1 files changed, 25 insertions, 0 deletions
diff --git a/src/libs6/s6lock_check.c b/src/libs6/s6lock_check.c
new file mode 100644
index 0000000..e794128
--- /dev/null
+++ b/src/libs6/s6lock_check.c
@@ -0,0 +1,25 @@
+/* ISC license. */
+
+#include <errno.h>
+#include <skalibs/error.h>
+#include <skalibs/uint16.h>
+#include <skalibs/gensetdyn.h>
+#include <s6/s6lock.h>
+
+int s6lock_check (s6lock_t *a, uint16 id)
+{
+  char *p = GENSETDYN_P(char, &a->data, id) ;
+  switch (*p)
+  {
+    case EBUSY : return 1 ;
+    case EINVAL : return (errno = EINVAL, -1) ;
+    default :
+    {
+      if (error_isagain(*p)) return 0 ;
+      errno = *p ;
+      *p = EINVAL ;
+      gensetdyn_delete(&a->data, id) ;
+      return -1 ;
+    }
+  }
+}