SERVER-94846 Move WiredTigerEventHandler out of wiredtiger_util files (#27126)

GitOrigin-RevId: 3caf18a9e418919dcc4e844ad9e68d57b33b1b43

5 files changed, 195 insertions, 118 deletions

diff --git a/src/mongo/db/storage/wiredtiger/SConscript b/src/mongo/db/storage/wiredtiger/SConscript
index 743491f1897..05571287841 100644
--- a/src/mongo/db/storage/wiredtiger/SConscript
+++ b/src/mongo/db/storage/wiredtiger/SConscript
@@ -23,6 +23,7 @@ wtEnv.Library(
         "wiredtiger_compiled_configuration.cpp",
         "wiredtiger_cursor.cpp",
         "wiredtiger_cursor_helpers.cpp",
+        "wiredtiger_event_handler.cpp",
         "wiredtiger_global_options.cpp",
         "wiredtiger_index.cpp",
         "wiredtiger_index_util.cpp",
diff --git a/src/mongo/db/storage/wiredtiger/wiredtiger_event_handler.cpp b/src/mongo/db/storage/wiredtiger/wiredtiger_event_handler.cpp
new file mode 100644
index 00000000000..0f236d67383
--- /dev/null
+++ b/src/mongo/db/storage/wiredtiger/wiredtiger_event_handler.cpp
@@ -0,0 +1,66 @@
+/**
+ *    Copyright (C) 2024-present MongoDB, Inc.
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the Server Side Public License, version 1,
+ *    as published by MongoDB, Inc.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    Server Side Public License for more details.
+ *
+ *    You should have received a copy of the Server Side Public License
+ *    along with this program. If not, see
+ *    <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the Server Side Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
+
+#include "mongo/db/storage/wiredtiger/wiredtiger_event_handler.h"
+#include "mongo/logv2/log.h"
+
+namespace mongo {
+
+#define MONGO_LOGV2_DEFAULT_COMPONENT ::mongo::logv2::LogComponent::kWiredTiger
+
+void WiredTigerEventHandler::setWtConnReady(WT_CONNECTION* conn) {
+    stdx::unique_lock<mongo::Mutex> lock(_mutex);
+    _wtConn = conn;
+    if (_activeReaders == 0 || conn) {
+        return;
+    }
+    LOGV2(7003100,
+          "WiredTiger connection close is waiting for active statistics readers to finish",
+          "activeReaders"_attr = _activeReaders);
+    _idleCondition.wait(lock, [this]() { return _activeReaders == 0; });
+}
+
+WT_CONNECTION* WiredTigerEventHandler::getStatsCollectionPermit() {
+    stdx::lock_guard<mongo::Mutex> lock(_mutex);
+    if (_wtConn) {
+        _activeReaders++;
+        return _wtConn;
+    }
+    return nullptr;
+}
+
+void WiredTigerEventHandler::releaseStatsCollectionPermit() {
+    stdx::unique_lock<mongo::Mutex> lock(_mutex);
+    _activeReaders--;
+    if (_activeReaders == 0 && !_wtConn) {
+        _idleCondition.notify_all();
+        return;
+    }
+}
+}  // namespace mongo
diff --git a/src/mongo/db/storage/wiredtiger/wiredtiger_event_handler.h b/src/mongo/db/storage/wiredtiger/wiredtiger_event_handler.h
new file mode 100644
index 00000000000..891f0cbe480
--- /dev/null
+++ b/src/mongo/db/storage/wiredtiger/wiredtiger_event_handler.h
@@ -0,0 +1,127 @@
+/**
+ *    Copyright (C) 2024-present MongoDB, Inc.
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the Server Side Public License, version 1,
+ *    as published by MongoDB, Inc.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    Server Side Public License for more details.
+ *
+ *    You should have received a copy of the Server Side Public License
+ *    along with this program. If not, see
+ *    <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the Server Side Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
+
+#pragma once
+
+#include <boost/optional/optional.hpp>
+#include <cstdint>
+#include <wiredtiger.h>
+
+#include "mongo/platform/mutex.h"
+#include "mongo/stdx/condition_variable.h"
+
+namespace mongo {
+/**
+ * Returns a WT_EVENT_HANDLER with MongoDB's default handlers.
+ * The default handlers just log so it is recommended that you consider calling them even if
+ * you are capturing the output.
+ *
+ * There is no default "close" handler. You only need to provide one if you need to call a
+ * destructor.
+ */
+class WiredTigerEventHandler : private WT_EVENT_HANDLER {
+public:
+    WiredTigerEventHandler();
+
+    WT_EVENT_HANDLER* getWtEventHandler();
+
+    bool wasStartupSuccessful() {
+        return _startupSuccessful;
+    }
+
+    void setStartupSuccessful() {
+        _startupSuccessful = true;
+    }
+
+    bool isWtIncompatible() {
+        return _wtIncompatible;
+    }
+
+    void setWtIncompatible() {
+        _wtIncompatible = true;
+    }
+
+    /**
+     * Updates the current WT connection usable for safe statistics collection, or nullptr if
+     * statistics collection is no longer safe.
+     *
+     * If the WT_CONNECTION is non-null or there are no active statistics readers, the following
+     * function returns immediately. Otherwise, if there are active statistics readers and a
+     * WT_CONN_CLOSE event is setting this connection to be unavailable for statistics collection,
+     * this function waits until all active readers release their collection permits.
+     */
+    void setWtConnReady(WT_CONNECTION* conn);
+    void setWtConnNotReady() {
+        setWtConnReady(nullptr);
+    }
+
+    /**
+     * This function obtains one permit to safely use WiredTiger statistics cursors. When this
+     * function returns a non-null connection pointer, the caller may safely collect metrics using
+     * this connection, but storage engine shutdown is blocked. The caller *must* make a subsequent
+     * call to `releaseStatsCollectionPermit` to allow the storage engine to shut down.
+     *
+     * If this function returns nullptr, statistics collection is not available due to startup or
+     * shutdown.
+     */
+    WT_CONNECTION* getStatsCollectionPermit();
+
+    /**
+     * The following call releases one statistics collection permit. When there are no outstanding
+     * permits, the WT connection is allowed to shut down cleanly.
+     */
+    void releaseStatsCollectionPermit();
+
+    /**
+     * Returns the number of outstanding, active statistics collection permits.
+     */
+    int32_t getActiveStatsReaders() const {
+        stdx::lock_guard<mongo::Mutex> lock(_mutex);
+        return _activeReaders;
+    }
+
+    /**
+     * Returns true if the WT connection is ready for statistics cursors to be used. This is unsafe
+     * because the connection can become invalid immediately after returning. To ensure the
+     * connection stays valid, a permit must be obtained with getStatsCollectionPermit().
+     */
+    bool isWtConnReadyForStatsCollection() const {
+        stdx::lock_guard<mongo::Mutex> lock(_mutex);
+        return _wtConn != nullptr;
+    }
+
+private:
+    bool _startupSuccessful = false;
+    bool _wtIncompatible = false;
+    mutable mongo::Mutex _mutex = MONGO_MAKE_LATCH("mongo::WiredTigerEventHandler::_mutex");
+    WT_CONNECTION* _wtConn = nullptr;
+    stdx::condition_variable _idleCondition;
+    int32_t _activeReaders{0};
+};
+}  // namespace mongo
diff --git a/src/mongo/db/storage/wiredtiger/wiredtiger_util.cpp b/src/mongo/db/storage/wiredtiger/wiredtiger_util.cpp
index 9c163400f22..5c8aa8db1a2 100644
--- a/src/mongo/db/storage/wiredtiger/wiredtiger_util.cpp
+++ b/src/mongo/db/storage/wiredtiger/wiredtiger_util.cpp
@@ -93,36 +93,6 @@
     "transaction is too large and will not fit in the storage engine cache"
 namespace mongo {
 
-void WiredTigerEventHandler::setWtConnReady(WT_CONNECTION* conn) {
-    stdx::unique_lock<mongo::Mutex> lock(_mutex);
-    _wtConn = conn;
-    if (_activeReaders == 0 || conn) {
-        return;
-    }
-    LOGV2(7003100,
-          "WiredTiger connection close is waiting for active statistics readers to finish",
-          "activeReaders"_attr = _activeReaders);
-    _idleCondition.wait(lock, [this]() { return _activeReaders == 0; });
-}
-
-WT_CONNECTION* WiredTigerEventHandler::getStatsCollectionPermit() {
-    stdx::lock_guard<mongo::Mutex> lock(_mutex);
-    if (_wtConn) {
-        _activeReaders++;
-        return _wtConn;
-    }
-    return nullptr;
-}
-
-void WiredTigerEventHandler::releaseStatsCollectionPermit() {
-    stdx::unique_lock<mongo::Mutex> lock(_mutex);
-    _activeReaders--;
-    if (_activeReaders == 0 && !_wtConn) {
-        _idleCondition.notify_all();
-        return;
-    }
-}
-
 namespace {
 
 // TODO SERVER-81069: Remove this.
diff --git a/src/mongo/db/storage/wiredtiger/wiredtiger_util.h b/src/mongo/db/storage/wiredtiger/wiredtiger_util.h
index 14f5f6c6da9..b937ca0b309 100644
--- a/src/mongo/db/storage/wiredtiger/wiredtiger_util.h
+++ b/src/mongo/db/storage/wiredtiger/wiredtiger_util.h
@@ -48,6 +48,7 @@
 #include "mongo/db/catalog/validate_results.h"
 #include "mongo/db/namespace_string.h"
 #include "mongo/db/storage/durable_catalog.h"
+#include "mongo/db/storage/wiredtiger/wiredtiger_event_handler.h"
 #include "mongo/db/storage/wiredtiger/wiredtiger_recovery_unit.h"
 #include "mongo/platform/compiler.h"
 #include "mongo/platform/mutex.h"
@@ -137,94 +138,6 @@ struct WiredTigerItem : public WT_ITEM {
     }
 };
 
-/**
- * Returns a WT_EVENT_HANDLER with MongoDB's default handlers.
- * The default handlers just log so it is recommended that you consider calling them even if
- * you are capturing the output.
- *
- * There is no default "close" handler. You only need to provide one if you need to call a
- * destructor.
- */
-class WiredTigerEventHandler : private WT_EVENT_HANDLER {
-public:
-    WiredTigerEventHandler();
-
-    WT_EVENT_HANDLER* getWtEventHandler();
-
-    bool wasStartupSuccessful() {
-        return _startupSuccessful;
-    }
-
-    void setStartupSuccessful() {
-        _startupSuccessful = true;
-    }
-
-    bool isWtIncompatible() {
-        return _wtIncompatible;
-    }
-
-    void setWtIncompatible() {
-        _wtIncompatible = true;
-    }
-
-    /**
-     * Updates the current WT connection usable for safe statistics collection, or nullptr if
-     * statistics collection is no longer safe.
-     *
-     * If the WT_CONNECTION is non-null or there are no active statistics readers, the following
-     * function returns immediately. Otherwise, if there are active statistics readers and a
-     * WT_CONN_CLOSE event is setting this connection to be unavailable for statistics collection,
-     * this function waits until all active readers release their collection permits.
-     */
-    void setWtConnReady(WT_CONNECTION* conn);
-    void setWtConnNotReady() {
-        setWtConnReady(nullptr);
-    }
-
-    /**
-     * This function obtains one permit to safely use WiredTiger statistics cursors. When this
-     * function returns a non-null connection pointer, the caller may safely collect metrics using
-     * this connection, but storage engine shutdown is blocked. The caller *must* make a subsequent
-     * call to `releaseStatsCollectionPermit` to allow the storage engine to shut down.
-     *
-     * If this function returns nullptr, statistics collection is not available due to startup or
-     * shutdown.
-     */
-    WT_CONNECTION* getStatsCollectionPermit();
-
-    /**
-     * The following call releases one statistics collection permit. When there are no outstanding
-     * permits, the WT connection is allowed to shut down cleanly.
-     */
-    void releaseStatsCollectionPermit();
-
-    /**
-     * Returns the number of outstanding, active statistics collection permits.
-     */
-    int32_t getActiveStatsReaders() const {
-        stdx::lock_guard<mongo::Mutex> lock(_mutex);
-        return _activeReaders;
-    }
-
-    /**
-     * Returns true if the WT connection is ready for statistics cursors to be used. This is unsafe
-     * because the connection can become invalid immediately after returning. To ensure the
-     * connection stays valid, a permit must be obtained with getStatsCollectionPermit().
-     */
-    bool isWtConnReadyForStatsCollection() const {
-        stdx::lock_guard<mongo::Mutex> lock(_mutex);
-        return _wtConn != nullptr;
-    }
-
-private:
-    bool _startupSuccessful = false;
-    bool _wtIncompatible = false;
-    mutable mongo::Mutex _mutex = MONGO_MAKE_LATCH("mongo::WiredTigerEventHandler::_mutex");
-    WT_CONNECTION* _wtConn = nullptr;
-    stdx::condition_variable _idleCondition;
-    int32_t _activeReaders{0};
-};
-
 class WiredTigerUtil {
     WiredTigerUtil(const WiredTigerUtil&) = delete;
     WiredTigerUtil& operator=(const WiredTigerUtil&) = delete;