From 313d7d243709e98f9472100757dd5f9c12ee0dc3 Mon Sep 17 00:00:00 2001
From: Teemu Ollakka <teemu.ollakka@galeracluster.com>
Date: Fri, 11 Jun 2021 12:54:23 +0300
Subject: [PATCH] Enable DBMS initialization from applying codepath

In general the provider might not guarantee that after joining
to replication group, the first applied event is view event.

Made init_initialized_ atomic and check it also from applying
codepath. If the DBMS is not yet initialized when applying the
first event, change state to initializing and wait for DBMS
initialization completion.

Notes:
- Allow connected -> initializing state change.
- Handle bootstrap_view in mock_connect to make server state synced
  for tests.
---
 include/wsrep/server_state.hpp |  5 ++++-
 src/server_state.cpp           | 22 +++++++++++++++++++++-
 test/mock_server_state.hpp     |  8 ++++++++
 test/server_context_test.cpp   | 16 ++++++++++++++++
 4 files changed, 49 insertions(+), 2 deletions(-)

diff --git a/include/wsrep/server_state.hpp b/include/wsrep/server_state.hpp
index 0fa6420b..c6636f6d 100644
--- a/include/wsrep/server_state.hpp
+++ b/include/wsrep/server_state.hpp
@@ -92,10 +92,13 @@
 #include "compiler.hpp"
 #include "xid.hpp"
 
+#include <atomic>
 #include <deque>
 #include <vector>
 #include <string>
 #include <map>
+#include <string>
+#include <vector>
 
 /**
  * Magic string to tell provider to engage into trivial (empty)
@@ -686,7 +689,7 @@ namespace wsrep
         mutable std::vector<int> state_waiters_;
         bool bootstrap_;
         const wsrep::gtid initial_position_;
-        bool init_initialized_;
+        std::atomic<bool> init_initialized_;
         bool init_synced_;
         wsrep::gtid sst_gtid_;
         size_t desync_count_;
diff --git a/src/server_state.cpp b/src/server_state.cpp
index 79a720be..5b64428e 100644
--- a/src/server_state.cpp
+++ b/src/server_state.cpp
@@ -1098,6 +1098,26 @@ int wsrep::server_state::on_apply(
     const wsrep::ws_meta& ws_meta,
     const wsrep::const_buffer& data)
 {
+    if (not init_initialized_.load())
+    {
+        wsrep::unique_lock<wsrep::mutex> lock(mutex_);
+        if (state(lock) == s_connected)
+        {
+            state(lock, s_initializing);
+            lock.unlock();
+            server_service_.debug_sync("on_view_wait_initialized");
+            lock.lock();
+        }
+        while (not init_initialized_.load())
+        {
+            wait_until_state(lock, s_initialized);
+        }
+        if (state(lock) == s_initialized)
+        {
+            state(lock, s_joined);
+        }
+    }
+
     if (is_toi(ws_meta.flags()))
     {
         return apply_toi(provider(), high_priority_service,
@@ -1330,7 +1350,7 @@ void wsrep::server_state::state(
             {  0,   1,   0,    1,    0,   0,   0,   0,   0}, /* dis */
             {  1,   0,   1,    0,    0,   0,   0,   0,   1}, /* ing */
             {  1,   0,   0,    1,    0,   1,   0,   0,   1}, /* ized */
-            {  1,   0,   0,    1,    1,   0,   0,   1,   1}, /* cted */
+            {  1,   1,   0,    1,    1,   0,   0,   1,   1}, /* cted */
             {  1,   1,   0,    0,    0,   1,   0,   0,   1}, /* jer */
             {  1,   0,   0,    1,    0,   0,   1,   1,   1}, /* jed */
             {  1,   0,   0,    1,    0,   1,   0,   0,   1}, /* dor */
diff --git a/test/mock_server_state.hpp b/test/mock_server_state.hpp
index 730c9c04..d22656df 100644
--- a/test/mock_server_state.hpp
+++ b/test/mock_server_state.hpp
@@ -278,6 +278,14 @@ namespace wsrep
                                            1,
                                            members);
                 server_state::on_connect(bootstrap_view);
+                server_state::initialized();
+                wsrep::mock_client cs(*this, wsrep::client_id(0),
+                                      wsrep::client_state::m_high_priority);
+                wsrep::mock_high_priority_service hps(*this, &cs, false);
+                server_state::on_view(bootstrap_view, &hps);
+                BOOST_REQUIRE(state() == wsrep::server_state::s_joined);
+                server_state::on_sync();
+                BOOST_REQUIRE(state() == wsrep::server_state::s_synced);
             }
             else
             {
diff --git a/test/server_context_test.cpp b/test/server_context_test.cpp
index 1c0b8bde..9ac8ccf6 100644
--- a/test/server_context_test.cpp
+++ b/test/server_context_test.cpp
@@ -485,6 +485,22 @@ BOOST_FIXTURE_TEST_CASE(
     BOOST_REQUIRE(ss.state() == wsrep::server_state::s_disconnected);
 }
 
+BOOST_FIXTURE_TEST_CASE(
+    server_state_sst_first_init_on_apply,
+    sst_first_server_fixture)
+{
+    connect_in_view(second_view);
+    BOOST_REQUIRE(ss.state() == wsrep::server_state::s_connected);
+    sst_received_action();
+    char buf[1] = { 1 };
+    BOOST_REQUIRE(ss.on_apply(hps, ws_handle, ws_meta,
+                              wsrep::const_buffer(buf, 1)) == 0);
+    const wsrep::transaction& txc(cc.transaction());
+    BOOST_REQUIRE(txc.state() == wsrep::transaction::s_committed);
+    BOOST_REQUIRE(ss.state() == wsrep::server_state::s_joined);
+
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 //                     Test cases for init first                             //
 ///////////////////////////////////////////////////////////////////////////////