SERVER-29908 Move more libraries from sharding into sharding_api_d/sharding_runtime_d

1 files changed, 28 insertions, 0 deletions

diff --git a/src/mongo/db/op_observer.cpp b/src/mongo/db/op_observer.cpp
index 7e0532b2225..87ce0fcfcfa 100644
--- a/src/mongo/db/op_observer.cpp
+++ b/src/mongo/db/op_observer.cpp
@@ -26,9 +26,12 @@
  *    it in the license file.
  */
 
+#include "mongo/platform/basic.h"
+
 #include "mongo/db/op_observer.h"
 
 #include "mongo/db/operation_context.h"
+
 namespace mongo {
 namespace {
 const auto getOpObserverTimes = OperationContext::declareDecoration<OpObserver::Times>();
@@ -38,4 +41,29 @@ auto OpObserver::Times::get(OperationContext* const opCtx) -> Times& {
     return getOpObserverTimes(opCtx);
 }
 
+OpObserver::ReservedTimes::ReservedTimes(OperationContext* const opCtx)
+    : _times(Times::get(opCtx)) {
+    // Every time that a `ReservedTimes` scope object is instantiated, we have to track if there was
+    // a potentially recursive call. When there was no `OpObserver` chain being executed before this
+    // instantiation, we should have an empty `reservedOpTimes` vector.
+    if (!_times._recursionDepth++) {
+        invariant(_times.reservedOpTimes.empty());
+    }
+
+    invariant(_times._recursionDepth > 0);
+    invariant(_times._recursionDepth == 1 || !opCtx->writesAreReplicated());
+}
+
+OpObserver::ReservedTimes::~ReservedTimes() {
+    // Every time the `ReservedTimes` guard goes out of scope, this indicates one fewer level of
+    // recursion in the `OpObserver` registered chain.
+    if (!--_times._recursionDepth) {
+        // When the depth hits 0, the `OpObserver` is considered to have finished, and therefore the
+        // `reservedOpTimes` state needs to be reset.
+        _times.reservedOpTimes.clear();
+    }
+
+    invariant(_times._recursionDepth >= 0);
+}
+
 }  // namespace mongo