diff options
Diffstat (limited to 'src/memdb.c')
| -rw-r--r-- | src/memdb.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/src/memdb.c b/src/memdb.c index 0aecb7102..7485f51ff 100644 --- a/src/memdb.c +++ b/src/memdb.c @@ -371,9 +371,22 @@ static int memdbLock(sqlite3_file *pFile, int eLock){ if( eLock==pThis->eLock ) return SQLITE_OK; memdbEnter(p); if( eLock>SQLITE_LOCK_SHARED ){ + assert( pThis->eLock>=SQLITE_LOCK_SHARED ); if( p->mFlags & SQLITE_DESERIALIZE_READONLY ){ rc = SQLITE_READONLY; + }else if( eLock==SQLITE_LOCK_EXCLUSIVE ){ + /* Taking an EXCLUSIVE lock. Fail if we only have SHARED and any + ** other client has any kind of write-lock. Also fail if any other + ** client is holding read-lock. */ + if( pThis->eLock<=SQLITE_LOCK_SHARED && p->nWrLock ){ + rc = SQLITE_BUSY; + }else if( p->nRdLock>1 ){ + rc = SQLITE_BUSY; + } + p->nWrLock = 1; }else if( pThis->eLock<=SQLITE_LOCK_SHARED ){ + /* Upgrading to RESERVED or PENDING from SHARED. Fail if any other + ** client has a write-lock of any kind. */ if( p->nWrLock ){ rc = SQLITE_BUSY; }else{ |