwmutex_read;
functionsToRunReader[1] = (omrthread_entrypoint_t) &exit_rwmutex_read;
info = createSupportThreadInfo(functionsToRun, 2);
infoReader = createSupportThreadInfo(functionsToRunReader, 2);
/* set the two SupporThreadInfo structures so that they use the same rwmutex */
saveHandle = infoReader->handle;
infoReader->handle = info->handle;
/* first enter the mutex for read */
ASSERT_TRUE(0 == info->writeCounter);
omrthread_rwmutex_enter_read(info->handle);
/* start the concurrent thread that will try to enter for write and
* check that it is blocked
*/
startConcurrentThread(info);
ASSERT_TRUE(0 == info->writeCounter);
/* start the concurrent thread that will try to enter for read and
* check that it is not blocked
*/
startConcurrentThread(infoReader);
ASSERT_TRUE(1 == infoReader->readCounter);
/* now release the rwmutex and validate that the second readers still excludes the writer */
omrthread_monitor_enter(info->synchronization);
omrthread_rwmutex_exit_read(infoReader->handle);
ASSERT_TRUE(0 == info->writeCounter);
ASSERT_TRUE(1 == infoReader->readCounter);
/* now ask the reader to exit the mutex */
triggerNextStepDone(infoReader);
ASSERT_TRUE(0 == infoReader->readCounter);
/* now validate that the writer has now entered the mutex */
omrthread_monitor_wait_interruptable(info->synchronization, MILLI_TIMEOUT, NANO_TIMEOUT);
omrthread_monitor_exit(info->synchronization);
ASSERT_TRUE(1 == info->writeCounter);
/* ok now let the writer exit */
triggerNextStepDone(info);
ASSERT_TRUE(0 == info->writeCounter);
/* now let the threads clean up. First fix up handle in infoReader so that we
* can clean up properly
*/
infoReader->handle = saveHandle;
freeSupportThreadInfo(info);
freeSupportThreadInfo(infoReader);
}
void
CRWMutex::EnterRead(void)
{
omrthread_rwmutex_enter_read(m_monitor);
}