1 files changed, 96 insertions, 0 deletions
diff --git a/src/gallium/auxiliary/util/u_idalloc.c b/src/gallium/auxiliary/util/u_idalloc.c
new file mode 100644
index 00000000000..26104552e57
--- /dev/null
+++ b/src/gallium/auxiliary/util/u_idalloc.c
@@ -0,0 +1,96 @@
+/**************************************************************************
+ *
+ * Copyright 2017 Valve Corporation
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR
+ * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ **************************************************************************/
+
+/**
+ * @file
+ * A simple allocator that allocates and release "numbers".
+ *
+ * @author Samuel Pitoiset <[email protected]>
+ */
+
+#include "util/u_idalloc.h"
+#include "util/u_math.h"
+#include "util/u_memory.h"
+
+void
+util_idalloc_init(struct util_idalloc *buf)
+{
+   memset(buf, 0, sizeof(*buf));
+}
+
+void
+util_idalloc_fini(struct util_idalloc *buf)
+{
+   if (buf->data)
+      free(buf->data);
+}
+
+void
+util_idalloc_resize(struct util_idalloc *buf, unsigned new_num_elements)
+{
+   new_num_elements = align(new_num_elements, 32);
+
+   if (new_num_elements > buf->num_elements) {
+      unsigned i;
+
+      buf->data = realloc(buf->data,
+                          (new_num_elements / 32) * sizeof(*buf->data));
+
+      for (i = buf->num_elements / 32; i < new_num_elements / 32; i++)
+         buf->data[i] = 0;
+      buf->num_elements = new_num_elements;
+   }
+}
+
+unsigned
+util_idalloc_alloc(struct util_idalloc *buf)
+{
+   unsigned num_elements = buf->num_elements;
+
+   for (unsigned i = 0; i < num_elements / 32; i++) {
+      if (buf->data[i] == 0xffffffff)
+         continue;
+
+      unsigned bit = ffs(~buf->data[i]) - 1;
+      buf->data[i] |= 1u << bit;
+      return i * 32 + bit;
+   }
+
+   /* No slots available, resize and return the first free. */
+   util_idalloc_resize(buf, num_elements * 2);
+
+   buf->data[num_elements / 32] |= 1 << (num_elements % 32);
+
+   return num_elements;
+}
+
+void
+util_idalloc_free(struct util_idalloc *buf, unsigned id)
+{
+   assert(id < buf->num_elements);
+   buf->data[id / 32] &= ~(1 << (id % 32));
+}