avoid multi-thread issue

* postpone actual work to scheduled tasks, to avoid
  multiple threads doing callbacks at the same time

4 files changed, 21 insertions, 3 deletions

diff --git a/slobrok/src/vespa/slobrok/server/exchange_manager.cpp b/slobrok/src/vespa/slobrok/server/exchange_manager.cpp
index e74724803e8..9c02b7bda45 100644
--- a/slobrok/src/vespa/slobrok/server/exchange_manager.cpp
+++ b/slobrok/src/vespa/slobrok/server/exchange_manager.cpp
@@ -120,15 +120,22 @@ ExchangeManager::healthCheck()
 ExchangeManager::WorkPackage::WorkItem::WorkItem(WorkPackage &pkg,
                                                  RemoteSlobrok *rem,
                                                  FRT_RPCRequest *req)
-    : _pkg(pkg), _pendingReq(req), _remslob(rem)
+    : FNET_Task(pkg._exchanger._env.getScheduler()), _pkg(pkg), _pendingReq(req), _remslob(rem)
 {
 }
 
 void
 ExchangeManager::WorkPackage::WorkItem::RequestDone(FRT_RPCRequest *req)
 {
-    bool denied = false;
     LOG_ASSERT(req == _pendingReq);
+    ScheduleNow();
+}
+
+void
+ExchangeManager::WorkPackage::WorkItem::PerformTask()
+{
+    bool denied = false;
+    FRT_RPCRequest *req = _pendingReq;
     FRT_Values &answer = *(req->GetReturn());
 
     if (!req->IsError() && strcmp(answer.GetTypeString(), "is") == 0) {
diff --git a/slobrok/src/vespa/slobrok/server/exchange_manager.h b/slobrok/src/vespa/slobrok/server/exchange_manager.h
index ea335cbb3c0..fc691daa089 100644
--- a/slobrok/src/vespa/slobrok/server/exchange_manager.h
+++ b/slobrok/src/vespa/slobrok/server/exchange_manager.h
@@ -44,7 +44,7 @@ private:
     class WorkPackage
     {
     private:
-        class WorkItem: public FRT_IRequestWait
+        class WorkItem: public FRT_IRequestWait, public FNET_Task
         {
         private:
             WorkPackage    &_pkg;
@@ -53,6 +53,7 @@ private:
         public:
             void expedite();
             void RequestDone(FRT_RPCRequest *req) override;
+            void PerformTask() override;
             WorkItem(WorkPackage &pkg, RemoteSlobrok *rem, FRT_RPCRequest *req);
             WorkItem(const WorkItem&) = delete;
             WorkItem& operator= (const WorkItem&) = delete;
diff --git a/slobrok/src/vespa/slobrok/server/managed_rpc_server.cpp b/slobrok/src/vespa/slobrok/server/managed_rpc_server.cpp
index 065dac04304..b9e8b8d032d 100644
--- a/slobrok/src/vespa/slobrok/server/managed_rpc_server.cpp
+++ b/slobrok/src/vespa/slobrok/server/managed_rpc_server.cpp
@@ -16,6 +16,7 @@ ManagedRpcServer::ManagedRpcServer(const std::string & name,
                                    const std::string & spec,
                                    IRpcServerManager &manager)
     : NamedService(name, spec),
+      FNET_Task(manager.getSupervisor()->GetScheduler()),
       _mmanager(manager),
       _monitor(*this, *manager.getSupervisor()),
       _monitoredServer(nullptr),
@@ -87,6 +88,13 @@ void
 ManagedRpcServer::RequestDone(FRT_RPCRequest *req)
 {
     LOG_ASSERT(req == _checkServerReq);
+    ScheduleNow();
+}
+
+void
+ManagedRpcServer::PerformTask()
+{
+    FRT_RPCRequest *req = _checkServerReq;
     FRT_Values &answer = *(req->GetReturn());
 
     if (req->GetErrorCode() == FRTE_RPC_ABORT) {
diff --git a/slobrok/src/vespa/slobrok/server/managed_rpc_server.h b/slobrok/src/vespa/slobrok/server/managed_rpc_server.h
index 072aebd7850..6c978d03299 100644
--- a/slobrok/src/vespa/slobrok/server/managed_rpc_server.h
+++ b/slobrok/src/vespa/slobrok/server/managed_rpc_server.h
@@ -23,6 +23,7 @@ class IRpcServerManager;
 
 class ManagedRpcServer: public NamedService,
                         public FRT_IRequestWait,
+                        public FNET_Task,
                         public IMonitoredServer
 {
 public:
@@ -44,6 +45,7 @@ private:
                            FRT_StringValue *strings);
 public:
     void RequestDone(FRT_RPCRequest *req) override;
+    void PerformTask() override;
     void notifyDisconnected() override; // lost connection to service
 };