The Filter Process Model
By default, Filter runs independently from the calling application process. This is called out-of-process filtering. Out-of-process filtering protects the stability of the calling application in the rare case when a malformed document causes Filter to fail. You can configure Filter to run in the same process as the calling application. This is called in-process filtering. However, it is strongly recommended you run Filter out of process whenever possible.
The creation of child processes on UNIX usually adheres to Portable Operating System Interface (POSIX) standards. AIX uses different thread semantics. If required, a version of kvfilter
with POSIX thread semantics is available for AIX. This file is kvfilter_nsl.a
. It must be renamed to kvfilter.a
to be used by Filter.
To monitor and debug filtering operations during out-of-process filtering, you can generate an error log at run time. See Generate an Error Log.
The following methods run in process or out of process:
Filter API
canFilter |
canFilterEx |
doFilter |
doFilterChunk |
getSummaryInfo |
GetDocFormatInfo |
File Extraction API
extCloseDocument | extGetMainFileInfo |
extGetSubFileInfo | extOpenDocument |
extGetSubFileMetadata | getSummaryInfo |
extExtractSubFile | KVGetExtractInterface() |
Other Filter API methods always run in process.