1 /* 2 * Copyright 2016-2021 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license. 3 */ 4 5 package kotlinx.coroutines 6 7 import kotlinx.coroutines.internal.* 8 import kotlin.coroutines.* 9 10 11 public actual object Dispatchers { 12 public actual val Default: CoroutineDispatcher = createDefaultDispatcher() 13 public actual val Main: MainCoroutineDispatcher 14 get() = injectedMainDispatcher ?: mainDispatcher 15 public actual val Unconfined: CoroutineDispatcher get() = kotlinx.coroutines.Unconfined // Avoid freezing 16 17 private val mainDispatcher = createMainDispatcher(Default) 18 19 private var injectedMainDispatcher: MainCoroutineDispatcher? = null 20 21 @PublishedApi injectMainnull22 internal fun injectMain(dispatcher: MainCoroutineDispatcher) { 23 injectedMainDispatcher = dispatcher 24 } 25 26 internal val IO: CoroutineDispatcher = DefaultIoScheduler 27 } 28 29 internal object DefaultIoScheduler : CoroutineDispatcher() { 30 // 2048 is an arbitrary KMP-friendly constant 31 private val unlimitedPool = newFixedThreadPoolContext(2048, "Dispatchers.IO") 32 private val io = unlimitedPool.limitedParallelism(64) // Default JVM size 33 34 @ExperimentalCoroutinesApi limitedParallelismnull35 override fun limitedParallelism(parallelism: Int): CoroutineDispatcher { 36 // See documentation to Dispatchers.IO for the rationale 37 return unlimitedPool.limitedParallelism(parallelism) 38 } 39 dispatchnull40 override fun dispatch(context: CoroutineContext, block: Runnable) { 41 io.dispatch(context, block) 42 } 43 44 @InternalCoroutinesApi dispatchYieldnull45 override fun dispatchYield(context: CoroutineContext, block: Runnable) { 46 io.dispatchYield(context, block) 47 } 48 toStringnull49 override fun toString(): String = "Dispatchers.IO" 50 } 51 52 53 @Suppress("EXTENSION_SHADOWED_BY_MEMBER") 54 public actual val Dispatchers.IO: CoroutineDispatcher get() = IO 55 56 internal expect fun createMainDispatcher(default: CoroutineDispatcher): MainCoroutineDispatcher 57