Author: Gregor Wegberg <c...@gregorwegberg.com>
Branch: gc-incminimark-pinning-improve
Changeset: r76519:1fdd47a9602c
Date: 2014-12-11 20:43 +0100
http://bitbucket.org/pypy/pypy/changeset/1fdd47a9602c/
Log: added comments to collect_and_reserve
diff --git a/rpython/memory/gc/incminimark.py b/rpython/memory/gc/incminimark.py
--- a/rpython/memory/gc/incminimark.py
+++ b/rpython/memory/gc/incminimark.py
@@ -682,7 +682,7 @@
def collect_and_reserve(self, totalsize):
"""To call when nursery_free overflows nursery_top.
First check if the nursery_top is the real top, otherwise we
- can just move the top of one cleanup and continue
+ can just move the top of one cleanup and continue.
Do a minor collection, and possibly also a major collection,
and finally reserve 'totalsize' bytes at the start of the
@@ -694,10 +694,22 @@
self.nursery_free = llmemory.NULL # debug: don't use me
if self.nursery_barriers.non_empty():
+ # Pinned object in front of nursery_top. Try by jumping into
the
+ # next area inside the nursery. 'Next area' is in this case the
+ # pinned object after the next pinned one and the one after the
+ # next or the end of the nursery. Graphically explained:
+ #
+ # |- allocating totalsize failed in this are
+ # v v- next pinned object, jump over
+ # +---------+--------+--------+--------+-----------+
+ # | unknown | pinned | empty | pinned | empty | <- nursery
+ # +---------+--------+--------+--------+-----------+
+ # ^- try allocating totalsize in here next
+ #
size_gc_header = self.gcheaderbuilder.size_gc_header
pinned_obj_size = size_gc_header + self.get_size(
self.nursery_top + size_gc_header)
-
+ #
self.nursery_free = self.nursery_top + pinned_obj_size
self.nursery_top = self.nursery_barriers.popleft()
else:
@@ -725,6 +737,8 @@
"Seeing minor_collection() at least twice."
"Too many pinned objects?")
#
+ # GC tried to do something about nursery_free overflowing
+ # nursery_top before this point. Try to allocate totalsize now.
result = self.nursery_free
if self.nursery_free + totalsize <= self.nursery_top:
self.nursery_free = result + totalsize
_______________________________________________
pypy-commit mailing list
pypy-commit@python.org
https://mail.python.org/mailman/listinfo/pypy-commit
