add and expose alpm_unlock

alpm_unlock is a limited version of alpm_release that does nothing but
the actual unlinking of the lock file and is therefore safe to call from
signal handlers.

Signed-off-by: Andrew Gregory <andrew.gregory.8@gmail.com>
Signed-off-by: Allan McRae <allan@archlinux.org>

2 files changed, 18 insertions, 2 deletions

diff --git a/lib/libalpm/alpm.h b/lib/libalpm/alpm.h
index 3049f2fa..6cbcd24d 100644
--- a/lib/libalpm/alpm.h
+++ b/lib/libalpm/alpm.h
@@ -1559,6 +1559,7 @@ char *alpm_compute_sha256sum(const char *filename);
 alpm_handle_t *alpm_initialize(const char *root, const char *dbpath,
 		alpm_errno_t *err);
 int alpm_release(alpm_handle_t *handle);
+int alpm_unlock(alpm_handle_t *handle);
 
 enum alpm_caps {
 	ALPM_CAPABILITY_NLS = (1 << 0),
diff --git a/lib/libalpm/handle.c b/lib/libalpm/handle.c
index b2a10c86..0d8e292a 100644
--- a/lib/libalpm/handle.c
+++ b/lib/libalpm/handle.c
@@ -126,8 +126,13 @@ int _alpm_handle_lock(alpm_handle_t *handle)
 	return (handle->lockfd >= 0 ? 0 : -1);
 }
 
-/** Remove a lock file */
-int _alpm_handle_unlock(alpm_handle_t *handle)
+/** Remove the database lock file
+ * @param handle the context handle
+ * @return 0 on success, -1 on error
+ *
+ * @note Safe to call from inside signal handlers.
+ */
+int SYMEXPORT alpm_unlock(alpm_handle_t *handle)
 {
 	ASSERT(handle->lockfile != NULL, return 0);
 	ASSERT(handle->lockfd >= 0, return 0);
@@ -136,6 +141,15 @@ int _alpm_handle_unlock(alpm_handle_t *handle)
 	handle->lockfd = -1;
 
 	if(unlink(handle->lockfile) != 0) {
+		RET_ERR(handle, ALPM_ERR_SYSTEM, -1);
+	} else {
+		return 0;
+	}
+}
+
+int _alpm_handle_unlock(alpm_handle_t *handle)
+{
+	if(alpm_unlock(handle) != 0) {
 		if(errno == ENOENT) {
 			_alpm_log(handle, ALPM_LOG_WARNING,
 					_("lock file missing %s\n"), handle->lockfile);
@@ -150,6 +164,7 @@ int _alpm_handle_unlock(alpm_handle_t *handle)
 			return -1;
 		}
 	}
+
 	return 0;
 }