improve SmartKeyRWLockerTests and fix SmartSemaphore

coroutines/src/commonMain/kotlin/dev/inmo/micro_utils/coroutines/SmartSemaphore.kt

@@ -72,7 +72,7 @@ sealed interface SmartSemaphore {
                         acquiredPermits != checkedPermits
                     }
                     if (shouldContinue) {
-                        waitRelease()
+                        waitRelease(checkedPermits - acquiredPermits)
                     }
                 } while (shouldContinue && currentCoroutineContext().isActive)
             } catch (e: Throwable) {

coroutines/src/commonTest/kotlin/SmartKeyRWLockerTests.kt

@@ -4,6 +4,7 @@ import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.sync.Mutex
 import kotlinx.coroutines.sync.withLock
 import kotlinx.coroutines.test.runTest
+import kotlin.test.BeforeTest
 import kotlin.test.Test
 import kotlin.test.assertEquals
 import kotlin.test.assertFails
@@ -13,184 +14,517 @@ import kotlin.time.Duration.Companion.milliseconds
 import kotlin.time.Duration.Companion.seconds
 
 class SmartKeyRWLockerTests {
-    @Test
+    private lateinit var locker: SmartKeyRWLocker<String>
-    fun writeLockKeyFailedOnGlobalWriteLockTest() = runTest {
-        val locker = SmartKeyRWLocker<String>()
-        val testKey = "test"
-        locker.lockWrite()
 
-        assertTrue { locker.isWriteLocked() }
+    @BeforeTest
-
+    fun setup() {
-        assertFails {
+        locker = SmartKeyRWLocker()
-            realWithTimeout(1.seconds) {
-                locker.lockWrite(testKey)
-            }
-        }
-        assertFalse { locker.isWriteLocked(testKey) }
-
-        locker.unlockWrite()
-        assertFalse { locker.isWriteLocked() }
-
-        realWithTimeout(1.seconds) {
-            locker.lockWrite(testKey)
-        }
-        assertTrue { locker.isWriteLocked(testKey) }
-        assertTrue { locker.unlockWrite(testKey) }
-        assertFalse { locker.isWriteLocked(testKey) }
     }
+
+    // ==================== Global Read Tests ====================
+
     @Test
-    fun writeLockKeyFailedOnGlobalReadLockTest() = runTest {
+    fun testGlobalReadAllowsMultipleConcurrentReads() = runTest {
-        val locker = SmartKeyRWLocker<String>()
+        val results = mutableListOf<Boolean>()
-        val testKey = "test"
+
         locker.acquireRead()
 
-        assertEquals(Int.MAX_VALUE - 1, locker.readSemaphore().freePermits)
+        val jobs = List(5) {
-
+            launch {
-        assertFails {
+                locker.acquireRead()
-            realWithTimeout(1.seconds) {
+                delay(100.milliseconds)
-                locker.lockWrite(testKey)
+                results.add(true)
+                locker.releaseRead()
             }
         }
-        assertFalse { locker.isWriteLocked(testKey) }
+
+        jobs.joinAll()
+        locker.releaseRead()
+
+        assertEquals(5, results.size)
+    }
+
+    @Test
+    fun testGlobalReadBlocksGlobalWrite() = runTest {
+        locker.acquireRead()
+
+        var writeAcquired = false
+        val writeJob = launch {
+            locker.lockWrite()
+            writeAcquired = true
+            locker.unlockWrite()
+        }
+
+        delay(200.milliseconds)
+        assertFalse(writeAcquired, "Write should be blocked by global read")
 
         locker.releaseRead()
-        assertEquals(Int.MAX_VALUE, locker.readSemaphore().freePermits)
+        writeJob.join()
 
-        realWithTimeout(1.seconds) {
+        assertTrue(writeAcquired, "Write should succeed after read released")
-            locker.lockWrite(testKey)
-        }
-        assertTrue { locker.isWriteLocked(testKey) }
-        assertTrue { locker.unlockWrite(testKey) }
-        assertFalse { locker.isWriteLocked(testKey) }
     }
+
     @Test
-    fun readLockFailedOnWriteLockKeyTest() = runTest {
+    fun testGlobalReadBlocksAllKeyWrites() = runTest {
-        val locker = SmartKeyRWLocker<String>()
+        locker.acquireRead()
-        val testKey = "test"
-        locker.lockWrite(testKey)
 
-        assertTrue { locker.isWriteLocked(testKey) }
+        val writeFlags = mutableMapOf<String, Boolean>()
+        val keys = listOf("key1", "key2", "key3")
 
-        assertFails {
+        val jobs = keys.map { key ->
-            realWithTimeout(1.seconds) {
+            launch {
+                locker.lockWrite(key)
+                writeFlags[key] = true
+                locker.unlockWrite(key)
+            }
+        }
+
+        delay(200.milliseconds)
+        assertTrue(writeFlags.isEmpty(), "No writes should succeed while global read active")
+
+        locker.releaseRead()
+        jobs.joinAll()
+
+        assertEquals(keys.size, writeFlags.size, "All writes should succeed after global read released")
+    }
+
+    // ==================== Global Write Tests ====================
+
+    @Test
+    fun testGlobalWriteBlocksAllOperations() = runTest {
+        locker.lockWrite()
+
+        var globalReadAcquired = false
+        var keyReadAcquired = false
+        var keyWriteAcquired = false
+
+        val jobs = listOf(
+            launch {
                 locker.acquireRead()
+                globalReadAcquired = true
+                locker.releaseRead()
+            },
+            launch {
+                locker.acquireRead("key1")
+                keyReadAcquired = true
+                locker.releaseRead("key1")
+            },
+            launch {
+                locker.lockWrite("key2")
+                keyWriteAcquired = true
+                locker.unlockWrite("key2")
             }
-        }
+        )
-        assertEquals(locker.readSemaphore().maxPermits - 1, locker.readSemaphore().freePermits)
 
-        locker.unlockWrite(testKey)
+        delay(200.milliseconds)
-        assertFalse { locker.isWriteLocked(testKey) }
+        assertFalse(globalReadAcquired, "Global read should be blocked")
+        assertFalse(keyReadAcquired, "Key read should be blocked")
+        assertFalse(keyWriteAcquired, "Key write should be blocked")
 
-        realWithTimeout(1.seconds) {
+        locker.unlockWrite()
-            locker.acquireRead()
+        jobs.joinAll()
-        }
+
-        assertEquals(locker.readSemaphore().maxPermits - 1, locker.readSemaphore().freePermits)
+        assertTrue(globalReadAcquired)
-        assertTrue { locker.releaseRead() }
+        assertTrue(keyReadAcquired)
-        assertEquals(locker.readSemaphore().maxPermits, locker.readSemaphore().freePermits)
+        assertTrue(keyWriteAcquired)
     }
+
     @Test
-    fun writeLockFailedOnWriteLockKeyTest() = runTest {
+    fun testGlobalWriteIsExclusive() = runTest {
-        val locker = SmartKeyRWLocker<String>()
+        locker.lockWrite()
-        val testKey = "test"
-        locker.lockWrite(testKey)
 
-        assertTrue { locker.isWriteLocked(testKey) }
+        var secondWriteAcquired = false
-
+        val job = launch {
-        assertFails {
-            realWithTimeout(1.seconds) {
-                locker.lockWrite()
-            }
-        }
-        assertFalse(locker.isWriteLocked())
-
-        locker.unlockWrite(testKey)
-        assertFalse { locker.isWriteLocked(testKey) }
-
-        realWithTimeout(1.seconds) {
             locker.lockWrite()
+            secondWriteAcquired = true
+            locker.unlockWrite()
         }
-        assertTrue(locker.isWriteLocked())
+
-        assertTrue { locker.unlockWrite() }
+        delay(200.milliseconds)
-        assertFalse(locker.isWriteLocked())
+        assertFalse(secondWriteAcquired, "Second global write should be blocked")
+
+        locker.unlockWrite()
+        job.join()
+
+        assertTrue(secondWriteAcquired)
     }
+
+    // ==================== Key Read Tests ====================
+
     @Test
-    fun readsBlockingGlobalWrite() = runTest {
+    fun testKeyReadAllowsMultipleConcurrentReadsForSameKey() = runTest {
-        val locker = SmartKeyRWLocker<String>()
+        val key = "testKey"
+        val results = mutableListOf<Boolean>()
 
-        val testKeys = (0 until 100).map { "test$it" }
+        locker.acquireRead(key)
 
-        for (i in testKeys.indices) {
+        val jobs = List(5) {
-            val it = testKeys[i]
+            launch {
-            locker.acquireRead(it)
+                locker.acquireRead(key)
-            val previous = testKeys.take(i)
+                delay(50.milliseconds)
-            val next = testKeys.drop(i + 1)
+                results.add(true)
-
+                locker.releaseRead(key)
-            previous.forEach {
-                assertTrue { locker.readSemaphoreOrNull(it) ?.freePermits == Int.MAX_VALUE - 1 }
-            }
-            next.forEach {
-                assertTrue { locker.readSemaphoreOrNull(it) ?.freePermits == null }
             }
         }
 
-        for (i in testKeys.indices) {
+        jobs.joinAll()
-            val it = testKeys[i]
+        locker.releaseRead(key)
-            assertFails {
+
-                realWithTimeout(13.milliseconds) { locker.lockWrite() }
+        assertEquals(5, results.size)
+    }
+
+    @Test
+    fun testKeyReadAllowsReadsForDifferentKeys() = runTest {
+        val results = mutableMapOf<String, Boolean>()
+
+        locker.acquireRead("key1")
+
+        val jobs = listOf("key2", "key3", "key4").map { key ->
+            launch {
+                locker.acquireRead(key)
+                delay(50.milliseconds)
+                results[key] = true
+                locker.releaseRead(key)
             }
-            val readPermitsBeforeLock = locker.readSemaphore().freePermits
+        }
-            realWithTimeout(1.seconds) { locker.acquireRead() }
+
+        jobs.joinAll()
+        locker.releaseRead("key1")
+
+        assertEquals(3, results.size)
+    }
+
+    @Test
+    fun testKeyReadBlocksWriteForSameKey() = runTest {
+        val key = "testKey"
+        locker.acquireRead(key)
+
+        var writeAcquired = false
+        val job = launch {
+            locker.lockWrite(key)
+            writeAcquired = true
+            locker.unlockWrite(key)
+        }
+
+        delay(200.milliseconds)
+        assertFalse(writeAcquired, "Write for same key should be blocked")
+
+        locker.releaseRead(key)
+        job.join()
+
+        assertTrue(writeAcquired)
+    }
+
+    @Test
+    fun testKeyReadBlocksGlobalWrite() = runTest {
+        locker.acquireRead("key1")
+
+        var globalWriteAcquired = false
+        val job = launch {
+            locker.lockWrite()
+            globalWriteAcquired = true
+            locker.unlockWrite()
+        }
+
+        delay(200.milliseconds)
+        assertFalse(globalWriteAcquired, "Global write should be blocked by key read")
+
+        locker.releaseRead("key1")
+        job.join()
+
+        assertTrue(globalWriteAcquired)
+    }
+
+    @Test
+    fun testKeyReadAllowsWriteForDifferentKey() = runTest {
+        locker.acquireRead("key1")
+
+        var writeAcquired = false
+        val job = launch {
+            locker.lockWrite("key2")
+            writeAcquired = true
+            locker.unlockWrite("key2")
+        }
+
+        job.join()
+        assertTrue(writeAcquired, "Write for different key should succeed")
+
+        locker.releaseRead("key1")
+    }
+
+    // ==================== Key Write Tests ====================
+
+    @Test
+    fun testKeyWriteBlocksReadForSameKey() = runTest {
+        val key = "testKey"
+        locker.lockWrite(key)
+
+        var readAcquired = false
+        val job = launch {
+            locker.acquireRead(key)
+            readAcquired = true
+            locker.releaseRead(key)
+        }
+
+        delay(200.milliseconds)
+        assertFalse(readAcquired, "Read for same key should be blocked")
+
+        locker.unlockWrite(key)
+        job.join()
+
+        assertTrue(readAcquired)
+    }
+
+    @Test
+    fun testKeyWriteBlocksGlobalRead() = runTest {
+        locker.lockWrite("key1")
+
+        var globalReadAcquired = false
+        val job = launch {
+            locker.acquireRead()
+            globalReadAcquired = true
             locker.releaseRead()
-            assertEquals(readPermitsBeforeLock, locker.readSemaphore().freePermits)
-
-            locker.releaseRead(it)
         }
 
-        assertTrue { locker.readSemaphore().freePermits == Int.MAX_VALUE }
+        delay(200.milliseconds)
-        realWithTimeout(1.seconds) { locker.lockWrite() }
+        assertFalse(globalReadAcquired, "Global read should be blocked by key write")
-        assertFails {
+
-            realWithTimeout(13.milliseconds) { locker.acquireRead() }
+        locker.unlockWrite("key1")
-        }
+        job.join()
-        assertTrue { locker.unlockWrite() }
+
-        assertTrue { locker.readSemaphore().freePermits == Int.MAX_VALUE }
+        assertTrue(globalReadAcquired)
     }
+
     @Test
-    fun writesBlockingGlobalWrite() = runTest {
+    fun testKeyWriteIsExclusiveForSameKey() = runTest {
-        val locker = SmartKeyRWLocker<String>()
+        val key = "testKey"
+        locker.lockWrite(key)
 
-        val testKeys = (0 until 100).map { "test$it" }
+        var secondWriteAcquired = false
+        val job = launch {
+            locker.lockWrite(key)
+            secondWriteAcquired = true
+            locker.unlockWrite(key)
+        }
 
-        for (i in testKeys.indices) {
+        delay(200.milliseconds)
-            val it = testKeys[i]
+        assertFalse(secondWriteAcquired, "Second write for same key should be blocked")
-            locker.lockWrite(it)
-            val previous = testKeys.take(i)
-            val next = testKeys.drop(i + 1)
 
-            previous.forEach {
+        locker.unlockWrite(key)
-                assertTrue { locker.writeMutexOrNull(it) ?.isLocked == true }
+        job.join()
+
+        assertTrue(secondWriteAcquired)
+    }
+
+    @Test
+    fun testKeyWriteAllowsOperationsOnDifferentKeys() = runTest {
+        locker.lockWrite("key1")
+
+        val results = mutableMapOf<String, Boolean>()
+
+        val jobs = listOf(
+            launch {
+                locker.acquireRead("key2")
+                results["read-key2"] = true
+                locker.releaseRead("key2")
+            },
+            launch {
+                locker.lockWrite("key3")
+                results["write-key3"] = true
+                locker.unlockWrite("key3")
             }
-            next.forEach {
+        )
-                assertTrue { locker.writeMutexOrNull(it) ?.isLocked != true }
+
+        jobs.joinAll()
+        assertEquals(2, results.size, "Operations on different keys should succeed")
+
+        locker.unlockWrite("key1")
+    }
+
+    // ==================== Complex Scenarios ====================
+
+    @Test
+    fun testMultipleReadersThenWriter() = runTest {
+        val key = "testKey"
+        val readCount = 5
+        val readers = mutableListOf<Job>()
+
+        repeat(readCount) {
+            readers.add(launch {
+                locker.acquireRead(key)
+                delay(100.milliseconds)
+                locker.releaseRead(key)
+            })
+        }
+
+        delay(50.milliseconds) // Let readers acquire
+
+        var writerExecuted = false
+        val writer = launch {
+            locker.lockWrite(key)
+            writerExecuted = true
+            locker.unlockWrite(key)
+        }
+
+        delay(50.milliseconds)
+        assertFalse(writerExecuted, "Writer should wait for all readers")
+
+        readers.joinAll()
+        writer.join()
+
+        assertTrue(writerExecuted, "Writer should execute after all readers done")
+    }
+
+    @Test
+    fun testWriterThenMultipleReaders() = runTest {
+        val key = "testKey"
+
+        locker.lockWrite(key)
+
+        val readerFlags = mutableListOf<Boolean>()
+        val readers = List(5) {
+            launch {
+                locker.acquireRead(key)
+                readerFlags.add(true)
+                locker.releaseRead(key)
             }
         }
 
-        for (i in testKeys.indices) {
+        delay(200.milliseconds)
-            val it = testKeys[i]
+        assertTrue(readerFlags.isEmpty(), "Readers should be blocked by writer")
-            assertFails { realWithTimeout(13.milliseconds) { locker.lockWrite() } }
 
-            val readPermitsBeforeLock = locker.readSemaphore().freePermits
+        locker.unlockWrite(key)
-            assertFails { realWithTimeout(13.milliseconds) { locker.acquireRead() } }
+        readers.joinAll()
-            assertEquals(readPermitsBeforeLock, locker.readSemaphore().freePermits)
 
-            locker.unlockWrite(it)
+        assertEquals(5, readerFlags.size, "All readers should succeed after writer")
+    }
+
+    @Test
+    fun testCascadingLocksWithDifferentKeys() = runTest {
+        val executed = mutableMapOf<String, Boolean>()
+
+        launch {
+            locker.lockWrite("key1")
+            executed["write-key1-start"] = true
+            delay(100.milliseconds)
+            locker.unlockWrite("key1")
+            executed["write-key1-end"] = true
         }
 
-        assertTrue { locker.readSemaphore().freePermits == Int.MAX_VALUE }
+        delay(50.milliseconds)
-        realWithTimeout(1.seconds) { locker.lockWrite() }
+
-        assertFails {
+        launch {
-            realWithTimeout(13.milliseconds) { locker.acquireRead() }
+            locker.acquireRead("key2")
+            executed["read-key2"] = true
+            delay(100.milliseconds)
+            locker.releaseRead("key2")
         }
-        assertTrue { locker.unlockWrite() }
+
-        assertTrue { locker.readSemaphore().freePermits == Int.MAX_VALUE }
+        delay(200.milliseconds)
+
+        assertTrue(executed["write-key1-start"] == true)
+        assertTrue(executed["read-key2"] == true)
+        assertTrue(executed["write-key1-end"] == true)
+    }
+
+    @Test
+    fun testReleaseWithoutAcquireReturnsFalse() = runTest {
+        assertFalse(locker.releaseRead(), "Release without acquire should return false")
+        assertFalse(locker.releaseRead("key1"), "Release without acquire should return false")
+    }
+
+    @Test
+    fun testUnlockWithoutLockReturnsFalse() = runTest {
+        assertFalse(locker.unlockWrite(), "Unlock without lock should return false")
+        assertFalse(locker.unlockWrite("key1"), "Unlock without lock should return false")
+    }
+
+    @Test
+    fun testProperReleaseReturnsTrue() = runTest {
+        locker.acquireRead()
+        assertTrue(locker.releaseRead(), "Release after acquire should return true")
+
+        locker.acquireRead("key1")
+        assertTrue(locker.releaseRead("key1"), "Release after acquire should return true")
+    }
+
+    @Test
+    fun testProperUnlockReturnsTrue() = runTest {
+        locker.lockWrite()
+        assertTrue(locker.unlockWrite(), "Unlock after lock should return true")
+
+        locker.lockWrite("key1")
+        assertTrue(locker.unlockWrite("key1"), "Unlock after lock should return true")
+    }
+
+    // ==================== Stress Tests ====================
+
+    @Test
+    fun stressTestWithMixedOperations() = runTest(timeout = 10.seconds) {
+        val operations = 100
+        val keys = listOf("key1", "key2", "key3", "key4", "key5")
+        val jobs = mutableListOf<Job>()
+
+        repeat(operations) { i ->
+            val key = keys[i % keys.size]
+
+            when (i % 4) {
+                0 -> jobs.add(launch {
+                    locker.acquireRead(key)
+                    delay(10.milliseconds)
+                    locker.releaseRead(key)
+                })
+                1 -> jobs.add(launch {
+                    locker.lockWrite(key)
+                    delay(10.milliseconds)
+                    locker.unlockWrite(key)
+                })
+                2 -> jobs.add(launch {
+                    locker.acquireRead()
+                    delay(10.milliseconds)
+                    locker.releaseRead()
+                })
+                3 -> jobs.add(launch {
+                    locker.lockWrite()
+                    delay(10.milliseconds)
+                    locker.unlockWrite()
+                })
+            }
+        }
+
+        jobs.joinAll()
+        // If we reach here without deadlock or exceptions, test passes
+    }
+
+    @Test
+    fun testFairnessReadersDontStarveWriters() = runTest(timeout = 5.seconds) {
+        val key = "testKey"
+        var writerExecuted = false
+
+        // Start continuous readers
+        val readers = List(10) {
+            launch {
+                repeat(5) {
+                    locker.acquireRead(key)
+                    delay(50.milliseconds)
+                    locker.releaseRead(key)
+                    delay(10.milliseconds)
+                }
+            }
+        }
+
+        delay(100.milliseconds)
+
+        // Try to acquire write lock
+        val writer = launch {
+            locker.lockWrite(key)
+            writerExecuted = true
+            locker.unlockWrite(key)
+        }
+
+        readers.joinAll()
+        writer.join()
+
+        assertTrue(writerExecuted, "Writer should eventually execute")
     }
 }