reactos/win32ss/gdi/eng/float.c

   1 /*
   2  * COPYRIGHT:         See COPYING in the top level directory
   3  * PROJECT:           ReactOS kernel
   4  * PURPOSE:           Engine floating point functions
   5  * FILE:              win32ss/gdi/eng/float.c
   6  * PROGRAMER:         David Welch
   7  */
   8
   9 /* INCLUDES *****************************************************************/
  10
  11 #include <win32k.h>
  12
  13 #define NDEBUG
  14 #include <debug.h>
  15
  16 /* FUNCTIONS *****************************************************************/
  17
  18 #ifdef _PREFAST_
  19 #pragma warning(disable:__WARNING_WRONG_KIND)
  20 #endif
  21
  22 _Check_return_
  23 _Success_(return)
  24 _Kernel_float_restored_
  25 _At_(*pBuffer, _Kernel_requires_resource_held_(EngFloatState)
  26                _Kernel_releases_resource_(EngFloatState))
  27 ENGAPI
  28 BOOL
  29 APIENTRY
  30 EngRestoreFloatingPointState(
  31     _In_reads_(_Inexpressible_(statesize)) PVOID pBuffer)
  32 {
  33     NTSTATUS Status;
  34
  35     Status = KeRestoreFloatingPointState((PKFLOATING_SAVE)pBuffer);
  36     if (!NT_SUCCESS(Status))
  37     {
  38         return FALSE;
  39     }
  40
  41     return TRUE;
  42 }
  43
  44 _Check_return_
  45 _Success_(((pBuffer != NULL && cjBufferSize != 0) && return == 1) ||
  46           ((pBuffer == NULL || cjBufferSize == 0) && return > 0))
  47 _When_(pBuffer != NULL && cjBufferSize != 0 && return == 1, _Kernel_float_saved_
  48     _At_(*pBuffer, _Post_valid_ _Kernel_acquires_resource_(EngFloatState)))
  49 _On_failure_(_Post_satisfies_(return == 0))
  50 ENGAPI
  51 ULONG
  52 APIENTRY
  53 EngSaveFloatingPointState(
  54     _At_(*pBuffer, _Kernel_requires_resource_not_held_(EngFloatState))
  55     _Out_writes_bytes_opt_(cjBufferSize) PVOID pBuffer,
  56     _Inout_ ULONG cjBufferSize)
  57 {
  58     KFLOATING_SAVE TempBuffer;
  59     NTSTATUS Status;
  60
  61     if ((pBuffer == NULL) || (cjBufferSize == 0))
  62     {
  63         /* Check for floating point support. */
  64         Status = KeSaveFloatingPointState(&TempBuffer);
  65         if (Status != STATUS_SUCCESS)
  66         {
  67             return(0);
  68         }
  69
  70         KeRestoreFloatingPointState(&TempBuffer);
  71         return(sizeof(KFLOATING_SAVE));
  72     }
  73
  74     if (cjBufferSize < sizeof(KFLOATING_SAVE))
  75     {
  76         return(0);
  77     }
  78
  79     Status = KeSaveFloatingPointState((PKFLOATING_SAVE)pBuffer);
  80     if (!NT_SUCCESS(Status))
  81     {
  82         return FALSE;
  83     }
  84
  85     return TRUE;
  86 }
  87