[llvm] 320832c - [ORC] Wait for handleDisconnect to complete in SimpleRemoteEPC::disconnect.

[Lang Hames via llvm-commits]

Author: Lang Hames
Date: 2021-09-26T10:19:26+10:00
New Revision: 320832cc9b7e7fea5fc8afbed75c34c4a43287ba

URL: https://github.com/llvm/llvm-project/commit/320832cc9b7e7fea5fc8afbed75c34c4a43287ba
DIFF: https://github.com/llvm/llvm-project/commit/320832cc9b7e7fea5fc8afbed75c34c4a43287ba.diff

LOG: [ORC] Wait for handleDisconnect to complete in SimpleRemoteEPC::disconnect.

Disconnect should block until handleDisconnect completes, otherwise we might
destroy the SimpleRemoteEPC instance while it's still in use.

Thanks to Dave Blaikie for helping me track this down.

Added: 
    

Modified: 
    llvm/include/llvm/ExecutionEngine/Orc/SimpleRemoteEPC.h
    llvm/lib/ExecutionEngine/Orc/SimpleRemoteEPC.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/ExecutionEngine/Orc/SimpleRemoteEPC.h b/llvm/include/llvm/ExecutionEngine/Orc/SimpleRemoteEPC.h
index c7ca3ae4c8637..b334b566ed886 100644
--- a/llvm/include/llvm/ExecutionEngine/Orc/SimpleRemoteEPC.h
+++ b/llvm/include/llvm/ExecutionEngine/Orc/SimpleRemoteEPC.h
@@ -108,8 +108,11 @@ class SimpleRemoteEPC : public ExecutorProcessControl,
 
   using PendingCallWrapperResultsMap = DenseMap<uint64_t, SendResultFunction>;
 
-  std::atomic_bool Disconnected{false};
   std::mutex SimpleRemoteEPCMutex;
+  std::condition_variable DisconnectCV;
+  bool Disconnected = false;
+  Error DisconnectErr = Error::success();
+
   std::unique_ptr<SimpleRemoteEPCTransport> T;
   std::unique_ptr<jitlink::JITLinkMemoryManager> OwnedMemMgr;
   std::unique_ptr<MemoryAccess> OwnedMemAccess;

diff  --git a/llvm/lib/ExecutionEngine/Orc/SimpleRemoteEPC.cpp b/llvm/lib/ExecutionEngine/Orc/SimpleRemoteEPC.cpp
index 11859fde74198..64e2a1e54adba 100644
--- a/llvm/lib/ExecutionEngine/Orc/SimpleRemoteEPC.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/SimpleRemoteEPC.cpp
@@ -18,7 +18,10 @@ namespace llvm {
 namespace orc {
 
 SimpleRemoteEPC::~SimpleRemoteEPC() {
+#ifndef NDEBUG
+  std::lock_guard<std::mutex> Lock(SimpleRemoteEPCMutex);
   assert(Disconnected && "Destroyed without disconnection");
+#endif // NDEBUG
 }
 
 Expected<tpctypes::DylibHandle>
@@ -69,9 +72,10 @@ void SimpleRemoteEPC::callWrapperAsync(SendResultFunction OnComplete,
 }
 
 Error SimpleRemoteEPC::disconnect() {
-  Disconnected = true;
   T->disconnect();
-  return Error::success();
+  std::unique_lock<std::mutex> Lock(SimpleRemoteEPCMutex);
+  DisconnectCV.wait(Lock, [this] { return Disconnected; });
+  return std::move(DisconnectErr);
 }
 
 Expected<SimpleRemoteEPCTransportClient::HandleMessageAction>
@@ -114,13 +118,10 @@ void SimpleRemoteEPC::handleDisconnect(Error Err) {
     KV.second(
         shared::WrapperFunctionResult::createOutOfBandError("disconnecting"));
 
-  if (Err) {
-    // FIXME: Move ReportError to EPC.
-    if (ES)
-      ES->reportError(std::move(Err));
-    else
-      logAllUnhandledErrors(std::move(Err), errs(), "SimpleRemoteEPC: ");
-  }
+  std::lock_guard<std::mutex> Lock(SimpleRemoteEPCMutex);
+  DisconnectErr = joinErrors(std::move(DisconnectErr), std::move(Err));
+  Disconnected = true;
+  DisconnectCV.notify_all();
 }
 
 Expected<std::unique_ptr<jitlink::JITLinkMemoryManager>>