SERVER-25694 Eliminate race in PlanExecutor cleanup.

Ensures that a collection lock is held in at least MODE_IS while
deregistering a PlanExecutor from the cursor manager. Introduces new
PlanExecutor::dispose() and ClientCursor::dispose() methods that must be
called before destruction of those classes, and ensures they are called
before destruction. These calls will thread an OperationContext all the
way through to DocumentSource::dispose() for each stage in a Pipeline,
which will give DocumentSourceCursor a chance to acquire locks and
deregister its PlanExecutor if necessary.

1 files changed, 3 insertions, 2 deletions

diff --git a/src/mongo/db/commands/list_indexes.cpp b/src/mongo/db/commands/list_indexes.cpp
index 387cb7a376d..46d5d842d97 100644
--- a/src/mongo/db/commands/list_indexes.cpp
+++ b/src/mongo/db/commands/list_indexes.cpp
@@ -197,11 +197,11 @@ public:
         dassert(ns == cursorNss.getTargetNSForListIndexes());
 
         auto statusWithPlanExecutor = PlanExecutor::make(
-            opCtx, std::move(ws), std::move(root), cursorNss, PlanExecutor::YIELD_MANUAL);
+            opCtx, std::move(ws), std::move(root), cursorNss, PlanExecutor::NO_YIELD);
         if (!statusWithPlanExecutor.isOK()) {
             return appendCommandStatus(result, statusWithPlanExecutor.getStatus());
         }
-        unique_ptr<PlanExecutor> exec = std::move(statusWithPlanExecutor.getValue());
+        auto exec = std::move(statusWithPlanExecutor.getValue());
 
         BSONArrayBuilder firstBatch;
 
@@ -227,6 +227,7 @@ public:
             exec->saveState();
             exec->detachFromOperationContext();
             auto pinnedCursor = CursorManager::getGlobalCursorManager()->registerCursor(
+                opCtx,
                 {std::move(exec),
                  cursorNss,
                  AuthorizationSession::get(opCtx->getClient())->getAuthenticatedUserNames(),