Clarify some comments around SharedRecoveryState in xlog.c
SharedRecoveryState has been switched from a boolean to an enum as of
commit but some comments still referred to it as a boolean.
Author: Amul Sul
Discussion:
@@ -7998,17 +7998,16 @@ StartupXLOG(void)
* All done with end-of-recovery actions.
*
* Now allow backends to write WAL and update the control file status in
- * consequence. The boolean flag allowing backends to write WAL is
- * updated while holding ControlFileLock to prevent other backends to look
- * at an inconsistent state of the control file in shared memory. There
- * is still a small window during which backends can write WAL and the
- * control file is still referring to a system not in DB_IN_PRODUCTION
+ * consequence. SharedRecoveryState, that controls if backends can write
+ * WAL, is updated while holding ControlFileLock to prevent other backends
+ * to look at an inconsistent state of the control file in shared memory.
+ * There is still a small window during which backends can write WAL and
+ * the control file is still referring to a system not in DB_IN_PRODUCTION
* state while looking at the on-disk control file.
*
- * Also, although the boolean flag to allow WAL is probably atomic in
- * itself, we use the info_lck here to ensure that there are no race
- * conditions concerning visibility of other recent updates to shared
- * memory.
+ * Also, we use info_lck to update SharedRecoveryState to ensure that
+ * there are no race conditions concerning visibility of other recent
+ * updates to shared memory.
*/
LWLockAcquire(ControlFileLock, LW_EXCLUSIVE);
ControlFile->state = DB_IN_PRODUCTION;
