Expiration: Fix race with GC when handling already disposed Disposable

On a rare occasion an instance of DisposableExpiration created for an
already disposed Disposable could have been left non-expired. This used
to happen when the GC had already collected a weakly-referenced child
disposable by the time we disposed the instance of
eakReferenceDisposableWrapper referencing the child.

This also fixes
NonBlockingReadActionTest.testSyncExecutionThrowsPCEWhenExpired failing
randomly.

GitOrigin-RevId: 28dfeef0e7d1ef501db0554a5d8069f82603211d

platform/platform-impl/src/com/intellij/openapi/application/constraints/Expiration.kt

@@ -5,6 +5,7 @@ import com.intellij.openapi.Disposable
 import com.intellij.openapi.WeakReferenceDisposableWrapper
 import com.intellij.openapi.util.Disposer
 import com.intellij.util.IncorrectOperationException
+import com.intellij.util.ObjectUtils
 import kotlinx.coroutines.*
 
 /**
@@ -146,6 +147,7 @@ internal fun Disposable.cancelJobOnDisposal(job: Job,
 
   if (!tryRegisterDisposable(this, childRef)) {
     Disposer.dispose(childRef)  // runs disposableBlock()
+    ObjectUtils.reachabilityFence(child)
     return AutoCloseable { }
   }
   else {

platform/platform-tests/testSrc/com/intellij/openapi/application/constraints/ExpirationTest.kt

@@ -12,7 +12,7 @@ import kotlinx.coroutines.Job
 class ExpirationTest : LightPlatformTestCase() {
 
   private fun createTestDisposable(): Disposable {
-    return Disposable { }.also { Disposer.register(testRootDisposable, it) }
+    return Disposer.newDisposable(name).also { Disposer.register(testRootDisposable, it) }
   }
 
   private fun createCompositeExpiration(vararg expiration: Expiration): Expiration {
@@ -20,6 +20,13 @@ class ExpirationTest : LightPlatformTestCase() {
     return Expiration.composeExpiration(expiration.toList())!!
   }
 
+  fun `test isExpired for already disposed Disposable`() {
+    val disposable = createTestDisposable()
+    Disposer.dispose(disposable)
+    val expiration = DisposableExpiration(disposable)
+    assertTrue("Expiration.isExpired must be true", expiration.isExpired)
+  }
+
   fun `test isExpired for JobExpiration`() {
     val job = Job()
     val expiration = JobExpiration(job)