[llvm] [Offload] Stop the RPC server faiilng with more than one GPU (PR #125982)

[Joseph Huber via llvm-commits]

https://github.com/jhuber6 created https://github.com/llvm/llvm-project/pull/125982

Summary:
Pretty dumb mistake of me, forgot that this is run per-device and
per-plugin, which fell through the cracks with my testing because I have
two GPUs that use different plugins.


>From 17fd516c1bb4b29ff23fb79f4a6deb409766b008 Mon Sep 17 00:00:00 2001
From: Joseph Huber <huberjn at outlook.com>
Date: Wed, 5 Feb 2025 20:41:32 -0600
Subject: [PATCH] [Offload] Stop the RPC server faiilng with more than one GPU

Summary:
Pretty dumb mistake of me, forgot that this is run per-device and
per-plugin, which fell through the cracks with my testing because I have
two GPUs that use different plugins.
---
 offload/plugins-nextgen/common/src/PluginInterface.cpp | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/offload/plugins-nextgen/common/src/PluginInterface.cpp b/offload/plugins-nextgen/common/src/PluginInterface.cpp
index d2451d8a3422121..76ae0a2dd9c4523 100644
--- a/offload/plugins-nextgen/common/src/PluginInterface.cpp
+++ b/offload/plugins-nextgen/common/src/PluginInterface.cpp
@@ -1058,8 +1058,9 @@ Error GenericDeviceTy::setupRPCServer(GenericPluginTy &Plugin,
   if (auto Err = Server.initDevice(*this, Plugin.getGlobalHandler(), Image))
     return Err;
 
-  if (auto Err = Server.startThread())
-    return Err;
+  if (!Server.Thread->Running.load(std::memory_order_acquire))
+    if (auto Err = Server.startThread())
+      return Err;
 
   RPCServer = &Server;
   DP("Running an RPC server on device %d\n", getDeviceId());
@@ -1634,7 +1635,7 @@ Error GenericPluginTy::deinit() {
   if (GlobalHandler)
     delete GlobalHandler;
 
-  if (RPCServer && RPCServer->Thread->Running.load(std::memory_order_relaxed))
+  if (RPCServer && RPCServer->Thread->Running.load(std::memory_order_acquire))
     if (Error Err = RPCServer->shutDown())
       return Err;