Do incremental mark some in GC_collect_a_little even if GC is disabled

Previous behavior was not documented but this API function did nothing
in this case.  That might cause a deadlock in the client code if the
incremental collection was ongoing and the client called
GC_collect_a_little() repeatedly (while the result is true).

The new behavior, for the cause of disabled garbage collection, is to
perform some amount of marking if the incremental collection is
ongoing (but not stopping the world and, thus, not causing the memory
reclaim to start), returning true if there is something more to mark.

* alloc.c (GC_try_to_collect_inner): Change a loop to do-while one.
* alloc.c (GC_collect_a_little): Do not check GC_dont_gc (i.e. call
GC_collect_a_little_inner() unconditionally); add comment.
* include/gc/gc.h (GC_collect_a_little): Update comment (describe the
case when GC is disabled).
* tests/gctest.c (check_heap_stats): Do not call GC_is_disabled(); add
comment.

0 files changed, 0 insertions, 0 deletions