diff options
Diffstat (limited to 'src/pager.c')
| -rw-r--r-- | src/pager.c | 22 |
1 files changed, 9 insertions, 13 deletions
diff --git a/src/pager.c b/src/pager.c index 3a655b745..f6e297bd7 100644 --- a/src/pager.c +++ b/src/pager.c @@ -18,7 +18,7 @@ ** file simultaneously, or one process from reading the database while ** another is writing. ** -** @(#) $Id: pager.c,v 1.112 2004/06/04 10:38:31 danielk1977 Exp $ +** @(#) $Id: pager.c,v 1.113 2004/06/07 16:27:46 drh Exp $ */ #include "os.h" /* Must be first to enable large file support */ #include "sqliteInt.h" @@ -1554,20 +1554,16 @@ static int pager_write_pagelist(PgHdr *pList){ ** database file. If there is already an EXCLUSIVE lock, the following ** calls to sqlite3OsLock() are no-ops. ** - ** The upgrade from a RESERVED to PENDING lock cannot return SQLITE_BUSY, - ** unless someone is not following the locking protocol. + ** The upgrade from a RESERVED to PENDING might return SQLITE_BUSY on + ** windows because the windows locking mechanism acquires a transient + ** PENDING lock during its attempts to get a SHARED lock. So if another + ** process were trying to get a SHARED lock at the same time this process + ** is upgrading from RESERVED to PENDING, the two could collide. ** - ** The upgrade from PENDING to EXCLUSIVE can return SQLITE_BUSY. It's - ** not totally clear that the busy-callback should be invoked here - ** though. (?) + ** The upgrade from PENDING to EXCLUSIVE can return SQLITE_BUSY if there + ** are still active readers that were created before the PENDING lock + ** was acquired. */ - rc = sqlite3OsLock(&pPager->fd, PENDING_LOCK); - if( rc==SQLITE_BUSY ){ - return SQLITE_PROTOCOL; - } - if( rc!=SQLITE_OK ){ - return rc; - } do { rc = sqlite3OsLock(&pPager->fd, EXCLUSIVE_LOCK); }while( rc==SQLITE_BUSY && |