Fix BlockHound false positives related to channels that use locks

Solves #2302

kotlinx-coroutines-debug/src/CoroutinesBlockHoundIntegration.kt

@@ -1,16 +1,38 @@
 @file:Suppress("INVISIBLE_REFERENCE", "INVISIBLE_MEMBER")
+
 package kotlinx.coroutines.debug
 
-import reactor.blockhound.BlockHound
 import kotlinx.coroutines.scheduling.*
+import reactor.blockhound.*
 import reactor.blockhound.integration.*
 
 @Suppress("UNUSED")
-public class CoroutinesBlockHoundIntegration: BlockHoundIntegration {
+public class CoroutinesBlockHoundIntegration : BlockHoundIntegration {
 
-    override fun applyTo(builder: BlockHound.Builder) {
-        builder.addDynamicThreadPredicate { isSchedulerWorker(it) }
-        builder.nonBlockingThreadPredicate { p -> p.or { mayNotBlock(it) } }
+    override fun applyTo(builder: BlockHound.Builder): Unit = with(builder) {
+        allowBlockingCallsInside("kotlinx.coroutines.channels.AbstractSendChannel", "sendSuspend")
+        // these classes use a lock internally
+        for (method in listOf(
+            "pollInternal", "isEmpty", "isFull", "isClosedForReceive", "offerInternal", "offerSelectInternal",
+            "enqueueSend", "pollInternal", "pollSelectInternal", "enqueueReceiveInternal", "onCancelIdempotent" ))
+        {
+            allowBlockingCallsInside("kotlinx.coroutines.channels.ArrayChannel", method)
+        }
+        for (method in listOf("offerInternal", "offerSelectInternal", "updateHead")) {
+            allowBlockingCallsInside("kotlinx.coroutines.channels.ArrayBroadcastChannel", method)
+        }
+        for (method in listOf("checkOffer", "pollInternal", "pollSelectInternal")) {
+            allowBlockingCallsInside("kotlinx.coroutines.channels.ArrayBroadcastChannel\$Subscriber", method)
+        }
+        for (method in listOf("offerInternal", "offerSelectInternal", "pollInternal", "pollSelectInternal",
+            "onCancelIdempotent"))
+        {
+            allowBlockingCallsInside("kotlinx.coroutines.channels.ConflatedChannel", method)
+        }
+        // should be safe; used for sending tasks to a thread pool
+        allowBlockingCallsInside("java.util.concurrent.ScheduledThreadPoolExecutor", "execute")
+        addDynamicThreadPredicate { isSchedulerWorker(it) }
+        nonBlockingThreadPredicate { p -> p.or { mayNotBlock(it) } }
     }
 
 }