From f343d0adfe9ab787cb65cd38e4c4c83aaeea76b7 Mon Sep 17 00:00:00 2001 From: Scott Wood Date: Sun, 10 Dec 2006 12:03:16 -0600 Subject: [PATCH] Update the PIB documentation. --- doc/orb/parameter-info-block | 52 +++++++++++++----------------------- 1 file changed, 19 insertions(+), 33 deletions(-) diff --git a/doc/orb/parameter-info-block b/doc/orb/parameter-info-block index 9438d1d..eeeb800 100644 --- a/doc/orb/parameter-info-block +++ b/doc/orb/parameter-info-block @@ -10,38 +10,23 @@ Parameter Info Block (PIB), all offsets in pointer-length words caller; "inout" segments where the caller specified a non-NULL ptr, and the callee did not increase the length, are not included (because the kernel does not need to allocate a caller-side buffer - for them). - + for them). The kernel may throw an exception if the actual + size is greater than specified in this field. + objlist_ptr 1 Pointer to the object list objlist_len 2 Length of the object list - The object list is a list of pointers into segment data describing - where object IDs can be found. When copying a segment to the - destination address space, it will convert all IDs (allocating a new - ID if necessary). The object list must be in order (first by - segment, then by address); an exception may be thrown if it is out - of order or if it contains invalid entries. Segments with object - IDs cannot have the Shared flag. Unmarshalling code should always - verify that any ID it expects is actually in the object list. - - ptrlist_ptr 3 Pointer to the pointer list - ptrlist_len 4 Length of the pointer list - - The pointer list, like the object list, is a list of pointers to - segment data. Each pointer pointed to must also point within - segment data, and will be modified by the ORB when copied to point - to the equivalent location in the destination address space. The - pointer list must be in order (first by segment, then by address); - an exception may be thrown if it is out of order of if it contains - invalid entries. Segments with internal pointers cannot have the - Shared flag (shared segments can still be pointed to, of course). - Unmarshalling code should always verify that any internal pointer it - expects actually points within a valid segment. + The object list is a special segment that contains object IDs + rather than arbitrary data. Each object ID will be translated + into the destination ID-space, allocating new IDs when + necessary. - num_segments 5 Number of data segments - segment.ptr 6+n*3 Pointer to data segment - segment.len 7+n*3 Length of data segment in bytes - segment.flags 8+n*3 Attributes of data segment + num_segments 3 Number of data segments + segment.ptr 4+n*4 Pointer to data segment + segment.len 5+n*4 Length of data segment in bytes + segment.flags 6+n*4 Attributes of data segment + reserved 7+n*4 Reserved for future use, and to + ensure power-of-two indexing Each segment describes data being transmitted to and/or from the callee. For out segments, the caller may designate a buffer to hold @@ -53,15 +38,16 @@ Parameter Info Block (PIB), all offsets in pointer-length words size, page-alignment, and overmap status of the segment. Segment Flags (see doc/orb/memory-management for more details): - In 0x01 Data is copied/mapped from caller to callee - Out 0x02 Data is copied/mapped from callee to caller - Shared 0x04 A permanent shared mapping is created + In 0x01 Data is copied/mapped from caller to callee. + Out 0x02 Data is copied/mapped from callee to caller. + Shared 0x04 A permanent shared mapping is created. Push 0x08 The region is unmapped from the source and transferred to the destination. Inline 0x10 The callee cannot change the length of an Out segment. Ignored for In segments. Immutable 0x20 The segment is to be mapped read-only in - the destination. + the destination. Ignored unless Shared is + set. Copy 0x8000 The segment is permanently copied into the destination address space, with read/write - access (unless Immutable is set). + access. -- 2.39.2