Improve coroutines library layout

- Split CoroutinesLibrary into common and JVM parts
- Get rid of startCoroutine duplications
- Make suspendCoroutine implementation to be platform independent

js/js.libraries/src/core/coroutines.kt

@@ -34,19 +34,6 @@ public fun <R, T> (suspend R.() -> T).createCoroutine(
                 COROUTINE_SUSPENDED
         )
 
-/**
- * Starts coroutine with receiver type [R] and result type [T].
- * This function creates and start a new, fresh instance of suspendable computation every time it is invoked.
- * The [completion] continuation is invoked when coroutine completes with result of exception.
- */
-@SinceKotlin("1.1")
-public fun <R, T> (suspend R.() -> T).startCoroutine(
-        receiver: R,
-        completion: Continuation<T>
-) {
-    createCoroutine(receiver, completion).resume(Unit)
-}
-
 /**
  * Creates coroutine without receiver and with result type [T].
  * This function creates a new, fresh instance of suspendable computation every time it is invoked.
@@ -62,33 +49,6 @@ public fun <T> (suspend () -> T).createCoroutine(
                 COROUTINE_SUSPENDED
         )
 
-/**
- * Starts coroutine without receiver and with result type [T].
- * This function creates and start a new, fresh instance of suspendable computation every time it is invoked.
- * The [completion] continuation is invoked when coroutine completes with result of exception.
- */
-@SinceKotlin("1.1")
-public fun <T> (suspend  () -> T).startCoroutine(
-        completion: Continuation<T>
-) {
-    createCoroutine(completion).resume(Unit)
-}
-
-/**
- * Obtains the current continuation instance inside suspend functions and suspends
- * currently running coroutine.
- *
- * In this function both [Continuation.resume] and [Continuation.resumeWithException] can be used either synchronously in
- * the same stack-frame where suspension function is run or asynchronously later in the same thread or
- * from a different thread of execution. Repeated invocation of any resume function produces [IllegalStateException].
- */
-@SinceKotlin("1.1")
-public suspend fun <T> suspendCoroutine(block: (Continuation<T>) -> Unit): T = suspendCoroutineOrReturn { c ->
-    val safe = SafeContinuation(c)
-    block(safe)
-    safe.getResult()
-}
-
 // ------- internal stuff -------
 
 @JsName("CoroutineImpl")
@@ -135,11 +95,16 @@ private val UNDECIDED: Any? = Any()
 private val RESUMED: Any? = Any()
 private class Fail(val exception: Throwable)
 
+@PublishedApi
 internal class SafeContinuation<in T>
-@PublishedApi internal constructor(
+internal constructor(
         private val delegate: Continuation<T>,
-        initialResult: Any? = UNDECIDED
+        initialResult: Any?
 ) : Continuation<T> {
+
+    @PublishedApi
+    internal constructor(delegate: Continuation<T>) : this(delegate, UNDECIDED)
+
     public override val context: CoroutineContext
         get() = delegate.context
 
@@ -175,6 +140,7 @@ internal class SafeContinuation<in T>
         }
     }
 
+    @PublishedApi
     internal fun getResult(): Any? {
         if (result === UNDECIDED) {
             result = COROUTINE_SUSPENDED

libraries/stdlib/common/src/kotlin/CoroutinesH.kt

@@ -14,18 +14,6 @@ public header fun <R, T> (suspend R.() -> T).createCoroutine(
         completion: Continuation<T>
 ): Continuation<Unit>
 
-/**
- * Starts coroutine with receiver type [R] and result type [T].
- * This function creates and start a new, fresh instance of suspendable computation every time it is invoked.
- * The [completion] continuation is invoked when coroutine completes with result of exception.
- * An optional [dispatcher] may be specified to customise dispatch of continuations between suspension points inside the coroutine.
- */
-@SinceKotlin("1.1")
-public header fun <R, T> (suspend R.() -> T).startCoroutine(
-        receiver: R,
-        completion: Continuation<T>
-)
-
 /**
  * Creates coroutine without receiver and with result type [T].
  * This function creates a new, fresh instance of suspendable computation every time it is invoked.
@@ -38,25 +26,17 @@ public header fun <T> (suspend () -> T).createCoroutine(
         completion: Continuation<T>
 ): Continuation<Unit>
 
-/**
- * Starts coroutine without receiver and with result type [T].
- * This function creates and start a new, fresh instance of suspendable computation every time it is invoked.
- * The [completion] continuation is invoked when coroutine completes with result of exception.
- * An optional [dispatcher] may be specified to customise dispatch of continuations between suspension points inside the coroutine.
- */
-@SinceKotlin("1.1")
-@Suppress("UNCHECKED_CAST")
-public header fun <T> (suspend  () -> T).startCoroutine(
-        completion: Continuation<T>
-)
+@PublishedApi
+internal header class SafeContinuation<in T> : Continuation<T> {
+    internal constructor(delegate: Continuation<T>, initialResult: Any?)
 
-/**
- * Obtains the current continuation instance inside suspend functions and suspends
- * currently running coroutine.
- *
- * In this function both [Continuation.resume] and [Continuation.resumeWithException] can be used either synchronously in
- * the same stack-frame where suspension function is run or asynchronously later in the same thread or
- * from a different thread of execution. Repeated invocation of any resume function produces [IllegalStateException].
- */
-@SinceKotlin("1.1")
-public header inline suspend fun <T> suspendCoroutine(crossinline block: (Continuation<T>) -> Unit): T
+    @PublishedApi
+    internal constructor(delegate: Continuation<T>)
+
+    @PublishedApi
+    internal fun getResult(): Any?
+
+    override val context: CoroutineContext
+    override fun resume(value: T): Unit
+    override fun resumeWithException(exception: Throwable): Unit
+}

libraries/stdlib/src/kotlin/coroutines/experimental/CoroutinesLibrary.kt

@@ -15,37 +15,10 @@
  */
 
 @file:kotlin.jvm.JvmName("CoroutinesKt")
-@file:kotlin.jvm.JvmVersion
 package kotlin.coroutines.experimental
 
-import java.lang.IllegalStateException
-import java.util.concurrent.atomic.AtomicReferenceFieldUpdater
 import kotlin.coroutines.experimental.intrinsics.COROUTINE_SUSPENDED
 import kotlin.coroutines.experimental.intrinsics.suspendCoroutineOrReturn
-import kotlin.coroutines.experimental.jvm.internal.CoroutineImpl
-import kotlin.coroutines.experimental.jvm.internal.interceptContinuationIfNeeded
-
-/**
- * Creates coroutine with receiver type [R] and result type [T].
- * This function creates a new, fresh instance of suspendable computation every time it is invoked.
- * To start executing the created coroutine, invoke `resume(Unit)` on the returned [Continuation] instance.
- * The [completion] continuation is invoked when coroutine completes with result or exception.
- */
-@SinceKotlin("1.1")
-@Suppress("UNCHECKED_CAST")
-public fun <R, T> (suspend R.() -> T).createCoroutine(
-        receiver: R,
-        completion: Continuation<T>
-): Continuation<Unit> =
-    SafeContinuation(
-        if (this !is CoroutineImpl)
-            buildContinuationByInvokeCall(completion) {
-                (this as Function2<R, Continuation<T>, Any?>).invoke(receiver, completion)
-            }
-        else
-            ((this as CoroutineImpl).create(receiver, completion) as CoroutineImpl).facade,
-        COROUTINE_SUSPENDED
-    )
 
 /**
  * Starts coroutine with receiver type [R] and result type [T].
@@ -61,27 +34,6 @@ public fun <R, T> (suspend R.() -> T).startCoroutine(
     createCoroutine(receiver, completion).resume(Unit)
 }
 
-/**
- * Creates coroutine without receiver and with result type [T].
- * This function creates a new, fresh instance of suspendable computation every time it is invoked.
- * To start executing the created coroutine, invoke `resume(Unit)` on the returned [Continuation] instance.
- * The [completion] continuation is invoked when coroutine completes with result or exception.
- */
-@SinceKotlin("1.1")
-@Suppress("UNCHECKED_CAST")
-public fun <T> (suspend () -> T).createCoroutine(
-        completion: Continuation<T>
-): Continuation<Unit> =
-    SafeContinuation(
-            if (this !is CoroutineImpl)
-                buildContinuationByInvokeCall(completion) {
-                    (this as Function1<Continuation<T>, Any?>).invoke(completion)
-                }
-            else
-                ((this as CoroutineImpl).create(completion) as CoroutineImpl).facade,
-            COROUTINE_SUSPENDED
-    )
-
 /**
  * Starts coroutine without receiver and with result type [T].
  * This function creates and start a new, fresh instance of suspendable computation every time it is invoked.
@@ -113,28 +65,7 @@ public inline suspend fun <T> suspendCoroutine(crossinline block: (Continuation<
 
 // INTERNAL DECLARATIONS
 
-private inline fun <T> buildContinuationByInvokeCall(
-        completion: Continuation<T>,
-        crossinline block: () -> Any?
-): Continuation<Unit> {
-    val continuation =
-            object : Continuation<Unit> {
-                override val context: CoroutineContext
-                    get() = completion.context
-
-                override fun resume(value: Unit) {
-                    processInvokeCallOnCoroutine(completion, block)
-                }
-
-                override fun resumeWithException(exception: Throwable) {
-                    completion.resumeWithException(exception)
-                }
-            }
-
-    return completion.context.interceptContinuationIfNeeded(continuation)
-}
-
-private inline fun processInvokeCallOnCoroutine(completion: Continuation<*>, block: () -> Any?) {
+internal inline fun processInvokeCallOnCoroutine(completion: Continuation<*>, block: () -> Any?) {
     try {
         val result = block()
         if (result !== COROUTINE_SUSPENDED) {
@@ -145,69 +76,3 @@ private inline fun processInvokeCallOnCoroutine(completion: Continuation<*>, blo
         completion.resumeWithException(t)
     }
 }
-
-private val UNDECIDED: Any? = Any()
-private val RESUMED: Any? = Any()
-private class Fail(val exception: Throwable)
-
-@PublishedApi
-internal class SafeContinuation<in T>
-@PublishedApi internal constructor(
-        private val delegate: Continuation<T>,
-        initialResult: Any? = UNDECIDED
-) : Continuation<T> {
-    public override val context: CoroutineContext
-        get() = delegate.context
-
-    @Volatile
-    private var result: Any? = initialResult
-
-    companion object {
-        @Suppress("UNCHECKED_CAST")
-        @JvmStatic
-        private val RESULT = AtomicReferenceFieldUpdater.newUpdater<SafeContinuation<*>, Any?>(
-                SafeContinuation::class.java, Any::class.java as Class<Any?>, "result")
-    }
-
-    override fun resume(value: T) {
-        while (true) { // lock-free loop
-            val result = this.result // atomic read
-            when {
-                result === UNDECIDED -> if (RESULT.compareAndSet(this, UNDECIDED, value)) return
-                result === COROUTINE_SUSPENDED -> if (RESULT.compareAndSet(this, COROUTINE_SUSPENDED, RESUMED)) {
-                    delegate.resume(value)
-                    return
-                }
-                else -> throw IllegalStateException("Already resumed")
-            }
-        }
-    }
-
-    override fun resumeWithException(exception: Throwable) {
-        while (true) { // lock-free loop
-            val result = this.result // atomic read
-            when  {
-                result === UNDECIDED -> if (RESULT.compareAndSet(this, UNDECIDED, Fail(exception))) return
-                result === COROUTINE_SUSPENDED -> if (RESULT.compareAndSet(this, COROUTINE_SUSPENDED, RESUMED)) {
-                    delegate.resumeWithException(exception)
-                    return
-                }
-                else -> throw IllegalStateException("Already resumed")
-            }
-        }
-    }
-
-    @PublishedApi
-    internal fun getResult(): Any? {
-        var result = this.result // atomic read
-        if (result === UNDECIDED) {
-            if (RESULT.compareAndSet(this, UNDECIDED, COROUTINE_SUSPENDED)) return COROUTINE_SUSPENDED
-            result = this.result // reread volatile var
-        }
-        when {
-            result === RESUMED -> return COROUTINE_SUSPENDED // already called continuation, indicate COROUTINE_SUSPENDED upstream
-            result is Fail -> throw result.exception
-            else -> return result // either COROUTINE_SUSPENDED or data
-        }
-    }
-}

libraries/stdlib/src/kotlin/coroutines/experimental/CoroutinesLibraryJvm.kt

@@ -0,0 +1,90 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+@file:kotlin.jvm.JvmName("CoroutinesJvmKt")
+@file:kotlin.jvm.JvmVersion
+package kotlin.coroutines.experimental
+
+import kotlin.coroutines.experimental.intrinsics.COROUTINE_SUSPENDED
+import kotlin.coroutines.experimental.jvm.internal.CoroutineImpl
+import kotlin.coroutines.experimental.jvm.internal.interceptContinuationIfNeeded
+
+/**
+ * Creates coroutine with receiver type [R] and result type [T].
+ * This function creates a new, fresh instance of suspendable computation every time it is invoked.
+ * To start executing the created coroutine, invoke `resume(Unit)` on the returned [Continuation] instance.
+ * The [completion] continuation is invoked when coroutine completes with result or exception.
+ */
+@SinceKotlin("1.1")
+@Suppress("UNCHECKED_CAST")
+public fun <R, T> (suspend R.() -> T).createCoroutine(
+        receiver: R,
+        completion: Continuation<T>
+): Continuation<Unit> =
+    SafeContinuation(
+        if (this !is CoroutineImpl)
+            buildContinuationByInvokeCall(completion) {
+                (this as Function2<R, Continuation<T>, Any?>).invoke(receiver, completion)
+            }
+        else
+            ((this as CoroutineImpl).create(receiver, completion) as CoroutineImpl).facade,
+        COROUTINE_SUSPENDED
+    )
+
+/**
+ * Creates coroutine without receiver and with result type [T].
+ * This function creates a new, fresh instance of suspendable computation every time it is invoked.
+ * To start executing the created coroutine, invoke `resume(Unit)` on the returned [Continuation] instance.
+ * The [completion] continuation is invoked when coroutine completes with result or exception.
+ */
+@SinceKotlin("1.1")
+@Suppress("UNCHECKED_CAST")
+public fun <T> (suspend () -> T).createCoroutine(
+        completion: Continuation<T>
+): Continuation<Unit> =
+    SafeContinuation(
+            if (this !is CoroutineImpl)
+                buildContinuationByInvokeCall(completion) {
+                    (this as Function1<Continuation<T>, Any?>).invoke(completion)
+                }
+            else
+                ((this as CoroutineImpl).create(completion) as CoroutineImpl).facade,
+            COROUTINE_SUSPENDED
+    )
+
+// INTERNAL DECLARATIONS
+
+private inline fun <T> buildContinuationByInvokeCall(
+        completion: Continuation<T>,
+        crossinline block: () -> Any?
+): Continuation<Unit> {
+    val continuation =
+            object : Continuation<Unit> {
+                override val context: CoroutineContext
+                    get() = completion.context
+
+                override fun resume(value: Unit) {
+                    processInvokeCallOnCoroutine(completion, block)
+                }
+
+                override fun resumeWithException(exception: Throwable) {
+                    completion.resumeWithException(exception)
+                }
+            }
+
+    return completion.context.interceptContinuationIfNeeded(continuation)
+}
+

libraries/stdlib/src/kotlin/coroutines/experimental/SafeContinuationJvm.kt

@@ -0,0 +1,91 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+@file:kotlin.jvm.JvmVersion
+package kotlin.coroutines.experimental
+
+import java.util.concurrent.atomic.AtomicReferenceFieldUpdater
+import kotlin.coroutines.experimental.intrinsics.COROUTINE_SUSPENDED
+
+@PublishedApi
+internal class SafeContinuation<in T>
+internal constructor(
+        private val delegate: Continuation<T>,
+        initialResult: Any?
+) : Continuation<T> {
+
+    @PublishedApi
+    internal constructor(delegate: Continuation<T>) : this(delegate, UNDECIDED)
+
+    public override val context: CoroutineContext
+        get() = delegate.context
+
+    @Volatile
+    private var result: Any? = initialResult
+
+    companion object {
+        private val UNDECIDED: Any? = Any()
+        private val RESUMED: Any? = Any()
+
+        @Suppress("UNCHECKED_CAST")
+        @JvmStatic
+        private val RESULT = AtomicReferenceFieldUpdater.newUpdater<SafeContinuation<*>, Any?>(
+                SafeContinuation::class.java, Any::class.java as Class<Any?>, "result")
+    }
+
+    private class Fail(val exception: Throwable)
+
+    override fun resume(value: T) {
+        while (true) { // lock-free loop
+            val result = this.result // atomic read
+            when {
+                result === UNDECIDED -> if (RESULT.compareAndSet(this, UNDECIDED, value)) return
+                result === COROUTINE_SUSPENDED -> if (RESULT.compareAndSet(this, COROUTINE_SUSPENDED, RESUMED)) {
+                    delegate.resume(value)
+                    return
+                }
+                else -> throw IllegalStateException("Already resumed")
+            }
+        }
+    }
+
+    override fun resumeWithException(exception: Throwable) {
+        while (true) { // lock-free loop
+            val result = this.result // atomic read
+            when  {
+                result === UNDECIDED -> if (RESULT.compareAndSet(this, UNDECIDED, Fail(exception))) return
+                result === COROUTINE_SUSPENDED -> if (RESULT.compareAndSet(this, COROUTINE_SUSPENDED, RESUMED)) {
+                    delegate.resumeWithException(exception)
+                    return
+                }
+                else -> throw IllegalStateException("Already resumed")
+            }
+        }
+    }
+
+    @PublishedApi
+    internal fun getResult(): Any? {
+        var result = this.result // atomic read
+        if (result === UNDECIDED) {
+            if (RESULT.compareAndSet(this, UNDECIDED, COROUTINE_SUSPENDED)) return COROUTINE_SUSPENDED
+            result = this.result // reread volatile var
+        }
+        when {
+            result === RESUMED -> return COROUTINE_SUSPENDED // already called continuation, indicate COROUTINE_SUSPENDED upstream
+            result is Fail -> throw result.exception
+            else -> return result // either COROUTINE_SUSPENDED or data
+        }
+    }
+}