SERVER-29305 `dbdirectclient::call` uses OpContext

Presently it directly calls `assembleResponse`, which is responsible
for a cyclic dependency.  This functionality is available through
the `ServiceContext` mechanism, and thus needn't directly use
`assembleResponse`.

The `ServiceEntryPoint` member of `ServiceContext` is set through
a setter, which isn't always called, so we initialize the global
entry through a factory function.

7 files changed, 24 insertions, 15 deletions

diff --git a/src/mongo/SConscript b/src/mongo/SConscript
index 1687378dda5..742c2712d6e 100644
--- a/src/mongo/SConscript
+++ b/src/mongo/SConscript
@@ -279,7 +279,6 @@ mongod = env.Program(
     source=[
         "db/db.cpp",
         "db/mongod_options_init.cpp",
-        "db/service_entry_point_mongod.cpp",
     ] + env.WindowsResourceFile("db/db.rc"),
     LIBDEPS=[
         'db/assemble_response',
diff --git a/src/mongo/db/SConscript b/src/mongo/db/SConscript
index 0daaca784dd..620ba75bf7f 100644
--- a/src/mongo/db/SConscript
+++ b/src/mongo/db/SConscript
@@ -547,7 +547,6 @@ env.Library(
         '$BUILD_DIR/mongo/client/clientdriver',
         'curop',
         'lasterror',
-        'assemble_response',
     ],
 )
 
@@ -567,9 +566,13 @@ env.Library(
     target="service_context_d",
     source=[
         "service_context_d.cpp",
+        "service_entry_point_mongod.cpp",
     ],
     LIBDEPS=[
         '$BUILD_DIR/mongo/base',
+        '$BUILD_DIR/mongo/transport/service_entry_point',
+        '$BUILD_DIR/mongo/transport/transport_layer_common',
+        'assemble_response',
         'concurrency/lock_manager',
         'curop',
         'storage/storage_engine_lock_file',
diff --git a/src/mongo/db/db.cpp b/src/mongo/db/db.cpp
index 94cd4bbe97c..980310ec1ef 100644
--- a/src/mongo/db/db.cpp
+++ b/src/mongo/db/db.cpp
@@ -488,9 +488,6 @@ ExitCode _initAndListen(int listenPort) {
     options.port = listenPort;
     options.ipList = serverGlobalParams.bind_ip;
 
-    globalServiceContext->setServiceEntryPoint(
-        stdx::make_unique<ServiceEntryPointMongod>(globalServiceContext));
-
     // Create, start, and attach the TL
     auto transportLayer = stdx::make_unique<transport::TransportLayerLegacy>(
         options, globalServiceContext->getServiceEntryPoint());
diff --git a/src/mongo/db/dbdirectclient.cpp b/src/mongo/db/dbdirectclient.cpp
index 60a001f534e..46a7d30b0f9 100644
--- a/src/mongo/db/dbdirectclient.cpp
+++ b/src/mongo/db/dbdirectclient.cpp
@@ -32,7 +32,6 @@
 
 #include "mongo/db/dbdirectclient.h"
 
-#include "mongo/db/assemble_response.h"
 #include "mongo/db/client.h"
 #include "mongo/db/commands.h"
 #include "mongo/db/curop.h"
@@ -40,6 +39,7 @@
 #include "mongo/db/operation_context.h"
 #include "mongo/db/wire_version.h"
 #include "mongo/rpc/get_status_from_command_result.h"
+#include "mongo/transport/service_entry_point.h"
 #include "mongo/util/log.h"
 
 namespace mongo {
@@ -119,12 +119,19 @@ QueryOptions DBDirectClient::_lookupAvailableOptions() {
     return QueryOptions(DBClientBase::_lookupAvailableOptions() & ~QueryOption_Exhaust);
 }
 
+namespace {
+DbResponse loopbackBuildResponse(OperationContext* const opCtx, Message& toSend) {
+    return opCtx->getServiceContext()->getServiceEntryPoint()->handleRequest(
+        opCtx, toSend, HostAndPort{});
+}
+}  // namespace
+
 bool DBDirectClient::call(Message& toSend, Message& response, bool assertOk, string* actualServer) {
     DirectClientScope directClientScope(_opCtx);
     LastError::get(_opCtx->getClient()).startRequest();
 
     CurOp curOp(_opCtx);
-    auto dbResponse = assembleResponse(_opCtx, toSend, kHostAndPortForDirectClient);
+    auto dbResponse = loopbackBuildResponse(_opCtx, toSend);
     invariant(!dbResponse.response.empty());
     response = std::move(dbResponse.response);
 
@@ -136,7 +143,7 @@ void DBDirectClient::say(Message& toSend, bool isRetry, string* actualServer) {
     LastError::get(_opCtx->getClient()).startRequest();
 
     CurOp curOp(_opCtx);
-    auto dbResponse = assembleResponse(_opCtx, toSend, kHostAndPortForDirectClient);
+    auto dbResponse = loopbackBuildResponse(_opCtx, toSend);
     invariant(dbResponse.response.empty());
 }
 
diff --git a/src/mongo/db/service_context.h b/src/mongo/db/service_context.h
index 566ed7fb650..c4f41bd5651 100644
--- a/src/mongo/db/service_context.h
+++ b/src/mongo/db/service_context.h
@@ -389,7 +389,7 @@ public:
     void setPreciseClockSource(std::unique_ptr<ClockSource> newSource);
 
     /**
-     * Binds the service entry point implementation to the service context
+     * Binds the service entry point implementation to the service context.
      */
     void setServiceEntryPoint(std::unique_ptr<ServiceEntryPoint> sep);
 
diff --git a/src/mongo/db/service_context_d.cpp b/src/mongo/db/service_context_d.cpp
index f1dd329781b..f3e40ee053b 100644
--- a/src/mongo/db/service_context_d.cpp
+++ b/src/mongo/db/service_context_d.cpp
@@ -40,6 +40,7 @@
 #include "mongo/db/concurrency/lock_state.h"
 #include "mongo/db/op_observer.h"
 #include "mongo/db/service_context.h"
+#include "mongo/db/service_entry_point_mongod.h"
 #include "mongo/db/storage/storage_engine.h"
 #include "mongo/db/storage/storage_engine_lock_file.h"
 #include "mongo/db/storage/storage_engine_metadata.h"
@@ -56,14 +57,17 @@
 
 namespace mongo {
 namespace {
-
-MONGO_INITIALIZER(SetGlobalEnvironment)(InitializerContext* context) {
-    setGlobalServiceContext(stdx::make_unique<ServiceContextMongoD>());
-    auto service = getGlobalServiceContext();
-
+auto makeMongoDServiceContext() {
+    auto service = stdx::make_unique<ServiceContextMongoD>();
+    service->setServiceEntryPoint(stdx::make_unique<ServiceEntryPointMongod>(service.get()));
     service->setTickSource(stdx::make_unique<SystemTickSource>());
     service->setFastClockSource(stdx::make_unique<SystemClockSource>());
     service->setPreciseClockSource(stdx::make_unique<SystemClockSource>());
+    return service;
+}
+
+MONGO_INITIALIZER(SetGlobalEnvironment)(InitializerContext* context) {
+    setGlobalServiceContext(makeMongoDServiceContext());
     return Status::OK();
 }
 }  // namespace
diff --git a/src/mongo/db/service_context_noop.cpp b/src/mongo/db/service_context_noop.cpp
index 42fd30f3f3c..993d7fccfeb 100644
--- a/src/mongo/db/service_context_noop.cpp
+++ b/src/mongo/db/service_context_noop.cpp
@@ -35,7 +35,6 @@
 #include "mongo/stdx/memory.h"
 
 namespace mongo {
-
 StorageEngine* ServiceContextNoop::getGlobalStorageEngine() {
     return NULL;
 }