gnu-efi/lib/lock.c

   1 /*++
   2
   3 Copyright (c) 1998  Intel Corporation
   4
   5 Module Name:
   6
   7     lock.c
   8
   9 Abstract:
  10
  11     Implements FLOCK
  12
  13
  14
  15 Revision History
  16
  17 --*/
  18
  19
  20 #include "lib.h"
  21
  22
  23 VOID
  24 InitializeLock (
  25     IN OUT FLOCK    *Lock,
  26     IN EFI_TPL      Priority
  27     )
  28 /*++
  29
  30 Routine Description:
  31
  32     Initialize a basic mutual exclusion lock.   Each lock
  33     provides mutual exclusion access at it's task priority
  34     level.  Since there is no-premption (at any TPL) or
  35     multiprocessor support, acquiring the lock only consists
  36     of raising to the locks TPL.
  37
  38     Note on a debug build the lock is acquired and released
  39     to help ensure proper usage.
  40
  41 Arguments:
  42
  43     Lock        - The FLOCK structure to initialize
  44
  45     Priority    - The task priority level of the lock
  46
  47
  48 Returns:
  49
  50     An initialized F Lock structure.
  51
  52 --*/
  53 {
  54     Lock->Tpl = Priority;
  55     Lock->OwnerTpl = 0;
  56     Lock->Lock = 0;
  57 }
  58
  59
  60 VOID
  61 AcquireLock (
  62     IN FLOCK    *Lock
  63     )
  64 /*++
  65
  66 Routine Description:
  67
  68     Raising to the task priority level of the mutual exclusion
  69     lock, and then acquires ownership of the lock.
  70
  71 Arguments:
  72
  73     Lock        - The lock to acquire
  74
  75 Returns:
  76
  77     Lock owned
  78
  79 --*/
  80 {
  81     RtAcquireLock (Lock);
  82 }
  83
  84
  85 VOID
  86 ReleaseLock (
  87     IN FLOCK    *Lock
  88     )
  89 /*++
  90
  91 Routine Description:
  92
  93     Releases ownership of the mutual exclusion lock, and
  94     restores the previous task priority level.
  95
  96 Arguments:
  97
  98     Lock        - The lock to release
  99
 100 Returns:
 101
 102     Lock unowned
 103
 104 --*/
 105 {
 106     RtReleaseLock (Lock);
 107 }