SERVER-113843 Ignore an expected data race. (#43932)

GitOrigin-RevId: d3627e49777057871059ddf311194f3c289070d1

src/mongo/db/local_catalog/lock_manager/locker.cpp

@@ -40,6 +40,7 @@
 #include "mongo/stdx/unordered_map.h"
 #include "mongo/stdx/unordered_set.h"
 #include "mongo/util/background.h"
+#include "mongo/util/concurrency/tsan_ignore.h"
 #include "mongo/util/fail_point.h"
 #include "mongo/util/testing_proctor.h"
 
@@ -48,15 +49,6 @@
 namespace mongo {
 namespace {
 
-// Ignore data races in certain functions when running with TSAN. For performance reasons,
-// diagnostic commands are expected to race with concurrent lock acquisitions while gathering
-// statistics.
-#if __has_feature(thread_sanitizer)
-#define MONGO_TSAN_IGNORE __attribute__((no_sanitize("thread")))
-#else
-#define MONGO_TSAN_IGNORE
-#endif
-
 MONGO_FAIL_POINT_DEFINE(enableTestOnlyFlagforRSTL);
 MONGO_FAIL_POINT_DEFINE(failNonIntentLocksIfWaitNeeded);
 
@@ -303,6 +295,8 @@ void Locker::getFlowControlTicket(OperationContext* opCtx, LockMode lockMode) {
     }
 }
 
+// For performance reasons, diagnostic commands are expected to race with concurrent lock
+// acquisitions while gathering statistics.
 MONGO_TSAN_IGNORE
 FlowControlTicketholder::CurOp Locker::getFlowControlStats() const {
     return _flowControlStats;
@@ -528,6 +522,8 @@ ResourceId Locker::getWaitingResource() const {
     return _waitingResource;
 }
 
+// For performance reasons, diagnostic commands are expected to race with concurrent lock
+// acquisitions while gathering statistics.
 MONGO_TSAN_IGNORE
 void Locker::getLockerInfo(
     LockerInfo* lockerInfo,
@@ -862,6 +858,8 @@ void Locker::dump() const {
     LOGV2(20523, "Locker status", "id"_attr = _id, "requests"_attr = entries);
 }
 
+// For performance reasons, diagnostic commands are expected to race with concurrent lock
+// acquisitions while gathering statistics.
 MONGO_TSAN_IGNORE
 LockResult Locker::_lockBegin(OperationContext* opCtx, ResourceId resId, LockMode mode) {
     dassert(!getWaitingResource().isValid());

src/mongo/db/repl/data_with_lock_free_reads.h

@@ -31,6 +31,7 @@
 
 #include "mongo/platform/compiler.h"
 #include "mongo/stdx/new.h"
+#include "mongo/util/concurrency/tsan_ignore.h"
 #include "mongo/util/concurrency/with_lock.h"
 
 namespace mongo {
@@ -54,8 +55,13 @@ class DataWithLockFreeReads {
 public:
     using datum_type = DatumT;
 
+    // Ignore data races in certain functions when running with TSAN. In
+    // particular, ignore concurrent access to _buffers[x] because it is
+    // protected by WithLock on write and by the generation counter on read.
+
     // store() requires the caller to hold the lock that protects the
     // uncached value to avoid races.
+    MONGO_TSAN_IGNORE
     void store(WithLock lk, const datum_type& datum) {
         auto curGen = _generation.load();
         auto nextGen = curGen + 1;
@@ -63,6 +69,7 @@ public:
         invariant(_generation.compareAndSwap(&curGen, nextGen));
     }
 
+    MONGO_TSAN_IGNORE
     datum_type load() const {
         while (true) {
             // Get the counter, use it to index buffers and perform a read, and

src/mongo/util/concurrency/BUILD.bazel

@@ -15,6 +15,7 @@ filegroup(
         "lock_free_read_list.h",
         "spin_lock.h",
         "ticketholder.h",
+        "tsan_ignore.h",
     ],
 )
 

src/mongo/util/concurrency/tsan_ignore.h

@@ -0,0 +1,39 @@
+/**
+ *    Copyright (C) 2025-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 "mongo/platform/compiler.h"
+
+// Ignore data races in certain functions when running with TSAN.
+#if __has_feature(thread_sanitizer)
+#define MONGO_TSAN_IGNORE __attribute__((no_sanitize("thread")))
+#else
+#define MONGO_TSAN_IGNORE
+#endif