SERVER-34260 Move bookkeeping functions into ConnectionInterface

8 files changed, 97 insertions, 114 deletions

diff --git a/src/mongo/executor/connection_pool.cpp b/src/mongo/executor/connection_pool.cpp
index 54107e04a2e..45b75798d80 100644
--- a/src/mongo/executor/connection_pool.cpp
+++ b/src/mongo/executor/connection_pool.cpp
@@ -28,7 +28,7 @@
  *    it in the license file.
  */
 
-#define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kASIO
+#define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kConnectionPool
 
 #include "mongo/platform/basic.h"
 
@@ -54,6 +54,36 @@
 namespace mongo {
 namespace executor {
 
+void ConnectionPool::ConnectionInterface::indicateUsed() {
+    // It is illegal to attempt to use a connection after calling indicateFailure().
+    invariant(_status.isOK() || _status == ConnectionPool::kConnectionStateUnknown);
+    _lastUsed = now();
+}
+
+void ConnectionPool::ConnectionInterface::indicateSuccess() {
+    _status = Status::OK();
+}
+
+void ConnectionPool::ConnectionInterface::indicateFailure(Status status) {
+    _status = std::move(status);
+}
+
+Date_t ConnectionPool::ConnectionInterface::getLastUsed() const {
+    return _lastUsed;
+}
+
+const Status& ConnectionPool::ConnectionInterface::getStatus() const {
+    return _status;
+}
+
+void ConnectionPool::ConnectionInterface::resetToUnknown() {
+    _status = ConnectionPool::kConnectionStateUnknown;
+}
+
+size_t ConnectionPool::ConnectionInterface::getGeneration() const {
+    return _generation;
+}
+
 /**
  * A pool for a specific HostAndPort
  *
diff --git a/src/mongo/executor/connection_pool.h b/src/mongo/executor/connection_pool.h
index e6525319571..ed3dac9c261 100644
--- a/src/mongo/executor/connection_pool.h
+++ b/src/mongo/executor/connection_pool.h
@@ -208,6 +208,11 @@ public:
      * It should be safe to cancel a previously canceled, or never set, timer.
      */
     virtual void cancelTimeout() = 0;
+
+    /**
+     * Returns the current time for the clock used by the timer
+     */
+    virtual Date_t now() = 0;
 };
 
 /**
@@ -223,21 +228,22 @@ class ConnectionPool::ConnectionInterface : public TimerInterface {
     friend class ConnectionPool;
 
 public:
-    ConnectionInterface() = default;
+    explicit ConnectionInterface(size_t generation) : _generation(generation) {}
+
     virtual ~ConnectionInterface() = default;
 
     /**
      * Indicates that the user is now done with this connection. Users MUST call either
      * this method or indicateFailure() before returning the connection to its pool.
      */
-    virtual void indicateSuccess() = 0;
+    void indicateSuccess();
 
     /**
      * Indicates that a connection has failed. This will prevent the connection
      * from re-entering the connection pool. Users MUST call either this method or
      * indicateSuccess() before returning connections to the pool.
      */
-    virtual void indicateFailure(Status status) = 0;
+    void indicateFailure(Status status);
 
     /**
      * This method updates a 'liveness' timestamp to avoid unnecessarily refreshing
@@ -248,7 +254,7 @@ public:
      * back in without use, one would expect an indicateSuccess without an indicateUsed.  Only if we
      * checked it out and did work would we call indicateUsed.
      */
-    virtual void indicateUsed() = 0;
+    void indicateUsed();
 
     /**
      * The HostAndPort for the connection. This should be the same as the
@@ -262,25 +268,33 @@ public:
      */
     virtual bool isHealthy() = 0;
 
-protected:
-    /**
-     * Making these protected makes the definitions available to override in
-     * children.
-     */
-    using SetupCallback = stdx::function<void(ConnectionInterface*, Status)>;
-    using RefreshCallback = stdx::function<void(ConnectionInterface*, Status)>;
-
-private:
     /**
      * Returns the last used time point for the connection
      */
-    virtual Date_t getLastUsed() const = 0;
+    Date_t getLastUsed() const;
 
     /**
      * Returns the status associated with the connection. If the status is not
      * OK, the connection will not be returned to the pool.
      */
-    virtual const Status& getStatus() const = 0;
+    const Status& getStatus() const;
+
+    /**
+     * Get the generation of the connection. This is used to track whether to
+     * continue using a connection after a call to dropConnections() by noting
+     * if the generation on the specific pool is the same as the generation on
+     * a connection (if not the connection is from a previous era and should
+     * not be re-used).
+     */
+    size_t getGeneration() const;
+
+protected:
+    /**
+     * Making these protected makes the definitions available to override in
+     * children.
+     */
+    using SetupCallback = stdx::function<void(ConnectionInterface*, Status)>;
+    using RefreshCallback = stdx::function<void(ConnectionInterface*, Status)>;
 
     /**
      * Sets up the connection. This should include connection + auth + any
@@ -291,7 +305,7 @@ private:
     /**
      * Resets the connection's state to kConnectionStateUnknown for the next user.
      */
-    virtual void resetToUnknown() = 0;
+    void resetToUnknown();
 
     /**
      * Refreshes the connection. This should involve a network round trip and
@@ -299,14 +313,10 @@ private:
      */
     virtual void refresh(Milliseconds timeout, RefreshCallback cb) = 0;
 
-    /**
-     * Get the generation of the connection. This is used to track whether to
-     * continue using a connection after a call to dropConnections() by noting
-     * if the generation on the specific pool is the same as the generation on
-     * a connection (if not the connection is from a previous era and should
-     * not be re-used).
-     */
-    virtual size_t getGeneration() const = 0;
+private:
+    size_t _generation;
+    Date_t _lastUsed;
+    Status _status = ConnectionPool::kConnectionStateUnknown;
 };
 
 /**
diff --git a/src/mongo/executor/connection_pool_test_fixture.cpp b/src/mongo/executor/connection_pool_test_fixture.cpp
index f032b81039e..9e5f5338c47 100644
--- a/src/mongo/executor/connection_pool_test_fixture.cpp
+++ b/src/mongo/executor/connection_pool_test_fixture.cpp
@@ -77,29 +77,21 @@ void TimerImpl::fireIfNecessary() {
     }
 }
 
+Date_t TimerImpl::now() {
+    return _global->now();
+}
+
 std::set<TimerImpl*> TimerImpl::_timers;
 
 ConnectionImpl::ConnectionImpl(const HostAndPort& hostAndPort, size_t generation, PoolImpl* global)
-    : _hostAndPort(hostAndPort),
+    : ConnectionInterface(generation),
+      _hostAndPort(hostAndPort),
       _timer(global),
       _global(global),
-      _id(_idCounter++),
-      _generation(generation) {}
-
-void ConnectionImpl::indicateUsed() {
-    _lastUsed = _global->now();
-}
-
-void ConnectionImpl::indicateSuccess() {
-    _status = Status::OK();
-}
-
-void ConnectionImpl::indicateFailure(Status status) {
-    _status = std::move(status);
-}
+      _id(_idCounter++) {}
 
-void ConnectionImpl::resetToUnknown() {
-    _status = ConnectionPool::kConnectionStateUnknown;
+Date_t ConnectionImpl::now() {
+    return _timer.now();
 }
 
 size_t ConnectionImpl::id() const {
@@ -168,14 +160,6 @@ size_t ConnectionImpl::refreshQueueDepth() {
     return _refreshQueue.size();
 }
 
-Date_t ConnectionImpl::getLastUsed() const {
-    return _lastUsed;
-}
-
-const Status& ConnectionImpl::getStatus() const {
-    return _status;
-}
-
 void ConnectionImpl::setTimeout(Milliseconds timeout, TimeoutCallback cb) {
     _timer.setTimeout(timeout, cb);
 }
@@ -227,10 +211,6 @@ void ConnectionImpl::refresh(Milliseconds timeout, RefreshCallback cb) {
     }
 }
 
-size_t ConnectionImpl::getGeneration() const {
-    return _generation;
-}
-
 std::deque<ConnectionImpl::PushSetupCallback> ConnectionImpl::_pushSetupQueue;
 std::deque<ConnectionImpl::PushRefreshCallback> ConnectionImpl::_pushRefreshQueue;
 std::deque<ConnectionImpl*> ConnectionImpl::_setupQueue;
diff --git a/src/mongo/executor/connection_pool_test_fixture.h b/src/mongo/executor/connection_pool_test_fixture.h
index e9215e3244f..eb3760d7b5b 100644
--- a/src/mongo/executor/connection_pool_test_fixture.h
+++ b/src/mongo/executor/connection_pool_test_fixture.h
@@ -53,6 +53,8 @@ public:
 
     void cancelTimeout() override;
 
+    Date_t now() override;
+
     // launches all timers for whom now() has passed
     static void fireIfNecessary();
 
@@ -83,11 +85,6 @@ public:
 
     size_t id() const;
 
-    void indicateSuccess() override;
-    void indicateFailure(Status status) override;
-
-    void resetToUnknown() override;
-
     const HostAndPort& getHostAndPort() const override;
     transport::ConnectSSLMode getSslMode() const override {
         return transport::kGlobalSSLMode;
@@ -108,32 +105,23 @@ public:
     static void pushRefresh(Status status);
     static size_t refreshQueueDepth();
 
-private:
-    void indicateUsed() override;
-
-    Date_t getLastUsed() const override;
-
-    const Status& getStatus() const override;
-
     void setTimeout(Milliseconds timeout, TimeoutCallback cb) override;
 
     void cancelTimeout() override;
 
+    Date_t now() override;
+
+private:
     void setup(Milliseconds timeout, SetupCallback cb) override;
 
     void refresh(Milliseconds timeout, RefreshCallback cb) override;
 
-    size_t getGeneration() const override;
-
     HostAndPort _hostAndPort;
-    Date_t _lastUsed;
-    Status _status = Status::OK();
     SetupCallback _setupCallback;
     RefreshCallback _refreshCallback;
     TimerImpl _timer;
     PoolImpl* _global;
     size_t _id;
-    size_t _generation;
 
     // Answer queues
     static std::deque<PushSetupCallback> _pushSetupQueue;
diff --git a/src/mongo/executor/connection_pool_tl.cpp b/src/mongo/executor/connection_pool_tl.cpp
index 344fcac81cc..14c73d50cba 100644
--- a/src/mongo/executor/connection_pool_tl.cpp
+++ b/src/mongo/executor/connection_pool_tl.cpp
@@ -115,12 +115,8 @@ void TLTimer::cancelTimeout() {
     _timer->cancel();
 }
 
-void TLConnection::indicateSuccess() {
-    _status = Status::OK();
-}
-
-void TLConnection::indicateFailure(Status status) {
-    _status = std::move(status);
+Date_t TLTimer::now() {
+    return _reactor->now();
 }
 
 const HostAndPort& TLConnection::getHostAndPort() const {
@@ -139,20 +135,6 @@ AsyncDBClient* TLConnection::client() {
     return _client.get();
 }
 
-void TLConnection::indicateUsed() {
-    // It is illegal to attempt to use a connection after calling indicateFailure().
-    invariant(_status.isOK() || _status == ConnectionPool::kConnectionStateUnknown);
-    _lastUsed = _reactor->now();
-}
-
-Date_t TLConnection::getLastUsed() const {
-    return _lastUsed;
-}
-
-const Status& TLConnection::getStatus() const {
-    return _status;
-}
-
 void TLConnection::setTimeout(Milliseconds timeout, TimeoutCallback cb) {
     auto anchor = shared_from_this();
     _timer->setTimeout(timeout, [ cb = std::move(cb), anchor = std::move(anchor) ] { cb(); });
@@ -292,10 +274,6 @@ void TLConnection::setup(Milliseconds timeout, SetupCallback cb) {
     LOG(2) << "Finished connection setup.";
 }
 
-void TLConnection::resetToUnknown() {
-    _status = ConnectionPool::kConnectionStateUnknown;
-}
-
 void TLConnection::refresh(Milliseconds timeout, RefreshCallback cb) {
     auto anchor = shared_from_this();
 
@@ -309,10 +287,10 @@ void TLConnection::refresh(Milliseconds timeout, RefreshCallback cb) {
             return;
         }
 
-        _status = {ErrorCodes::HostUnreachable, "Timed out refreshing host"};
+        indicateFailure({ErrorCodes::HostUnreachable, "Timed out refreshing host"});
         _client->cancel();
 
-        handler->promise.setError(_status);
+        handler->promise.setError(getStatus());
     });
 
     _client
@@ -328,17 +306,18 @@ void TLConnection::refresh(Milliseconds timeout, RefreshCallback cb) {
 
             cancelTimeout();
 
-            _status = status;
             if (status.isOK()) {
+                indicateSuccess();
                 handler->promise.emplaceValue();
             } else {
+                indicateFailure(status);
                 handler->promise.setError(status);
             }
         });
 }
 
-size_t TLConnection::getGeneration() const {
-    return _generation;
+Date_t TLConnection::now() {
+    return _reactor->now();
 }
 
 void TLConnection::cancelAsync() {
diff --git a/src/mongo/executor/connection_pool_tl.h b/src/mongo/executor/connection_pool_tl.h
index e97dda4c44e..3c40b62047d 100644
--- a/src/mongo/executor/connection_pool_tl.h
+++ b/src/mongo/executor/connection_pool_tl.h
@@ -112,6 +112,7 @@ public:
 
     void setTimeout(Milliseconds timeout, TimeoutCallback cb) override;
     void cancelTimeout() override;
+    Date_t now() override;
 
 private:
     transport::ReactorHandle _reactor;
@@ -127,13 +128,13 @@ public:
                  transport::ConnectSSLMode sslMode,
                  size_t generation,
                  NetworkConnectionHook* onConnectHook)
-        : TLTypeFactory::Type(factory),
+        : ConnectionInterface(generation),
+          TLTypeFactory::Type(factory),
           _reactor(reactor),
           _serviceContext(serviceContext),
           _timer(factory->makeTimer()),
           _peer(std::move(peer)),
           _sslMode(sslMode),
-          _generation(generation),
           _onConnectHook(onConnectHook) {}
     ~TLConnection() {
         // Release must be the first expression of this dtor
@@ -144,27 +145,19 @@ public:
         cancelAsync();
     }
 
-    void indicateSuccess() override;
-    void indicateFailure(Status status) override;
-    void indicateUsed() override;
     const HostAndPort& getHostAndPort() const override;
     transport::ConnectSSLMode getSslMode() const override;
     bool isHealthy() override;
     AsyncDBClient* client();
+    Date_t now() override;
 
 private:
-    Date_t getLastUsed() const override;
-    const Status& getStatus() const override;
-
     void setTimeout(Milliseconds timeout, TimeoutCallback cb) override;
     void cancelTimeout() override;
     void setup(Milliseconds timeout, SetupCallback cb) override;
-    void resetToUnknown() override;
     void refresh(Milliseconds timeout, RefreshCallback cb) override;
     void cancelAsync();
 
-    size_t getGeneration() const override;
-
 private:
     transport::ReactorHandle _reactor;
     ServiceContext* const _serviceContext;
@@ -172,11 +165,8 @@ private:
 
     HostAndPort _peer;
     transport::ConnectSSLMode _sslMode;
-    size_t _generation;
     NetworkConnectionHook* const _onConnectHook;
     AsyncDBClient::Handle _client;
-    Date_t _lastUsed;
-    Status _status = ConnectionPool::kConnectionStateUnknown;
 };
 
 }  // namespace connection_pool_asio
diff --git a/src/mongo/logger/log_component.cpp b/src/mongo/logger/log_component.cpp
index 5d1d8fd22be..9e2115eeefc 100644
--- a/src/mongo/logger/log_component.cpp
+++ b/src/mongo/logger/log_component.cpp
@@ -77,6 +77,7 @@ LogComponent LogComponent::parent() const {
             return kNumLogComponents;
             DECLARE_LOG_COMPONENT_PARENT(kJournal, kStorage);
             DECLARE_LOG_COMPONENT_PARENT(kASIO, kNetwork);
+            DECLARE_LOG_COMPONENT_PARENT(kConnectionPool, kNetwork);
             DECLARE_LOG_COMPONENT_PARENT(kBridge, kNetwork);
             DECLARE_LOG_COMPONENT_PARENT(kReplicationElection, kReplication);
             DECLARE_LOG_COMPONENT_PARENT(kReplicationHeartbeats, kReplication);
@@ -144,6 +145,8 @@ StringData LogComponent::toStringData() const {
             return "tracking"_sd;
         case kTransaction:
             return "transaction"_sd;
+        case kConnectionPool:
+            return "connectionPool"_sd;
         case kNumLogComponents:
             return "total"_sd;
             // No default. Compiler should complain if there's a log component that's not handled.
@@ -230,6 +233,8 @@ StringData LogComponent::getNameForLog() const {
             return "TRACKING"_sd;
         case kTransaction:
             return "TXN     "_sd;
+        case kConnectionPool:
+            return "CONNPOOL"_sd;
         case kNumLogComponents:
             return "TOTAL   "_sd;
             // No default. Compiler should complain if there's a log component that's not handled.
diff --git a/src/mongo/logger/log_component.h b/src/mongo/logger/log_component.h
index 8bf52c8b3f8..e4e328db154 100644
--- a/src/mongo/logger/log_component.h
+++ b/src/mongo/logger/log_component.h
@@ -71,6 +71,7 @@ public:
         kBridge,
         kTracking,
         kTransaction,
+        kConnectionPool,
         kNumLogComponents
     };