fix about wp for project-tsurugi/tsurugi-issues#326

src/concurrency_control/interface/long_tx/helper.cpp

@@ -66,6 +66,44 @@ void preprocess_read_area(transaction_options::read_area& ra) {
     }
 }
 
+void update_wp_at_commit(session* const ti, std::set<Storage> const& sts) {
+    /**
+     * write preserve はTX開始時点に宣言したものよりも実体の方が同じか小さくなる。
+     * 小さくできるなら小さくすることで、他Txへの影響を軽減する。
+     * */
+    for (auto itr = ti->get_wp_set().begin(); itr != ti->get_wp_set().end();) {
+        bool hit_actual{false};
+        for (auto actual_write_storage : sts) {
+            if (actual_write_storage == itr->first) {
+                // exactly, write this storage
+                hit_actual = true;
+                break;
+            }
+        }
+        if (hit_actual) {
+            ++itr;
+            continue;
+        } // else
+          /**
+         * wp したが、実際には書かなかったストレージである。コミット処理前にこれを
+         * 取り除く
+        */
+        {
+            itr->second->get_wp_lock().lock();
+            auto ret =
+                    itr->second->remove_wp_without_lock(ti->get_long_tx_id());
+            if (ret == Status::OK) {
+                // 縮退成功
+                itr = ti->get_wp_set().erase(itr);
+                continue;
+            }
+            LOG(ERROR) << log_location_prefix << "unexpected code path";
+            itr->second->get_wp_lock().unlock();
+        }
+        ++itr;
+    }
+}
+
 Status tx_begin(session* const ti, std::vector<Storage> write_preserve,
                 transaction_options::read_area ra) { // NOLINT
     // get wp mutex, exclude long tx's coming and epoch update

src/concurrency_control/interface/long_tx/include/long_tx.h

@@ -29,6 +29,8 @@ extern Status search_key(session* ti, Storage storage, std::string_view key,
 extern Status tx_begin(session* ti, std::vector<Storage> write_preserve,
                        transaction_options::read_area ra);
 
+extern void update_wp_at_commit(session* ti, std::set<Storage> const& sts);
+
 /**
  * @brief version function for long tx.
  * @param[in] rec pointer to record.

src/concurrency_control/interface/long_tx/termination.cpp

@@ -327,23 +327,6 @@ static inline void register_wp_result_and_remove_wps(
         std::map<Storage, std::tuple<std::string, std::string>>& write_range) {
     for (auto&& elem : ti->get_wp_set()) {
         Storage storage = elem.first;
-        Storage page_set_meta_storage = wp::get_page_set_meta_storage();
-        std::string_view page_set_meta_storage_view = {
-                reinterpret_cast<char*>( // NOLINT
-                        &page_set_meta_storage),
-                sizeof(page_set_meta_storage)};
-        std::string_view storage_view = {
-                reinterpret_cast<char*>(&storage), // NOLINT
-                sizeof(storage)};
-        std::pair<wp::page_set_meta**, std::size_t> out{};
-        auto rc{yakushima::get<wp::page_set_meta*>(page_set_meta_storage_view,
-                                                   storage_view, out)};
-        if (rc != yakushima::status::OK) {
-            LOG(ERROR) << log_location_prefix << "Error: " << rc
-                       << ". It strongly suspect that DML and DDL are "
-                          "mixed.";
-            return;
-        }
 
         // check write range
         auto wr_itr = write_range.find(storage);
@@ -357,14 +340,11 @@ static inline void register_wp_result_and_remove_wps(
 
         // register wp result and remove wp
         if (Status::OK !=
-            (reinterpret_cast<wp::page_set_meta*>(out.first)) // NOLINT
-                    ->get_wp_meta_ptr()
-                    ->register_wp_result_and_remove_wp(std::make_tuple(
-                            ti->get_valid_epoch(), ti->get_long_tx_id(),
-                            was_committed,
-                            std::make_tuple(write_something,
-                                            std::string(write_range_left),
-                                            std::string(write_range_right))))) {
+            (elem.second->register_wp_result_and_remove_wp(std::make_tuple(
+                    ti->get_valid_epoch(), ti->get_long_tx_id(), was_committed,
+                    std::make_tuple(write_something,
+                                    std::string(write_range_left),
+                                    std::string(write_range_right)))))) {
             LOG(ERROR) << "Fail to register wp result and remove wp.";
         }
     }
@@ -518,6 +498,10 @@ Status verify(session* const ti) {
                     ++wp_result_itr;
                 }
             }
+            /**
+             * wp result set から見つからないということは、相手は wp 宣言をしたが
+             * 実際には書かなくて wp が縮退されたということ。そのままスルーしてよい。
+            */
         }
     }
 

src/concurrency_control/ongoing_tx.cpp

@@ -1,6 +1,7 @@
 
 #include "concurrency_control/include/ongoing_tx.h"
 #include "concurrency_control/include/wp.h"
+#include "concurrency_control/interface/long_tx/include/long_tx.h"
 
 namespace shirakami {
 
@@ -33,6 +34,10 @@ bool ongoing_tx::exist_wait_for(session* ti) {
     std::set<Storage> st_set{};
     // create and compaction about storage set
     ti->get_write_set().get_storage_set(st_set);
+    if (!ti->get_requested_commit()) {
+        // first request, so update wp
+        long_tx::update_wp_at_commit(ti, st_set);
+    }
 
     // check wait
     for (auto&& elem : tx_info_) {

src/concurrency_control/wp_meta.cpp

@@ -143,7 +143,10 @@ wp_meta::register_wp_result_and_remove_wp(wp_result_elem_type const& elem) {
         wp_result_set_.emplace_back(elem);
     }
     wp_lock_.lock();
-    return remove_wp_without_lock(wp_result_elem_extract_id(elem));
+    auto ret = remove_wp_without_lock(wp_result_elem_extract_id(elem));
+    if (ret == Status::OK) { return ret; }
+    wp_lock_.unlock();
+    return ret;
 }
 
 [[nodiscard]] Status wp_meta::remove_wp_without_lock(std::size_t const id) {
@@ -155,6 +158,7 @@ wp_meta::register_wp_result_and_remove_wp(wp_result_elem_type const& elem) {
             return Status::OK;
         }
     }
+    LOG(ERROR) << log_location_prefix << "unexpected code path";
     return Status::WARN_NOT_FOUND;
 }