diff options
Diffstat (limited to 'src/include/storage/ipc.h')
| -rw-r--r-- | src/include/storage/ipc.h | 48 |
1 files changed, 45 insertions, 3 deletions
diff --git a/src/include/storage/ipc.h b/src/include/storage/ipc.h index eb89f9a7dae..2123852bb73 100644 --- a/src/include/storage/ipc.h +++ b/src/include/storage/ipc.h @@ -11,21 +11,63 @@ * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/storage/ipc.h,v 1.74 2008/01/01 19:45:59 momjian Exp $ + * $PostgreSQL: pgsql/src/include/storage/ipc.h,v 1.75 2008/04/16 23:59:40 tgl Exp $ * *------------------------------------------------------------------------- */ #ifndef IPC_H #define IPC_H +typedef void (*pg_on_exit_callback) (int code, Datum arg); + +/*---------- + * 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 { \ + on_shmem_exit(cleanup_function, arg); \ + PG_TRY() + +#define PG_END_ENSURE_ERROR_CLEANUP(cleanup_function, arg) \ + cancel_shmem_exit(cleanup_function, arg); \ + PG_CATCH(); \ + { \ + cancel_shmem_exit(cleanup_function, arg); \ + cleanup_function (0, arg); \ + PG_RE_THROW(); \ + } \ + PG_END_TRY(); \ + } while (0) + /* ipc.c */ extern bool proc_exit_inprogress; extern void proc_exit(int code); extern void shmem_exit(int code); -extern void on_proc_exit(void (*function) (int code, Datum arg), Datum arg); -extern void on_shmem_exit(void (*function) (int code, Datum arg), Datum arg); +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 cancel_shmem_exit(pg_on_exit_callback function, Datum arg); extern void on_exit_reset(void); /* ipci.c */ |