1 | /* Copyright 2016 Google Inc. |
2 | |
3 | Licensed under the Apache License, Version 2.0 (the "License"); |
4 | you may not use this file except in compliance with the License. |
5 | You may obtain a copy of the License at |
6 | |
7 | http://www.apache.org/licenses/LICENSE-2.0 |
8 | |
9 | Unless required by applicable law or agreed to in writing, software |
10 | distributed under the License is distributed on an "AS IS" BASIS, |
11 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
12 | See the License for the specific language governing permissions and |
13 | limitations under the License. */ |
14 | |
15 | #ifndef NSYNC_INTERNAL_SEM_H_ |
16 | #define NSYNC_INTERNAL_SEM_H_ |
17 | |
18 | /* A semaphore. |
19 | It may be counting or binary, and it need have no destructor. */ |
20 | |
21 | #include "nsync_cpp.h" |
22 | |
23 | NSYNC_CPP_START_ |
24 | |
25 | typedef struct nsync_semaphore_s_ { |
26 | void *sem_space[32]; /* space used by implementation */ |
27 | } nsync_semaphore; |
28 | |
29 | /* Initialize *s; the initial value is 0. */ |
30 | void nsync_mu_semaphore_init (nsync_semaphore *s); |
31 | |
32 | /* Wait until the count of *s exceeds 0, and decrement it. */ |
33 | void nsync_mu_semaphore_p (nsync_semaphore *s); |
34 | |
35 | /* Wait until one of: |
36 | the count of *s is non-zero, in which case decrement *s and return 0; |
37 | or abs_deadline expires, in which case return ETIMEDOUT. */ |
38 | int nsync_mu_semaphore_p_with_deadline (nsync_semaphore *s, nsync_time abs_deadline); |
39 | |
40 | /* Ensure that the count of *s is at least 1. */ |
41 | void nsync_mu_semaphore_v (nsync_semaphore *s); |
42 | |
43 | NSYNC_CPP_END_ |
44 | |
45 | #endif /*NSYNC_INTERNAL_SEM_H_*/ |
46 | |