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authorBen Caimano <ben.caimano@mongodb.com>2019-12-16 21:39:41 +0000
committerevergreen <evergreen@mongodb.com>2019-12-16 21:39:41 +0000
commit86efdd6b047927d3a37577a6033bacc709c7ae89 (patch)
tree0fc01e4928e001914731159ce8c2dec7116929d0 /src
parentec498c5968974012d50d6d04c26cd2cd0db87d22 (diff)
downloadmongo-86efdd6b047927d3a37577a6033bacc709c7ae89.tar.gz
SERVER-43945 Expose out of order latch acquisitions in serverStatus
This review does several related things: - Modifies the Mutex type to have one Identity object per invocation context - Adds a latchAnalysis field to serverStatus - Officially turns on CI-only failure for acq level violations - Changes a few acq level declarations to be more permissive
Diffstat (limited to 'src')
-rw-r--r--src/mongo/SConscript2
-rw-r--r--src/mongo/client/replica_set_monitor_manager.h2
-rw-r--r--src/mongo/db/db.cpp3
-rw-r--r--src/mongo/db/session_killer.h2
-rw-r--r--src/mongo/embedded/SConscript1
-rw-r--r--src/mongo/executor/thread_pool_task_executor.h5
-rw-r--r--src/mongo/platform/mutex.cpp65
-rw-r--r--src/mongo/platform/mutex.h249
-rw-r--r--src/mongo/platform/mutex_test.cpp2
-rw-r--r--src/mongo/platform/source_location.h13
-rw-r--r--src/mongo/s/server.cpp3
-rw-r--r--src/mongo/util/SConscript4
-rw-r--r--src/mongo/util/background.cpp4
-rw-r--r--src/mongo/util/diagnostic_info.cpp12
-rw-r--r--src/mongo/util/latch_analyzer.cpp352
-rw-r--r--src/mongo/util/latch_analyzer.h69
-rw-r--r--src/mongo/util/latch_analyzer_test.cpp51
17 files changed, 653 insertions, 186 deletions
diff --git a/src/mongo/SConscript b/src/mongo/SConscript
index c114999ae51..fd7123f49e4 100644
--- a/src/mongo/SConscript
+++ b/src/mongo/SConscript
@@ -463,6 +463,7 @@ mongod = env.Program(
'util/clock_sources',
'util/elapsed_tracker',
'util/fail_point',
+ 'util/latch_analyzer',
'util/net/network',
'util/ntservice',
'util/options_parser/options_parser_init',
@@ -571,6 +572,7 @@ mongos = env.Program(
'transport/transport_layer_manager',
'util/clock_sources',
'util/fail_point',
+ 'util/latch_analyzer',
'util/net/ssl_options_server' if get_option('ssl') == 'on' else '',
'util/ntservice',
'util/version_impl',
diff --git a/src/mongo/client/replica_set_monitor_manager.h b/src/mongo/client/replica_set_monitor_manager.h
index c464551145f..49c3e2e7f12 100644
--- a/src/mongo/client/replica_set_monitor_manager.h
+++ b/src/mongo/client/replica_set_monitor_manager.h
@@ -106,7 +106,7 @@ private:
// Protects access to the replica set monitors
mutable Mutex _mutex =
- MONGO_MAKE_LATCH(HierarchicalAcquisitionLevel(0), "ReplicaSetMonitorManager::_mutex");
+ MONGO_MAKE_LATCH(HierarchicalAcquisitionLevel(4), "ReplicaSetMonitorManager::_mutex");
// Executor for monitoring replica sets.
std::unique_ptr<executor::TaskExecutor> _taskExecutor;
diff --git a/src/mongo/db/db.cpp b/src/mongo/db/db.cpp
index fb02bce6ed4..75e3321a280 100644
--- a/src/mongo/db/db.cpp
+++ b/src/mongo/db/db.cpp
@@ -167,6 +167,7 @@
#include "mongo/util/exit.h"
#include "mongo/util/fail_point.h"
#include "mongo/util/fast_clock_source_factory.h"
+#include "mongo/util/latch_analyzer.h"
#include "mongo/util/log.h"
#include "mongo/util/net/socket_utils.h"
#include "mongo/util/net/ssl_manager.h"
@@ -1050,6 +1051,8 @@ void shutdownTask(const ShutdownTaskArgs& shutdownArgs) {
log(LogComponent::kControl) << "now exiting";
audit::logShutdown(client);
+
+ LatchAnalyzer::get(serviceContext).dump();
}
int mongoDbMain(int argc, char* argv[], char** envp) {
diff --git a/src/mongo/db/session_killer.h b/src/mongo/db/session_killer.h
index 8b5c14bd2ba..45ca8b27a86 100644
--- a/src/mongo/db/session_killer.h
+++ b/src/mongo/db/session_killer.h
@@ -132,7 +132,7 @@ private:
stdx::thread _thread;
- Mutex _mutex = MONGO_MAKE_LATCH(HierarchicalAcquisitionLevel(0), "SessionKiller::_mutex");
+ Mutex _mutex = MONGO_MAKE_LATCH(HierarchicalAcquisitionLevel(2), "SessionKiller::_mutex");
stdx::condition_variable _callerCV;
stdx::condition_variable _killerCV;
diff --git a/src/mongo/embedded/SConscript b/src/mongo/embedded/SConscript
index c5a9ed4da18..dad3c6865f9 100644
--- a/src/mongo/embedded/SConscript
+++ b/src/mongo/embedded/SConscript
@@ -122,6 +122,7 @@ env.Library(
'$BUILD_DIR/mongo/db/storage/storage_options',
'$BUILD_DIR/mongo/db/wire_version',
'$BUILD_DIR/mongo/rpc/client_metadata',
+ '$BUILD_DIR/mongo/util/latch_analyzer',
'$BUILD_DIR/mongo/util/options_parser/options_parser',
'$BUILD_DIR/mongo/util/version_impl',
]
diff --git a/src/mongo/executor/thread_pool_task_executor.h b/src/mongo/executor/thread_pool_task_executor.h
index 1ac9c385a98..1bcfe806a39 100644
--- a/src/mongo/executor/thread_pool_task_executor.h
+++ b/src/mongo/executor/thread_pool_task_executor.h
@@ -189,8 +189,9 @@ private:
std::shared_ptr<ThreadPoolInterface> _pool;
// Mutex guarding all remaining fields.
- mutable Mutex _mutex =
- MONGO_MAKE_LATCH(HierarchicalAcquisitionLevel(1), "ThreadPoolTaskExecutor::_mutex");
+ mutable Mutex _mutex = MONGO_MAKE_LATCH(
+ // This is sadly held for a subset of task execution HierarchicalAcquisitionLevel(1),
+ "ThreadPoolTaskExecutor::_mutex");
// Queue containing all items currently scheduled into the thread pool but not yet completed.
WorkQueue _poolInProgressQueue;
diff --git a/src/mongo/platform/mutex.cpp b/src/mongo/platform/mutex.cpp
index f284697be07..131103f561d 100644
--- a/src/mongo/platform/mutex.cpp
+++ b/src/mongo/platform/mutex.cpp
@@ -31,24 +31,33 @@
namespace mongo {
+Mutex::Mutex(std::shared_ptr<latch_detail::Data> data) : _data{std::move(data)} {
+ invariant(_data);
+
+ _data->counts().created.fetchAndAdd(1);
+}
+
Mutex::~Mutex() {
invariant(!_isLocked);
+
+ _data->counts().destroyed.fetchAndAdd(1);
}
void Mutex::lock() {
if (_mutex.try_lock()) {
_isLocked = true;
- _onQuickLock(_id);
+ _onQuickLock();
return;
}
- _onContendedLock(_id);
+ _onContendedLock();
_mutex.lock();
_isLocked = true;
- _onSlowLock(_id);
+ _onSlowLock();
}
+
void Mutex::unlock() {
- _onUnlock(_id);
+ _onUnlock();
_isLocked = false;
_mutex.unlock();
}
@@ -58,41 +67,53 @@ bool Mutex::try_lock() {
}
_isLocked = true;
- _onQuickLock(_id);
+ _onQuickLock();
return true;
}
+StringData Mutex::getName() const {
+ return StringData(_data->identity().name());
+}
+
void Mutex::addLockListener(LockListener* listener) {
auto& state = _getListenerState();
- state.list.push_back(listener);
+ state.list.add(listener);
}
-void Mutex::_onContendedLock(const Identity& id) noexcept {
- auto& state = _getListenerState();
- for (auto listener : state.list) {
- listener->onContendedLock(id);
+void Mutex::_onContendedLock() noexcept {
+ _data->counts().contended.fetchAndAdd(1);
+
+ auto it = _getListenerState().list.iter();
+ while (auto listener = it.next()) {
+ listener->onContendedLock(_data->identity());
}
}
-void Mutex::_onQuickLock(const Identity& id) noexcept {
- auto& state = _getListenerState();
- for (auto listener : state.list) {
- listener->onQuickLock(id);
+void Mutex::_onQuickLock() noexcept {
+ _data->counts().acquired.fetchAndAdd(1);
+
+ auto it = _getListenerState().list.iter();
+ while (auto listener = it.next()) {
+ listener->onQuickLock(_data->identity());
}
}
-void Mutex::_onSlowLock(const Identity& id) noexcept {
- auto& state = _getListenerState();
- for (auto listener : state.list) {
- listener->onSlowLock(id);
+void Mutex::_onSlowLock() noexcept {
+ _data->counts().acquired.fetchAndAdd(1);
+
+ auto it = _getListenerState().list.iter();
+ while (auto listener = it.next()) {
+ listener->onSlowLock(_data->identity());
}
}
-void Mutex::_onUnlock(const Identity& id) noexcept {
- auto& state = _getListenerState();
- for (auto listener : state.list) {
- listener->onUnlock(id);
+void Mutex::_onUnlock() noexcept {
+ _data->counts().released.fetchAndAdd(1);
+
+ auto it = _getListenerState().list.iter();
+ while (auto listener = it.next()) {
+ listener->onUnlock(_data->identity());
}
}
diff --git a/src/mongo/platform/mutex.h b/src/mongo/platform/mutex.h
index 10705d5386c..7776f94adea 100644
--- a/src/mongo/platform/mutex.h
+++ b/src/mongo/platform/mutex.h
@@ -37,11 +37,183 @@
#include "mongo/platform/source_location.h"
#include "mongo/stdx/mutex.h"
#include "mongo/util/assert_util.h"
+#include "mongo/util/decorable.h"
#include "mongo/util/duration.h"
#include "mongo/util/hierarchical_acquisition.h"
+#include "mongo/util/registry_list.h"
namespace mongo {
+class Mutex;
+
+namespace latch_detail {
+
+using Level = hierarchical_acquisition_detail::Level;
+
+static constexpr auto kAnonymousName = "AnonymousLatch"_sd;
+
+/**
+ * An Identity encapsulates the context around a latch
+ */
+class Identity {
+public:
+ Identity() : Identity(boost::none, kAnonymousName) {}
+
+ explicit Identity(StringData name) : Identity(boost::none, name) {}
+
+ Identity(boost::optional<Level> level, StringData name)
+ : _index(_nextIndex()), _level(level), _name(name.toString()) {}
+
+ /**
+ * Since SouceLocations usually come from macros, this function is a setter that allows
+ * a SourceLocation to be paired with __VA_ARGS__ construction.
+ */
+ Identity& setSourceLocation(const SourceLocationHolder& sourceLocation) {
+ invariant(!_sourceLocation);
+ _sourceLocation = sourceLocation;
+ return *this;
+ }
+
+ /**
+ * Return an optional that may contain the SourceLocation for this latch
+ */
+ const boost::optional<SourceLocationHolder>& sourceLocation() const {
+ return _sourceLocation;
+ }
+
+ /**
+ * Return an optional that may contain the HierarchicalAcquisitionLevel for this latch
+ */
+ const boost::optional<Level>& level() const {
+ return _level;
+ }
+
+ /**
+ * Return the name for this latch
+ *
+ * If there was no name provided on construction, this will be latch_detail::kAnonymousName.
+ */
+ StringData name() const {
+ return _name;
+ }
+
+ /**
+ * Return the index for this latch
+ *
+ * Latch indexes are assigned as Identity objects are created. Any given ordering is only valid
+ * for a single process lifetime.
+ */
+ size_t index() const {
+ return _index;
+ }
+
+private:
+ static int64_t _nextIndex() {
+ static auto nextLatchIndex = AtomicWord<int64_t>(0);
+ return nextLatchIndex.fetchAndAdd(1);
+ }
+
+ int64_t _index;
+ boost::optional<Level> _level;
+ std::string _name;
+
+ boost::optional<SourceLocationHolder> _sourceLocation;
+};
+
+/**
+ * This class holds working data for a latchable resource
+ *
+ * All member data is either i) synchronized or ii) constant.
+ */
+class Data {
+public:
+ explicit Data(Identity identity) : _identity(std::move(identity)) {}
+
+ auto& counts() {
+ return _counts;
+ }
+
+ const auto& counts() const {
+ return _counts;
+ }
+
+ const auto& identity() const {
+ return _identity;
+ }
+
+private:
+ const Identity _identity;
+
+ struct Counts {
+ AtomicWord<int> created{0};
+ AtomicWord<int> destroyed{0};
+
+ AtomicWord<int> contended{0};
+ AtomicWord<int> acquired{0};
+ AtomicWord<int> released{0};
+ };
+
+ Counts _counts;
+};
+
+/**
+ * latch_details::Catalog holds a collection of Data objects for use with Mutexes
+ *
+ * All rules for LockFreeCollection apply:
+ * - Synchronization is provided internally
+ * - All entries are expected to exist for the lifetime of the Catalog
+ */
+class Catalog final : public WeakPtrRegistryList<Data> {
+public:
+ static auto& get() {
+ static Catalog gCatalog;
+ return gCatalog;
+ }
+};
+
+/**
+ * Simple registration object that construct with an Identity and provides access to a Data
+ *
+ * This object actually owns the Data object to make lifetime management simpler.
+ */
+class Registration {
+public:
+ explicit Registration(Identity identity)
+ : _data(std::make_shared<Data>(std::move(identity))), _index{Catalog::get().add(_data)} {}
+
+ const auto& data() {
+ return _data;
+ }
+
+private:
+ std::shared_ptr<Data> _data;
+ size_t _index;
+};
+
+/**
+ * Get a Data object (Identity, Counts) for a unique type Tag (which can be a noop lambda)
+ *
+ * When used with a macro (or converted to have a c++20-style <typename Tag = decltype([]{})>), this
+ * function provides a unique Data object per invocation context. This function also sets the
+ * Identity identity to contain sourceLocation. This is explicitly intended to work with
+ * preprocessor macros that generate SourceLocation objects and unique Tags.
+ */
+template <typename Tag>
+auto getOrMakeLatchData(Tag&&, Identity identity, const SourceLocationHolder& sourceLocation) {
+ static auto reg = Registration( //
+ std::move(identity) //
+ .setSourceLocation(sourceLocation));
+ return reg.data();
+}
+
+/**
+ * Provide a very generic Data object for use with default-constructed Mutexes
+ */
+inline auto defaultData() {
+ return getOrMakeLatchData([] {}, Identity(kAnonymousName), MONGO_SOURCE_LOCATION());
+}
+} // namespace latch_detail
+
class Latch {
public:
virtual ~Latch() = default;
@@ -51,54 +223,30 @@ public:
virtual bool try_lock() = 0;
virtual StringData getName() const {
- return "AnonymousLatch"_sd;
+ return latch_detail::kAnonymousName;
}
};
+/**
+ * Mutex is a Lockable type that wraps a stdx::mutex
+ *
+ * This class is intended to be used wherever a stdx::mutex would previously be used. It provides
+ * a generic event-listener interface for instrumenting around lock()/unlock()/try_lock().
+ */
class Mutex : public Latch {
- class LockNotifier;
-
public:
class LockListener;
- static constexpr auto kAnonymousMutexStr = "AnonymousMutex"_sd;
-
void lock() override;
void unlock() override;
bool try_lock() override;
- StringData getName() const override {
- return StringData(_id.name);
- }
-
- struct Identity {
- Identity(StringData name = kAnonymousMutexStr) : Identity(boost::none, boost::none, name) {}
-
- Identity(SourceLocationHolder sourceLocation, StringData name = kAnonymousMutexStr)
- : Identity(boost::none, sourceLocation, name) {}
+ StringData getName() const override;
- Identity(hierarchical_acquisition_detail::Level level, StringData name = kAnonymousMutexStr)
- : Identity(level, boost::none, name) {}
-
- Identity(boost::optional<hierarchical_acquisition_detail::Level> level,
- boost::optional<SourceLocationHolder> sourceLocation,
- StringData name = kAnonymousMutexStr)
- : level(level), sourceLocation(sourceLocation), name(name.toString()) {}
-
- boost::optional<hierarchical_acquisition_detail::Level> level;
- boost::optional<SourceLocationHolder> sourceLocation;
- std::string name;
- };
-
- Mutex() : Mutex(Identity()) {}
-
- Mutex(const Identity& id) : _id(id) {}
+ Mutex() : Mutex(latch_detail::defaultData()) {}
+ explicit Mutex(std::shared_ptr<latch_detail::Data> data);
~Mutex();
- struct LatchSetState {
- hierarchical_acquisition_detail::Set levelsHeld;
- };
-
/**
* This function adds a LockListener subclass to the triggers for certain actions.
*
@@ -111,25 +259,22 @@ public:
private:
static auto& _getListenerState() noexcept {
struct State {
- std::vector<LockListener*> list;
+ RegistryList<LockListener*> list;
};
- // Note that state should no longer be mutated after init-time (ala MONGO_INITIALIZERS). If
- // this changes, than this state needs to be synchronized.
static State state;
return state;
}
- static void _onContendedLock(const Identity& id) noexcept;
- static void _onQuickLock(const Identity& id) noexcept;
- static void _onSlowLock(const Identity& id) noexcept;
- static void _onUnlock(const Identity& id) noexcept;
-
- bool _isLocked = false;
+ void _onContendedLock() noexcept;
+ void _onQuickLock() noexcept;
+ void _onSlowLock() noexcept;
+ void _onUnlock() noexcept;
- const Identity _id;
+ const std::shared_ptr<latch_detail::Data> _data;
stdx::mutex _mutex; // NOLINT
+ bool _isLocked = false;
};
/**
@@ -139,6 +284,8 @@ class Mutex::LockListener {
friend class Mutex;
public:
+ using Identity = latch_detail::Identity;
+
virtual ~LockListener() = default;
/**
@@ -165,9 +312,13 @@ public:
} // namespace mongo
/**
- * Define a mongo::Mutex with all arguments passed through to the ctor
+ * Construct and register a latch_detail::Data object exactly once per call site
*/
-#define MONGO_MAKE_LATCH(...) \
- mongo::Mutex { \
- mongo::Mutex::Identity(__VA_ARGS__) \
- }
+#define MONGO_GET_LATCH_DATA(...) \
+ ::mongo::latch_detail::getOrMakeLatchData( \
+ [] {}, ::mongo::latch_detail::Identity(__VA_ARGS__), MONGO_SOURCE_LOCATION_NO_FUNC())
+
+/**
+ * Construct a mongo::Mutex using the result of MONGO_GET_LATCH_DATA with all arguments forwarded
+ */
+#define MONGO_MAKE_LATCH(...) ::mongo::Mutex(MONGO_GET_LATCH_DATA(__VA_ARGS__));
diff --git a/src/mongo/platform/mutex_test.cpp b/src/mongo/platform/mutex_test.cpp
index 739734c0e46..e85f8290466 100644
--- a/src/mongo/platform/mutex_test.cpp
+++ b/src/mongo/platform/mutex_test.cpp
@@ -63,6 +63,6 @@ TEST(MutexTest, Macros) {
// Verify the global named latch
static_assert(std::is_same_v<decltype(gMutex), Mutex>);
- ASSERT_EQ(gMutex.getName(), Mutex::kAnonymousMutexStr);
+ ASSERT_EQ(gMutex.getName(), latch_detail::kAnonymousName);
}
} // namespace mongo
diff --git a/src/mongo/platform/source_location.h b/src/mongo/platform/source_location.h
index 272029635cd..3d9830ec97b 100644
--- a/src/mongo/platform/source_location.h
+++ b/src/mongo/platform/source_location.h
@@ -129,14 +129,14 @@ private:
// MSVC does not have any of N4810 yet. (see
// https://developercommunity.visualstudio.com/idea/354069/implement-c-library-fundamentals-ts-v2.html)
-#define MONGO_SOURCE_LOCATION() SourceLocation(__LINE__, 0ul, __FILE__, __func__)
-#define MONGO_SOURCE_LOCATION_NO_FUNC() SourceLocation(__LINE__, 0ul, __FILE__, "")
+#define MONGO_SOURCE_LOCATION() ::mongo::SourceLocation(__LINE__, 0ul, __FILE__, __func__)
+#define MONGO_SOURCE_LOCATION_NO_FUNC() ::mongo::SourceLocation(__LINE__, 0ul, __FILE__, "")
#elif defined(__clang__) // windows -> clang
// Clang got __builtin_FILE et al as of 8.0.1 (see https://reviews.llvm.org/D37035)
-#define MONGO_SOURCE_LOCATION() SourceLocation(__LINE__, 0ul, __FILE__, __func__)
-#define MONGO_SOURCE_LOCATION_NO_FUNC() SourceLocation(__LINE__, 0ul, __FILE__, "")
+#define MONGO_SOURCE_LOCATION() ::mongo::SourceLocation(__LINE__, 0ul, __FILE__, __func__)
+#define MONGO_SOURCE_LOCATION_NO_FUNC() ::mongo::SourceLocation(__LINE__, 0ul, __FILE__, "")
#elif defined(__GNUG__) // clang -> gcc
@@ -145,9 +145,10 @@ constexpr auto toSourceLocation(std::experimental::source_location loc) {
return SourceLocation(loc.line(), loc.column(), loc.file_name(), loc.function_name());
}
-#define MONGO_SOURCE_LOCATION() toSourceLocation(std::experimental::source_location::current())
+#define MONGO_SOURCE_LOCATION() \
+ ::mongo::toSourceLocation(std::experimental::source_location::current())
#define MONGO_SOURCE_LOCATION_NO_FUNC() \
- toSourceLocation(std::experimental::source_location::current())
+ ::mongo::toSourceLocation(std::experimental::source_location::current())
#else // gcc -> ?
diff --git a/src/mongo/s/server.cpp b/src/mongo/s/server.cpp
index 1870814d80e..020393769ba 100644
--- a/src/mongo/s/server.cpp
+++ b/src/mongo/s/server.cpp
@@ -102,6 +102,7 @@
#include "mongo/util/exception_filter_win32.h"
#include "mongo/util/exit.h"
#include "mongo/util/fast_clock_source_factory.h"
+#include "mongo/util/latch_analyzer.h"
#include "mongo/util/log.h"
#include "mongo/util/net/socket_exception.h"
#include "mongo/util/net/socket_utils.h"
@@ -343,6 +344,8 @@ void cleanupTask(ServiceContext* serviceContext) {
}
audit::logShutdown(Client::getCurrent());
+
+ LatchAnalyzer::get(serviceContext).dump();
}
Status initializeSharding(OperationContext* opCtx) {
diff --git a/src/mongo/util/SConscript b/src/mongo/util/SConscript
index 06ae54e98cc..02bc09e44ff 100644
--- a/src/mongo/util/SConscript
+++ b/src/mongo/util/SConscript
@@ -291,8 +291,12 @@ env.Library(
],
LIBDEPS=[
'$BUILD_DIR/mongo/base',
+ '$BUILD_DIR/mongo/db/commands/test_commands_enabled',
'$BUILD_DIR/mongo/db/service_context',
],
+ LIBDEPS_PRIVATE=[
+ '$BUILD_DIR/mongo/db/commands/server_status',
+ ],
)
env.Benchmark(
diff --git a/src/mongo/util/background.cpp b/src/mongo/util/background.cpp
index 9dff4675fc7..6951bf86681 100644
--- a/src/mongo/util/background.cpp
+++ b/src/mongo/util/background.cpp
@@ -81,7 +81,9 @@ private:
void _runTask(PeriodicTask* task);
// _mutex protects the _shutdownRequested flag and the _tasks vector.
- Mutex _mutex = MONGO_MAKE_LATCH(HierarchicalAcquisitionLevel(0), "PeriodicTaskRunner::_mutex");
+ Mutex _mutex = MONGO_MAKE_LATCH(
+ // This mutex is held around task execution HierarchicalAcquisitionLevel(0),
+ "PeriodicTaskRunner::_mutex");
// The condition variable is used to sleep for the interval between task
// executions, and is notified when the _shutdownRequested flag is toggled.
diff --git a/src/mongo/util/diagnostic_info.cpp b/src/mongo/util/diagnostic_info.cpp
index edf19a279df..c323dbfa521 100644
--- a/src/mongo/util/diagnostic_info.cpp
+++ b/src/mongo/util/diagnostic_info.cpp
@@ -176,24 +176,24 @@ const auto getDiagnosticInfoHandle = Client::declareDecoration<DiagnosticInfoHan
MONGO_INITIALIZER(LockListener)(InitializerContext* context) {
class LockListener : public Mutex::LockListener {
- void onContendedLock(const Mutex::Identity& id) override {
+ void onContendedLock(const Identity& id) override {
if (auto client = Client::getCurrent()) {
auto& handle = getDiagnosticInfoHandle(client);
stdx::lock_guard<stdx::mutex> lk(handle.mutex);
- handle.list.emplace_front(DiagnosticInfo::capture(id.name));
+ handle.list.emplace_front(DiagnosticInfo::capture(id.name()));
if (currentOpSpawnsThreadWaitingForLatch.shouldFail() &&
- (id.name == kBlockedOpMutexName)) {
+ (id.name() == kBlockedOpMutexName)) {
gBlockedOp.setIsContended(true);
}
}
}
- void onQuickLock(const Mutex::Identity&) override {
+ void onQuickLock(const Identity&) override {
// Do nothing
}
- void onSlowLock(const Mutex::Identity& id) override {
+ void onSlowLock(const Identity& id) override {
if (auto client = Client::getCurrent()) {
auto& handle = getDiagnosticInfoHandle(client);
stdx::lock_guard<stdx::mutex> lk(handle.mutex);
@@ -203,7 +203,7 @@ MONGO_INITIALIZER(LockListener)(InitializerContext* context) {
}
}
- void onUnlock(const Mutex::Identity&) override {
+ void onUnlock(const Identity&) override {
// Do nothing
}
};
diff --git a/src/mongo/util/latch_analyzer.cpp b/src/mongo/util/latch_analyzer.cpp
index 112cf79dbfb..318090b8bc8 100644
--- a/src/mongo/util/latch_analyzer.cpp
+++ b/src/mongo/util/latch_analyzer.cpp
@@ -1,5 +1,5 @@
/**
- * Copyright (C) 2018-present MongoDB, Inc.
+ * Copyright (C) 2019-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,
@@ -27,99 +27,333 @@
* it in the license file.
*/
+#define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kDefault
+
#include "mongo/platform/basic.h"
+#include "mongo/util/latch_analyzer.h"
+
+#include <fmt/format.h>
+
+#include "mongo/util/hierarchical_acquisition.h"
+
+#include "mongo/base/init.h"
#include "mongo/db/client.h"
+#include "mongo/db/commands/test_commands_enabled.h"
+#include "mongo/db/service_context.h"
#include "mongo/platform/mutex.h"
+#include "mongo/util/fail_point.h"
#include "mongo/util/latch_analyzer.h"
+#include "mongo/util/log.h"
namespace mongo {
-using Set = HierarchicalAcquisitionSet;
+namespace {
+
+auto kLatchAnalysisName = "latchAnalysis"_sd;
+auto kLatchViolationKey = "hierarchicalAcquisitionLevelViolations"_sd;
-LatchAnalyzer& LatchAnalyzer::get() {
- static LatchAnalyzer gLatchAnalyzer;
- return gLatchAnalyzer;
+// LatchAnalyzer Decoration getter
+const auto getLatchAnalyzer = ServiceContext::declareDecoration<LatchAnalyzer>();
+
+/**
+ * LockListener sub-class to implement updating set in LatchSetState
+ */
+class LockListener : public Mutex::LockListener {
+public:
+ void onContendedLock(const Identity& id) override {
+ if (auto client = Client::getCurrent()) {
+ LatchAnalyzer::get(client).onContention(id);
+ }
+ }
+
+ void onQuickLock(const Identity& id) override {
+ if (auto client = Client::getCurrent()) {
+ LatchAnalyzer::get(client).onAcquire(id);
+ }
+ }
+
+ void onSlowLock(const Identity& id) override {
+ if (auto client = Client::getCurrent()) {
+ LatchAnalyzer::get(client).onAcquire(id);
+ }
+ }
+
+ void onUnlock(const Identity& id) override {
+ if (auto client = Client::getCurrent()) {
+ LatchAnalyzer::get(client).onRelease(id);
+ }
+ }
+};
+
+// Register our LockListener with the Mutex class
+MONGO_INITIALIZER(LatchAnalysis)(InitializerContext* context) {
+
+ // Intentionally leaked, people use Latches in detached threads
+ static auto& listener = *new LockListener;
+ Mutex::addLockListener(&listener);
+
+ return Status::OK();
}
-LatchAnalyzerDisabledBlock::LatchAnalyzerDisabledBlock() {
- LatchAnalyzer::get().setEnabled(false);
+// Create a FailPoint to analyze latches more seriously for diagnostic purposes. This can be used
+// with a new set of test suites to verify our lock hierarchies.
+MONGO_FAIL_POINT_DEFINE(enableLatchAnalysis);
+
+bool shouldAnalyzeLatches() {
+ return enableLatchAnalysis.shouldFail();
}
-LatchAnalyzerDisabledBlock::~LatchAnalyzerDisabledBlock() {
- LatchAnalyzer::get().setEnabled(true);
+
+// Define a new serverStatus section "latchAnalysis"
+class LatchAnalysisSection final : public ServerStatusSection {
+public:
+ LatchAnalysisSection() : ServerStatusSection(kLatchAnalysisName.toString()) {}
+
+ bool includeByDefault() const override {
+ return false;
+ }
+
+ BSONObj generateSection(OperationContext* opCtx, const BSONElement&) const override {
+ BSONObjBuilder analysis;
+ LatchAnalyzer::get(opCtx->getClient()).appendToBSON(analysis);
+ return analysis.obj();
+ };
+} gLatchAnalysisSection;
+
+// Latching state object to pin onto the Client (i.e. thread)
+struct LatchSetState {
+ HierarchicalAcquisitionSet levelsHeld;
+ stdx::unordered_set<const latch_detail::Identity*> latchesHeld;
+};
+
+const auto getLatchSetState = Client::declareDecoration<LatchSetState>();
+
+} // namespace
+
+void LatchAnalyzer::setAllowExitOnViolation(bool allowExitOnViolation) {
+ _allowExitOnViolation.store(allowExitOnViolation);
}
-namespace {
+bool LatchAnalyzer::allowExitOnViolation() {
+ return _allowExitOnViolation.load() && (getTestCommandsEnabled());
+}
-const auto getLatchSetState = Client::declareDecoration<Mutex::LatchSetState>();
+LatchAnalyzer& LatchAnalyzer::get(ServiceContext* serviceContext) {
+ return getLatchAnalyzer(serviceContext);
+}
-/**
- * LockListener sub-class to implement updating set in LatchSetState
- */
-class MutexLockListener : public Mutex::LockListener {
+LatchAnalyzer& LatchAnalyzer::get(Client* client) {
+ return get(client->getServiceContext());
+}
-public:
- void onContendedLock(const Mutex::Identity&) {
- // Do nothing
+LatchAnalyzer& LatchAnalyzer::get() {
+ auto serviceContext = getCurrentServiceContext();
+ invariant(serviceContext);
+ return get(serviceContext);
+}
+
+void LatchAnalyzer::onContention(const latch_detail::Identity&) {
+ // Nothing at the moment
+}
+
+void LatchAnalyzer::onAcquire(const latch_detail::Identity& identity) {
+ auto client = Client::getCurrent();
+ if (!client) {
+ return;
}
- void onQuickLock(const Mutex::Identity& id) {
- onAcquire(id);
+ if (shouldAnalyzeLatches()) {
+ // If we should analyze latches, annotate the Client state
+ auto& latchSet = getLatchSetState(client).latchesHeld;
+
+ stdx::lock_guard lk(_mutex);
+ for (auto otherIdentity : latchSet) {
+ auto& stat = _hierarchies[identity.index()][otherIdentity->index()];
+ stat.identity = otherIdentity;
+ ++stat.acquiredAfter;
+ }
+
+ latchSet.insert(&identity);
}
- void onSlowLock(const Mutex::Identity& id) {
- onAcquire(id);
+ if (!identity.level()) {
+ // If we weren't given a HierarchicalAcquisitionLevel, don't verify hierarchies
+ return;
}
- void onUnlock(const Mutex::Identity& id) {
- onRelease(id);
+ auto level = *identity.level();
+ auto& handle = getLatchSetState(client);
+ auto result = handle.levelsHeld.add(level);
+ if (result != HierarchicalAcquisitionSet::AddResult::kValidWasAbsent) {
+ using namespace fmt::literals;
+
+ auto errorMessage =
+ "Theoretical deadlock alert - {} latch acquisition at {}:{:d} on latch {}"_format(
+ toString(result),
+ identity.sourceLocation()->file_name(),
+ identity.sourceLocation()->line(),
+ identity.name());
+
+ if (allowExitOnViolation()) {
+ fassert(31360, Status(ErrorCodes::HierarchicalAcquisitionLevelViolation, errorMessage));
+ } else {
+ warning() << errorMessage;
+
+ {
+ stdx::lock_guard lk(_mutex);
+
+ auto& violation = _violations[identity.index()];
+ ++violation.onAcquire;
+ }
+ }
+ }
+}
+
+void LatchAnalyzer::onRelease(const latch_detail::Identity& identity) {
+ auto client = Client::getCurrent();
+ if (!client) {
+ return;
}
-private:
- void onAcquire(const Mutex::Identity& id) {
- if (!id.level) {
- return;
+ if (shouldAnalyzeLatches()) {
+ // If we should analyze latches, annotate the Client state
+ auto& latchSet = getLatchSetState(client).latchesHeld;
+ latchSet.erase(&identity);
+
+ stdx::lock_guard lk(_mutex);
+ for (auto otherIdentity : latchSet) {
+ auto& stat = _hierarchies[identity.index()][otherIdentity->index()];
+ stat.identity = otherIdentity;
+ ++stat.releasedBefore;
}
- if (auto client = Client::getCurrent()) {
- auto& handle = getLatchSetState(client);
- auto result = handle.levelsHeld.add(id.level.get());
- if (result != Set::AddResult::kValidWasAbsent && LatchAnalyzer::get().isEnabled()) {
- // TODO: SERVER-44570 Create a non process-fatal variant of invariant()
- fassert(31360,
- Status(ErrorCodes::HierarchicalAcquisitionLevelViolation,
- str::stream()
- << "Theoretical deadlock alert - " << toString(result)
- << " latch acquisition at " << id.sourceLocation->toString()
- << " on " << id.name));
+ }
+
+ if (!identity.level()) {
+ // If we weren't given a HierarchicalAcquisitionLevel, don't verify hierarchies
+ return;
+ }
+
+ auto level = *identity.level();
+ auto& handle = getLatchSetState(client);
+ auto result = handle.levelsHeld.remove(level);
+ if (result != HierarchicalAcquisitionSet::RemoveResult::kValidWasPresent) {
+ using namespace fmt::literals;
+
+ auto errorMessage =
+ "Theoretical deadlock alert - {} latch release at {}:{} on latch {}"_format(
+ toString(result),
+ identity.sourceLocation()->file_name(),
+ identity.sourceLocation()->line(),
+ identity.name());
+
+ if (allowExitOnViolation()) {
+ fassert(31361, Status(ErrorCodes::HierarchicalAcquisitionLevelViolation, errorMessage));
+ } else {
+ warning() << errorMessage;
+
+ {
+ stdx::lock_guard lk(_mutex);
+
+ auto& violation = _violations[identity.index()];
+ ++violation.onRelease;
}
}
}
+}
- void onRelease(const Mutex::Identity& id) {
- if (!id.level) {
- return;
+void LatchAnalyzer::appendToBSON(mongo::BSONObjBuilder& result) const {
+ for (auto iter = latch_detail::Catalog::get().iter(); iter.more();) {
+ auto data = iter.next();
+ if (!data) {
+ continue;
}
- if (auto client = Client::getCurrent()) {
- auto& handle = getLatchSetState(client);
- auto result = handle.levelsHeld.remove(id.level.get());
- if (result != Set::RemoveResult::kValidWasPresent && LatchAnalyzer::get().isEnabled()) {
- // TODO: SERVER-44570 Create a non process-fatal variant of invariant()
- fassert(31361,
- Status(ErrorCodes::HierarchicalAcquisitionLevelViolation,
- str::stream()
- << "Theoretical deadlock alert - " << toString(result)
- << " latch release at " << id.sourceLocation->toString()
- << " on " << id.name));
+
+ auto& identity = data->identity();
+
+ BSONObjBuilder latchObj = result.subobjStart(identity.name());
+ latchObj.append("created", data->counts().created.loadRelaxed());
+ latchObj.append("destroyed", data->counts().destroyed.loadRelaxed());
+ latchObj.append("acquired", data->counts().acquired.loadRelaxed());
+ latchObj.append("released", data->counts().released.loadRelaxed());
+ latchObj.append("contended", data->counts().contended.loadRelaxed());
+
+ auto appendViolations = [&] {
+ stdx::lock_guard lk(_mutex);
+ auto it = _violations.find(identity.index());
+ if (it == _violations.end()) {
+ return;
+ }
+ auto& violation = it->second;
+
+ BSONObjBuilder violationObj = latchObj.subobjStart(kLatchViolationKey);
+ violationObj.append("onAcquire", violation.onAcquire);
+ violationObj.append("onRelease", violation.onRelease);
+ };
+
+ appendViolations();
+
+ if (!shouldAnalyzeLatches()) {
+ // Only append hierarchical information if we should analyze latches
+ continue;
+ }
+
+ stdx::lock_guard lk(_mutex);
+ auto it = _hierarchies.find(identity.index());
+ if (it == _hierarchies.end()) {
+ continue;
+ }
+
+ auto& latchHierarchy = it->second;
+ if (latchHierarchy.empty()) {
+ continue;
+ }
+
+ {
+ BSONObjBuilder acquiredAfterObj = latchObj.subobjStart("acquiredAfter");
+ for (auto& [_, stat] : latchHierarchy) {
+ auto count = stat.acquiredAfter;
+ if (count == 0) {
+ continue;
+ }
+ acquiredAfterObj.append(stat.identity->name(), count);
+ }
+ }
+
+ {
+ BSONObjBuilder releasedBeforeObj = latchObj.subobjStart("releasedBefore");
+ for (auto& [_, stat] : latchHierarchy) {
+ auto count = stat.releasedBefore;
+ if (count == 0) {
+ continue;
+ }
+ releasedBeforeObj.append(stat.identity->name(), count);
}
}
}
-};
+}
-MONGO_INITIALIZER(CreateMutexLockListener)(InitializerContext* context) {
- static auto& listener = *new MutexLockListener;
- Mutex::addLockListener(&listener);
- return Status::OK();
+void LatchAnalyzer::dump() {
+ if (!shouldAnalyzeLatches()) {
+ return;
+ }
+
+ BSONObjBuilder bob(1024 * 1024);
+ {
+ BSONObjBuilder analysis = bob.subobjStart("latchAnalysis");
+ appendToBSON(analysis);
+ }
+
+ auto obj = bob.done();
+ log().setIsTruncatable(false) << "=====LATCHES=====\n"
+ << obj.jsonString() << "\n===END LATCHES===";
+}
+
+LatchAnalyzerDisabledBlock::LatchAnalyzerDisabledBlock() {
+ LatchAnalyzer::get().setAllowExitOnViolation(false);
+}
+
+LatchAnalyzerDisabledBlock::~LatchAnalyzerDisabledBlock() {
+ LatchAnalyzer::get().setAllowExitOnViolation(true);
}
-} // namespace
} // namespace mongo
diff --git a/src/mongo/util/latch_analyzer.h b/src/mongo/util/latch_analyzer.h
index af4c9f8b626..41f41dca15f 100644
--- a/src/mongo/util/latch_analyzer.h
+++ b/src/mongo/util/latch_analyzer.h
@@ -1,5 +1,5 @@
/**
- * Copyright (C) 2018-present MongoDB, Inc.
+ * Copyright (C) 2019-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,
@@ -29,22 +29,71 @@
#pragma once
+#include "mongo/base/simple_string_data_comparator.h"
+#include "mongo/base/string_data.h"
+#include "mongo/base/string_data_comparator_interface.h"
+#include "mongo/db/client.h"
+#include "mongo/db/commands/server_status.h"
+#include "mongo/db/service_context.h"
+#include "mongo/stdx/unordered_map.h"
+#include "mongo/stdx/unordered_set.h"
+
namespace mongo {
+/**
+ * LatchAnalyzer is a ServiceContext decoration that aggregates latch events
+ *
+ * This class is intended to provide a platform for hierarchical analysis on latches. To that end,
+ * onContention(), onAcquire(), and onRelease() are currently called by a Mutex::LockListener
+ * subclass defined in source. This class does much more work for each event when the
+ * enableLatchAnalysis failpoint is set to "alwaysOn". This failpoint provides a wealth of data for
+ * future analysis, but involves additional mutexes and mapping structures that may prove too costly
+ * for production usage at the least.
+ */
class LatchAnalyzer {
-
public:
+ static LatchAnalyzer& get(ServiceContext* serviceContext);
+ static LatchAnalyzer& get(Client* client);
static LatchAnalyzer& get();
- void setEnabled(bool isEnabled) {
- enabled.store(isEnabled);
- }
- bool isEnabled() {
- return enabled.load();
- }
+ // Handler function for a failed latch acquire
+ void onContention(const latch_detail::Identity& id);
+
+ // Handler function for a successful latch acquire
+ void onAcquire(const latch_detail::Identity& id);
+
+ // Handler function for a latch release
+ void onRelease(const latch_detail::Identity& id);
+
+ // Append the current statistics in a form appropriate for server status to a BOB
+ void appendToBSON(mongo::BSONObjBuilder& result) const;
+
+ // Log the current statistics in JSON form to INFO
+ void dump();
+
+ void setAllowExitOnViolation(bool allowExitOnViolation);
+ bool allowExitOnViolation();
private:
- AtomicWord<bool> enabled{true};
+ struct HierarchyStats {
+ const latch_detail::Identity* identity = nullptr;
+
+ int acquiredAfter = 0;
+ int releasedBefore = 0;
+ };
+
+ using SingleLatchHierarchy = stdx::unordered_map<int64_t, HierarchyStats>;
+
+ struct HierarchicalAcquisitionLevelViolation {
+ int onAcquire = 0;
+ int onRelease = 0;
+ };
+
+ AtomicWord<bool> _allowExitOnViolation{true};
+
+ mutable stdx::mutex _mutex; // NOLINT
+ stdx::unordered_map<int64_t, SingleLatchHierarchy> _hierarchies;
+ stdx::unordered_map<int64_t, HierarchicalAcquisitionLevelViolation> _violations;
};
class LatchAnalyzerDisabledBlock {
@@ -54,4 +103,4 @@ public:
~LatchAnalyzerDisabledBlock();
};
-} // namespace mongo \ No newline at end of file
+} // namespace mongo
diff --git a/src/mongo/util/latch_analyzer_test.cpp b/src/mongo/util/latch_analyzer_test.cpp
index b8b519b6c90..993cf14fbe8 100644
--- a/src/mongo/util/latch_analyzer_test.cpp
+++ b/src/mongo/util/latch_analyzer_test.cpp
@@ -27,6 +27,7 @@
* it in the license file.
*/
+#include "mongo/db/commands/test_commands_enabled.h"
#include "mongo/db/service_context_test_fixture.h"
#include "mongo/platform/mutex.h"
#include "mongo/platform/source_location.h"
@@ -40,44 +41,44 @@ namespace {
using Level = HierarchicalAcquisitionLevel;
-class LatchAnalyzerTest : public ServiceContextTest {};
+class LatchAnalyzerTest : public ServiceContextTest {
+ void setUp() override {
+ ServiceContextTest::setUp();
+ setTestCommandsEnabled(true);
+ }
+
+ void tearDown() override {
+ setTestCommandsEnabled(false);
+ ServiceContextTest::tearDown();
+ }
+};
DEATH_TEST_F(LatchAnalyzerTest, AddInvalidWasAbsent, "Fatal assertion 31360") {
- Mutex lowerLevel = MONGO_MAKE_LATCH(
- Level(1), (SourceLocationHolder)MONGO_SOURCE_LOCATION(), "AddInvalidWasAbsent::lowerLevel");
- Mutex higherLevel = MONGO_MAKE_LATCH(Level(2),
- (SourceLocationHolder)MONGO_SOURCE_LOCATION(),
- "AddInvalidWasAbsent::higherLevel");
+ Mutex lowerLevel = MONGO_MAKE_LATCH(Level(1), "AddInvalidWasAbsent::lowerLevel");
+ Mutex higherLevel = MONGO_MAKE_LATCH(Level(2), "AddInvalidWasAbsent::higherLevel");
lowerLevel.lock();
higherLevel.lock();
}
DEATH_TEST_F(LatchAnalyzerTest, AddInvalidWasPresent, "Fatal assertion 31360") {
- Mutex m1 = MONGO_MAKE_LATCH(
- Level(1), (SourceLocationHolder)MONGO_SOURCE_LOCATION(), "AddInvalidWasPresent::m1");
- Mutex m2 = MONGO_MAKE_LATCH(
- Level(1), (SourceLocationHolder)MONGO_SOURCE_LOCATION(), "AddInvalidWasPresent::m2");
+ Mutex m1 = MONGO_MAKE_LATCH(Level(1), "AddInvalidWasPresent::m1");
+ Mutex m2 = MONGO_MAKE_LATCH(Level(1), "AddInvalidWasPresent::m2");
m1.lock();
m2.lock();
}
DEATH_TEST_F(LatchAnalyzerTest, RemoveInvalidWasAbsent, "Fatal assertion 31361") {
- Mutex m = MONGO_MAKE_LATCH(
- Level(1), (SourceLocationHolder)MONGO_SOURCE_LOCATION(), "RemoveInvalidWasAbsent::m");
+ Mutex m = MONGO_MAKE_LATCH(Level(1), "RemoveInvalidWasAbsent::m");
m.unlock();
}
DEATH_TEST_F(LatchAnalyzerTest, RemoveInvalidWasPresent, "Fatal assertion 31361") {
- Mutex higherLevel = MONGO_MAKE_LATCH(Level(2),
- (SourceLocationHolder)MONGO_SOURCE_LOCATION(),
- "RemoveInvalidWasPresent::higherLevel");
- Mutex lowerLevel = MONGO_MAKE_LATCH(Level(1),
- (SourceLocationHolder)MONGO_SOURCE_LOCATION(),
- "RemoveInvalidWasPresent::lowerLevel");
+ Mutex higherLevel = MONGO_MAKE_LATCH(Level(2), "RemoveInvalidWasPresent::higherLevel");
+ Mutex lowerLevel = MONGO_MAKE_LATCH(Level(1), "RemoveInvalidWasPresent::lowerLevel");
higherLevel.lock();
lowerLevel.lock();
@@ -85,10 +86,8 @@ DEATH_TEST_F(LatchAnalyzerTest, RemoveInvalidWasPresent, "Fatal assertion 31361"
}
TEST_F(LatchAnalyzerTest, AddValidWasAbsent) {
- Mutex higherLevel = MONGO_MAKE_LATCH(
- Level(2), (SourceLocationHolder)MONGO_SOURCE_LOCATION(), "AddValidWasAbsent::higherLevel");
- Mutex lowerLevel = MONGO_MAKE_LATCH(
- Level(1), (SourceLocationHolder)MONGO_SOURCE_LOCATION(), "AddValidWasAbsent::lowerLevel");
+ Mutex higherLevel = MONGO_MAKE_LATCH(Level(2), "AddValidWasAbsent::higherLevel");
+ Mutex lowerLevel = MONGO_MAKE_LATCH(Level(1), "AddValidWasAbsent::lowerLevel");
higherLevel.lock();
lowerLevel.lock();
@@ -102,12 +101,8 @@ TEST_F(LatchAnalyzerTest, AddValidWasAbsent) {
TEST_F(LatchAnalyzerTest, RemoveValidWasPresent) {
- Mutex higherLevel = MONGO_MAKE_LATCH(Level(2),
- (SourceLocationHolder)MONGO_SOURCE_LOCATION(),
- "RemoveValidWasPresent::higherLevel");
- Mutex lowerLevel = MONGO_MAKE_LATCH(Level(1),
- (SourceLocationHolder)MONGO_SOURCE_LOCATION(),
- "RemoveValidWasPresent::lowerLevel");
+ Mutex higherLevel = MONGO_MAKE_LATCH(Level(2), "RemoveValidWasPresent::higherLevel");
+ Mutex lowerLevel = MONGO_MAKE_LATCH(Level(1), "RemoveValidWasPresent::lowerLevel");
{
LatchAnalyzerDisabledBlock block;