SERVER-33625 replace use of OldThreadPool in cloners and TaskRunner with ThreadPool

25 files changed, 72 insertions, 82 deletions

diff --git a/src/mongo/db/repl/base_cloner_test_fixture.cpp b/src/mongo/db/repl/base_cloner_test_fixture.cpp
index fa418d338fb..c38663a54cf 100644
--- a/src/mongo/db/repl/base_cloner_test_fixture.cpp
+++ b/src/mongo/db/repl/base_cloner_test_fixture.cpp
@@ -111,7 +111,13 @@ void BaseClonerTest::setUp() {
     executor::ThreadPoolExecutorTest::setUp();
     clear();
     launchExecutorThread();
-    dbWorkThreadPool = stdx::make_unique<OldThreadPool>(1);
+
+    ThreadPool::Options options;
+    options.minThreads = 1U;
+    options.maxThreads = 1U;
+    dbWorkThreadPool = stdx::make_unique<ThreadPool>(options);
+    dbWorkThreadPool->startup();
+
     storageInterface.reset(new StorageInterfaceMock());
 }
 
@@ -120,7 +126,7 @@ void BaseClonerTest::tearDown() {
     getExecutor().join();
 
     storageInterface.reset();
-    dbWorkThreadPool->join();
+
     dbWorkThreadPool.reset();
 }
 
diff --git a/src/mongo/db/repl/base_cloner_test_fixture.h b/src/mongo/db/repl/base_cloner_test_fixture.h
index e5615806fc6..7e6900a2785 100644
--- a/src/mongo/db/repl/base_cloner_test_fixture.h
+++ b/src/mongo/db/repl/base_cloner_test_fixture.h
@@ -41,7 +41,7 @@
 #include "mongo/executor/thread_pool_task_executor_test_fixture.h"
 #include "mongo/stdx/condition_variable.h"
 #include "mongo/stdx/mutex.h"
-#include "mongo/util/concurrency/old_thread_pool.h"
+#include "mongo/util/concurrency/thread_pool.h"
 #include "mongo/util/net/hostandport.h"
 
 namespace mongo {
@@ -128,7 +128,7 @@ protected:
     void tearDown() override;
 
     std::unique_ptr<StorageInterfaceMock> storageInterface;
-    std::unique_ptr<OldThreadPool> dbWorkThreadPool;
+    std::unique_ptr<ThreadPool> dbWorkThreadPool;
 
 private:
     // Protects member data of this base cloner fixture.
diff --git a/src/mongo/db/repl/collection_cloner.cpp b/src/mongo/db/repl/collection_cloner.cpp
index 159a664ccb8..773f54a0b8b 100644
--- a/src/mongo/db/repl/collection_cloner.cpp
+++ b/src/mongo/db/repl/collection_cloner.cpp
@@ -99,7 +99,7 @@ BSONObj makeCommandWithUUIDorCollectionName(StringData command,
 }
 
 CollectionCloner::CollectionCloner(executor::TaskExecutor* executor,
-                                   OldThreadPool* dbWorkThreadPool,
+                                   ThreadPool* dbWorkThreadPool,
                                    const HostAndPort& source,
                                    const NamespaceString& sourceNss,
                                    const CollectionOptions& options,
diff --git a/src/mongo/db/repl/collection_cloner.h b/src/mongo/db/repl/collection_cloner.h
index 46dd6d7903f..e79258e3734 100644
--- a/src/mongo/db/repl/collection_cloner.h
+++ b/src/mongo/db/repl/collection_cloner.h
@@ -50,14 +50,11 @@
 #include "mongo/stdx/condition_variable.h"
 #include "mongo/stdx/functional.h"
 #include "mongo/stdx/mutex.h"
-#include "mongo/util/concurrency/old_thread_pool.h"
+#include "mongo/util/concurrency/thread_pool.h"
 #include "mongo/util/net/hostandport.h"
 #include "mongo/util/progress_meter.h"
 
 namespace mongo {
-
-class OldThreadPool;
-
 namespace repl {
 
 class StorageInterface;
@@ -106,7 +103,7 @@ public:
      * Takes ownership of the passed StorageInterface object.
      */
     CollectionCloner(executor::TaskExecutor* executor,
-                     OldThreadPool* dbWorkThreadPool,
+                     ThreadPool* dbWorkThreadPool,
                      const HostAndPort& source,
                      const NamespaceString& sourceNss,
                      const CollectionOptions& options,
@@ -278,7 +275,7 @@ private:
     mutable stdx::mutex _mutex;
     mutable stdx::condition_variable _condition;        // (M)
     executor::TaskExecutor* _executor;                  // (R) Not owned by us.
-    OldThreadPool* _dbWorkThreadPool;                   // (R) Not owned by us.
+    ThreadPool* _dbWorkThreadPool;                      // (R) Not owned by us.
     HostAndPort _source;                                // (R)
     NamespaceString _sourceNss;                         // (R)
     NamespaceString _destNss;                           // (R)
diff --git a/src/mongo/db/repl/data_replicator_external_state.h b/src/mongo/db/repl/data_replicator_external_state.h
index 818a9fdd38a..442022eeeeb 100644
--- a/src/mongo/db/repl/data_replicator_external_state.h
+++ b/src/mongo/db/repl/data_replicator_external_state.h
@@ -37,13 +37,12 @@
 #include "mongo/db/repl/repl_set_config.h"
 #include "mongo/rpc/metadata/oplog_query_metadata.h"
 #include "mongo/rpc/metadata/repl_set_metadata.h"
+#include "mongo/util/concurrency/thread_pool.h"
 #include "mongo/util/net/hostandport.h"
 #include "mongo/util/time_support.h"
 
 namespace mongo {
 
-class OldThreadPool;
-
 namespace executor {
 class TaskExecutor;
 }  // namespace executor
@@ -79,7 +78,7 @@ public:
     /**
      * Returns shared db worker thread pool for collection cloning.
      */
-    virtual OldThreadPool* getDbWorkThreadPool() const = 0;
+    virtual ThreadPool* getDbWorkThreadPool() const = 0;
 
     /**
      * Returns the current term and last committed optime.
diff --git a/src/mongo/db/repl/data_replicator_external_state_impl.cpp b/src/mongo/db/repl/data_replicator_external_state_impl.cpp
index 49ea11001b1..1d93a2fb5cf 100644
--- a/src/mongo/db/repl/data_replicator_external_state_impl.cpp
+++ b/src/mongo/db/repl/data_replicator_external_state_impl.cpp
@@ -49,7 +49,7 @@ executor::TaskExecutor* DataReplicatorExternalStateImpl::getTaskExecutor() const
     return _replicationCoordinatorExternalState->getTaskExecutor();
 }
 
-OldThreadPool* DataReplicatorExternalStateImpl::getDbWorkThreadPool() const {
+ThreadPool* DataReplicatorExternalStateImpl::getDbWorkThreadPool() const {
     return _replicationCoordinatorExternalState->getDbWorkThreadPool();
 }
 
diff --git a/src/mongo/db/repl/data_replicator_external_state_impl.h b/src/mongo/db/repl/data_replicator_external_state_impl.h
index 586409b2b50..b66dbaff53b 100644
--- a/src/mongo/db/repl/data_replicator_external_state_impl.h
+++ b/src/mongo/db/repl/data_replicator_external_state_impl.h
@@ -48,7 +48,7 @@ public:
 
     executor::TaskExecutor* getTaskExecutor() const override;
 
-    OldThreadPool* getDbWorkThreadPool() const override;
+    ThreadPool* getDbWorkThreadPool() const override;
 
     OpTimeWithTerm getCurrentTermAndLastCommittedOpTime() override;
 
diff --git a/src/mongo/db/repl/data_replicator_external_state_mock.cpp b/src/mongo/db/repl/data_replicator_external_state_mock.cpp
index de00a40efbf..71ad72d166d 100644
--- a/src/mongo/db/repl/data_replicator_external_state_mock.cpp
+++ b/src/mongo/db/repl/data_replicator_external_state_mock.cpp
@@ -45,7 +45,7 @@ executor::TaskExecutor* DataReplicatorExternalStateMock::getTaskExecutor() const
     return taskExecutor;
 }
 
-OldThreadPool* DataReplicatorExternalStateMock::getDbWorkThreadPool() const {
+ThreadPool* DataReplicatorExternalStateMock::getDbWorkThreadPool() const {
     return dbWorkThreadPool;
 }
 
diff --git a/src/mongo/db/repl/data_replicator_external_state_mock.h b/src/mongo/db/repl/data_replicator_external_state_mock.h
index c556b822315..1b93307f2fa 100644
--- a/src/mongo/db/repl/data_replicator_external_state_mock.h
+++ b/src/mongo/db/repl/data_replicator_external_state_mock.h
@@ -45,7 +45,7 @@ public:
 
     executor::TaskExecutor* getTaskExecutor() const override;
 
-    OldThreadPool* getDbWorkThreadPool() const override;
+    ThreadPool* getDbWorkThreadPool() const override;
 
     OpTimeWithTerm getCurrentTermAndLastCommittedOpTime() override;
 
@@ -66,7 +66,7 @@ public:
     executor::TaskExecutor* taskExecutor = nullptr;
 
     // DB worker thread pool. Not owned by us.
-    OldThreadPool* dbWorkThreadPool = nullptr;
+    ThreadPool* dbWorkThreadPool = nullptr;
 
     // Returned by getCurrentTermAndLastCommittedOpTime.
     long long currentTerm = OpTime::kUninitializedTerm;
diff --git a/src/mongo/db/repl/database_cloner.cpp b/src/mongo/db/repl/database_cloner.cpp
index 71d11c1436a..74da2fe22be 100644
--- a/src/mongo/db/repl/database_cloner.cpp
+++ b/src/mongo/db/repl/database_cloner.cpp
@@ -101,7 +101,7 @@ BSONObj createListCollectionsCommandObject(const BSONObj& filter) {
 }  // namespace
 
 DatabaseCloner::DatabaseCloner(executor::TaskExecutor* executor,
-                               OldThreadPool* dbWorkThreadPool,
+                               ThreadPool* dbWorkThreadPool,
                                const HostAndPort& source,
                                const std::string& dbname,
                                const BSONObj& listCollectionsFilter,
diff --git a/src/mongo/db/repl/database_cloner.h b/src/mongo/db/repl/database_cloner.h
index e6692428efb..b32ce95f584 100644
--- a/src/mongo/db/repl/database_cloner.h
+++ b/src/mongo/db/repl/database_cloner.h
@@ -43,12 +43,10 @@
 #include "mongo/executor/task_executor.h"
 #include "mongo/stdx/condition_variable.h"
 #include "mongo/stdx/mutex.h"
+#include "mongo/util/concurrency/thread_pool.h"
 #include "mongo/util/net/hostandport.h"
 
 namespace mongo {
-
-class OldThreadPool;
-
 namespace repl {
 
 class StorageInterface;
@@ -109,7 +107,7 @@ public:
      * 'listCollectionsFilter' will be extended to include collections only, filtering out views.
      */
     DatabaseCloner(executor::TaskExecutor* executor,
-                   OldThreadPool* dbWorkThreadPool,
+                   ThreadPool* dbWorkThreadPool,
                    const HostAndPort& source,
                    const std::string& dbname,
                    const BSONObj& listCollectionsFilter,
@@ -213,7 +211,7 @@ private:
     mutable stdx::mutex _mutex;
     mutable stdx::condition_variable _condition;                 // (M)
     executor::TaskExecutor* _executor;                           // (R)
-    OldThreadPool* _dbWorkThreadPool;                            // (R)
+    ThreadPool* _dbWorkThreadPool;                               // (R)
     const HostAndPort _source;                                   // (R)
     const std::string _dbname;                                   // (R)
     const BSONObj _listCollectionsFilter;                        // (R)
diff --git a/src/mongo/db/repl/databases_cloner.cpp b/src/mongo/db/repl/databases_cloner.cpp
index 2a4e47edbf2..e4cad653e4f 100644
--- a/src/mongo/db/repl/databases_cloner.cpp
+++ b/src/mongo/db/repl/databases_cloner.cpp
@@ -66,7 +66,7 @@ MONGO_EXPORT_SERVER_PARAMETER(numInitialSyncListDatabasesAttempts, int, 3);
 
 DatabasesCloner::DatabasesCloner(StorageInterface* si,
                                  executor::TaskExecutor* exec,
-                                 OldThreadPool* dbWorkThreadPool,
+                                 ThreadPool* dbWorkThreadPool,
                                  HostAndPort source,
                                  IncludeDbFilterFn includeDbPred,
                                  OnFinishFn finishFn)
diff --git a/src/mongo/db/repl/databases_cloner.h b/src/mongo/db/repl/databases_cloner.h
index f47ef569614..afb69c4ade9 100644
--- a/src/mongo/db/repl/databases_cloner.h
+++ b/src/mongo/db/repl/databases_cloner.h
@@ -44,12 +44,10 @@
 #include "mongo/executor/task_executor.h"
 #include "mongo/stdx/condition_variable.h"
 #include "mongo/stdx/mutex.h"
+#include "mongo/util/concurrency/thread_pool.h"
 #include "mongo/util/net/hostandport.h"
 
 namespace mongo {
-
-class OldThreadPool;
-
 namespace repl {
 
 /**
@@ -70,7 +68,7 @@ public:
     using OnFinishFn = stdx::function<void(const Status&)>;
     DatabasesCloner(StorageInterface* si,
                     executor::TaskExecutor* exec,
-                    OldThreadPool* dbWorkThreadPool,
+                    ThreadPool* dbWorkThreadPool,
                     HostAndPort source,
                     IncludeDbFilterFn includeDbPred,
                     OnFinishFn finishFn);
@@ -169,8 +167,8 @@ private:
     mutable stdx::mutex _mutex;                         // (S)
     Status _status{ErrorCodes::NotYetInitialized, ""};  // (M) If it is not OK, we stop everything.
     executor::TaskExecutor* _exec;                      // (R) executor to schedule things with
-    OldThreadPool* _dbWorkThreadPool;  // (R) db worker thread pool for collection cloning.
-    const HostAndPort _source;         // (R) The source to use.
+    ThreadPool* _dbWorkThreadPool;  // (R) db worker thread pool for collection cloning.
+    const HostAndPort _source;      // (R) The source to use.
     CollectionCloner::ScheduleDbWorkFn _scheduleDbWorkFn;  // (M)
 
     const IncludeDbFilterFn _includeDbFn;  // (R) function which decides which dbs are cloned.
diff --git a/src/mongo/db/repl/databases_cloner_test.cpp b/src/mongo/db/repl/databases_cloner_test.cpp
index 3705afed383..369b8a27c38 100644
--- a/src/mongo/db/repl/databases_cloner_test.cpp
+++ b/src/mongo/db/repl/databases_cloner_test.cpp
@@ -43,8 +43,8 @@
 #include "mongo/stdx/mutex.h"
 #include "mongo/unittest/task_executor_proxy.h"
 #include "mongo/unittest/unittest.h"
-#include "mongo/util/concurrency/old_thread_pool.h"
 #include "mongo/util/concurrency/thread_name.h"
+#include "mongo/util/concurrency/thread_pool.h"
 #include "mongo/util/mongoutils/str.h"
 #include "mongo/util/scopeguard.h"
 
@@ -79,14 +79,13 @@ struct StorageInterfaceResults {
 
 class DBsClonerTest : public executor::ThreadPoolExecutorTest {
 public:
-    DBsClonerTest()
-        : _storageInterface{}, _dbWorkThreadPool{OldThreadPool::DoNotStartThreadsTag(), 1} {}
+    DBsClonerTest() : _storageInterface{}, _dbWorkThreadPool(ThreadPool::Options()) {}
 
     StorageInterface& getStorage() {
         return _storageInterface;
     }
 
-    OldThreadPool& getDbWorkThreadPool() {
+    ThreadPool& getDbWorkThreadPool() {
         return _dbWorkThreadPool;
     }
 
@@ -186,13 +185,12 @@ protected:
                     std::unique_ptr<CollectionBulkLoader>(collInfo->loader));
             };
 
-        _dbWorkThreadPool.startThreads();
+        _dbWorkThreadPool.startup();
     }
 
     void tearDown() override {
         getExecutor().shutdown();
         getExecutor().join();
-        _dbWorkThreadPool.join();
     }
 
     /**
@@ -330,7 +328,7 @@ protected:
     StorageInterfaceMock _storageInterface;
 
 private:
-    OldThreadPool _dbWorkThreadPool;
+    ThreadPool _dbWorkThreadPool;
     std::map<NamespaceString, CollectionMockStats> _collectionStats;
     std::map<NamespaceString, CollectionCloneInfo> _collections;
     StorageInterfaceResults _storageInterfaceWorkDone;
diff --git a/src/mongo/db/repl/initial_syncer_test.cpp b/src/mongo/db/repl/initial_syncer_test.cpp
index 428be3cdb14..9d01a75c1c9 100644
--- a/src/mongo/db/repl/initial_syncer_test.cpp
+++ b/src/mongo/db/repl/initial_syncer_test.cpp
@@ -59,8 +59,8 @@
 #include "mongo/executor/network_interface_mock.h"
 #include "mongo/executor/thread_pool_task_executor_test_fixture.h"
 #include "mongo/stdx/mutex.h"
-#include "mongo/util/concurrency/old_thread_pool.h"
 #include "mongo/util/concurrency/thread_name.h"
+#include "mongo/util/concurrency/thread_pool.h"
 #include "mongo/util/fail_point_service.h"
 #include "mongo/util/mongoutils/str.h"
 #include "mongo/util/scopeguard.h"
@@ -227,7 +227,7 @@ public:
         return *_storageInterface;
     }
 
-    OldThreadPool& getDbWorkThreadPool() {
+    ThreadPool& getDbWorkThreadPool() {
         return *_dbWorkThreadPool;
     }
 
@@ -305,7 +305,8 @@ protected:
                     std::unique_ptr<CollectionBulkLoader>(collInfo->loader));
             };
 
-        _dbWorkThreadPool = stdx::make_unique<OldThreadPool>(1);
+        _dbWorkThreadPool = stdx::make_unique<ThreadPool>(ThreadPool::Options());
+        _dbWorkThreadPool->startup();
 
         Client::initThreadIfNotAlready();
         reset();
@@ -403,7 +404,6 @@ protected:
     void tearDown() override {
         tearDownExecutorThread();
         _initialSyncer.reset();
-        _dbWorkThreadPool->join();
         _dbWorkThreadPool.reset();
         _replicationProcess.reset();
         _storageInterface.reset();
@@ -439,7 +439,7 @@ protected:
     std::unique_ptr<SyncSourceSelectorMock> _syncSourceSelector;
     std::unique_ptr<StorageInterfaceMock> _storageInterface;
     std::unique_ptr<ReplicationProcess> _replicationProcess;
-    std::unique_ptr<OldThreadPool> _dbWorkThreadPool;
+    std::unique_ptr<ThreadPool> _dbWorkThreadPool;
     std::map<NamespaceString, CollectionMockStats> _collectionStats;
     std::map<NamespaceString, CollectionCloneInfo> _collections;
 
diff --git a/src/mongo/db/repl/replication_coordinator_external_state.h b/src/mongo/db/repl/replication_coordinator_external_state.h
index 0730e1bed42..ec457252d2b 100644
--- a/src/mongo/db/repl/replication_coordinator_external_state.h
+++ b/src/mongo/db/repl/replication_coordinator_external_state.h
@@ -38,13 +38,13 @@
 #include "mongo/db/repl/oplog_buffer.h"
 #include "mongo/db/repl/optime.h"
 #include "mongo/stdx/functional.h"
+#include "mongo/util/concurrency/thread_pool.h"
 #include "mongo/util/time_support.h"
 
 namespace mongo {
 
 class BSONObj;
 class OID;
-class OldThreadPool;
 class OperationContext;
 class ServiceContext;
 class Status;
@@ -115,7 +115,7 @@ public:
     /**
      * Returns shared db worker thread pool for collection cloning.
      */
-    virtual OldThreadPool* getDbWorkThreadPool() const = 0;
+    virtual ThreadPool* getDbWorkThreadPool() const = 0;
 
     /**
      * Runs the repair database command on the "local" db, if the storage engine is MMapV1.
diff --git a/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp b/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp
index 0bced2a2351..81e4f554b22 100644
--- a/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp
+++ b/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp
@@ -312,7 +312,6 @@ void ReplicationCoordinatorExternalStateImpl::startThreads(const ReplSettings& s
         executor::makeNetworkInterface("NetworkInterfaceASIO-RS", nullptr, std::move(hookList)));
     _taskExecutor->startup();
 
-    _dbWorkerPool = std::make_unique<OldThreadPool>(16, "db worker");
     _writerPool = SyncTail::makeWriterPool();
 
     _startedThreads = true;
@@ -360,8 +359,8 @@ executor::TaskExecutor* ReplicationCoordinatorExternalStateImpl::getTaskExecutor
     return _taskExecutor.get();
 }
 
-OldThreadPool* ReplicationCoordinatorExternalStateImpl::getDbWorkThreadPool() const {
-    return _dbWorkerPool.get();
+ThreadPool* ReplicationCoordinatorExternalStateImpl::getDbWorkThreadPool() const {
+    return _writerPool.get();
 }
 
 Status ReplicationCoordinatorExternalStateImpl::runRepairOnLocalDB(OperationContext* opCtx) {
diff --git a/src/mongo/db/repl/replication_coordinator_external_state_impl.h b/src/mongo/db/repl/replication_coordinator_external_state_impl.h
index 291e29ec7af..a303c88e990 100644
--- a/src/mongo/db/repl/replication_coordinator_external_state_impl.h
+++ b/src/mongo/db/repl/replication_coordinator_external_state_impl.h
@@ -41,7 +41,6 @@
 #include "mongo/db/storage/journal_listener.h"
 #include "mongo/db/storage/snapshot_manager.h"
 #include "mongo/stdx/mutex.h"
-#include "mongo/util/concurrency/old_thread_pool.h"
 #include "mongo/util/concurrency/thread_pool.h"
 
 namespace mongo {
@@ -78,7 +77,7 @@ public:
     virtual void startMasterSlave(OperationContext* opCtx);
     virtual void shutdown(OperationContext* opCtx);
     virtual executor::TaskExecutor* getTaskExecutor() const override;
-    virtual OldThreadPool* getDbWorkThreadPool() const override;
+    virtual ThreadPool* getDbWorkThreadPool() const override;
     virtual Status runRepairOnLocalDB(OperationContext* opCtx) override;
     virtual Status initializeReplSetStorage(OperationContext* opCtx, const BSONObj& config);
     virtual void waitForAllEarlierOplogWritesToBeVisible(OperationContext* opCtx);
@@ -199,10 +198,10 @@ private:
     // Task executor used to run replication tasks.
     std::unique_ptr<executor::TaskExecutor> _taskExecutor;
 
-    // Used by database and collection cloners to perform storage operations.
-    std::unique_ptr<OldThreadPool> _dbWorkerPool;
-
     // Used by repl::multiApply() to apply the sync source's operations in parallel.
+    // Also used by database and collection cloners to perform storage operations.
+    // Cloners and oplog application run in separate phases of initial sync so it is fine to share
+    // this thread pool.
     std::unique_ptr<ThreadPool> _writerPool;
 
     // Writes a noop every 10 seconds.
diff --git a/src/mongo/db/repl/replication_coordinator_external_state_mock.cpp b/src/mongo/db/repl/replication_coordinator_external_state_mock.cpp
index 0cec9f77524..bf908281c33 100644
--- a/src/mongo/db/repl/replication_coordinator_external_state_mock.cpp
+++ b/src/mongo/db/repl/replication_coordinator_external_state_mock.cpp
@@ -92,7 +92,7 @@ executor::TaskExecutor* ReplicationCoordinatorExternalStateMock::getTaskExecutor
     return nullptr;
 }
 
-OldThreadPool* ReplicationCoordinatorExternalStateMock::getDbWorkThreadPool() const {
+ThreadPool* ReplicationCoordinatorExternalStateMock::getDbWorkThreadPool() const {
     return nullptr;
 }
 
diff --git a/src/mongo/db/repl/replication_coordinator_external_state_mock.h b/src/mongo/db/repl/replication_coordinator_external_state_mock.h
index f227fef5489..675b9ca94fe 100644
--- a/src/mongo/db/repl/replication_coordinator_external_state_mock.h
+++ b/src/mongo/db/repl/replication_coordinator_external_state_mock.h
@@ -65,7 +65,7 @@ public:
     virtual void startMasterSlave(OperationContext*);
     virtual void shutdown(OperationContext* opCtx);
     virtual executor::TaskExecutor* getTaskExecutor() const override;
-    virtual OldThreadPool* getDbWorkThreadPool() const override;
+    virtual ThreadPool* getDbWorkThreadPool() const override;
     virtual Status runRepairOnLocalDB(OperationContext* opCtx) override;
     virtual Status initializeReplSetStorage(OperationContext* opCtx, const BSONObj& config);
     virtual void waitForAllEarlierOplogWritesToBeVisible(OperationContext* opCtx);
diff --git a/src/mongo/db/repl/task_runner.cpp b/src/mongo/db/repl/task_runner.cpp
index 909bb594ad2..8d08c21b746 100644
--- a/src/mongo/db/repl/task_runner.cpp
+++ b/src/mongo/db/repl/task_runner.cpp
@@ -40,7 +40,6 @@
 #include "mongo/db/operation_context.h"
 #include "mongo/db/service_context.h"
 #include "mongo/util/assert_util.h"
-#include "mongo/util/concurrency/old_thread_pool.h"
 #include "mongo/util/concurrency/thread_name.h"
 #include "mongo/util/destructor_guard.h"
 #include "mongo/util/log.h"
@@ -77,7 +76,7 @@ TaskRunner::Task TaskRunner::makeCancelTask() {
     return [](OperationContext* opCtx, const Status& status) { return NextAction::kCancel; };
 }
 
-TaskRunner::TaskRunner(OldThreadPool* threadPool)
+TaskRunner::TaskRunner(ThreadPool* threadPool)
     : _threadPool(threadPool), _active(false), _cancelRequested(false) {
     uassert(ErrorCodes::BadValue, "null thread pool", threadPool);
 }
@@ -113,7 +112,7 @@ void TaskRunner::schedule(const Task& task) {
         return;
     }
 
-    _threadPool->schedule([this] { _runTasks(); });
+    invariantOK(_threadPool->schedule([this] { _runTasks(); }));
 
     _active = true;
     _cancelRequested = false;
diff --git a/src/mongo/db/repl/task_runner.h b/src/mongo/db/repl/task_runner.h
index b7dcf4c05d6..310f432379d 100644
--- a/src/mongo/db/repl/task_runner.h
+++ b/src/mongo/db/repl/task_runner.h
@@ -35,11 +35,11 @@
 #include "mongo/stdx/condition_variable.h"
 #include "mongo/stdx/functional.h"
 #include "mongo/stdx/mutex.h"
+#include "mongo/util/concurrency/thread_pool.h"
 
 namespace mongo {
 
 class Status;
-class OldThreadPool;
 class OperationContext;
 
 namespace repl {
@@ -79,7 +79,7 @@ public:
      */
     static Task makeCancelTask();
 
-    explicit TaskRunner(OldThreadPool* threadPool);
+    explicit TaskRunner(ThreadPool* threadPool);
 
     virtual ~TaskRunner();
 
@@ -156,7 +156,7 @@ private:
      */
     Task _waitForNextTask();
 
-    OldThreadPool* _threadPool;
+    ThreadPool* _threadPool;
 
     // Protects member data of this TaskRunner.
     mutable stdx::mutex _mutex;
diff --git a/src/mongo/db/repl/task_runner_test.cpp b/src/mongo/db/repl/task_runner_test.cpp
index d2f9d3440e0..0be2eebb0cd 100644
--- a/src/mongo/db/repl/task_runner_test.cpp
+++ b/src/mongo/db/repl/task_runner_test.cpp
@@ -36,7 +36,7 @@
 #include "mongo/stdx/condition_variable.h"
 #include "mongo/stdx/mutex.h"
 #include "mongo/unittest/barrier.h"
-#include "mongo/util/concurrency/old_thread_pool.h"
+#include "mongo/util/concurrency/thread_pool.h"
 
 namespace {
 
@@ -68,7 +68,7 @@ TEST_F(TaskRunnerTest, CallbackValues) {
         return TaskRunner::NextAction::kCancel;
     };
     getTaskRunner().schedule(task);
-    getThreadPool().join();
+    getThreadPool().waitForIdle();
     ASSERT_FALSE(getTaskRunner().isActive());
 
     stdx::lock_guard<stdx::mutex> lk(mutex);
@@ -107,7 +107,7 @@ OpIdVector _testRunTaskTwice(TaskRunnerTest& test,
     ASSERT_TRUE(test.getTaskRunner().isActive());
     barrier.countDownAndWait();
 
-    test.getThreadPool().join();
+    test.getThreadPool().waitForIdle();
     ASSERT_FALSE(test.getTaskRunner().isActive());
 
     stdx::lock_guard<stdx::mutex> lk(mutex);
@@ -133,7 +133,7 @@ TEST_F(TaskRunnerTest, RunTaskTwiceDisposeOperationContext) {
 // thread back to pool after disposing of operation context.
 TEST_F(TaskRunnerTest, RunTaskTwiceDisposeOperationContextJoinThreadPoolBeforeScheduling) {
     auto schedule = [this](const Task& task) {
-        getThreadPool().join();
+        getThreadPool().waitForIdle();
         getTaskRunner().schedule(task);
     };
     auto txnId =
@@ -177,7 +177,7 @@ TEST_F(TaskRunnerTest, SkipSecondTask) {
         schedulingDone = true;
         condition.notify_all();
     }
-    getThreadPool().join();
+    getThreadPool().waitForIdle();
     ASSERT_FALSE(getTaskRunner().isActive());
 
     stdx::lock_guard<stdx::mutex> lk(mutex);
@@ -226,7 +226,7 @@ TEST_F(TaskRunnerTest, FirstTaskThrowsException) {
         schedulingDone = true;
         condition.notify_all();
     }
-    getThreadPool().join();
+    getThreadPool().waitForIdle();
     ASSERT_FALSE(getTaskRunner().isActive());
 
     stdx::lock_guard<stdx::mutex> lk(mutex);
@@ -270,7 +270,7 @@ TEST_F(TaskRunnerTest, Cancel) {
     getTaskRunner().cancel();
     getTaskRunner().cancel();
 
-    getThreadPool().join();
+    getThreadPool().waitForIdle();
     ASSERT_FALSE(getTaskRunner().isActive());
 
     // This status will not be OK if canceling the task runner
@@ -345,7 +345,7 @@ TEST_F(TaskRunnerTest, DestroyShouldWaitForTasksToComplete) {
 
     destroyTaskRunner();
 
-    getThreadPool().join();
+    getThreadPool().waitForIdle();
 
     // This status will not be OK if canceling the task runner
     // before scheduling the task results in the task being canceled.
diff --git a/src/mongo/db/repl/task_runner_test_fixture.cpp b/src/mongo/db/repl/task_runner_test_fixture.cpp
index 25360440871..f16bfa67be0 100644
--- a/src/mongo/db/repl/task_runner_test_fixture.cpp
+++ b/src/mongo/db/repl/task_runner_test_fixture.cpp
@@ -34,7 +34,6 @@
 #include "mongo/db/repl/task_runner.h"
 #include "mongo/stdx/functional.h"
 #include "mongo/stdx/memory.h"
-#include "mongo/util/concurrency/old_thread_pool.h"
 
 namespace mongo {
 namespace repl {
@@ -42,12 +41,6 @@ namespace repl {
 using namespace mongo;
 using namespace mongo::repl;
 
-namespace {
-
-const int kNumThreads = 3;
-
-}  // namespace
-
 Status TaskRunnerTest::getDetectableErrorStatus() {
     return Status(ErrorCodes::InternalError, "Not mutated");
 }
@@ -57,7 +50,7 @@ TaskRunner& TaskRunnerTest::getTaskRunner() const {
     return *_taskRunner;
 }
 
-OldThreadPool& TaskRunnerTest::getThreadPool() const {
+ThreadPool& TaskRunnerTest::getThreadPool() const {
     ASSERT(_threadPool.get());
     return *_threadPool;
 }
@@ -67,7 +60,11 @@ void TaskRunnerTest::destroyTaskRunner() {
 }
 
 void TaskRunnerTest::setUp() {
-    _threadPool = stdx::make_unique<OldThreadPool>(kNumThreads, "TaskRunnerTest-");
+    ThreadPool::Options options;
+    options.poolName = "TaskRunnerTest";
+    _threadPool = stdx::make_unique<ThreadPool>(options);
+    _threadPool->startup();
+
     _taskRunner = stdx::make_unique<TaskRunner>(_threadPool.get());
 }
 
diff --git a/src/mongo/db/repl/task_runner_test_fixture.h b/src/mongo/db/repl/task_runner_test_fixture.h
index 84351c01926..2787419a1e5 100644
--- a/src/mongo/db/repl/task_runner_test_fixture.h
+++ b/src/mongo/db/repl/task_runner_test_fixture.h
@@ -33,11 +33,11 @@
 #include "mongo/base/status.h"
 #include "mongo/db/service_context.h"
 #include "mongo/unittest/unittest.h"
+#include "mongo/util/concurrency/thread_pool.h"
 
 namespace mongo {
 
 class Client;
-class OldThreadPool;
 class OperationContext;
 
 namespace repl {
@@ -52,7 +52,7 @@ class TaskRunnerTest : public unittest::Test {
 public:
     static Status getDetectableErrorStatus();
 
-    OldThreadPool& getThreadPool() const;
+    ThreadPool& getThreadPool() const;
     TaskRunner& getTaskRunner() const;
 
     void destroyTaskRunner();
@@ -62,7 +62,7 @@ protected:
     void tearDown() override;
 
 private:
-    std::unique_ptr<OldThreadPool> _threadPool;
+    std::unique_ptr<ThreadPool> _threadPool;
     std::unique_ptr<TaskRunner> _taskRunner;
 };