mono/utils/mono-proclib-windows-uwp.c

   1 /*
   2  * mono-proclib-windows-uwp.c: UWP proclib support for Mono.
   3  *
   4  * Copyright 2016 Microsoft
   5  * Licensed under the MIT license. See LICENSE file in the project root for full license information.
   6 */
   7 #include <config.h>
   8 #include <glib.h>
   9
  10 #if G_HAVE_API_SUPPORT(HAVE_UWP_WINAPI_SUPPORT)
  11 #include <Windows.h>
  12 #include <mono/utils/mono-proclib.h>
  13
  14 gint32
  15 mono_cpu_usage (MonoCpuUsageState *prev)
  16 {
  17         gint32 cpu_usage = 0;
  18         gint64 cpu_total_time;
  19         gint64 cpu_busy_time;
  20         guint64 idle_time;
  21         guint64 kernel_time;
  22         guint64 user_time;
  23         guint64 current_time;
  24         guint64 creation_time;
  25         guint64 exit_time;
  26
  27         GetSystemTimeAsFileTime ((FILETIME*)&current_time);
  28         if (!GetProcessTimes (GetCurrentProcess (), (FILETIME*)&creation_time, (FILETIME*)&exit_time, (FILETIME*)&kernel_time, (FILETIME*)&user_time)) {
  29                 g_error ("GetProcessTimes() failed, error code is %d\n", GetLastError ());
  30                 return -1;
  31         }
  32
  33         // GetProcessTimes user_time is a sum of user time spend by all threads in the process.
  34         // This means that the total user time can be more than real time. In order to adjust for this
  35         // the total available time that we can be scheduled depends on the number of available cores.
  36         // For example, having 2 threads running 100% on a 2 core system for 100 ms will return a user_time of 200ms
  37         // but the current_time - creation_time will only be 100ms but by adjusting the available time based on number of
  38         // of availalbe cores will gives use the total load of the process.
  39         guint64 total_available_time = (current_time - creation_time) * mono_cpu_count ();
  40
  41         idle_time = total_available_time - (kernel_time + user_time);
  42
  43         cpu_total_time = (gint64)((idle_time - (prev ? prev->idle_time : 0)) + (user_time - (prev ? prev->user_time : 0)) + (kernel_time - (prev ? prev->kernel_time : 0)));
  44         cpu_busy_time = (gint64)(cpu_total_time - (idle_time - (prev ? prev->idle_time : 0)));
  45
  46         if (prev) {
  47                 prev->idle_time = idle_time;
  48                 prev->kernel_time = kernel_time;
  49                 prev->user_time = user_time;
  50         }
  51
  52         if (cpu_total_time > 0 && cpu_busy_time > 0)
  53                 cpu_usage = (gint32)(cpu_busy_time * 100 / cpu_total_time);
  54
  55         return cpu_usage;
  56 }
  57
  58 #else /* G_HAVE_API_SUPPORT(HAVE_UWP_WINAPI_SUPPORT) */
  59
  60 #ifdef _MSC_VER
  61 // Quiet Visual Studio linker warning, LNK4221, in cases when this source file intentional ends up empty.
  62 void __mono_win32_mono_proclib_windows_uwp_quiet_lnk4221(void) {}
  63 #endif
  64 #endif /* G_HAVE_API_SUPPORT(HAVE_UWP_WINAPI_SUPPORT) */