Greg Hartman | 76d05dc | 2016-11-23 15:51:27 -0800 | [diff] [blame] | 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 | } |