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Diffstat (limited to '')
| -rw-r--r-- | doc/ChangeLog | 4 | ||||
| -rw-r--r-- | doc/user/region.t | 67 |
2 files changed, 71 insertions, 0 deletions
diff --git a/doc/ChangeLog b/doc/ChangeLog index 31def4975b..51b533e0e8 100644 --- a/doc/ChangeLog +++ b/doc/ChangeLog @@ -1,3 +1,7 @@ +2005-06-17 Joel Sherrill <joel@OARcorp.com> + + * user/region.t: Add documentation on region_resize_segment. + 2005-04-28 Joel Sherrill <joel@OARcorp.com> * bsp_howto/rtc.t: Rewritten to account for removal of dmv177. diff --git a/doc/user/region.t b/doc/user/region.t index 4b90443049..b11cf1c2ae 100644 --- a/doc/user/region.t +++ b/doc/user/region.t @@ -24,6 +24,7 @@ provided by the region manager are: @item @code{@value{DIRPREFIX}region_get_segment} - Get segment from a region @item @code{@value{DIRPREFIX}region_return_segment} - Return segment to a region @item @code{@value{DIRPREFIX}region_get_segment_size} - Obtain size of a segment +@item @code{@value{DIRPREFIX}region_resize_segment} - Change size of a segment @end itemize @section Background @@ -202,6 +203,15 @@ size in bytes of the specified segment. The size returned includes any "extra" memory included in the segment because of rounding up to a page size boundary. +@subsection Changing the Size of a Segment + +The @code{@value{DIRPREFIX}region_resize_segment} directive +is used to change the size in bytes of the specified segment. The +size may be increased or decreased. When increasing the +size of a segment, it is possible that the request cannot be +satisfied. This directive is used to support the @code{realloc()} +function in the Standard C Library. + @subsection Deleting a Region A region can be removed from the system and returned @@ -663,3 +673,60 @@ The actual length of the allocated segment may be larger than the requested size because a segment size is always a multiple of the region's page size. +@c +@c +@c +@page +@subsection REGION_RESIZE_SEGMENT - Change size of a segment + +@cindex resize segment + +@subheading CALLING SEQUENCE: + +@ifset is-C +@findex rtems_region_resize_segment +@example +rtems_status_code rtems_region_resize_segment( + rtems_id id, + void *segment, + size_t size, + size_t *old_size +); +@end example +@end ifset + +@ifset is-Ada +@example +procedure Region_Resize_Segment ( + ID : in RTEMS.ID; + Segment : in RTEMS.Address; + Size : in RTEMS.Unsigned32; + Old_Size : out RTEMS.Unsigned32; + Result : out RTEMS.Status_Codes +); +@end example +@end ifset + +@subheading DIRECTIVE STATUS CODES: + +@code{@value{RPREFIX}SUCCESSFUL} - segment obtained successfully@* +@code{@value{RPREFIX}INVALID_ADDRESS} - @code{segment} is NULL@* +@code{@value{RPREFIX}INVALID_ADDRESS} - @code{old_size} is NULL@* +@code{@value{RPREFIX}INVALID_ID} - invalid region id@* +@code{@value{RPREFIX}INVALID_ADDRESS} - segment address not in region +@code{@value{RPREFIX}UNSATISFIED} - unable to make segment larger + +@subheading DESCRIPTION: + +This directive is used to increase or decrease the size of +a @a{segment}. When increasing the size of a segment, it +is possible that there is not memory available contiguous +to the segment. In this case, the request is unsatisfied. + +@subheading NOTES: + +If an attempt to increase the size of a @a{segment} fails, then +the application may want to allocate a new segment of the desired +size, copy the contents of the original segment to the new, larger +segment and then return the original segment. + |