forked from Kotlin/kotlinx.coroutines
/
MutexTest.kt
144 lines (128 loc) · 3.82 KB
/
MutexTest.kt
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/*
* Copyright 2016-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
*/
package kotlinx.coroutines.sync
import kotlinx.atomicfu.*
import kotlinx.coroutines.*
import kotlin.test.*
class MutexTest : TestBase() {
private val enterCount = atomic(0)
private val releasedCount = atomic(0)
@Test
fun testSimple() = runTest {
val mutex = Mutex()
expect(1)
launch {
expect(4)
mutex.lock() // suspends
expect(7) // now got lock
mutex.unlock()
expect(8)
}
expect(2)
mutex.lock() // locked
expect(3)
yield() // yield to child
expect(5)
mutex.unlock()
expect(6)
yield() // now child has lock
finish(9)
}
@Test
fun tryLockTest() {
val mutex = Mutex()
assertFalse(mutex.isLocked)
assertTrue(mutex.tryLock())
assertTrue(mutex.isLocked)
assertFalse(mutex.tryLock())
assertTrue(mutex.isLocked)
mutex.unlock()
assertFalse(mutex.isLocked)
assertTrue(mutex.tryLock())
assertTrue(mutex.isLocked)
assertFalse(mutex.tryLock())
assertTrue(mutex.isLocked)
mutex.unlock()
assertFalse(mutex.isLocked)
}
@Test
fun withLockTest() = runTest {
val mutex = Mutex()
assertFalse(mutex.isLocked)
mutex.withLock {
assertTrue(mutex.isLocked)
}
assertFalse(mutex.isLocked)
}
@Test
fun testUnconfinedStackOverflow() {
val waiters = 10000
val mutex = Mutex(true)
var done = 0
repeat(waiters) {
GlobalScope.launch(Dispatchers.Unconfined) { // a lot of unconfined waiters
mutex.withLock {
done++
}
}
}
mutex.unlock() // should not produce StackOverflowError
assertEquals(waiters, done)
}
@Test
fun holdLock() = runTest {
val mutex = Mutex()
val firstOwner = Any()
val secondOwner = Any()
// no lock
assertFalse(mutex.holdsLock(firstOwner))
assertFalse(mutex.holdsLock(secondOwner))
// owner firstOwner
mutex.lock(firstOwner)
val secondLockJob = launch {
mutex.lock(secondOwner)
}
assertTrue(mutex.holdsLock(firstOwner))
assertFalse(mutex.holdsLock(secondOwner))
// owner secondOwner
mutex.unlock(firstOwner)
secondLockJob.join()
assertFalse(mutex.holdsLock(firstOwner))
assertTrue(mutex.holdsLock(secondOwner))
mutex.unlock(secondOwner)
// no lock
assertFalse(mutex.holdsLock(firstOwner))
assertFalse(mutex.holdsLock(secondOwner))
}
@Test
fun cancelLock() = runTest() {
val mutex = Mutex()
enterCount.value = 0
releasedCount.value = 0
repeat(1000) {
val job = launch(Dispatchers.Default) {
val owner = Any()
try {
enterCount.incrementAndGet()
mutex.withLock(owner) {}
// repeat to give an increase in race probability
mutex.withLock(owner) {}
} finally {
// should be no way lock is still held by owner here
if (mutex.holdsLock(owner)) {
// if it is held, ensure test case doesn't lockup
mutex.unlock(owner)
} else {
releasedCount.incrementAndGet()
}
}
}
mutex.withLock {
job.cancel()
}
job.join()
}
assertEquals(enterCount.value, releasedCount.value)
}
}