Added missing lib/bigalloc.c from dev-async-shep.

diff --git a/lib/bigalloc.c b/lib/bigalloc.c
new file mode 100644 (file)
index 0000000..b4589c4
--- /dev/null
+++ b/lib/bigalloc.c
@@ -0,0 +1,62 @@
+/*
+ *     UCW Library -- Allocation of Large Aligned Buffers
+ *
+ *     (c) 2006 Martin Mares <mj@ucw.cz>
+ *
+ *     This software may be freely distributed and used according to the terms
+ *     of the GNU Lesser General Public License.
+ */
+
+#include "lib/lib.h"
+
+#include <sys/mman.h>
+#include <sys/user.h>
+
+static unsigned int
+big_round(unsigned int len)
+{
+  return ALIGN_TO(len, PAGE_SIZE);
+}
+
+void *
+big_alloc(unsigned int len)
+{
+  len = big_round(len);
+#ifdef CONFIG_DEBUG
+  len += 2*PAGE_SIZE;
+#endif
+  byte *p = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
+  if (p == (byte*) MAP_FAILED)
+    die("Cannot mmap %d bytes of memory: %m", len);
+#ifdef CONFIG_DEBUG
+  mprotect(p, PAGE_SIZE, PROT_NONE);
+  mprotect(p+len-PAGE_SIZE, PAGE_SIZE, PROT_NONE);
+  p += PAGE_SIZE;
+#endif
+  return p;
+}
+
+void
+big_free(void *start, unsigned int len)
+{
+  byte *p = start;
+  ASSERT(!((addr_int_t) p & (PAGE_SIZE-1)));
+  len = big_round(len);
+#ifdef CONFIG_DEBUG
+  p -= PAGE_SIZE;
+  len += 2*PAGE_SIZE;
+#endif
+  munmap(p, len);
+}
+
+#ifdef TEST
+
+int main(void)
+{
+  byte *p = big_alloc(123456);
+  // p[-1] = 1;
+  big_free(p, 123456);
+  return 0;
+}
+
+#endif