Make the windows_version.h functions threadsafe by using a singleton.

base/sys_info_win.cc

Index: base/sys_info_win.cc
===================================================================
--- base/sys_info_win.cc	(revision 80528)
+++ base/sys_info_win.cc	(working copy)
@@ -10,14 +10,13 @@
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/stringprintf.h"
+#include "base/win/windows_version.h"
 
 namespace base {
 
 // static
 int SysInfo::NumberOfProcessors() {
-  SYSTEM_INFO info;
-  GetSystemInfo(&info);
-  return static_cast<int>(info.dwNumberOfProcessors);
+  return win::OSInfo::GetInstance()->processors();
 }
 
 // static
@@ -54,12 +53,8 @@
 
 // static
 std::string SysInfo::OperatingSystemVersion() {
-  OSVERSIONINFO info = {0};
-  info.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
-  GetVersionEx(&info);
-
-  return base::StringPrintf("%lu.%lu",
-                            info.dwMajorVersion, info.dwMinorVersion);
+  const int* version_number = win::OSInfo::GetInstance()->version_number();
+  return StringPrintf("%d.%d", version_number[0], version_number[1]);
 }
 
 // TODO: Implement OperatingSystemVersionComplete, which would include
@@ -88,21 +83,16 @@
 
 // static
 size_t SysInfo::VMAllocationGranularity() {
-  SYSTEM_INFO sysinfo;
-  GetSystemInfo(&sysinfo);
-
-  return sysinfo.dwAllocationGranularity;
+  return win::OSInfo::GetInstance()->allocation_granularity();
 }
 
 // static
-void SysInfo::OperatingSystemVersionNumbers(int32 *major_version,
-                                            int32 *minor_version,
-                                            int32 *bugfix_version) {
-  OSVERSIONINFO info = {0};
-  info.dwOSVersionInfoSize = sizeof(info);
-  GetVersionEx(&info);
-  *major_version = info.dwMajorVersion;
-  *minor_version = info.dwMinorVersion;
+void SysInfo::OperatingSystemVersionNumbers(int32* major_version,
+                                            int32* minor_version,
+                                            int32* bugfix_version) {
+  win::OSInfo* os_info = win::OSInfo::GetInstance();
+  *major_version = os_info->version_number()[0];
+  *minor_version = os_info->version_number()[1];
   *bugfix_version = 0;
 }