81 lines
2.7 KiB
C
81 lines
2.7 KiB
C
/*-------------------------------------------------------------------------
|
|
*
|
|
* ipc.h
|
|
* POSTGRES inter-process communication definitions.
|
|
*
|
|
* This file is misnamed, as it no longer has much of anything directly
|
|
* to do with IPC. The functionality here is concerned with managing
|
|
* exit-time cleanup for either a postmaster or a backend.
|
|
*
|
|
*
|
|
* Portions Copyright (c) 1996-2015, PostgreSQL Global Development Group
|
|
* Portions Copyright (c) 1994, Regents of the University of California
|
|
*
|
|
* src/include/storage/ipc.h
|
|
*
|
|
*-------------------------------------------------------------------------
|
|
*/
|
|
#ifndef IPC_H
|
|
#define IPC_H
|
|
|
|
typedef void (*pg_on_exit_callback) (int code, Datum arg);
|
|
typedef void (*shmem_startup_hook_type) (void);
|
|
|
|
/*----------
|
|
* API for handling cleanup that must occur during either ereport(ERROR)
|
|
* or ereport(FATAL) exits from a block of code. (Typical examples are
|
|
* undoing transient changes to shared-memory state.)
|
|
*
|
|
* PG_ENSURE_ERROR_CLEANUP(cleanup_function, arg);
|
|
* {
|
|
* ... code that might throw ereport(ERROR) or ereport(FATAL) ...
|
|
* }
|
|
* PG_END_ENSURE_ERROR_CLEANUP(cleanup_function, arg);
|
|
*
|
|
* where the cleanup code is in a function declared per pg_on_exit_callback.
|
|
* The Datum value "arg" can carry any information the cleanup function
|
|
* needs.
|
|
*
|
|
* This construct ensures that cleanup_function() will be called during
|
|
* either ERROR or FATAL exits. It will not be called on successful
|
|
* exit from the controlled code. (If you want it to happen then too,
|
|
* call the function yourself from just after the construct.)
|
|
*
|
|
* Note: the macro arguments are multiply evaluated, so avoid side-effects.
|
|
*----------
|
|
*/
|
|
#define PG_ENSURE_ERROR_CLEANUP(cleanup_function, arg) \
|
|
do { \
|
|
before_shmem_exit(cleanup_function, arg); \
|
|
PG_TRY()
|
|
|
|
#define PG_END_ENSURE_ERROR_CLEANUP(cleanup_function, arg) \
|
|
cancel_before_shmem_exit(cleanup_function, arg); \
|
|
PG_CATCH(); \
|
|
{ \
|
|
cancel_before_shmem_exit(cleanup_function, arg); \
|
|
cleanup_function (0, arg); \
|
|
PG_RE_THROW(); \
|
|
} \
|
|
PG_END_TRY(); \
|
|
} while (0)
|
|
|
|
|
|
/* ipc.c */
|
|
extern PGDLLIMPORT bool proc_exit_inprogress;
|
|
|
|
extern void proc_exit(int code) __attribute__((noreturn));
|
|
extern void shmem_exit(int code);
|
|
extern void on_proc_exit(pg_on_exit_callback function, Datum arg);
|
|
extern void on_shmem_exit(pg_on_exit_callback function, Datum arg);
|
|
extern void before_shmem_exit(pg_on_exit_callback function, Datum arg);
|
|
extern void cancel_before_shmem_exit(pg_on_exit_callback function, Datum arg);
|
|
extern void on_exit_reset(void);
|
|
|
|
/* ipci.c */
|
|
extern PGDLLIMPORT shmem_startup_hook_type shmem_startup_hook;
|
|
|
|
extern void CreateSharedMemoryAndSemaphores(bool makePrivate, int port);
|
|
|
|
#endif /* IPC_H */
|