diff options
Diffstat (limited to 'db2/include/lock.h')
| -rw-r--r-- | db2/include/lock.h | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/db2/include/lock.h b/db2/include/lock.h index 47a38b8783..13364ca7a5 100644 --- a/db2/include/lock.h +++ b/db2/include/lock.h @@ -4,7 +4,7 @@ * Copyright (c) 1996, 1997, 1998 * Sleepycat Software. All rights reserved. * - * @(#)lock.h 10.15 (Sleepycat) 5/10/98 + * @(#)lock.h 10.17 (Sleepycat) 1/3/99 */ typedef struct __db_lockobj DB_LOCKOBJ; @@ -22,6 +22,12 @@ typedef struct __db_lockobj DB_LOCKOBJ; */ #define DB_LOCK_MAXID 0x7fffffff +/* Check for region catastrophic shutdown. */ +#define LOCK_PANIC_CHECK(lt) { \ + if ((lt)->region->hdr.panic) \ + return (DB_RUNRECOVERY); \ +} + /* * The lock region consists of: * The DB_LOCKREGION structure (sizeof(DB_LOCKREGION)). @@ -135,10 +141,24 @@ struct __db_lock { u_int32_t refcount; /* Reference count the lock. */ db_lockmode_t mode; /* What sort of lock. */ ssize_t obj; /* Relative offset of object struct. */ + size_t txnoff; /* Offset of holding transaction. */ db_status_t status; /* Status of this lock. */ }; /* + * This is a serious layering violation. To support nested transactions, we + * need to be able to tell that a lock is held by a transaction (as opposed to + * some other locker) and to be able to traverse the parent/descendent chain. + * In order to do this, each lock held by a transaction maintains a reference + * to the shared memory transaction structure so it can be accessed during lock + * promotion. As the structure is in shared memory, we cannot store a pointer + * to it, so we use the offset within the region. As nothing lives at region + * offset 0, we use that to indicate that there is no transaction associated + * with the current lock. + */ +#define TXN_IS_HOLDING(L) ((L)->txnoff != 0 /* INVALID_REG_OFFSET */) + +/* * We cannot return pointers to the user (else we cannot easily grow regions), * so we return offsets in the region. These must be converted to and from * regular pointers. Always use the macros below. |