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, 4 insertions, 3 deletions

diff --git a/src/mongo/db/db.cpp b/src/mongo/db/db.cpp
index cacb7f941a3..beb87a5d086 100644
--- a/src/mongo/db/db.cpp
+++ b/src/mongo/db/db.cpp
@@ -118,6 +118,7 @@
 #include "mongo/db/server_parameters.h"
 #include "mongo/db/service_context.h"
 #include "mongo/db/service_context_d.h"
+#include "mongo/db/service_context_registrar.h"
 #include "mongo/db/service_entry_point_mongod.h"
 #include "mongo/db/session_catalog.h"
 #include "mongo/db/session_killer.h"
@@ -757,8 +758,7 @@ auto makeReplicationExecutor(ServiceContext* serviceContext) {
             "NetworkInterfaceASIO-Replication", nullptr, std::move(hookList)));
 }
 
-MONGO_INITIALIZER_WITH_PREREQUISITES(CreateReplicationManager,
-                                     ("SetGlobalEnvironment", "SSLManager", "default"))
+MONGO_INITIALIZER_WITH_PREREQUISITES(CreateReplicationManager, ("SSLManager", "default"))
 (InitializerContext* context) {
     auto serviceContext = getGlobalServiceContext();
     repl::StorageInterface::set(serviceContext, stdx::make_unique<repl::StorageInterfaceImpl>());
@@ -958,7 +958,8 @@ int mongoDbMain(int argc, char* argv[], char** envp) {
 
     srand(static_cast<unsigned>(curTimeMicros64()));
 
-    Status status = mongo::runGlobalInitializers(argc, argv, envp);
+    setGlobalServiceContext(createServiceContext());
+    Status status = mongo::runGlobalInitializers(argc, argv, envp, getGlobalServiceContext());
     if (!status.isOK()) {
         severe(LogComponent::kControl) << "Failed global initialization: " << status;
         quickExit(EXIT_FAILURE);