Manage int IDs via id_alloc

kernel/id/id_alloc.c

@@ -0,0 +1,52 @@
+#include <id/id_alloc.h>
+#include <libk/bm.h>
+#include <libk/std.h>
+#include <mm/liballoc.h>
+#include <status.h>
+#include <sync/spin_lock.h>
+#include <sys/debug.h>
+
+bool id_alloc_init (struct id_alloc* ida, size_t nbits) {
+  size_t buffer_size = (nbits + 7) / 8;
+
+  uint8_t* buffer = malloc (buffer_size);
+
+  if (buffer == NULL)
+    return false;
+
+  bm_init (&ida->bm, buffer, nbits);
+  ida->lock = SPIN_LOCK_INIT;
+
+  return true;
+}
+
+void id_alloc_fini (struct id_alloc* ida) {
+  free (ida->bm.base);
+  ida->bm.base = NULL;
+  ida->bm.nbits = 0;
+}
+
+int id_alloc (struct id_alloc* ida) {
+  spin_lock (&ida->lock);
+
+  for (size_t bit = 0; bit < ida->bm.nbits; bit++) {
+    if (!bm_test (&ida->bm, bit)) {
+      bm_set (&ida->bm, bit);
+
+      spin_unlock (&ida->lock);
+      return (int)bit;
+    }
+  }
+
+  spin_unlock (&ida->lock);
+  return -ST_OOM_ERROR;
+}
+
+void id_free (struct id_alloc* ida, int id) {
+  if (id < 0)
+    return;
+
+  spin_lock (&ida->lock);
+  bm_clear (&ida->bm, (size_t)id);
+  spin_unlock (&ida->lock);
+}