Execution context switching for high priority service.

dbsim/db_high_priority_service.hpp

@@ -28,6 +28,8 @@ namespace db
         void after_apply() override;
         void store_globals() override { }
         void reset_globals() override { }
+        void switch_execution_context(wsrep::high_priority_service&) override
+        { }
         int log_dummy_write_set(const wsrep::ws_handle&,
                                 const wsrep::ws_meta&)
         { return 0; }

dbsim/db_server_service.cpp

@@ -25,7 +25,14 @@ void db::server_service::release_storage_service(
     delete storage_service;
 }
 
-wsrep::high_priority_service* db::server_service::streaming_applier_service()
+wsrep::high_priority_service* db::server_service::streaming_applier_service(
+    wsrep::client_service&)
+{
+    return server_.streaming_applier_service();
+}
+
+wsrep::high_priority_service* db::server_service::streaming_applier_service(
+    wsrep::high_priority_service&)
 {
     return server_.streaming_applier_service();
 }

dbsim/db_server_service.hpp

@@ -17,7 +17,8 @@ namespace db
         server_service(db::server& server);
         wsrep::storage_service* storage_service(wsrep::client_service&) override;
         void release_storage_service(wsrep::storage_service*) override;
-        wsrep::high_priority_service* streaming_applier_service() override;
+        wsrep::high_priority_service* streaming_applier_service(wsrep::client_service&) override;
+        wsrep::high_priority_service* streaming_applier_service(wsrep::high_priority_service&) override;
         void release_high_priority_service(wsrep::high_priority_service*) override;
 
         bool sst_before_init() const override;

include/wsrep/high_priority_service.hpp

@@ -80,9 +80,24 @@ namespace wsrep
          */
         virtual void after_apply() = 0;
 
+        /**
+         * Store global execution context for high priority service.
+         */
         virtual void store_globals() = 0;
+
+        /**
+         * Reset global execution context for high priority service.
+         */
         virtual void reset_globals() = 0;
 
+        /**
+         * Switch exection context to context of orig_hps.
+         *
+         * @param orig_hps Original high priority service.
+         */
+        virtual void switch_execution_context(
+            wsrep::high_priority_service& orig_hps) = 0;
+
         virtual int log_dummy_write_set(const ws_handle&, const ws_meta&) = 0;
 
         virtual bool is_replaying() const = 0;
@@ -102,6 +117,7 @@ namespace wsrep
             , current_service_(current_service)
         {
             orig_service_.reset_globals();
+            current_service_.switch_execution_context(orig_service_);
             current_service_.store_globals();
         }
         ~high_priority_switch()

include/wsrep/server_service.hpp

@@ -34,13 +34,30 @@ namespace wsrep
             wsrep::client_service&) = 0;
 
         virtual void release_storage_service(wsrep::storage_service*) = 0;
+
+        /**
+         * Create an applier state for streaming transaction applying.
+         *
+         * @param orig_cs  Reference to client service which is
+         *                 requesting a new streaming applier service
+         *                 instance.
+         *
+         * @return Pointer to streaming applier client state.
+         */
+        virtual wsrep::high_priority_service*
+        streaming_applier_service(wsrep::client_service& orig_cs) = 0;
+
         /**
          * Create an applier state for streaming transaction applying.
          *
+         * @param orig_hps Reference to high priority service which is
+         *                 requesting a new streaming applier service
+         *                 instance.
+         *
          * @return Pointer to streaming applier client state.
          */
         virtual wsrep::high_priority_service*
-        streaming_applier_service() = 0;
+        streaming_applier_service(wsrep::high_priority_service& orig_hps) = 0;
 
         /**
          * Release a client state allocated by either local_client_state()

include/wsrep/transaction_id.hpp

@@ -25,6 +25,7 @@ namespace wsrep
         { }
         type get() const { return id_; }
         static unsigned long long undefined() { return type(-1); }
+        bool is_undefined() const { return (id_ == type(-1)); }
         bool operator<(const transaction_id& other) const
         {
             return (id_ < other.id_);

src/server_state.cpp

@@ -61,7 +61,8 @@ namespace
             assert(server_state.find_streaming_applier(
                        ws_meta.server_id(), ws_meta.transaction_id()) == 0);
             wsrep::high_priority_service* sa(
-                server_state.server_service().streaming_applier_service());
+                server_state.server_service().streaming_applier_service(
+                    high_priority_service));
             server_state.start_streaming_applier(
                 ws_meta.server_id(), ws_meta.transaction_id(), sa);
             sa->start_transaction(ws_handle, ws_meta);
@@ -84,14 +85,13 @@ namespace
                 // commit fragment comes in. Although this is a valid
                 // situation, log a warning if a sac cannot be found as
                 // it may be an indication of  a bug too.
-                assert(0);
                 wsrep::log_warning() << "Could not find applier context for "
                                      << ws_meta.server_id()
                                      << ": " << ws_meta.transaction_id();
             }
             else
             {
-                wsrep::high_priority_switch(high_priority_service, *sa);
+                wsrep::high_priority_switch sw(high_priority_service, *sa);
                 ret = sa->apply_write_set(data);
                 sa->after_apply();
             }
@@ -117,17 +117,21 @@ namespace
                     // commit fragment comes in. Although this is a valid
                     // situation, log a warning if a sac cannot be found as
                     // it may be an indication of  a bug too.
-                    assert(0);
                     wsrep::log_warning()
                         << "Could not find applier context for "
                         << ws_meta.server_id()
                         << ": " << ws_meta.transaction_id();
                 }
                 else
                 {
-                    wsrep::high_priority_switch(high_priority_service, *sa);
-                    ret = sa->commit();
-                    sa->after_apply();
+                    // Make high priority switch to go out of scope
+                    // before the streaming applier is released.
+                    {
+                        wsrep::high_priority_switch sw(
+                            high_priority_service, *sa);
+                        ret = sa->commit();
+                        sa->after_apply();
+                    }
                     server_state.stop_streaming_applier(
                         ws_meta.server_id(), ws_meta.transaction_id());
                     server_state.server_service().release_high_priority_service(sa);

src/transaction.cpp

@@ -1080,7 +1080,8 @@ void wsrep::transaction::streaming_rollback()
 {
     assert(streaming_context_.rolled_back() == false);
     wsrep::high_priority_service* sa(
-        server_service_.streaming_applier_service());
+        server_service_.streaming_applier_service(
+            client_state_.client_service()));
     client_state_.server_state().start_streaming_applier(
         client_state_.server_state().id(), id(), sa);
     sa->adopt_transaction(*this);

test/mock_high_priority_service.hpp

@@ -43,6 +43,8 @@ namespace wsrep
         void after_apply() WSREP_OVERRIDE;
         void store_globals() WSREP_OVERRIDE { }
         void reset_globals() WSREP_OVERRIDE { }
+        void switch_execution_context(wsrep::high_priority_service&)
+            WSREP_OVERRIDE { }
         int log_dummy_write_set(const wsrep::ws_handle&,
                                 const wsrep::ws_meta&)
             WSREP_OVERRIDE { return 0; }

test/mock_server_state.hpp

@@ -63,7 +63,21 @@ namespace wsrep
             delete client_state;
         }
 
-        wsrep::high_priority_service* streaming_applier_service()
+        wsrep::high_priority_service* streaming_applier_service(
+            wsrep::client_service&)
+        {
+            wsrep::mock_client* cs(new wsrep::mock_client(
+                                       *this, ++last_client_id_,
+                                       wsrep::client_state::m_high_priority));
+            wsrep::mock_high_priority_service* ret(
+                new wsrep::mock_high_priority_service(*this, cs, false));
+            cs->open(cs->id());
+            cs->before_command();
+            return ret;
+        }
+
+        wsrep::high_priority_service* streaming_applier_service(
+            wsrep::high_priority_service&)
         {
             wsrep::mock_client* cs(new wsrep::mock_client(
                                        *this, ++last_client_id_,