SERVER-29802 add applyOps 'allowAtomic' flag.

This flag supports non-atomic application of CRUD operations if set to false.
Defaults to true.

(cherry picked from commit e7de30308564cead80857592ed27d938f73a91f1)

2 files changed, 10 insertions, 11 deletions

diff --git a/jstests/replsets/libs/apply_ops_insert_write_conflict.js b/jstests/replsets/libs/apply_ops_insert_write_conflict.js
index 88b299c08b6..d0a47f5b6d8 100644
--- a/jstests/replsets/libs/apply_ops_insert_write_conflict.js
+++ b/jstests/replsets/libs/apply_ops_insert_write_conflict.js
@@ -36,14 +36,6 @@ var ApplyOpsInsertWriteConflictTest = function(options) {
             return {op: 'i', ns: t.getFullName(), o: {_id: i}};
         });
 
-        if (!options.atomic) {
-            // Adding a command to the list of operations to prevent the applyOps command from
-            // applying
-            // all the operations atomically.
-            ops.push({ns: "test.$cmd", op: "c", o: {applyOps: []}});
-            numOps++;
-        }
-
         // Probabilities for WCE are chosen based on empirical testing.
         // The probability for WCE during an atomic applyOps should be much smaller than that for
         // the non-atomic case because we have to attempt to re-apply the entire batch of 'numOps'
@@ -62,7 +54,7 @@ var ApplyOpsInsertWriteConflictTest = function(options) {
         var previousLogLevel =
             assert.commandWorked(primaryDB.setLogLevel(3, 'replication')).was.replication.verbosity;
 
-        var applyOpsResult = primaryDB.adminCommand({applyOps: ops});
+        var applyOpsResult = primaryDB.adminCommand({applyOps: ops, allowAtomic: options.atomic});
 
         // Reset log level.
         primaryDB.setLogLevel(previousLogLevel, 'replication');
diff --git a/src/mongo/db/catalog/apply_ops.cpp b/src/mongo/db/catalog/apply_ops.cpp
index 154df461dd4..9118c2b6d18 100644
--- a/src/mongo/db/catalog/apply_ops.cpp
+++ b/src/mongo/db/catalog/apply_ops.cpp
@@ -32,6 +32,7 @@
 
 #include "mongo/db/catalog/apply_ops.h"
 
+#include "mongo/bson/util/bson_extract.h"
 #include "mongo/db/catalog/collection.h"
 #include "mongo/db/catalog/database.h"
 #include "mongo/db/catalog/database_holder.h"
@@ -56,7 +57,7 @@ namespace {
 /**
  * Return true iff the applyOpsCmd can be executed in a single WriteUnitOfWork.
  */
-bool canBeAtomic(const BSONObj& applyOpCmd) {
+bool _areOpsCrudOnly(const BSONObj& applyOpCmd) {
     for (const auto& elem : applyOpCmd.firstElement().Obj()) {
         const char* names[] = {"ns", "op"};
         BSONElement fields[2];
@@ -309,6 +310,12 @@ Status applyOps(OperationContext* opCtx,
                 const std::string& dbName,
                 const BSONObj& applyOpCmd,
                 BSONObjBuilder* result) {
+    bool allowAtomic = false;
+    uassertStatusOK(
+        bsonExtractBooleanFieldWithDefault(applyOpCmd, "allowAtomic", true, &allowAtomic));
+    auto areOpsCrudOnly = _areOpsCrudOnly(applyOpCmd);
+    auto isAtomic = allowAtomic && areOpsCrudOnly;
+
     ScopedTransaction scopedXact(opCtx, MODE_X);
     Lock::GlobalWrite globalWriteLock(opCtx->lockState());
 
@@ -325,7 +332,7 @@ Status applyOps(OperationContext* opCtx,
     }
 
     int numApplied = 0;
-    if (!canBeAtomic(applyOpCmd))
+    if (!isAtomic)
         return _applyOps(opCtx, dbName, applyOpCmd, result, &numApplied);
 
     // Perform write ops atomically