1 files changed, 133 insertions, 0 deletions
diff --git a/lib/mempool.c b/lib/mempool.c
new file mode 100644
index 00000000..d2f2c092
--- /dev/null
+++ b/lib/mempool.c
@@ -0,0 +1,133 @@
+/*
+ *	BIRD Resource Manager -- Memory Pools
+ *
+ *	(c) 1998 Martin Mares <mj@ucw.cz>
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "nest/bird.h"
+#include "lib/resource.h"
+
+struct mp_chunk {
+  struct mp_chunk *next;
+  byte data[0];
+};
+
+struct mempool {
+  resource r;
+  byte *ptr, *end;
+  struct mp_chunk *first, **plast;
+  unsigned chunk_size, threshold, total;
+};
+
+void mp_free(resource *);
+void mp_dump(resource *);
+
+struct resclass mp_class = {
+  "MemPool",
+  sizeof(struct mempool),
+  mp_free,
+  mp_dump
+};
+
+mempool
+*mp_new(pool *p, unsigned blk)
+{
+  mempool *m = ralloc(p, &mp_class);
+  m->ptr = m->end = NULL;
+  m->first = NULL;
+  m->plast = &m->first;
+  m->chunk_size = blk;
+  m->threshold = 3*blk/4;
+  m->total = 0;
+  return m;
+}
+
+void *
+mp_alloc(mempool *m, unsigned size)
+{
+  byte *a = (byte *) ALIGN((unsigned long) m->ptr, CPU_STRUCT_ALIGN);
+  byte *e = a + size;
+
+  if (e <= m->end)
+    {
+      m->ptr = e;
+      return a;
+    }
+  else
+    {
+      struct mp_chunk *c;
+      if (size >= m->threshold)
+	{
+	  c = xmalloc(sizeof(struct mp_chunk) + size);
+	  m->total += size;
+	}
+      else
+	{
+	  c = xmalloc(sizeof(struct mp_chunk) + m->chunk_size);
+	  m->ptr = c->data + size;
+	  m->end = c->data + m->chunk_size;
+	  m->total += m->chunk_size;
+	}
+      *m->plast = c;
+      m->plast = &c->next;
+      c->next = NULL;
+      return c->data;
+    }
+}
+
+void *
+mp_allocu(mempool *m, unsigned size)
+{
+  byte *a = m->ptr;
+  byte *e = a + size;
+
+  if (e <= m->end)
+    {
+      m->ptr = e;
+      return a;
+    }
+  return mp_alloc(m, size);
+}
+
+void *
+mp_allocz(mempool *m, unsigned size)
+{
+  void *z = mp_alloc(m, size);
+
+  bzero(z, size);
+  return z;
+}
+
+void
+mp_free(resource *r)
+{
+  mempool *m = (mempool *) r;
+  struct mp_chunk *c, *d;
+
+  for(d=m->first; d; d = c)
+    {
+      c = d->next;
+      xfree(d);
+    }
+}
+
+void
+mp_dump(resource *r)
+{
+  mempool *m = (mempool *) r;
+  struct mp_chunk *c;
+  int cnt;
+
+  for(cnt=0, c=m->first; c; c=c->next, cnt++)
+    ;
+  debug("(chunk=%d threshold=%d count=%d total=%d)\n",
+	m->chunk_size,
+	m->threshold,
+	cnt,
+	m->total);
+}