summaryrefslogtreecommitdiff
path: root/db2/os/db_os_mmap.c
diff options
context:
space:
mode:
Diffstat (limited to 'db2/os/db_os_mmap.c')
-rw-r--r--db2/os/db_os_mmap.c106
1 files changed, 106 insertions, 0 deletions
diff --git a/db2/os/db_os_mmap.c b/db2/os/db_os_mmap.c
new file mode 100644
index 0000000000..0cd8fad0b0
--- /dev/null
+++ b/db2/os/db_os_mmap.c
@@ -0,0 +1,106 @@
+/*-
+ * 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[] = "@(#)db_os_mmap.c 10.4 (Sleepycat) 6/28/97";
+#endif /* not lint */
+
+#ifndef NO_SYSTEM_INCLUDES
+#include <sys/types.h>
+#include <sys/mman.h>
+
+#include <errno.h>
+#endif
+
+#include "db_int.h"
+#include "os_ext.h"
+
+/*
+ * __db_mmap --
+ * Map in some shared memory backed by a file descriptor.
+ *
+ * PUBLIC: int __db_mmap __P((int, size_t, int, int, void *));
+ */
+int
+__db_mmap(fd, len, is_private, rdonly, addr)
+ int fd, is_private, rdonly;
+ size_t len;
+ void *addr;
+{
+#ifdef _WIN32
+ /* We have not implemented copy-on-write here */
+ void * pMemory = 0;
+ HANDLE hFile = (HANDLE)_get_osfhandle(fd);
+ HANDLE hMemory = CreateFileMapping(
+ hFile,
+ 0,
+ (rdonly ? PAGE_READONLY : PAGE_READWRITE),
+ 0,
+ len, /* This code fails if the library is ever compiled on a 64-bit machine */
+ 0
+ );
+ if (NULL == hMemory)
+ {
+ return errno;
+ }
+ pMemory = MapViewOfFile(
+ hMemory,
+ (rdonly ? FILE_MAP_READ : FILE_MAP_ALL_ACCESS),
+ 0,
+ 0,
+ len
+ );
+ CloseHandle(hMemory);
+ *(void **)addr = pMemory;
+ return 0;
+
+#else /* !_WIN32 */
+
+ void *p;
+ int flags, prot;
+
+ flags = is_private ? MAP_PRIVATE : MAP_SHARED;
+#ifdef MAP_HASSEMAPHORE
+ flags += MAP_HASSEMAPHORE;
+#endif
+ prot = PROT_READ | (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);
+
+ *(void **)addr = p;
+ return (0);
+#endif /* _WIN32 */
+}
+
+/*
+ * __db_unmap --
+ * Release the specified shared memory.
+ *
+ * PUBLIC: int __db_munmap __P((void *, size_t));
+ */
+int
+__db_munmap(addr, len)
+ void *addr;
+ size_t len;
+{
+ /*
+ * !!!
+ * The argument len is always the same length as was mapped.
+ */
+#ifdef _WIN32
+ return (!UnmapViewOfFile(addr) ? errno : 0);
+#else
+ return (munmap(addr, len) ? errno : 0);
+#endif
+}