projects / rustc.git / blame
| Commit | Line | Data |
|---|---|---|
| 54a0048b SL |
1 | void mq_nanosleep(unsigned ns); |
| 2 | ||
| 1a4d82fc JJ |
3 | /* |
| 4 | * Simple templated message queue implementation that relies on only mutexes for | |
| 5 | * synchronization (which reduces portability issues). Given the following | |
| 6 | * setup: | |
| 7 | * | |
| 8 | * typedef struct mq_msg_s mq_msg_t; | |
| 9 | * struct mq_msg_s { | |
| 10 | * mq_msg(mq_msg_t) link; | |
| 11 | * [message data] | |
| 12 | * }; | |
| 13 | * mq_gen(, mq_, mq_t, mq_msg_t, link) | |
| 14 | * | |
| 15 | * The API is as follows: | |
| 16 | * | |
| 17 | * bool mq_init(mq_t *mq); | |
| 18 | * void mq_fini(mq_t *mq); | |
| 19 | * unsigned mq_count(mq_t *mq); | |
| 20 | * mq_msg_t *mq_tryget(mq_t *mq); | |
| 21 | * mq_msg_t *mq_get(mq_t *mq); | |
| 22 | * void mq_put(mq_t *mq, mq_msg_t *msg); | |
| 23 | * | |
| 24 | * The message queue linkage embedded in each message is to be treated as | |
| 25 | * externally opaque (no need to initialize or clean up externally). mq_fini() | |
| 26 | * does not perform any cleanup of messages, since it knows nothing of their | |
| 27 | * payloads. | |
| 28 | */ | |
| 29 | #define mq_msg(a_mq_msg_type) ql_elm(a_mq_msg_type) | |
| 30 | ||
| 31 | #define mq_gen(a_attr, a_prefix, a_mq_type, a_mq_msg_type, a_field) \ | |
| 32 | typedef struct { \ | |
| 33 | mtx_t lock; \ | |
| 34 | ql_head(a_mq_msg_type) msgs; \ | |
| 35 | unsigned count; \ | |
| 36 | } a_mq_type; \ | |
| 37 | a_attr bool \ | |
| 38 | a_prefix##init(a_mq_type *mq) { \ | |
| 39 | \ | |
| 40 | if (mtx_init(&mq->lock)) \ | |
| 41 | return (true); \ | |
| 42 | ql_new(&mq->msgs); \ | |
| 43 | mq->count = 0; \ | |
| 44 | return (false); \ | |
| 45 | } \ | |
| 46 | a_attr void \ | |
| 47 | a_prefix##fini(a_mq_type *mq) \ | |
| 48 | { \ | |
| 49 | \ | |
| 50 | mtx_fini(&mq->lock); \ | |
| 51 | } \ | |
| 52 | a_attr unsigned \ | |
| 53 | a_prefix##count(a_mq_type *mq) \ | |
| 54 | { \ | |
| 55 | unsigned count; \ | |
| 56 | \ | |
| 57 | mtx_lock(&mq->lock); \ | |
| 58 | count = mq->count; \ | |
| 59 | mtx_unlock(&mq->lock); \ | |
| 60 | return (count); \ | |
| 61 | } \ | |
| 62 | a_attr a_mq_msg_type * \ | |
| 63 | a_prefix##tryget(a_mq_type *mq) \ | |
| 64 | { \ | |
| 65 | a_mq_msg_type *msg; \ | |
| 66 | \ | |
| 67 | mtx_lock(&mq->lock); \ | |
| 68 | msg = ql_first(&mq->msgs); \ | |
| 69 | if (msg != NULL) { \ | |
| 70 | ql_head_remove(&mq->msgs, a_mq_msg_type, a_field); \ | |
| 71 | mq->count--; \ | |
| 72 | } \ | |
| 73 | mtx_unlock(&mq->lock); \ | |
| 74 | return (msg); \ | |
| 75 | } \ | |
| 76 | a_attr a_mq_msg_type * \ | |
| 77 | a_prefix##get(a_mq_type *mq) \ | |
| 78 | { \ | |
| 79 | a_mq_msg_type *msg; \ | |
| 54a0048b | 80 | unsigned ns; \ |
| 1a4d82fc JJ |
81 | \ |
| 82 | msg = a_prefix##tryget(mq); \ | |
| 83 | if (msg != NULL) \ | |
| 84 | return (msg); \ | |
| 85 | \ | |
| 54a0048b | 86 | ns = 1; \ |
| 1a4d82fc | 87 | while (true) { \ |
| 54a0048b | 88 | mq_nanosleep(ns); \ |
| 1a4d82fc JJ |
89 | msg = a_prefix##tryget(mq); \ |
| 90 | if (msg != NULL) \ | |
| 91 | return (msg); \ | |
| 54a0048b | 92 | if (ns < 1000*1000*1000) { \ |
| 1a4d82fc | 93 | /* Double sleep time, up to max 1 second. */ \ |
| 54a0048b SL |
94 | ns <<= 1; \ |
| 95 | if (ns > 1000*1000*1000) \ | |
| 96 | ns = 1000*1000*1000; \ | |
| 1a4d82fc JJ |
97 | } \ |
| 98 | } \ | |
| 99 | } \ | |
| 100 | a_attr void \ | |
| 101 | a_prefix##put(a_mq_type *mq, a_mq_msg_type *msg) \ | |
| 102 | { \ | |
| 103 | \ | |
| 104 | mtx_lock(&mq->lock); \ | |
| 105 | ql_elm_new(msg, a_field); \ | |
| 106 | ql_tail_insert(&mq->msgs, msg, a_field); \ | |
| 107 | mq->count++; \ | |
| 108 | mtx_unlock(&mq->lock); \ | |
| 109 | } |