Initial implementation of the Process abstraction for Win32.

llvm-svn: 16359

llvm/lib/System/Win32/Process.cpp

@@ -0,0 +1,46 @@
+//===- Win32/Process.cpp - Win32 Process Implementation ------- -*- C++ -*-===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Jeff Cohen and is distributed under the 
+// University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+// This file provides the Win32 specific implementation of the Process class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Win32.h"
+#include "llvm/System/Process.h"
+
+//===----------------------------------------------------------------------===//
+//=== WARNING: Implementation here must contain only Win32 specific code 
+//===          and must not be UNIX code
+//===----------------------------------------------------------------------===//
+
+namespace llvm {
+using namespace sys;
+
+// This function retrieves the page size using GetSystemInfo and is present
+// solely so it can be called once in Process::GetPageSize to initialize the
+// static variable PageSize.
+inline unsigned GetPageSizeOnce() {
+  // NOTE: A 32-bit application running under WOW64 is supposed to use
+  // GetNativeSystemInfo.  However, this interface is not present prior
+  // to Windows XP so to use it requires dynamic linking.  It is not clear
+  // how this affects the reported page size, if at all.  One could argue
+  // that LLVM ought to run as 64-bits on a 64-bit system, anyway.
+  SYSTEM_INFO info;
+  GetSystemInfo(&info);
+  return static_cast<unsigned>(info.dwPageSize);
+}
+
+unsigned 
+Process::GetPageSize() {
+  static const unsigned PageSize = GetPageSizeOnce();
+  return PageSize;
+}
+
+}
+// vim: sw=2 smartindent smarttab tw=80 autoindent expandtab