feat(split): add check state task for split context (#743)

src/replica/replica_context.cpp

@@ -244,14 +244,22 @@ bool potential_secondary_context::is_cleaned()
 bool partition_split_context::cleanup(bool force)
 {
     CLEANUP_TASK(async_learn_task, force)
+    if (!force) {
+        CLEANUP_TASK_ALWAYS(check_state_task)
+    } else {
+        CLEANUP_TASK(check_state_task, force)
+    }
 
     parent_gpid.set_app_id(0);
     is_prepare_list_copied = false;
     is_caught_up = false;
     return true;
 }
 
-bool partition_split_context::is_cleaned() const { return async_learn_task == nullptr; }
+bool partition_split_context::is_cleaned() const
+{
+    return async_learn_task == nullptr && check_state_task == nullptr;
+}
 
 } // namespace replication
 } // namespace dsn

src/replica/replica_context.h

@@ -244,7 +244,11 @@ class partition_split_context
     bool is_caught_up{false};
 
     // child replica async learn parent states
-    dsn::task_ptr async_learn_task;
+    task_ptr async_learn_task;
+
+    // partition split states checker, start when initialize child replica
+    // see more in function `child_check_split_context` and `parent_check_states`
+    task_ptr check_state_task;
 };
 
 //---------------inline impl----------------------------------------------------------------

src/replica/split/replica_split_manager.cpp

@@ -121,6 +121,12 @@ void replica_split_manager::child_init_replica(gpid parent_gpid,
     _replica->_split_states.parent_gpid = parent_gpid;
     _replica->_split_states.is_prepare_list_copied = false;
     _replica->_split_states.is_caught_up = false;
+    _replica->_split_states.check_state_task =
+        tasking::enqueue(LPC_PARTITION_SPLIT,
+                         tracker(),
+                         std::bind(&replica_split_manager::child_check_split_context, this),
+                         get_gpid().thread_hash(),
+                         std::chrono::seconds(3));
     // TODO(heyuchen): add other states
 
     ddebug_replica(
@@ -137,6 +143,34 @@ void replica_split_manager::child_init_replica(gpid parent_gpid,
     }
 }
 
+// ThreadPool: THREAD_POOL_REPLICATION
+void replica_split_manager::child_check_split_context() // on child partition
+{
+    FAIL_POINT_INJECT_F("replica_child_check_split_context", [](dsn::string_view) {});
+
+    if (status() != partition_status::PS_PARTITION_SPLIT) {
+        derror_replica("wrong status({})", enum_to_string(status()));
+        _replica->_split_states.check_state_task = nullptr;
+        return;
+    }
+    // let parent partition check its status
+    error_code ec = _stub->split_replica_exec(
+        LPC_PARTITION_SPLIT,
+        _replica->_split_states.parent_gpid,
+        std::bind(&replica_split_manager::parent_check_states, std::placeholders::_1));
+    if (ec != ERR_OK) {
+        child_handle_split_error("check_child_state failed because parent gpid is invalid");
+        return;
+    }
+
+    _replica->_split_states.check_state_task =
+        tasking::enqueue(LPC_PARTITION_SPLIT,
+                         tracker(),
+                         std::bind(&replica_split_manager::child_check_split_context, this),
+                         get_gpid().thread_hash(),
+                         std::chrono::seconds(3));
+}
+
 // ThreadPool: THREAD_POOL_REPLICATION
 bool replica_split_manager::parent_check_states() // on parent partition
 {

src/replica/split/replica_split_manager.h

@@ -123,6 +123,8 @@ class replica_split_manager : replica_base
 
     // return true if parent status is valid
     bool parent_check_states();
+    // check if child status is valid
+    void child_check_split_context();
 
     // parent reset child information when partition split failed
     void parent_cleanup_split_context();

src/replica/split/test/replica_split_test.cpp

@@ -202,6 +202,21 @@ class replica_split_test : public replica_test_base
         _parent_replica->tracker()->wait_outstanding_tasks();
     }
 
+    void test_child_init_replica()
+    {
+        _child_replica = stub->generate_replica(
+            _app_info, CHILD_GPID, partition_status::PS_INACTIVE, INIT_BALLOT);
+        _child_split_mgr = make_unique<replica_split_manager>(_child_replica.get());
+        _child_split_mgr->child_init_replica(PARENT_GPID, PRIMARY, INIT_BALLOT);
+        // check_state_task will cost 3 seconds, cancel it immediatly
+        bool finished = false;
+        _child_replica->_split_states.check_state_task->cancel(false, &finished);
+        if (finished) {
+            _child_replica->_split_states.check_state_task = nullptr;
+        }
+        _child_replica->tracker()->wait_outstanding_tasks();
+    }
+
     bool test_parent_check_states()
     {
         bool flag = _parent_split_mgr->parent_check_states();
@@ -526,6 +541,16 @@ TEST_F(replica_split_test, parent_start_split_tests)
     }
 }
 
+// child_init_replica test
+TEST_F(replica_split_test, child_init_replica_test)
+{
+    fail::cfg("replica_stub_split_replica_exec", "return()");
+    test_child_init_replica();
+    ASSERT_EQ(_child_replica->status(), partition_status::PS_PARTITION_SPLIT);
+    ASSERT_FALSE(child_is_prepare_list_copied());
+    ASSERT_FALSE(child_is_caught_up());
+}
+
 // parent_check_states tests
 TEST_F(replica_split_test, parent_check_states_tests)
 {