Revert "Revert^14 "Thread suspension cleanup and deadlock fix""

This reverts commit f9fdd3ce0180972dc8d4f0c8410ea7702828a703.

Reason for revert: Very suspicious host-x86_64-debug failure on LUCI.

Change-Id: Ia01dd3df8d64d6bc0d12319b06a8380f64a46785

1 files changed, 12 insertions, 5 deletions

diff --git a/openjdkjvmti/ti_thread.cc b/openjdkjvmti/ti_thread.cc
index 22aa8fe302..13eebbff04 100644
--- a/openjdkjvmti/ti_thread.cc
+++ b/openjdkjvmti/ti_thread.cc
@@ -547,7 +547,6 @@ static jint GetJavaStateFromInternal(const InternalThreadState& state) {
 
 // Suspends the current thread if it has any suspend requests on it.
 void ThreadUtil::SuspendCheck(art::Thread* self) {
-  DCHECK(!self->ReadFlag(art::ThreadFlag::kSuspensionImmune));
   art::ScopedObjectAccess soa(self);
   // Really this is only needed if we are in FastJNI and actually have the mutator_lock_ already.
   self->FullSuspendCheck();
@@ -901,13 +900,17 @@ jvmtiError ThreadUtil::SuspendOther(art::Thread* self,
         }
       }
     }
+    bool timeout = true;
     art::Thread* ret_target = art::Runtime::Current()->GetThreadList()->SuspendThreadByPeer(
-        target_jthread, art::SuspendReason::kForUserCode);
-    if (ret_target == nullptr) {
+        target_jthread,
+        art::SuspendReason::kForUserCode,
+        &timeout);
+    if (ret_target == nullptr && !timeout) {
       // TODO It would be good to get more information about why exactly the thread failed to
       // suspend.
       return ERR(INTERNAL);
-    } else {
+    } else if (!timeout) {
+      // we didn't time out and got a result.
       return OK;
     }
     // We timed out. Just go around and try again.
@@ -924,7 +927,11 @@ jvmtiError ThreadUtil::SuspendSelf(art::Thread* self) {
       // This can only happen if we race with another thread to suspend 'self' and we lose.
       return ERR(THREAD_SUSPENDED);
     }
-    self->IncrementSuspendCount(self, nullptr, nullptr, art::SuspendReason::kForUserCode);
+    // We shouldn't be able to fail this.
+    if (!self->ModifySuspendCount(self, +1, nullptr, art::SuspendReason::kForUserCode)) {
+      // TODO More specific error would be nice.
+      return ERR(INTERNAL);
+    }
   }
   // Once we have requested the suspend we actually go to sleep. We need to do this after releasing
   // the suspend_lock to make sure we can be woken up. This call gains the mutator lock causing us