[GSoC][RFC WIP PATCH 2/3] grep: remove locks on object reading operations

[Matheus Tavares]

git-grep has locks around the object reading operations it performs. But
these have an internal lock now, which can be enabled through
enable_obj_read_lock(). So let's use it and drop git-grep's ones.

Signed-off-by: Matheus Tavares <matheus.bernard...@usp.br>
---
 builtin/grep.c | 18 +++---------------
 grep.c         |  3 ---
 2 files changed, 3 insertions(+), 18 deletions(-)

diff --git a/builtin/grep.c b/builtin/grep.c
index 580fd38f41..682e2461d0 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -206,6 +206,7 @@ static void start_threads(struct grep_opt *opt)
        pthread_cond_init(&cond_write, NULL);
        pthread_cond_init(&cond_result, NULL);
        grep_use_locks = 1;
+       enable_obj_read_lock();
 
        for (i = 0; i < ARRAY_SIZE(todo); i++) {
                strbuf_init(&todo[i].out, 0);
@@ -263,6 +264,7 @@ static int wait_all(void)
        pthread_cond_destroy(&cond_write);
        pthread_cond_destroy(&cond_result);
        grep_use_locks = 0;
+       disable_obj_read_lock();
 
        return hit;
 }
@@ -295,16 +297,6 @@ static int grep_cmd_config(const char *var, const char 
*value, void *cb)
        return st;
 }
 
-static void *lock_and_read_oid_file(const struct object_id *oid, enum 
object_type *type, unsigned long *size)
-{
-       void *data;
-
-       grep_read_lock();
-       data = read_object_file(oid, type, size);
-       grep_read_unlock();
-       return data;
-}
-
 static int grep_oid(struct grep_opt *opt, const struct object_id *oid,
                     const char *filename, int tree_name_len,
                     const char *path)
@@ -457,10 +449,8 @@ static int grep_submodule(struct grep_opt *opt,
 
                object = parse_object_or_die(oid, oid_to_hex(oid));
 
-               grep_read_lock();
                data = read_object_with_reference(&object->oid, tree_type,
                                                  &size, NULL);
-               grep_read_unlock();
 
                if (!data)
                        die(_("unable to read tree (%s)"), 
oid_to_hex(&object->oid));
@@ -585,7 +575,7 @@ static int grep_tree(struct grep_opt *opt, const struct 
pathspec *pathspec,
                        void *data;
                        unsigned long size;
 
-                       data = lock_and_read_oid_file(&entry.oid, &type, &size);
+                       data = read_object_file(&entry.oid, &type, &size);
                        if (!data)
                                die(_("unable to read tree (%s)"),
                                    oid_to_hex(&entry.oid));
@@ -622,10 +612,8 @@ static int grep_object(struct grep_opt *opt, const struct 
pathspec *pathspec,
                struct strbuf base;
                int hit, len;
 
-               grep_read_lock();
                data = read_object_with_reference(&obj->oid, tree_type,
                                                  &size, NULL);
-               grep_read_unlock();
 
                if (!data)
                        die(_("unable to read tree (%s)"), 
oid_to_hex(&obj->oid));
diff --git a/grep.c b/grep.c
index f7c3a5803e..984a9e99cf 100644
--- a/grep.c
+++ b/grep.c
@@ -2109,10 +2109,7 @@ static int grep_source_load_oid(struct grep_source *gs)
 {
        enum object_type type;
 
-       grep_read_lock();
        gs->buf = read_object_file(gs->identifier, &type, &gs->size);
-       grep_read_unlock();
-
        if (!gs->buf)
                return error(_("'%s': unable to read %s"),
                             gs->name,
-- 
2.22.0