commit a2af5c7e3262bb7165e9320426bd6925f1a3c90d
author Ian Rogers <irogers@google.com> Mon Sep 15 15:17:07 2014 -0700
committer Ian Rogers <irogers@google.com> Tue Sep 16 15:49:27 2014 -0700
tree e435735391dd903305fc00862c933354d6acff3d
parent bace0378d720a1d2938ec7f6be17e2814671d20a

Only log an error if an unattached thread is unregistered.

Turn a fatal check into a diagnostic error. It looks like this issue arises
when a runtime shutsdown without properly being started.
Bug: 17011539

Change-Id: I2983c8332e83769e9480e8f30a46ca3b80a2e90e
(cherry picked from commit e2bcf579b0bc2f53db68c38755d69543198c7b00)

runtime/thread_list.cc

diff --git a/runtime/thread_list.cc b/runtime/thread_list.cc
index 2dbfb3e..08e66ea 100644
--- a/runtime/thread_list.cc
+++ b/runtime/thread_list.cc
@@ -872,14 +872,21 @@
     // thread_suspend_count_lock_ so that the unregistering thread cannot be suspended.
     // Note: deliberately not using MutexLock that could hold a stale self pointer.
     Locks::thread_list_lock_->ExclusiveLock(self);
-    CHECK(Contains(self));
-    Locks::thread_suspend_count_lock_->ExclusiveLock(self);
-    bool removed = false;
-    if (!self->IsSuspended()) {
-      list_.remove(self);
-      removed = true;
+    bool removed = true;
+    if (!Contains(self)) {
+      std::ostringstream os;
+      DumpNativeStack(os, GetTid(), "  native: ", nullptr);
+      LOG(ERROR) << "Request to unregister unattached thread\n" << os.str();
+    } else {
+      Locks::thread_suspend_count_lock_->ExclusiveLock(self);
+      if (!self->IsSuspended()) {
+        list_.remove(self);
+      } else {
+        // We failed to remove the thread due to a suspend request, loop and try again.
+        removed = false;
+      }
+      Locks::thread_suspend_count_lock_->ExclusiveUnlock(self);
     }
-    Locks::thread_suspend_count_lock_->ExclusiveUnlock(self);
     Locks::thread_list_lock_->ExclusiveUnlock(self);
     if (removed) {
       delete self;