Roman Elizarov | f29203c | 2018-01-11 12:39:36 +0300 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2016-2017 JetBrains s.r.o. |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package kotlinx.coroutines.experimental |
| 18 | |
| 19 | import kotlinx.coroutines.experimental.internal.* |
Roman Elizarov | aa461cf | 2018-04-11 13:20:29 +0300 | [diff] [blame] | 20 | import kotlinx.coroutines.experimental.internalAnnotations.* |
Roman Elizarov | f29203c | 2018-01-11 12:39:36 +0300 | [diff] [blame] | 21 | import kotlin.coroutines.experimental.* |
| 22 | |
| 23 | @Suppress("PrivatePropertyName") |
| 24 | private val UNDEFINED = Symbol("UNDEFINED") |
| 25 | |
| 26 | internal class DispatchedContinuation<in T>( |
Roman Elizarov | aa461cf | 2018-04-11 13:20:29 +0300 | [diff] [blame] | 27 | @JvmField val dispatcher: CoroutineDispatcher, |
| 28 | @JvmField val continuation: Continuation<T> |
Roman Elizarov | f29203c | 2018-01-11 12:39:36 +0300 | [diff] [blame] | 29 | ) : Continuation<T> by continuation, DispatchedTask<T> { |
| 30 | private var _state: Any? = UNDEFINED |
| 31 | public override var resumeMode: Int = 0 |
| 32 | |
| 33 | override fun takeState(): Any? { |
| 34 | val state = _state |
| 35 | check(state !== UNDEFINED) // fail-fast if repeatedly invoked |
| 36 | _state = UNDEFINED |
| 37 | return state |
| 38 | } |
| 39 | |
| 40 | override val delegate: Continuation<T> |
| 41 | get() = this |
| 42 | |
| 43 | override fun resume(value: T) { |
| 44 | val context = continuation.context |
| 45 | if (dispatcher.isDispatchNeeded(context)) { |
| 46 | _state = value |
| 47 | resumeMode = MODE_ATOMIC_DEFAULT |
| 48 | dispatcher.dispatch(context, this) |
| 49 | } else |
| 50 | resumeUndispatched(value) |
| 51 | } |
| 52 | |
| 53 | override fun resumeWithException(exception: Throwable) { |
| 54 | val context = continuation.context |
| 55 | if (dispatcher.isDispatchNeeded(context)) { |
| 56 | _state = CompletedExceptionally(exception) |
| 57 | resumeMode = MODE_ATOMIC_DEFAULT |
| 58 | dispatcher.dispatch(context, this) |
| 59 | } else |
| 60 | resumeUndispatchedWithException(exception) |
| 61 | } |
| 62 | |
| 63 | @Suppress("NOTHING_TO_INLINE") // we need it inline to save us an entry on the stack |
| 64 | inline fun resumeCancellable(value: T) { |
| 65 | val context = continuation.context |
| 66 | if (dispatcher.isDispatchNeeded(context)) { |
| 67 | _state = value |
| 68 | resumeMode = MODE_CANCELLABLE |
| 69 | dispatcher.dispatch(context, this) |
| 70 | } else |
| 71 | resumeUndispatched(value) |
| 72 | } |
| 73 | |
| 74 | @Suppress("NOTHING_TO_INLINE") // we need it inline to save us an entry on the stack |
| 75 | inline fun resumeCancellableWithException(exception: Throwable) { |
| 76 | val context = continuation.context |
| 77 | if (dispatcher.isDispatchNeeded(context)) { |
| 78 | _state = CompletedExceptionally(exception) |
| 79 | resumeMode = MODE_CANCELLABLE |
| 80 | dispatcher.dispatch(context, this) |
| 81 | } else |
| 82 | resumeUndispatchedWithException(exception) |
| 83 | } |
| 84 | |
| 85 | @Suppress("NOTHING_TO_INLINE") // we need it inline to save us an entry on the stack |
| 86 | inline fun resumeUndispatched(value: T) { |
| 87 | withCoroutineContext(context) { |
| 88 | continuation.resume(value) |
| 89 | } |
| 90 | } |
| 91 | |
| 92 | @Suppress("NOTHING_TO_INLINE") // we need it inline to save us an entry on the stack |
| 93 | inline fun resumeUndispatchedWithException(exception: Throwable) { |
| 94 | withCoroutineContext(context) { |
| 95 | continuation.resumeWithException(exception) |
| 96 | } |
| 97 | } |
| 98 | |
| 99 | // used by "yield" implementation |
| 100 | internal fun dispatchYield(value: T) { |
| 101 | val context = continuation.context |
| 102 | _state = value |
| 103 | resumeMode = MODE_CANCELLABLE |
| 104 | dispatcher.dispatch(context, this) |
| 105 | } |
| 106 | |
| 107 | override fun toString(): String = |
| 108 | "DispatchedContinuation[$dispatcher, ${continuation.toDebugString()}]" |
| 109 | } |
| 110 | |
| 111 | internal fun <T> Continuation<T>.resumeCancellable(value: T) = when (this) { |
| 112 | is DispatchedContinuation -> resumeCancellable(value) |
| 113 | else -> resume(value) |
| 114 | } |
| 115 | |
| 116 | internal fun <T> Continuation<T>.resumeCancellableWithException(exception: Throwable) = when (this) { |
| 117 | is DispatchedContinuation -> resumeCancellableWithException(exception) |
| 118 | else -> resumeWithException(exception) |
| 119 | } |
| 120 | |
| 121 | internal fun <T> Continuation<T>.resumeDirect(value: T) = when (this) { |
| 122 | is DispatchedContinuation -> continuation.resume(value) |
| 123 | else -> resume(value) |
| 124 | } |
| 125 | |
| 126 | internal fun <T> Continuation<T>.resumeDirectWithException(exception: Throwable) = when (this) { |
| 127 | is DispatchedContinuation -> continuation.resumeWithException(exception) |
| 128 | else -> resumeWithException(exception) |
| 129 | } |
| 130 | |
| 131 | /** |
| 132 | * @suppress **This is unstable API and it is subject to change.** |
| 133 | */ |
| 134 | public interface DispatchedTask<in T> : Runnable { |
| 135 | public val delegate: Continuation<T> |
| 136 | public val resumeMode: Int get() = MODE_CANCELLABLE |
| 137 | |
| 138 | public fun takeState(): Any? |
| 139 | |
| 140 | @Suppress("UNCHECKED_CAST") |
| 141 | public fun <T> getSuccessfulResult(state: Any?): T = |
| 142 | state as T |
| 143 | |
| 144 | public fun getExceptionalResult(state: Any?): Throwable? = |
Vsevolod Tolstopyatov | c1092d5 | 2018-04-12 20:22:25 +0300 | [diff] [blame] | 145 | (state as? CompletedExceptionally)?.cause |
Roman Elizarov | f29203c | 2018-01-11 12:39:36 +0300 | [diff] [blame] | 146 | |
| 147 | public override fun run() { |
| 148 | try { |
| 149 | val delegate = delegate as DispatchedContinuation<T> |
| 150 | val continuation = delegate.continuation |
| 151 | val context = continuation.context |
| 152 | val job = if (resumeMode.isCancellableMode) context[Job] else null |
| 153 | val state = takeState() // NOTE: Must take state in any case, even if cancelled |
| 154 | withCoroutineContext(context) { |
| 155 | if (job != null && !job.isActive) |
| 156 | continuation.resumeWithException(job.getCancellationException()) |
| 157 | else { |
| 158 | val exception = getExceptionalResult(state) |
| 159 | if (exception != null) |
| 160 | continuation.resumeWithException(exception) |
| 161 | else |
| 162 | continuation.resume(getSuccessfulResult(state)) |
| 163 | } |
| 164 | } |
| 165 | } catch (e: Throwable) { |
| 166 | throw DispatchException("Unexpected exception running $this", e) |
| 167 | } |
| 168 | } |
| 169 | } |
| 170 | |
| 171 | /** |
| 172 | * @suppress **This is unstable API and it is subject to change.** |
| 173 | */ |
| 174 | public fun <T> DispatchedTask<T>.dispatch(mode: Int = MODE_CANCELLABLE) { |
| 175 | var useMode = mode |
| 176 | val delegate = this.delegate |
| 177 | if (mode.isDispatchedMode && delegate is DispatchedContinuation<*> && mode.isCancellableMode == resumeMode.isCancellableMode) { |
| 178 | // dispatch directly using this instance's Runnable implementation |
| 179 | val dispatcher = delegate.dispatcher |
| 180 | val context = delegate.context |
Roman Elizarov | 9a0d8ac | 2018-01-11 14:32:19 +0300 | [diff] [blame] | 181 | if (dispatcher.isDispatchNeeded(context)) { |
Roman Elizarov | f29203c | 2018-01-11 12:39:36 +0300 | [diff] [blame] | 182 | dispatcher.dispatch(context, this) |
| 183 | return // and that's it -- dispatched via fast-path |
| 184 | } else { |
| 185 | useMode = MODE_UNDISPATCHED |
| 186 | } |
| 187 | } |
| 188 | // slow-path - use delegate |
| 189 | val state = takeState() |
| 190 | val exception = getExceptionalResult(state) |
| 191 | if (exception != null) { |
| 192 | delegate.resumeWithExceptionMode(exception, useMode) |
| 193 | } else { |
| 194 | delegate.resumeMode(getSuccessfulResult(state), useMode) |
| 195 | } |
| 196 | } |