src/include/access/session.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * session.h
   4  *        Encapsulation of user session.
   5  *
   6  * Copyright (c) 2017-2021, PostgreSQL Global Development Group
   7  *
   8  * src/include/access/session.h
   9  *
  10  *-------------------------------------------------------------------------
  11  */
  12 #ifndef SESSION_H
  13 #define SESSION_H
  14
  15 #include "lib/dshash.h"
  16
  17 /* Avoid including typcache.h */
  18 struct SharedRecordTypmodRegistry;
  19
  20 /*
  21  * A struct encapsulating some elements of a user's session.  For now this
  22  * manages state that applies to parallel query, but in principle it could
  23  * include other things that are currently global variables.
  24  */
  25 typedef struct Session
  26 {
  27         dsm_segment *segment;           /* The session-scoped DSM segment. */
  28         dsa_area   *area;                       /* The session-scoped DSA area. */
  29
  30         /* State managed by typcache.c. */
  31         struct SharedRecordTypmodRegistry *shared_typmod_registry;
  32         dshash_table *shared_record_table;
  33         dshash_table *shared_typmod_table;
  34 } Session;
  35
  36 extern void InitializeSession(void);
  37 extern dsm_handle GetSessionDsmHandle(void);
  38 extern void AttachSession(dsm_handle handle);
  39 extern void DetachSession(void);
  40
  41 /* The current session, or NULL for none. */
  42 extern Session *CurrentSession;
  43
  44 #endif                                                  /* SESSION_H */