SERVER-17328 add invariant that collection is non-null to planning stages (CachedPlan/Subplan/MultiPlan)

6 files changed, 14 insertions, 5 deletions

diff --git a/src/mongo/db/exec/cached_plan.cpp b/src/mongo/db/exec/cached_plan.cpp
index d08d0e1bfd9..a8d2d1d592b 100644
--- a/src/mongo/db/exec/cached_plan.cpp
+++ b/src/mongo/db/exec/cached_plan.cpp
@@ -66,7 +66,9 @@ namespace mongo {
           _plannerParams(params),
           _decisionWorks(decisionWorks),
           _root(root),
-          _commonStats(kStageType) {}
+          _commonStats(kStageType) {
+        invariant(_collection);
+    }
 
     Status CachedPlanStage::pickBestPlan(PlanYieldPolicy* yieldPolicy) {
         // Adds the amount of time taken by pickBestPlan() to executionTimeMillis. There's lots of
diff --git a/src/mongo/db/exec/cached_plan.h b/src/mongo/db/exec/cached_plan.h
index 206258736aa..c5d15fb7cac 100644
--- a/src/mongo/db/exec/cached_plan.h
+++ b/src/mongo/db/exec/cached_plan.h
@@ -121,7 +121,7 @@ namespace mongo {
         // Not owned.
         OperationContext* _txn;
 
-        // Not owned.
+        // Not owned. Must be non-null.
         Collection* _collection;
 
         // Not owned.
diff --git a/src/mongo/db/exec/multi_plan.cpp b/src/mongo/db/exec/multi_plan.cpp
index 96680c38029..3ad74d752ce 100644
--- a/src/mongo/db/exec/multi_plan.cpp
+++ b/src/mongo/db/exec/multi_plan.cpp
@@ -72,7 +72,9 @@ namespace mongo {
           _failure(false),
           _failureCount(0),
           _statusMemberId(WorkingSet::INVALID_ID),
-          _commonStats(kStageType) { }
+          _commonStats(kStageType) {
+        invariant(_collection);
+    }
 
     MultiPlanStage::~MultiPlanStage() {
         for (size_t ix = 0; ix < _candidates.size(); ++ix) {
diff --git a/src/mongo/db/exec/multi_plan.h b/src/mongo/db/exec/multi_plan.h
index ad55afa8d2e..43596aea247 100644
--- a/src/mongo/db/exec/multi_plan.h
+++ b/src/mongo/db/exec/multi_plan.h
@@ -173,8 +173,10 @@ namespace mongo {
 
         static const int kNoSuchPlan = -1;
 
-        // not owned here
+        // Not owned here.
         OperationContext* _txn;
+
+        // Not owned here. Must be non-null.
         const Collection* _collection;
 
         // Whether or not we should try to cache the winning plan in the plan cache.
diff --git a/src/mongo/db/exec/subplan.cpp b/src/mongo/db/exec/subplan.cpp
index d86640ed3f6..88cb23e5642 100644
--- a/src/mongo/db/exec/subplan.cpp
+++ b/src/mongo/db/exec/subplan.cpp
@@ -63,7 +63,9 @@ namespace mongo {
           _plannerParams(params),
           _query(cq),
           _child(NULL),
-          _commonStats(kStageType) { }
+          _commonStats(kStageType) {
+        invariant(_collection);
+    }
 
     // static
     bool SubplanStage::canUseSubplanning(const CanonicalQuery& query) {
diff --git a/src/mongo/db/exec/subplan.h b/src/mongo/db/exec/subplan.h
index ec275c66a92..190da7988f9 100644
--- a/src/mongo/db/exec/subplan.h
+++ b/src/mongo/db/exec/subplan.h
@@ -167,6 +167,7 @@ namespace mongo {
         // transactional context for read locks. Not owned by us
         OperationContext* _txn;
 
+        // Not owned here. Must be non-null.
         Collection* _collection;
 
         // Not owned here.