src/include/storage/pmsignal.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * pmsignal.h
   4  *        routines for signaling the postmaster from its child processes
   5  *
   6  *
   7  * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
   8  * Portions Copyright (c) 1994, Regents of the University of California
   9  *
  10  * $PostgreSQL$
  11  *
  12  *-------------------------------------------------------------------------
  13  */
  14 #ifndef PMSIGNAL_H
  15 #define PMSIGNAL_H
  16
  17 /*
  18  * Reasons for signaling the postmaster.  We can cope with simultaneous
  19  * signals for different reasons.  If the same reason is signaled multiple
  20  * times in quick succession, however, the postmaster is likely to observe
  21  * only one notification of it.  This is okay for the present uses.
  22  */
  23 typedef enum
  24 {
  25         PMSIGNAL_RECOVERY_STARTED,      /* recovery has started */
  26         PMSIGNAL_RECOVERY_CONSISTENT,           /* recovery has reached consistent
  27                                                                                  * state */
  28         PMSIGNAL_PASSWORD_CHANGE,       /* pg_auth file has changed */
  29         PMSIGNAL_WAKEN_ARCHIVER,        /* send a NOTIFY signal to xlog archiver */
  30         PMSIGNAL_ROTATE_LOGFILE,        /* send SIGUSR1 to syslogger to rotate logfile */
  31         PMSIGNAL_START_AUTOVAC_LAUNCHER,        /* start an autovacuum launcher */
  32         PMSIGNAL_START_AUTOVAC_WORKER,          /* start an autovacuum worker */
  33
  34         NUM_PMSIGNALS                           /* Must be last value of enum! */
  35 } PMSignalReason;
  36
  37 /* PMSignalData is an opaque struct, details known only within pmsignal.c */
  38 typedef struct PMSignalData PMSignalData;
  39
  40 /*
  41  * prototypes for functions in pmsignal.c
  42  */
  43 extern Size PMSignalShmemSize(void);
  44 extern void PMSignalShmemInit(void);
  45 extern void SendPostmasterSignal(PMSignalReason reason);
  46 extern bool CheckPostmasterSignal(PMSignalReason reason);
  47 extern int      AssignPostmasterChildSlot(void);
  48 extern bool ReleasePostmasterChildSlot(int slot);
  49 extern void MarkPostmasterChildActive(void);
  50 extern void MarkPostmasterChildInactive(void);
  51 extern bool PostmasterIsAlive(bool amDirectChild);
  52
  53 #endif   /* PMSIGNAL_H */