1 files changed, 71 insertions, 0 deletions
diff --git a/db2/os/os_map.c b/db2/os/os_map.c
new file mode 100644
index 0000000000..b1553188dc
--- /dev/null
+++ b/db2/os/os_map.c
@@ -0,0 +1,71 @@
+/*-
+ * See the file LICENSE for redistribution information.
+ *
+ * Copyright (c) 1996, 1997
+ *	Sleepycat Software.  All rights reserved.
+ */
+
+#include "config.h"
+
+#ifndef lint
+static const char sccsid[] = "@(#)os_map.c	10.7 (Sleepycat) 10/25/97";
+#endif /* not lint */
+
+#ifndef NO_SYSTEM_INCLUDES
+#include <sys/types.h>
+#include <sys/mman.h>
+
+#include <errno.h>
+#endif
+
+#include "db_int.h"
+
+/*
+ * __os_map --
+ *	Map in some shared memory backed by a file descriptor.
+ *
+ * PUBLIC: int __os_map __P((int, size_t, int, int, void **));
+ */
+int
+__os_map(fd, len, is_private, is_rdonly, addr)
+	int fd, is_private, is_rdonly;
+	size_t len;
+	void **addr;
+{
+	void *p;
+	int flags, prot;
+
+	flags = is_private ? MAP_PRIVATE : MAP_SHARED;
+#ifdef MAP_HASSEMAPHORE
+	flags |= MAP_HASSEMAPHORE;
+#endif
+	prot = PROT_READ | (is_rdonly ? 0 : PROT_WRITE);
+
+#ifndef MAP_FAILED			/* XXX: Mmap(2) failure return. */
+#define	MAP_FAILED	-1
+#endif
+	if ((p =
+	    mmap(NULL, len, prot, flags, fd, (off_t)0)) == (void *)MAP_FAILED)
+		return (errno);
+
+	*addr = p;
+	return (0);
+}
+
+/*
+ * __os_unmap --
+ *	Release the specified shared memory.
+ *
+ * PUBLIC: int __os_unmap __P((void *, size_t));
+ */
+int
+__os_unmap(addr, len)
+	void *addr;
+	size_t len;
+{
+	/*
+	 * !!!
+	 * The argument len is always the same length as was mapped.
+	 */
+	return (munmap(addr, len) ? errno : 0);
+}