| 1 | /* |
| 2 | * Copyright (C) 2020 Paul Cercueil <paul@crapouillou.net> |
| 3 | * |
| 4 | * This library is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU Lesser General Public |
| 6 | * License as published by the Free Software Foundation; either |
| 7 | * version 2.1 of the License, or (at your option) any later version. |
| 8 | * |
| 9 | * This library is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 12 | * Lesser General Public License for more details. |
| 13 | */ |
| 14 | |
| 15 | #include "blockcache.h" |
| 16 | #include "debug.h" |
| 17 | #include "lightrec-private.h" |
| 18 | #include "memmanager.h" |
| 19 | #include "slist.h" |
| 20 | #include "reaper.h" |
| 21 | |
| 22 | #include <errno.h> |
| 23 | #include <pthread.h> |
| 24 | #include <stdbool.h> |
| 25 | |
| 26 | struct reaper_elm { |
| 27 | reap_func_t func; |
| 28 | void *data; |
| 29 | struct slist_elm slist; |
| 30 | }; |
| 31 | |
| 32 | struct reaper { |
| 33 | struct lightrec_state *state; |
| 34 | pthread_mutex_t mutex; |
| 35 | struct slist_elm reap_list; |
| 36 | }; |
| 37 | |
| 38 | struct reaper *lightrec_reaper_init(struct lightrec_state *state) |
| 39 | { |
| 40 | struct reaper *reaper; |
| 41 | int ret; |
| 42 | |
| 43 | reaper = lightrec_malloc(state, MEM_FOR_LIGHTREC, sizeof(*reaper)); |
| 44 | if (!reaper) { |
| 45 | pr_err("Cannot create reaper: Out of memory\n"); |
| 46 | return NULL; |
| 47 | } |
| 48 | |
| 49 | reaper->state = state; |
| 50 | slist_init(&reaper->reap_list); |
| 51 | |
| 52 | ret = pthread_mutex_init(&reaper->mutex, NULL); |
| 53 | if (ret) { |
| 54 | pr_err("Cannot init mutex variable: %d\n", ret); |
| 55 | lightrec_free(reaper->state, MEM_FOR_LIGHTREC, |
| 56 | sizeof(*reaper), reaper); |
| 57 | return NULL; |
| 58 | } |
| 59 | |
| 60 | return reaper; |
| 61 | } |
| 62 | |
| 63 | void lightrec_reaper_destroy(struct reaper *reaper) |
| 64 | { |
| 65 | pthread_mutex_destroy(&reaper->mutex); |
| 66 | lightrec_free(reaper->state, MEM_FOR_LIGHTREC, sizeof(*reaper), reaper); |
| 67 | } |
| 68 | |
| 69 | int lightrec_reaper_add(struct reaper *reaper, reap_func_t f, void *data) |
| 70 | { |
| 71 | struct reaper_elm *reaper_elm; |
| 72 | struct slist_elm *elm; |
| 73 | int ret = 0; |
| 74 | |
| 75 | pthread_mutex_lock(&reaper->mutex); |
| 76 | |
| 77 | for (elm = reaper->reap_list.next; elm; elm = elm->next) { |
| 78 | reaper_elm = container_of(elm, struct reaper_elm, slist); |
| 79 | |
| 80 | if (reaper_elm->data == data) |
| 81 | goto out_unlock; |
| 82 | } |
| 83 | |
| 84 | reaper_elm = lightrec_malloc(reaper->state, MEM_FOR_LIGHTREC, |
| 85 | sizeof(*reaper_elm)); |
| 86 | if (!reaper_elm) { |
| 87 | pr_err("Cannot add reaper entry: Out of memory\n"); |
| 88 | ret = -ENOMEM; |
| 89 | goto out_unlock; |
| 90 | } |
| 91 | |
| 92 | reaper_elm->func = f; |
| 93 | reaper_elm->data = data; |
| 94 | slist_append(&reaper->reap_list, &reaper_elm->slist); |
| 95 | |
| 96 | out_unlock: |
| 97 | pthread_mutex_unlock(&reaper->mutex); |
| 98 | return ret; |
| 99 | } |
| 100 | |
| 101 | void lightrec_reaper_reap(struct reaper *reaper) |
| 102 | { |
| 103 | struct reaper_elm *reaper_elm; |
| 104 | struct slist_elm *elm; |
| 105 | |
| 106 | pthread_mutex_lock(&reaper->mutex); |
| 107 | |
| 108 | while (!!(elm = slist_first(&reaper->reap_list))) { |
| 109 | slist_remove(&reaper->reap_list, elm); |
| 110 | pthread_mutex_unlock(&reaper->mutex); |
| 111 | |
| 112 | reaper_elm = container_of(elm, struct reaper_elm, slist); |
| 113 | |
| 114 | (*reaper_elm->func)(reaper_elm->data); |
| 115 | |
| 116 | lightrec_free(reaper->state, MEM_FOR_LIGHTREC, |
| 117 | sizeof(*reaper_elm), reaper_elm); |
| 118 | |
| 119 | pthread_mutex_lock(&reaper->mutex); |
| 120 | } |
| 121 | |
| 122 | pthread_mutex_unlock(&reaper->mutex); |
| 123 | } |