mmap portability layer, mmap for Windows

new macro: thread_safe_decrement, thread_safe_dec_and_test, statistic_decrement


mysys/my_chsize.c:
  cleanup
include/config-win.h:
  mmap portability layer, mmap for Windows
include/my_pthread.h:
  thread_safe_decrement, thread_safe_dec_and_test, statistic_decrement
include/my_sys.h:
  mmap portability layer, mmap for Windows
mysys/Makefile.am:
  mmap portability layer, mmap for Windows

1 files changed, 89 insertions, 0 deletions

diff --git a/mysys/my_mmap.c b/mysys/my_mmap.c
new file mode 100644
index 00000000000..883181edd6c
--- /dev/null
+++ b/mysys/my_mmap.c
@@ -0,0 +1,89 @@
+/* Copyright (C) 2000-2003 MySQL AB
+
+   This program 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 2 of the License, or
+   (at your option) any later version.
+
+   This program 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 this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+#include "mysys_priv.h"
+
+#ifdef HAVE_MMAP
+
+/*
+  system msync() only syncs mmap'ed area to fs cache.
+  fsync() is required to really sync to disc
+*/
+int my_msync(int fd, void *addr, size_t len, int flags)
+{
+  msync(addr, len, flags);
+  return my_sync(fd, MYF(0));
+}
+
+#else
+#ifdef __WIN__
+
+static SECURITY_ATTRIBUTES mmap_security_attributes=
+  {sizeof(SECURITY_ATTRIBUTES), 0, TRUE};
+
+int my_getpagesize(void)
+{
+  SYSTEM_INFO si;
+  GetSystemInfo(&si);
+  return si.dwPageSize;
+}
+
+void *my_mmap(void *addr, size_t len, int prot,
+               int flags, int fd, my_off_t offset)
+{
+  DWORD flProtect=0;
+  HANDLE hFileMap;
+  LPVOID ptr;
+
+  flProtect|=SEC_COMMIT;
+
+  hFileMap=CreateFileMapping(fd, NULL, &mmap_security_attributes,
+                             PAGE_READWRITE, 0, len, 0);
+  if (hFileMap == 0)
+    return MAP_FAILED;
+
+  ptr=MapViewOfFile(hFileMap,
+                    flags & PROT_WRITE ? FILE_MAP_WRITE : FILE_MAP_READ,
+                    (DWORD)(offset >> 32), (DWORD)offset, len);
+
+  /*
+    MSDN explicitly states that it's possible to close File Mapping Object
+    even when a view is not unmapped - then the object will be held open
+    implicitly until unmap, as every view stores internally a handler of
+    a corresponding File Mapping Object
+   */
+  CloseHandle(hFileMap);
+
+  if (ptr)
+    return ptr;
+
+  return MAP_FAILED;
+}
+
+int my_munmap(void *addr, size_t len)
+{
+  return UnmapViewOfFile(addr) ? 0 : -1;
+}
+
+int my_msync(int fd, void *addr, size_t len, int flags)
+{
+  return FlushViewOfFile(addr, len) ? 0 : -1;
+}
+
+#endif
+#error "no mmap!"
+#endif
+