xref: /DragonStub/lib/lock.c (revision 530d68ba191850edafc6da22cb2df55bec0c5fa5)
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
InitializeLock(IN OUT FLOCK * Lock,IN EFI_TPL Priority)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
AcquireLock(IN FLOCK * Lock)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
ReleaseLock(IN FLOCK * Lock)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 }
108