Debug agent cleanup

  * Readme
  * Do not fail on Windows during signal handler installation
  * Do not warn about missing artificial stackframe

Author: qwwdfsad

common/kotlinx-coroutines-core-common/src/channels/AbstractChannel.kt

@@ -859,7 +859,7 @@ internal abstract class AbstractChannel<E> : AbstractSendChannel<E>(), Channel<E
 
         private fun hasNextResult(result: Any?): Boolean {
             if (result is Closed<*>) {
-                if (result.closeCause != null) recoverStackTrace(throw result.receiveException)
+                if (result.closeCause != null) throw recoverStackTrace(result.receiveException)
                 return false
             }
             return true

core/kotlinx-coroutines-debug/README.md

@@ -4,19 +4,19 @@ Debugging facilities for `kotlinx.coroutines` on JVM.
 
 ### Overview
 
-This module provides a debug JVM agent which allows to track and trace alive coroutines.
-Main entry point to debug facilities is [DebugProbes].
+This module provides a debug JVM agent which allows to track and trace existing coroutines.
+The main entry point to debug facilities is [DebugProbes] API.
 Call to [DebugProbes.install] installs debug agent via ByteBuddy and starts to spy on coroutines when they are created, suspended or resumed.
 
-After that you can use [DebugProbes.dumpCoroutines] to print all active (suspended or running) coroutines, including their state, creation and
+After that, you can use [DebugProbes.dumpCoroutines] to print all active (suspended or running) coroutines, including their state, creation and
 suspension stacktraces.
-Additionally, it is possible to process list of such coroutines via [DebugProbes.dumpCoroutinesState] or dump isolated parts
-of coroutines hierarchies referenced by [Job] instance using [DebugProbes.printHierarchy].
+Additionally, it is possible to process the list of such coroutines via [DebugProbes.dumpCoroutinesState] or dump isolated parts
+of coroutines hierarchy referenced by a [Job] instance using [DebugProbes.printHierarchy].
 
 ### Using as JVM agent
 
-Additionally, it is possible to use this module as standalone JVM agent to enable debug probes on the application startup.
-You can run your application with additional argument: `-javaagent:kotlinx-coroutines-debug-1.1.0.jar`.
+It is possible to use this module as a standalone JVM agent to enable debug probes on the application startup.
+You can run your application with an additional argument: `-javaagent:kotlinx-coroutines-debug-1.1.0.jar`.
 Additionally, on Linux and Mac OS X you can use `kill -5 $pid` command in order to force your application to print all alive coroutines.
 
 

core/kotlinx-coroutines-debug/src/AgentPremain.kt

@@ -19,8 +19,12 @@ internal object AgentPremain {
     }
 
     private fun installSignalHandler() {
-        Signal.handle(Signal("TRAP") ) { // kill -5
-            DebugProbes.dumpCoroutines()
+        try {
+            Signal.handle(Signal("TRAP")) { // kill -5
+                DebugProbes.dumpCoroutines()
+            }
+        } catch (t: Throwable) {
+            System.err.println("Failed to install signal handler: $t")
         }
     }
 }

core/kotlinx-coroutines-debug/src/internal/DebugProbesImpl.kt

@@ -151,11 +151,7 @@ internal object DebugProbesImpl {
 
     @Synchronized
     private fun updateState(owner: ArtificialStackFrame<*>?, frame: Continuation<*>, state: State) {
-        val coroutineState = capturedCoroutines[owner]
-        if (coroutineState == null) {
-            warn(frame, state)
-            return
-        }
+        val coroutineState = capturedCoroutines[owner] ?: return
         coroutineState.updateState(state, frame)
     }
 
@@ -257,9 +253,4 @@ internal object DebugProbesImpl {
     }
 
     private val StackTraceElement.isInternalMethod: Boolean get() = className.startsWith("kotlinx.coroutines")
-
-    private fun warn(frame: Continuation<*>, state: State) {
-        // TODO make this warning configurable or not a warning at all
-        System.err.println("Failed to find an owner of the frame $frame while transferring it to the state $state")
-    }
 }

core/kotlinx-coroutines-debug/test/DebugProbesTest.kt

@@ -66,6 +66,7 @@ class DebugProbesTest : TestBase() {
 
     @Test
     fun testAsyncWithSanitizedProbes() = DebugProbes.withDebugProbes {
+        DebugProbes.sanitizeStackTraces = true
         runTest {
             val deferred = createDeferred()
             val traces = listOf(