SERVER-18022 Read Majority Committed implementation for primary nodes

4 files changed, 24 insertions, 1 deletions

diff --git a/src/mongo/db/concurrency/d_concurrency.cpp b/src/mongo/db/concurrency/d_concurrency.cpp
index ae0526bb535..5e3c686f03d 100644
--- a/src/mongo/db/concurrency/d_concurrency.cpp
+++ b/src/mongo/db/concurrency/d_concurrency.cpp
@@ -206,4 +206,9 @@ void Lock::ResourceLock::unlock() {
     }
 }
 
+void synchronizeOnCappedInFlightResource(Locker* lockState) {
+    dassert(lockState->inAWriteUnitOfWork());
+    Lock::ResourceLock{lockState, resourceCappedInFlight, MODE_IX};  // held until end of WUOW.
+}
+
 }  // namespace mongo
diff --git a/src/mongo/db/concurrency/d_concurrency.h b/src/mongo/db/concurrency/d_concurrency.h
index b95b7b46fec..f6a115c61e9 100644
--- a/src/mongo/db/concurrency/d_concurrency.h
+++ b/src/mongo/db/concurrency/d_concurrency.h
@@ -280,4 +280,11 @@ public:
         ResourceLock _pbwm;
     };
 };
+
+/**
+ * Takes a lock on resourceCappedInFlight in MODE_IX which will be held until the end of your
+ * WUOW. This ensures that a MODE_X lock on this resource will wait for all in-flight capped
+ * inserts to either commit or rollback and block new ones from starting.
+ */
+void synchronizeOnCappedInFlightResource(Locker* txn);
 }
diff --git a/src/mongo/db/concurrency/lock_manager_defs.h b/src/mongo/db/concurrency/lock_manager_defs.h
index 63c3e6ebf50..86bce16a659 100644
--- a/src/mongo/db/concurrency/lock_manager_defs.h
+++ b/src/mongo/db/concurrency/lock_manager_defs.h
@@ -184,7 +184,8 @@ public:
         SINGLETON_INVALID = 0,
         SINGLETON_PARALLEL_BATCH_WRITER_MODE,
         SINGLETON_GLOBAL,
-        SINGLETON_MMAPV1_FLUSH
+        SINGLETON_MMAPV1_FLUSH,
+        SINGLETON_CAPPED_IN_FLIGHT,
     };
 
     ResourceId() : _fullHash(0) {}
@@ -260,6 +261,14 @@ extern const ResourceId resourceIdAdminDB;
 // TODO: Merge this with resourceIdGlobal
 extern const ResourceId resourceIdParallelBatchWriterMode;
 
+// Everywhere that starts in-flight capped inserts which allocate capped collection RecordIds in
+// a way that could trigger hiding of newer records takes this lock in MODE_IX and holds it
+// until the end of their WriteUnitOfWork.
+//
+// Threads that need a consistent view of the world can lock this in MODE_X to prevent
+// concurrent in-flight capped inserts.
+extern const ResourceId resourceCappedInFlight;
+
 /**
  * Interface on which granted lock requests will be notified. See the contract for the notify
  * method for more information and also the LockManager::lock call.
diff --git a/src/mongo/db/concurrency/lock_state.cpp b/src/mongo/db/concurrency/lock_state.cpp
index 37ca3c7f611..008646a586e 100644
--- a/src/mongo/db/concurrency/lock_state.cpp
+++ b/src/mongo/db/concurrency/lock_state.cpp
@@ -912,5 +912,7 @@ const ResourceId resourceIdOplog = ResourceId(RESOURCE_COLLECTION, StringData("l
 const ResourceId resourceIdAdminDB = ResourceId(RESOURCE_DATABASE, StringData("admin"));
 const ResourceId resourceIdParallelBatchWriterMode =
     ResourceId(RESOURCE_GLOBAL, ResourceId::SINGLETON_PARALLEL_BATCH_WRITER_MODE);
+const ResourceId resourceCappedInFlight =
+    ResourceId(RESOURCE_METADATA, ResourceId::SINGLETON_CAPPED_IN_FLIGHT);
 
 }  // namespace mongo