audk/MdePkg/Library/BasePerformanceLibNull/PerformanceLib.c

/** @file
  Base Performance Library which provides no service.

  Copyright (c) 2006, Intel Corporation<BR>
  All rights reserved. This program and the accompanying materials
  are licensed and made available under the terms and conditions of the BSD License
  which accompanies this distribution.  The full text of the license may be found at
  http://opensource.org/licenses/bsd-license.php

  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

  Module Name:  PerformanceLib.c

**/

/**
  Creates a record for the beginning of a performance measurement. 
  
  Creates a record that contains the Handle, Token, and Module.
  If TimeStamp is not zero, then TimeStamp is added to the record as the start time.
  If TimeStamp is zero, then this function reads the current time stamp
  and adds that time stamp value to the record as the start time.

  @param  Handle                  Pointer to environment specific context used
                                  to identify the component being measured.
  @param  Token                   Pointer to a Null-terminated ASCII string
                                  that identifies the component being measured.
  @param  Module                  Pointer to a Null-terminated ASCII string
                                  that identifies the module being measured.
  @param  TimeStamp               64-bit time stamp.

  @retval RETURN_SUCCESS          The start of the measurement was recorded.
  @retval RETURN_OUT_OF_RESOURCES There are not enough resources to record the measurement.

**/
RETURN_STATUS
EFIAPI
StartPerformanceMeasurement (
  IN CONST VOID   *Handle,  OPTIONAL
  IN CONST CHAR8  *Token,
  IN CONST CHAR8  *Module,
  IN UINT64       TimeStamp
  )
{
  return RETURN_SUCCESS;
}

/**
  Fills in the end time of a performance measurement. 
  
  Looks up the record that matches Handle, Token, and Module.
  If the record can not be found then return RETURN_NOT_FOUND.
  If the record is found and TimeStamp is not zero,
  then TimeStamp is added to the record as the end time.
  If the record is found and TimeStamp is zero, then this function reads
  the current time stamp and adds that time stamp value to the record as the end time.
  If this function is called multiple times for the same record, then the end time is overwritten.

  @param  Handle                  Pointer to environment specific context used
                                  to identify the component being measured.
  @param  Token                   Pointer to a Null-terminated ASCII string
                                  that identifies the component being measured.
  @param  Module                  Pointer to a Null-terminated ASCII string
                                  that identifies the module being measured.
  @param  TimeStamp               64-bit time stamp.

  @retval RETURN_SUCCESS          The end of  the measurement was recorded.
  @retval RETURN_NOT_FOUND        The specified measurement record could not be found.

**/
RETURN_STATUS
EFIAPI
EndPerformanceMeasurement (
  IN CONST VOID   *Handle,  OPTIONAL
  IN CONST CHAR8  *Token,
  IN CONST CHAR8  *Module,
  IN UINT64       TimeStamp
  )
{
  return RETURN_SUCCESS;
}

/**
  Attempts to retrieve a performance measurement log entry from the performance measurement log. 
  
  Attempts to retrieve the performance log entry specified by LogEntryKey.  If LogEntryKey is
  zero on entry, then an attempt is made to retrieve the first entry from the performance log,
  and the key for the second entry in the log is returned.  If the performance log is empty,
  then no entry is retrieved and zero is returned.  If LogEntryKey is not zero, then the performance
  log entry associated with LogEntryKey is retrieved, and the key for the next entry in the log is
  returned.  If LogEntryKey is the key for the last entry in the log, then the last log entry is
  retrieved and an implementation specific non-zero key value that specifies the end of the performance
  log is returned.  If LogEntryKey is equal this implementation specific non-zero key value, then no entry
  is retrieved and zero is returned.  In the cases where a performance log entry can be returned,
  the log entry is returned in Handle, Token, Module, StartTimeStamp, and EndTimeStamp.
  If LogEntryKey is not a valid log entry key for the performance measurement log, then ASSERT().
  If Handle is NULL, then ASSERT().
  If Token is NULL, then ASSERT().
  If Module is NULL, then ASSERT().
  If StartTimeStamp is NULL, then ASSERT().
  If EndTimeStamp is NULL, then ASSERT().

  @param  LogEntryKey             On entry, the key of the performance measurement log entry to retrieve.
                                  0, then the first performance measurement log entry is retrieved.
                                  On exit, the key of the next performance lof entry entry.
  @param  Handle                  Pointer to environment specific context used to identify the component
                                  being measured.  
  @param  Token                   Pointer to a Null-terminated ASCII string that identifies the component
                                  being measured. 
  @param  Module                  Pointer to a Null-terminated ASCII string that identifies the module
                                  being measured.
  @param  StartTimeStamp          Pointer to the 64-bit time stamp that was recorded when the measurement
                                  was started.
  @param  EndTimeStamp            Pointer to the 64-bit time stamp that was recorded when the measurement
                                  was ended.

  @return The key for the next performance log entry (in general case).

**/
UINTN
EFIAPI
GetPerformanceMeasurement (
  IN  UINTN       LogEntryKey, 
  OUT CONST VOID  **Handle,
  OUT CONST CHAR8 **Token,
  OUT CONST CHAR8 **Module,
  OUT UINT64      *StartTimeStamp,
  OUT UINT64      *EndTimeStamp
  )
{
  ASSERT (Handle != NULL);
  ASSERT (Token != NULL);
  ASSERT (Module != NULL);
  ASSERT (StartTimeStamp != NULL);
  ASSERT (EndTimeStamp != NULL);

  return 0;
}

/**
  Returns TRUE if the performance measurement macros are enabled. 
  
  This function returns TRUE if the PERFORMANCE_LIBRARY_PROPERTY_MEASUREMENT_ENABLED bit of
  PcdPerformanceLibraryPropertyMask is set.  Otherwise FALSE is returned.

  @retval TRUE                    The PERFORMANCE_LIBRARY_PROPERTY_MEASUREMENT_ENABLED bit of
                                  PcdPerformanceLibraryPropertyMask is set.
  @retval FALSE                   The PERFORMANCE_LIBRARY_PROPERTY_MEASUREMENT_ENABLED bit of
                                  PcdPerformanceLibraryPropertyMask is clear.

**/
BOOLEAN
EFIAPI
PerformanceMeasurementEnabled (
  VOID
  )
{
  return ((PcdGet8(PcdPerformanceLibraryPropertyMask) & PERFORMANCE_LIBRARY_PROPERTY_MEASUREMENT_ENABLED) != 0);
}