SERVER-30170 Embedded can now shutdown and re-initialize.

- ServiceContext* is now closer to be an instance context for the database. We still don't support multiple instances but I wrote the new code with this in mind. Teardown and reinitialize then becomes a matter of being able to delete and re-create the ServiceContext*.
- Use the new MONGO_INITIALIZER that supports deinit/reinit to be able to re-initialize global systems that are decorations on ServiceContext.
- Move creation/destruction of ServiceContext* out of MONGO_INITIALIZER. This so we can hold an exclusive lock during as much as possible of the shutdown (like how mongod does)
- New ServiceContext registrer where we can link in different implementations of ServiceContext (replaces the SetGlobalEnvironment MONGO_INITIALIZER)
- As a result the SetGlobalEnvironment prerequisite for MONGO_INITIALIZERs is gone.
- The ServiceContext is passed to runGlobalInitializers, put in InitializationContext/DeinitializationContext so the initializers know which context they operate on.

1 files changed, 6 insertions, 5 deletions

diff --git a/src/mongo/tools/bridge.cpp b/src/mongo/tools/bridge.cpp
index 375c88bbc1b..5e5fcbf7417 100644
--- a/src/mongo/tools/bridge.cpp
+++ b/src/mongo/tools/bridge.cpp
@@ -39,6 +39,7 @@
 #include "mongo/db/dbmessage.h"
 #include "mongo/db/service_context.h"
 #include "mongo/db/service_context_noop.h"
+#include "mongo/db/service_context_registrar.h"
 #include "mongo/platform/atomic_word.h"
 #include "mongo/platform/random.h"
 #include "mongo/rpc/command_request.h"
@@ -391,10 +392,9 @@ private:
 
 std::unique_ptr<mongo::BridgeListener> listener;
 
-MONGO_INITIALIZER(SetGlobalEnvironment)(InitializerContext* context) {
-    setGlobalServiceContext(stdx::make_unique<ServiceContextNoop>());
-    return Status::OK();
-}
+ServiceContextRegistrar serviceContextCreator([]() {
+    return std::make_unique<ServiceContextNoop>();
+});
 
 }  // namespace
 
@@ -409,7 +409,8 @@ int bridgeMain(int argc, char** argv, char** envp) {
     });
 
     setupSignalHandlers();
-    runGlobalInitializersOrDie(argc, argv, envp);
+    setGlobalServiceContext(createServiceContext());
+    runGlobalInitializersOrDie(argc, argv, envp, getGlobalServiceContext());
     startSignalProcessingThread(LogFileStatus::kNoLogFileToRotate);
 
     auto serviceContext = getGlobalServiceContext();