Re: [PATCH 5/7] grep: allocate subrepos on heap
- From
Emily Shaffer <emilyshaffer@google.com>
- Date
- Aug 11, 2021, 21:50 UTC
- Message-ID
- <YRRGKKYYQiYTxtJ5@google.com>
- In-Reply-To
- <f62608e88f125096c1f236a47e3ee670104c7b78.1628618950.git.jonathantanmy@google.com>
On Tue, Aug 10, 2021 at 11:28:43AM -0700, Jonathan Tan wrote:
Show 10 quoted lines
> diff --git a/builtin/grep.c b/builtin/grep.c > index 9e61c7c993..5a40e18e47 100644 > --- a/builtin/grep.c > +++ b/builtin/grep.c > @@ -65,6 +65,9 @@ static int todo_done; > /* Has all work items been added? */ > static int all_work_added; > > +static struct repository **repos_to_free; > +static size_t repos_to_free_nr, repos_to_free_alloc;
One thing I was curious about was whether it would make more sense to use an existing utility library in Git to handle this. But I think we kind of are, since ALLOC_GROW is used, so this is idiomatic for Git project. Ok, fine, I guess this is life at C ;)
Show 18 quoted lines
> +
> /* This lock protects all the variables above. */
> static pthread_mutex_t grep_mutex;
>
> @@ -168,6 +171,17 @@ static void work_done(struct work_item *w)
> grep_unlock();
> }
>
> +static void free_repos(void)
> +{
> + int i;
> +
> + for (i = 0; i < repos_to_free_nr; i++) {
> + repo_clear(repos_to_free[i]);
> + free(repos_to_free[i]);
> + }
> + free(repos_to_free);
> +}Should repos_to_free_nr be reset here? I guess it doesn't make sense to, since we'd be trying to use-after-free the initial repos_to_free head pointer too if we wanted to reuse this array.
Show 29 quoted lines
> +
> static void *run(void *arg)
> {
> int hit = 0;
> @@ -415,19 +429,24 @@ static int grep_submodule(struct grep_opt *opt,
> const struct object_id *oid,
> const char *filename, const char *path, int cached)
> {
> - struct repository subrepo;
> + struct repository *subrepo;
> struct repository *superproject = opt->repo;
> const struct submodule *sub;
> struct grep_opt subopt;
> - int hit;
> + int hit = 0;
>
> sub = submodule_from_path(superproject, null_oid(), path);
>
> if (!is_submodule_active(superproject, path))
> return 0;
>
> - if (repo_submodule_init(&subrepo, superproject, sub))
> + subrepo = xmalloc(sizeof(*subrepo));
> + if (repo_submodule_init(subrepo, superproject, sub)) {
> + free(subrepo);
> return 0;
> + }
> + ALLOC_GROW(repos_to_free, repos_to_free_nr + 1, repos_to_free_alloc);
> + repos_to_free[repos_to_free_nr++] = subrepo;Is this the only place we add to the repos_to_free array? It looks like yes, so I guess this doesn't need a helper.
Show 53 quoted lines
>
> /*
> * NEEDSWORK: repo_read_gitmodules() might call
> @@ -438,7 +457,7 @@ static int grep_submodule(struct grep_opt *opt,
> * subrepo's odbs to the in-memory alternates list.
> */
> obj_read_lock();
> - repo_read_gitmodules(&subrepo, 0);
> + repo_read_gitmodules(subrepo, 0);
>
> /*
> * NEEDSWORK: This adds the submodule's object directory to the list of
> @@ -450,11 +469,11 @@ static int grep_submodule(struct grep_opt *opt,
> * store is no longer global and instead is a member of the repository
> * object.
> */
> - add_submodule_odb_by_path(subrepo.objects->odb->path);
> + add_submodule_odb_by_path(subrepo->objects->odb->path);
> obj_read_unlock();
>
> memcpy(&subopt, opt, sizeof(subopt));
> - subopt.repo = &subrepo;
> + subopt.repo = subrepo;
>
> if (oid) {
> enum object_type object_type;
> @@ -464,9 +483,9 @@ static int grep_submodule(struct grep_opt *opt,
> struct strbuf base = STRBUF_INIT;
>
> obj_read_lock();
> - object_type = oid_object_info(&subrepo, oid, NULL);
> + object_type = oid_object_info(subrepo, oid, NULL);
> obj_read_unlock();
> - data = read_object_with_reference(&subrepo,
> + data = read_object_with_reference(subrepo,
> oid, tree_type,
> &size, NULL);
> if (!data)
> @@ -484,7 +503,6 @@ static int grep_submodule(struct grep_opt *opt,
> hit = grep_cache(&subopt, pathspec, cached);
> }
>
> - repo_clear(&subrepo);
> return hit;
> }
>
> @@ -1182,5 +1200,6 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
> run_pager(&opt, prefix);
> clear_pathspec(&pathspec);
> free_grep_patterns(&opt);
> + free_repos();
> return !hit;
> }The rest of the diff seems to be a pretty clear object-becomes-reference conversion, so...
Reviewed-by: Emily Shaffer <emilyshaffer@google.com>