[PATCH 1/2] fast-import: Avoid infinite loop after reset
- From
Shawn O. Pearce <spearce@spearce.org>
- Date
- Mar 5, 2007, 17:46 UTC
- Message-ID
- <20070305174603.GA22304@spearce.org>
Johannes Sixt noticed that a 'reset' command applied to a branch that is already active in the branch LRU cache can cause fast-import to relink the same branch into the LRU cache twice. This will cause the LRU cache to contain a cycle, making unload_one_branch run in an infinite loop as it tries to select the oldest branch for eviction.
I have trivially fixed the problem by adding an active bit to each branch object; this bit indicates if the branch is already in the LRU and allows us to avoid trying to add it a second time. Converting the pack_id field into a bitfield makes this change take up no additional memory.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org> ---
This two patch series was made on top of maint and is also pullable from my fast-import fork on repo.or.cz. Merging it with master/next may require a minor evil merge as Nico's API changes there might be conflicting.
fast-import.c | 16 +++++++++++----- 1 files changed, 11 insertions(+), 5 deletions(-)
diff --git a/fast-import.c b/fast-import.c index 1ae125a..490f640 100644 --- a/fast-import.c +++ b/fast-import.c @@ -220,7 +220,8 @@ struct branch const char *name; struct tree_entry branch_tree; uintmax_t last_commit; - unsigned int pack_id; + unsigned active : 1; + unsigned pack_id : PACK_ID_BITS; unsigned char sha1[20]; }; @@ -528,6 +529,7 @@ static struct branch *new_branch(const char *name) b->table_next_branch = branch_table[hc]; b->branch_tree.versions[0].mode = S_IFDIR; b->branch_tree.versions[1].mode = S_IFDIR; + b->active = 0; b->pack_id = MAX_PACK_ID; branch_table[hc] = b; branch_count++; @@ -1547,6 +1549,7 @@ static void unload_one_branch(void) e = active_branches; active_branches = e->active_next_branch; } + e->active = 0; e->active_next_branch = NULL; if (e->branch_tree.tree) { release_tree_content_recursive(e->branch_tree.tree); @@ -1559,10 +1562,13 @@ static void unload_one_branch(void) static void load_branch(struct branch *b) { load_tree(&b->branch_tree); - b->active_next_branch = active_branches; - active_branches = b; - cur_active_branches++; - branch_load_count++; + if (!b->active) { + b->active = 1; + b->active_next_branch = active_branches; + active_branches = b; + cur_active_branches++; + branch_load_count++; + } } static void file_change_m(struct branch *b)
-- 1.5.0.3.862.g71037