From 354bb40e75d94466e91fe6960523612c9d17ccfb Mon Sep 17 00:00:00 2001
From: Karen Arutyunov <karen@codesynthesis.com>
Date: Thu, 2 Nov 2017 23:11:29 +0300
Subject: Add implementation

---
 mysql/mysys/my_mmap.c | 89 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 89 insertions(+)
 create mode 100644 mysql/mysys/my_mmap.c

(limited to 'mysql/mysys/my_mmap.c')

diff --git a/mysql/mysys/my_mmap.c b/mysql/mysys/my_mmap.c
new file mode 100644
index 0000000..b58c657
--- /dev/null
+++ b/mysql/mysys/my_mmap.c
@@ -0,0 +1,89 @@
+/* Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.
+
+   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; version 2 of the License.
+
+   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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */
+
+#include "mysys_priv.h"
+#include "my_sys.h"
+
+#ifdef HAVE_SYS_MMAN_H
+
+/*
+  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));
+}
+
+#elif defined(_WIN32)
+
+static SECURITY_ATTRIBUTES mmap_security_attributes=
+  {sizeof(SECURITY_ATTRIBUTES), 0, TRUE};
+
+void *my_mmap(void *addr, size_t len, int prot,
+               int flags, File fd, my_off_t offset)
+{
+  HANDLE hFileMap;
+  LPVOID ptr;
+  HANDLE hFile= (HANDLE)my_get_osfhandle(fd);
+  DBUG_ENTER("my_mmap");
+  DBUG_PRINT("mysys", ("map fd: %d", fd));
+
+  if (hFile == INVALID_HANDLE_VALUE)
+    DBUG_RETURN(MAP_FAILED);
+
+  hFileMap=CreateFileMapping(hFile, &mmap_security_attributes,
+                             PAGE_READWRITE, 0, (DWORD) len, NULL);
+  if (hFileMap == 0)
+    DBUG_RETURN(MAP_FAILED);
+
+  ptr=MapViewOfFile(hFileMap,
+                    prot & 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)
+  {
+    DBUG_PRINT("mysys", ("mapped addr: %p", ptr));
+    DBUG_RETURN(ptr);
+  }
+
+  DBUG_RETURN(MAP_FAILED);
+}
+
+int my_munmap(void *addr, size_t len)
+{
+  DBUG_ENTER("my_munmap");
+  DBUG_PRINT("mysys", ("unmap addr: %p", addr));
+  DBUG_RETURN(UnmapViewOfFile(addr) ? 0 : -1);
+}
+
+int my_msync(int fd, void *addr, size_t len, int flags)
+{
+  return FlushViewOfFile(addr, len) ? 0 : -1;
+}
+
+#else
+#error "no mmap!"
+#endif
+
-- 
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