diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index 7200bd3e9..a31d9963c 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -1667,6 +1667,11 @@ module = {
enable = videomodules;
};
+module = {
+ name = priority_queue;
+ common = lib/priority_queue.c;
+};
+
module = {
name = time;
common = commands/time.c;
diff --git a/grub-core/lib/priority_queue.c b/grub-core/lib/priority_queue.c
new file mode 100644
index 000000000..5b02ef381
--- /dev/null
+++ b/grub-core/lib/priority_queue.c
@@ -0,0 +1,246 @@
+/*
+ * GRUB -- GRand Unified Bootloader
+ * Copyright (C) 2011 Free Software Foundation, Inc.
+ *
+ * GRUB is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GRUB is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GRUB. If not, see .
+ */
+
+#ifndef TEST
+#include
+#include
+#else
+#include
+#include
+#include
+
+#include
+
+using namespace std;
+
+typedef size_t grub_size_t;
+typedef int (*grub_comparator_t) (const void *a, const void *b);
+typedef unsigned char grub_uint8_t;
+#define grub_malloc malloc
+#define grub_memcpy memcpy
+#define grub_realloc realloc
+#define grub_free free
+
+typedef enum
+ {
+ GRUB_ERR_NONE,
+ grub_errno
+ } grub_err_t;
+#endif
+
+struct grub_priority_queue
+{
+ grub_size_t elsize;
+ grub_size_t allocated;
+ grub_size_t used;
+ grub_comparator_t cmp;
+ void *els;
+};
+
+#ifdef TEST
+typedef struct grub_priority_queue *grub_priority_queue_t;
+#endif
+
+static inline void *
+element (struct grub_priority_queue *pq, grub_size_t k)
+{
+ return ((grub_uint8_t *) pq->els) + k * pq->elsize;
+}
+
+static inline void
+swap (struct grub_priority_queue *pq, grub_size_t m, grub_size_t n)
+{
+ grub_uint8_t *p1, *p2;
+ grub_size_t l;
+ p1 = (grub_uint8_t *) element (pq, m);
+ p2 = (grub_uint8_t *) element (pq, n);
+ for (l = pq->elsize; l; l--, p1++, p2++)
+ {
+ grub_uint8_t t;
+ t = *p1;
+ *p1 = *p2;
+ *p2 = t;
+ }
+}
+
+static inline grub_size_t
+parent (grub_size_t v)
+{
+ return (v - 1) / 2;
+}
+
+static inline grub_size_t
+left_child (grub_size_t v)
+{
+ return 2 * v + 1;
+}
+
+static inline grub_size_t
+right_child (grub_size_t v)
+{
+ return 2 * v + 2;
+}
+
+void *
+grub_priority_queue_top (grub_priority_queue_t pq)
+{
+ if (!pq->used)
+ return 0;
+ return element (pq, 0);
+}
+
+grub_priority_queue_t
+grub_priority_queue_new (grub_size_t elsize,
+ grub_comparator_t cmp)
+{
+ struct grub_priority_queue *ret;
+ void *els;
+ els = grub_malloc (elsize * 8);
+ if (!els)
+ return 0;
+ ret = (struct grub_priority_queue *) grub_malloc (sizeof (*ret));
+ if (!ret)
+ {
+ grub_free (els);
+ return 0;
+ }
+ ret->elsize = elsize;
+ ret->allocated = 8;
+ ret->used = 0;
+ ret->cmp = cmp;
+ ret->els = els;
+ return ret;
+}
+
+/* Heap property: pq->cmp (element (pq, p), element (pq, parent (p))) <= 0. */
+grub_err_t
+grub_priority_queue_push (grub_priority_queue_t pq, void *el)
+{
+ grub_size_t p;
+ if (pq->used == pq->allocated)
+ {
+ void *els;
+ els = grub_realloc (pq->els, pq->elsize * 2 * pq->allocated);
+ if (!els)
+ return grub_errno;
+ pq->allocated *= 2;
+ pq->els = els;
+ }
+ pq->used++;
+ grub_memcpy (element (pq, pq->used - 1), el, pq->elsize);
+ for (p = pq->used - 1; p; p = parent (p))
+ {
+ if (pq->cmp (element (pq, p), element (pq, parent (p))) <= 0)
+ break;
+ swap (pq, p, parent (p));
+ }
+
+ return GRUB_ERR_NONE;
+}
+
+void
+grub_priority_queue_pop (grub_priority_queue_t pq)
+{
+ grub_size_t p;
+
+ swap (pq, 0, pq->used - 1);
+ pq->used--;
+ for (p = 0; left_child (p) < pq->used; )
+ {
+ grub_size_t c;
+ if (pq->cmp (element (pq, left_child (p)), element (pq, p)) <= 0
+ && (right_child (p) >= pq->used
+ || pq->cmp (element (pq, right_child (p)), element (pq, p)) <= 0))
+ break;
+ if (right_child (p) >= pq->used
+ || pq->cmp (element (pq, left_child (p)),
+ element (pq, right_child (p))) > 0)
+ c = left_child (p);
+ else
+ c = right_child (p);
+ swap (pq, p, c);
+ p = c;
+ }
+}
+
+#ifdef TEST
+
+static int
+compar (const void *a_, const void *b_)
+{
+ int a = *(int *) a_;
+ int b = *(int *) b_;
+ if (a < b)
+ return -1;
+ if (a > b)
+ return +1;
+ return 0;
+}
+
+int
+main (void)
+{
+ priority_queue pq;
+ grub_priority_queue_t pq2;
+ int counter;
+ int s = 0;
+ pq2 = grub_priority_queue_new (sizeof (int), compar);
+ if (!pq2)
+ return 1;
+ srand (1);
+
+ for (counter = 0; counter < 1000000; counter++)
+ {
+ int op = rand () % 10;
+ if (s && *(int *) grub_priority_queue_top (pq2) != pq.top ())
+ {
+ printf ("Error at %d\n", counter);
+ return 2;
+ }
+ if (op < 3 && s)
+ {
+ grub_priority_queue_pop (pq2);
+ pq.pop ();
+ s--;
+ }
+ else
+ {
+ int v = rand ();
+ int e;
+ pq.push (v);
+ e = grub_priority_queue_push (pq2, &v);
+ if (e)
+ return 3;
+ s++;
+ }
+ }
+ while (s)
+ {
+ if (*(int *) grub_priority_queue_top (pq2) != pq.top ())
+ {
+ printf ("Error at the end. %d elements remaining.\n", s);
+ return 4;
+ }
+ grub_priority_queue_pop (pq2);
+ pq.pop ();
+ s--;
+ }
+ printf ("All tests passed successfully\n");
+ return 0;
+}
+#endif
diff --git a/include/grub/priority_queue.h b/include/grub/priority_queue.h
new file mode 100644
index 000000000..335ea9a39
--- /dev/null
+++ b/include/grub/priority_queue.h
@@ -0,0 +1,36 @@
+/*
+ * GRUB -- GRand Unified Bootloader
+ * Copyright (C) 2011 Free Software Foundation, Inc.
+ *
+ * GRUB is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GRUB is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GRUB. If not, see .
+ */
+
+#ifndef GRUB_PRIORITY_QUEUE_HEADER
+#define GRUB_PRIORITY_QUEUE_HEADER 1
+
+#include
+#include
+
+struct grub_priority_queue;
+typedef struct grub_priority_queue *grub_priority_queue_t;
+typedef int (*grub_comparator_t) (const void *a, const void *b);
+
+grub_priority_queue_t grub_priority_queue_new (grub_size_t elsize,
+ grub_comparator_t cmp);
+void grub_priority_queue_destroy (grub_priority_queue_t pq);
+void *grub_priority_queue_top (grub_priority_queue_t pq);
+void grub_priority_queue_pop (grub_priority_queue_t pq);
+grub_err_t grub_priority_queue_push (grub_priority_queue_t pq, void *el);
+
+#endif