Implement rudimentary reference counting for sqfs_object_t

Implement grab/drop functions to increase/decrease reference count
and destroy the object if the count drops to 0.

Make sure that all objects that maintain internal references actually
grab that reference, duplicate it in the copy function, drop it in
the destroy handler.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 11 insertions, 7 deletions

diff --git a/lib/sqfs/block_processor/block_processor.c b/lib/sqfs/block_processor/block_processor.c
index e223718..d607437 100644
--- a/lib/sqfs/block_processor/block_processor.c
+++ b/lib/sqfs/block_processor/block_processor.c
@@ -186,10 +186,14 @@ static void block_processor_destroy(sqfs_object_t *base)
 		worker_data_t *worker = proc->workers;
 		proc->workers = worker->next;
 
-		sqfs_destroy(worker->cmp);
+		sqfs_drop(worker->cmp);
 		free(worker);
 	}
 
+	sqfs_drop(proc->frag_tbl);
+	sqfs_drop(proc->wr);
+	sqfs_drop(proc->file);
+	sqfs_drop(proc->uncmp);
 	free(proc);
 }
 
@@ -272,10 +276,10 @@ int sqfs_block_processor_create_ex(const sqfs_block_processor_desc_t *desc,
 
 	proc->max_backlog = desc->max_backlog;
 	proc->max_block_size = desc->max_block_size;
-	proc->frag_tbl = desc->tbl;
-	proc->wr = desc->wr;
-	proc->file = desc->file;
-	proc->uncmp = desc->uncmp;
+	proc->frag_tbl = sqfs_grab(desc->tbl);
+	proc->wr = sqfs_grab(desc->wr);
+	proc->file = sqfs_grab(desc->file);
+	proc->uncmp = sqfs_grab(desc->uncmp);
 	proc->stats.size = sizeof(proc->stats);
 
 	/* we need at least one current data block + one fragment block */
@@ -285,8 +289,8 @@ int sqfs_block_processor_create_ex(const sqfs_block_processor_desc_t *desc,
 	/* create the thread pool */
 	proc->pool = thread_pool_create(desc->num_workers, process_block);
 	if (proc->pool == NULL) {
-		free(proc);
-		return SQFS_ERROR_INTERNAL;
+		ret = SQFS_ERROR_INTERNAL;
+		goto fail_pool;
 	}
 
 	/* create the worker compressors & scratch buffer */