SERVER-5738 Remove MONGO_ONCE in favor of std::call_once

5 files changed, 20 insertions, 13 deletions

diff --git a/src/mongo/db/auth/authz_session_external_state_server_common.cpp b/src/mongo/db/auth/authz_session_external_state_server_common.cpp
index e2416596c4b..faf039ba7dc 100644
--- a/src/mongo/db/auth/authz_session_external_state_server_common.cpp
+++ b/src/mongo/db/auth/authz_session_external_state_server_common.cpp
@@ -32,6 +32,8 @@
 
 #include "mongo/db/auth/authz_session_external_state_server_common.h"
 
+#include <mutex>
+
 #include "mongo/base/status.h"
 #include "mongo/db/auth/authorization_manager.h"
 #include "mongo/db/client.h"
@@ -43,6 +45,7 @@ namespace mongo {
 
 namespace {
 MONGO_EXPORT_STARTUP_SERVER_PARAMETER(enableLocalhostAuthBypass, bool, true);
+std::once_flag checkShouldAllowLocalhostOnceFlag;
 }  // namespace
 
 // NOTE: we default _allowLocalhost to true under the assumption that _checkShouldAllowLocalhost
@@ -67,11 +70,11 @@ void AuthzSessionExternalStateServerCommon::_checkShouldAllowLocalhost(Operation
 
     _allowLocalhost = !_authzManager->hasAnyPrivilegeDocuments(txn);
     if (_allowLocalhost) {
-        ONCE {
+        std::call_once(checkShouldAllowLocalhostOnceFlag, []() {
             log() << "note: no users configured in admin.system.users, allowing localhost "
                      "access"
                   << std::endl;
-        }
+        });
     }
 }
 
diff --git a/src/mongo/db/storage/mmap_v1/btree/btree_logic.cpp b/src/mongo/db/storage/mmap_v1/btree/btree_logic.cpp
index b102d6f1b73..f6702fe27aa 100644
--- a/src/mongo/db/storage/mmap_v1/btree/btree_logic.cpp
+++ b/src/mongo/db/storage/mmap_v1/btree/btree_logic.cpp
@@ -30,6 +30,7 @@
 
 #include "mongo/platform/basic.h"
 
+#include <mutex>
 #include <numeric>
 
 #include "mongo/db/client.h"
@@ -69,6 +70,10 @@ using std::vector;
 //   creating a new right sibling, it is set as its parent's nextChild as all keys in the right
 //   sibling will be higher than all keys currently in the parent.
 
+namespace {
+std::once_flag assertValidFlag;
+}  // namespace
+
 //
 // Public Builder logic
 //
@@ -2136,9 +2141,7 @@ void BtreeLogic<BtreeLayout>::assertValid(const std::string& ns,
             // wassert( z <= 0 );
             if (z > 0) {
                 log() << "Btree keys out of order in collection " << ns;
-                ONCE {
-                    dumpBucket(bucket);
-                }
+                std::call_once(assertValidFlag, [&bucket]() { dumpBucket(bucket); });
                 invariant(false);
             }
         }
diff --git a/src/mongo/dbtests/basictests.cpp b/src/mongo/dbtests/basictests.cpp
index d9a16934d8e..0dd6f2a28d3 100644
--- a/src/mongo/dbtests/basictests.cpp
+++ b/src/mongo/dbtests/basictests.cpp
@@ -62,15 +62,12 @@ public:
     void run() {
         int first = 0;
         int second = 0;
-        int third = 0;
         for (int i = 0; i < 128; ++i) {
             incRarely(first);
             incRarely2(second);
-            ONCE++ third;
         }
         ASSERT_EQUALS(1, first);
         ASSERT_EQUALS(1, second);
-        ASSERT_EQUALS(1, third);
     }
 
 private:
diff --git a/src/mongo/util/debug_util.h b/src/mongo/util/debug_util.h
index 97b3011f1eb..f09072e63e9 100644
--- a/src/mongo/util/debug_util.h
+++ b/src/mongo/util/debug_util.h
@@ -54,7 +54,4 @@ const bool kDebugBuild = false;
 #define MONGO_RARELY SOMETIMES(rarely, 128)
 #define RARELY MONGO_RARELY
 
-#define MONGO_ONCE for (static bool undone = true; undone; undone = false)
-#define ONCE MONGO_ONCE
-
 }  // namespace mongo
diff --git a/src/mongo/util/debugger.cpp b/src/mongo/util/debugger.cpp
index 9682c54db14..cb9a8ca3598 100644
--- a/src/mongo/util/debugger.cpp
+++ b/src/mongo/util/debugger.cpp
@@ -32,6 +32,7 @@
 #include "mongo/util/debugger.h"
 
 #include <cstdlib>
+#include <mutex>
 
 #if defined(USE_GDBSERVER)
 #include <cstdio>
@@ -44,6 +45,12 @@
 
 #include "mongo/util/debug_util.h"
 
+#ifndef _WIN32
+namespace {
+std::once_flag breakpointOnceFlag;
+}  // namespace
+#endif
+
 namespace mongo {
 void breakpoint() {
 #ifdef _WIN32
@@ -53,7 +60,7 @@ void breakpoint() {
 #endif
 #ifndef _WIN32
     // code to raise a breakpoint in GDB
-    ONCE {
+    std::call_once(breakpointOnceFlag, []() {
         // prevent SIGTRAP from crashing the program if default action is specified and we are not
         // in gdb
         struct sigaction current;
@@ -63,7 +70,7 @@ void breakpoint() {
         if (current.sa_handler == SIG_DFL) {
             signal(SIGTRAP, SIG_IGN);
         }
-    }
+    });
 
     raise(SIGTRAP);
 #endif