SERVER-42398 On primary, abortTransaction and commitTransaction commands should not acquire ticket.

(cherry picked from commit 9dd11ed72971d6d5c00b9208e0200b6895658a87)

5 files changed, 20 insertions, 9 deletions

diff --git a/src/mongo/db/concurrency/d_concurrency_test.cpp b/src/mongo/db/concurrency/d_concurrency_test.cpp
index 191f74c219e..ab5ae795562 100644
--- a/src/mongo/db/concurrency/d_concurrency_test.cpp
+++ b/src/mongo/db/concurrency/d_concurrency_test.cpp
@@ -1196,7 +1196,7 @@ TEST_F(DConcurrencyTestFixture, NoThrottlingWhenNotAcquiringTickets) {
     UseGlobalThrottling throttle(opctx1, 1);
 
     // Prevent the enforcement of ticket throttling.
-    opctx1->lockState()->setShouldAcquireTicket(false);
+    opctx1->lockState()->skipAcquireTicket();
 
     // Both locks should be acquired immediately because there is no throttling.
     Lock::GlobalRead R1(opctx1, Date_t::now(), Lock::InterruptBehavior::kThrow);
diff --git a/src/mongo/db/concurrency/locker.h b/src/mongo/db/concurrency/locker.h
index db90b3b6e76..9bd9864794a 100644
--- a/src/mongo/db/concurrency/locker.h
+++ b/src/mongo/db/concurrency/locker.h
@@ -433,13 +433,15 @@ public:
     }
 
     /**
-     * If set to false, this opts out of the ticket mechanism. This should be used sparingly
-     * for special purpose threads, such as FTDC.
+     * This will opt out of the ticket mechanism. This should be used sparingly for special purpose
+     * threads, such as FTDC and committing or aborting transactions.
      */
-    void setShouldAcquireTicket(bool newValue) {
-        invariant(!isLocked() || isNoop());
-        _shouldAcquireTicket = newValue;
+    void skipAcquireTicket() {
+        // Should not hold or wait for the ticket.
+        invariant(isNoop() || getClientState() == Locker::ClientState::kInactive);
+        _shouldAcquireTicket = false;
     }
+
     bool shouldAcquireTicket() const {
         return _shouldAcquireTicket;
     }
diff --git a/src/mongo/db/ftdc/collector.cpp b/src/mongo/db/ftdc/collector.cpp
index 3f5696f95c8..3984c051083 100644
--- a/src/mongo/db/ftdc/collector.cpp
+++ b/src/mongo/db/ftdc/collector.cpp
@@ -69,7 +69,7 @@ std::tuple<BSONObj, Date_t> FTDCCollectorCollection::collect(Client* client) {
     // batches that are taking a long time.
     auto opCtx = client->makeOperationContext();
     ShouldNotConflictWithSecondaryBatchApplicationBlock shouldNotConflictBlock(opCtx->lockState());
-    opCtx->lockState()->setShouldAcquireTicket(false);
+    opCtx->lockState()->skipAcquireTicket();
 
     // Explicitly start future read transactions without a timestamp.
     opCtx->recoveryUnit()->setTimestampReadSource(RecoveryUnit::ReadSource::kNoTimestamp);
diff --git a/src/mongo/db/session.cpp b/src/mongo/db/session.cpp
index 337bd40baa5..7149b4fd085 100644
--- a/src/mongo/db/session.cpp
+++ b/src/mongo/db/session.cpp
@@ -779,6 +779,15 @@ void Session::unstashTransactionResources(OperationContext* opCtx, const std::st
             uassert(ErrorCodes::InvalidOptions,
                     "Only the first command in a transaction may specify a readConcern",
                     readConcernArgs.isEmpty());
+            // On primary, commitTransaction and abortTransaction commands can skip ticketing
+            // mechanism as they don't acquire any new storage resources (except writing to oplog)
+            // but they release any claimed storage resources.
+            if (opCtx->writesAreReplicated() &&
+                (cmdName == "commitTransaction" || cmdName == "abortTransaction")) {
+                auto stashLocker = _txnResourceStash->locker();
+                stashLocker->skipAcquireTicket();
+            }
+
             _txnResourceStash->release(opCtx);
             _txnResourceStash = boost::none;
             // Set the starting active time for this transaction.
diff --git a/src/mongo/db/session.h b/src/mongo/db/session.h
index 6070ddf109b..01d94721537 100644
--- a/src/mongo/db/session.h
+++ b/src/mongo/db/session.h
@@ -92,9 +92,9 @@ public:
         TxnResources& operator=(TxnResources&&) = default;
 
         /**
-         * Returns a const pointer to the stashed lock state, or nullptr if no stashed locks exist.
+         * Returns a pointer to the stashed lock state, or nullptr if no stashed locks exist.
          */
-        const Locker* locker() const {
+        Locker* locker() const {
             return _locker.get();
         }