From aa62d56456df8de199e57c21442bbe91ffb12c0c Mon Sep 17 00:00:00 2001
From: zhouxin <zx@lbx.dev>
Date: Mon, 11 May 2020 18:22:55 +0800
Subject: [PATCH 1/4] refactor(Mutex): added EXACTLY_ONCE contract

---
 kotlinx-coroutines-core/common/src/sync/Mutex.kt | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/kotlinx-coroutines-core/common/src/sync/Mutex.kt b/kotlinx-coroutines-core/common/src/sync/Mutex.kt
index 769c9f1168..763b8cb6d3 100644
--- a/kotlinx-coroutines-core/common/src/sync/Mutex.kt
+++ b/kotlinx-coroutines-core/common/src/sync/Mutex.kt
@@ -107,6 +107,10 @@ public fun Mutex(locked: Boolean = false): Mutex =
  * @return the return value of the action.
  */
 public suspend inline fun <T> Mutex.withLock(owner: Any? = null, action: () -> T): T {
+    contract { 
+        callsInPlace(action, InvocationKind.EXACTLY_ONCE)
+    }
+
     lock(owner)
     try {
         return action()

From 6a99b41767319e334d726e948cc1d5ab3dc09d70 Mon Sep 17 00:00:00 2001
From: zhouxin <zx@lbx.dev>
Date: Tue, 12 May 2020 17:44:23 +0800
Subject: [PATCH 2/4] refactor(Semaphore.kt): withPermit() added EXACTLY_ONCE
 contract

---
 kotlinx-coroutines-core/common/src/sync/Mutex.kt          | 4 ++++
 kotlinx-coroutines-core/common/src/sync/Semaphore.kt      | 8 ++++++++
 kotlinx-coroutines-core/common/test/sync/MutexTest.kt     | 2 ++
 kotlinx-coroutines-core/common/test/sync/SemaphoreTest.kt | 2 ++
 kotlinx-coroutines-core/jvm/test/guide/example-sync-06.kt | 2 ++
 5 files changed, 18 insertions(+)

diff --git a/kotlinx-coroutines-core/common/src/sync/Mutex.kt b/kotlinx-coroutines-core/common/src/sync/Mutex.kt
index 763b8cb6d3..7db51f1d23 100644
--- a/kotlinx-coroutines-core/common/src/sync/Mutex.kt
+++ b/kotlinx-coroutines-core/common/src/sync/Mutex.kt
@@ -9,6 +9,9 @@ import kotlinx.coroutines.*
 import kotlinx.coroutines.internal.*
 import kotlinx.coroutines.intrinsics.*
 import kotlinx.coroutines.selects.*
+import kotlin.contracts.ExperimentalContracts
+import kotlin.contracts.InvocationKind
+import kotlin.contracts.contract
 import kotlin.coroutines.*
 import kotlin.jvm.*
 import kotlin.native.concurrent.*
@@ -106,6 +109,7 @@ public fun Mutex(locked: Boolean = false): Mutex =
  *
  * @return the return value of the action.
  */
+@ExperimentalContracts
 public suspend inline fun <T> Mutex.withLock(owner: Any? = null, action: () -> T): T {
     contract { 
         callsInPlace(action, InvocationKind.EXACTLY_ONCE)
diff --git a/kotlinx-coroutines-core/common/src/sync/Semaphore.kt b/kotlinx-coroutines-core/common/src/sync/Semaphore.kt
index 125bbaaeb5..310db25f9d 100644
--- a/kotlinx-coroutines-core/common/src/sync/Semaphore.kt
+++ b/kotlinx-coroutines-core/common/src/sync/Semaphore.kt
@@ -7,6 +7,9 @@ package kotlinx.coroutines.sync
 import kotlinx.atomicfu.*
 import kotlinx.coroutines.*
 import kotlinx.coroutines.internal.*
+import kotlin.contracts.ExperimentalContracts
+import kotlin.contracts.InvocationKind
+import kotlin.contracts.contract
 import kotlin.coroutines.*
 import kotlin.math.*
 import kotlin.native.concurrent.SharedImmutable
@@ -74,7 +77,12 @@ public fun Semaphore(permits: Int, acquiredPermits: Int = 0): Semaphore = Semaph
  *
  * @return the return value of the [action].
  */
+@ExperimentalContracts
 public suspend inline fun <T> Semaphore.withPermit(action: () -> T): T {
+    contract {
+        callsInPlace(action, InvocationKind.EXACTLY_ONCE)
+    }
+
     acquire()
     try {
         return action()
diff --git a/kotlinx-coroutines-core/common/test/sync/MutexTest.kt b/kotlinx-coroutines-core/common/test/sync/MutexTest.kt
index c5d0ccf187..bf27bc3708 100644
--- a/kotlinx-coroutines-core/common/test/sync/MutexTest.kt
+++ b/kotlinx-coroutines-core/common/test/sync/MutexTest.kt
@@ -5,8 +5,10 @@
 package kotlinx.coroutines.sync
 
 import kotlinx.coroutines.*
+import kotlin.contracts.ExperimentalContracts
 import kotlin.test.*
 
+@ExperimentalContracts
 class MutexTest : TestBase() {
     @Test
     fun testSimple() = runTest {
diff --git a/kotlinx-coroutines-core/common/test/sync/SemaphoreTest.kt b/kotlinx-coroutines-core/common/test/sync/SemaphoreTest.kt
index b4ff88b895..a72bf6ca1e 100644
--- a/kotlinx-coroutines-core/common/test/sync/SemaphoreTest.kt
+++ b/kotlinx-coroutines-core/common/test/sync/SemaphoreTest.kt
@@ -1,6 +1,7 @@
 package kotlinx.coroutines.sync
 
 import kotlinx.coroutines.*
+import kotlin.contracts.ExperimentalContracts
 import kotlin.test.Test
 import kotlin.test.assertEquals
 import kotlin.test.assertFalse
@@ -59,6 +60,7 @@ class SemaphoreTest : TestBase() {
         assertEquals(0, semaphore.availablePermits)
     }
 
+    @ExperimentalContracts
     @Test
     fun withSemaphoreTest() = runTest {
         val semaphore = Semaphore(1)
diff --git a/kotlinx-coroutines-core/jvm/test/guide/example-sync-06.kt b/kotlinx-coroutines-core/jvm/test/guide/example-sync-06.kt
index e6c5f1bad3..c7798497bc 100644
--- a/kotlinx-coroutines-core/jvm/test/guide/example-sync-06.kt
+++ b/kotlinx-coroutines-core/jvm/test/guide/example-sync-06.kt
@@ -7,6 +7,7 @@ package kotlinx.coroutines.guide.exampleSync06
 
 import kotlinx.coroutines.*
 import kotlinx.coroutines.sync.*
+import kotlin.contracts.ExperimentalContracts
 import kotlin.system.*
 
 suspend fun massiveRun(action: suspend () -> Unit) {
@@ -27,6 +28,7 @@ suspend fun massiveRun(action: suspend () -> Unit) {
 val mutex = Mutex()
 var counter = 0
 
+@ExperimentalContracts
 fun main() = runBlocking {
     withContext(Dispatchers.Default) {
         massiveRun {

From a132210713c9278af60f38d5e80d1b5cf4e6c063 Mon Sep 17 00:00:00 2001
From: zhouxin <zx@lbx.dev>
Date: Wed, 13 May 2020 17:30:11 +0800
Subject: [PATCH 3/4] style: imports kotlin.contracts.*

---
 kotlinx-coroutines-core/common/src/sync/Mutex.kt          | 4 +---
 kotlinx-coroutines-core/common/src/sync/Semaphore.kt      | 4 +---
 kotlinx-coroutines-core/common/test/sync/MutexTest.kt     | 2 +-
 kotlinx-coroutines-core/common/test/sync/SemaphoreTest.kt | 2 +-
 kotlinx-coroutines-core/jvm/test/guide/example-sync-06.kt | 2 +-
 5 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/kotlinx-coroutines-core/common/src/sync/Mutex.kt b/kotlinx-coroutines-core/common/src/sync/Mutex.kt
index 7db51f1d23..b9beec3dbd 100644
--- a/kotlinx-coroutines-core/common/src/sync/Mutex.kt
+++ b/kotlinx-coroutines-core/common/src/sync/Mutex.kt
@@ -9,9 +9,7 @@ import kotlinx.coroutines.*
 import kotlinx.coroutines.internal.*
 import kotlinx.coroutines.intrinsics.*
 import kotlinx.coroutines.selects.*
-import kotlin.contracts.ExperimentalContracts
-import kotlin.contracts.InvocationKind
-import kotlin.contracts.contract
+import kotlin.contracts.*
 import kotlin.coroutines.*
 import kotlin.jvm.*
 import kotlin.native.concurrent.*
diff --git a/kotlinx-coroutines-core/common/src/sync/Semaphore.kt b/kotlinx-coroutines-core/common/src/sync/Semaphore.kt
index 310db25f9d..33365821bd 100644
--- a/kotlinx-coroutines-core/common/src/sync/Semaphore.kt
+++ b/kotlinx-coroutines-core/common/src/sync/Semaphore.kt
@@ -7,9 +7,7 @@ package kotlinx.coroutines.sync
 import kotlinx.atomicfu.*
 import kotlinx.coroutines.*
 import kotlinx.coroutines.internal.*
-import kotlin.contracts.ExperimentalContracts
-import kotlin.contracts.InvocationKind
-import kotlin.contracts.contract
+import kotlin.contracts.*
 import kotlin.coroutines.*
 import kotlin.math.*
 import kotlin.native.concurrent.SharedImmutable
diff --git a/kotlinx-coroutines-core/common/test/sync/MutexTest.kt b/kotlinx-coroutines-core/common/test/sync/MutexTest.kt
index bf27bc3708..36805d72cf 100644
--- a/kotlinx-coroutines-core/common/test/sync/MutexTest.kt
+++ b/kotlinx-coroutines-core/common/test/sync/MutexTest.kt
@@ -5,7 +5,7 @@
 package kotlinx.coroutines.sync
 
 import kotlinx.coroutines.*
-import kotlin.contracts.ExperimentalContracts
+import kotlin.contracts.*
 import kotlin.test.*
 
 @ExperimentalContracts
diff --git a/kotlinx-coroutines-core/common/test/sync/SemaphoreTest.kt b/kotlinx-coroutines-core/common/test/sync/SemaphoreTest.kt
index a72bf6ca1e..ae1cbde28d 100644
--- a/kotlinx-coroutines-core/common/test/sync/SemaphoreTest.kt
+++ b/kotlinx-coroutines-core/common/test/sync/SemaphoreTest.kt
@@ -1,7 +1,7 @@
 package kotlinx.coroutines.sync
 
 import kotlinx.coroutines.*
-import kotlin.contracts.ExperimentalContracts
+import kotlin.contracts.*
 import kotlin.test.Test
 import kotlin.test.assertEquals
 import kotlin.test.assertFalse
diff --git a/kotlinx-coroutines-core/jvm/test/guide/example-sync-06.kt b/kotlinx-coroutines-core/jvm/test/guide/example-sync-06.kt
index c7798497bc..e187877d94 100644
--- a/kotlinx-coroutines-core/jvm/test/guide/example-sync-06.kt
+++ b/kotlinx-coroutines-core/jvm/test/guide/example-sync-06.kt
@@ -7,7 +7,7 @@ package kotlinx.coroutines.guide.exampleSync06
 
 import kotlinx.coroutines.*
 import kotlinx.coroutines.sync.*
-import kotlin.contracts.ExperimentalContracts
+import kotlin.contracts.*
 import kotlin.system.*
 
 suspend fun massiveRun(action: suspend () -> Unit) {

From 752e0604d882eec219831dfe91c3cf2db0b3535b Mon Sep 17 00:00:00 2001
From: zhouxin <zx@lbx.dev>
Date: Wed, 13 May 2020 20:15:22 +0800
Subject: [PATCH 4/4] refacotr: Mutex.withLock()/Semaphore.withPermit() change
 @ExperimentalContracts to @OptIn(ExperimentalContracts::class)

---
 kotlinx-coroutines-core/common/src/sync/Mutex.kt          | 2 +-
 kotlinx-coroutines-core/common/src/sync/Semaphore.kt      | 2 +-
 kotlinx-coroutines-core/common/test/sync/MutexTest.kt     | 2 --
 kotlinx-coroutines-core/common/test/sync/SemaphoreTest.kt | 2 --
 kotlinx-coroutines-core/jvm/test/guide/example-sync-06.kt | 2 --
 5 files changed, 2 insertions(+), 8 deletions(-)

diff --git a/kotlinx-coroutines-core/common/src/sync/Mutex.kt b/kotlinx-coroutines-core/common/src/sync/Mutex.kt
index b9beec3dbd..61e046c77a 100644
--- a/kotlinx-coroutines-core/common/src/sync/Mutex.kt
+++ b/kotlinx-coroutines-core/common/src/sync/Mutex.kt
@@ -107,7 +107,7 @@ public fun Mutex(locked: Boolean = false): Mutex =
  *
  * @return the return value of the action.
  */
-@ExperimentalContracts
+@OptIn(ExperimentalContracts::class)
 public suspend inline fun <T> Mutex.withLock(owner: Any? = null, action: () -> T): T {
     contract { 
         callsInPlace(action, InvocationKind.EXACTLY_ONCE)
diff --git a/kotlinx-coroutines-core/common/src/sync/Semaphore.kt b/kotlinx-coroutines-core/common/src/sync/Semaphore.kt
index 33365821bd..27c976ce3f 100644
--- a/kotlinx-coroutines-core/common/src/sync/Semaphore.kt
+++ b/kotlinx-coroutines-core/common/src/sync/Semaphore.kt
@@ -75,7 +75,7 @@ public fun Semaphore(permits: Int, acquiredPermits: Int = 0): Semaphore = Semaph
  *
  * @return the return value of the [action].
  */
-@ExperimentalContracts
+@OptIn(ExperimentalContracts::class)
 public suspend inline fun <T> Semaphore.withPermit(action: () -> T): T {
     contract {
         callsInPlace(action, InvocationKind.EXACTLY_ONCE)
diff --git a/kotlinx-coroutines-core/common/test/sync/MutexTest.kt b/kotlinx-coroutines-core/common/test/sync/MutexTest.kt
index 36805d72cf..c5d0ccf187 100644
--- a/kotlinx-coroutines-core/common/test/sync/MutexTest.kt
+++ b/kotlinx-coroutines-core/common/test/sync/MutexTest.kt
@@ -5,10 +5,8 @@
 package kotlinx.coroutines.sync
 
 import kotlinx.coroutines.*
-import kotlin.contracts.*
 import kotlin.test.*
 
-@ExperimentalContracts
 class MutexTest : TestBase() {
     @Test
     fun testSimple() = runTest {
diff --git a/kotlinx-coroutines-core/common/test/sync/SemaphoreTest.kt b/kotlinx-coroutines-core/common/test/sync/SemaphoreTest.kt
index ae1cbde28d..b4ff88b895 100644
--- a/kotlinx-coroutines-core/common/test/sync/SemaphoreTest.kt
+++ b/kotlinx-coroutines-core/common/test/sync/SemaphoreTest.kt
@@ -1,7 +1,6 @@
 package kotlinx.coroutines.sync
 
 import kotlinx.coroutines.*
-import kotlin.contracts.*
 import kotlin.test.Test
 import kotlin.test.assertEquals
 import kotlin.test.assertFalse
@@ -60,7 +59,6 @@ class SemaphoreTest : TestBase() {
         assertEquals(0, semaphore.availablePermits)
     }
 
-    @ExperimentalContracts
     @Test
     fun withSemaphoreTest() = runTest {
         val semaphore = Semaphore(1)
diff --git a/kotlinx-coroutines-core/jvm/test/guide/example-sync-06.kt b/kotlinx-coroutines-core/jvm/test/guide/example-sync-06.kt
index e187877d94..e6c5f1bad3 100644
--- a/kotlinx-coroutines-core/jvm/test/guide/example-sync-06.kt
+++ b/kotlinx-coroutines-core/jvm/test/guide/example-sync-06.kt
@@ -7,7 +7,6 @@ package kotlinx.coroutines.guide.exampleSync06
 
 import kotlinx.coroutines.*
 import kotlinx.coroutines.sync.*
-import kotlin.contracts.*
 import kotlin.system.*
 
 suspend fun massiveRun(action: suspend () -> Unit) {
@@ -28,7 +27,6 @@ suspend fun massiveRun(action: suspend () -> Unit) {
 val mutex = Mutex()
 var counter = 0
 
-@ExperimentalContracts
 fun main() = runBlocking {
     withContext(Dispatchers.Default) {
         massiveRun {