diff options
Diffstat (limited to 'lib/libthr/thread/thr_pshared.c')
| -rw-r--r-- | lib/libthr/thread/thr_pshared.c | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/lib/libthr/thread/thr_pshared.c b/lib/libthr/thread/thr_pshared.c new file mode 100644 index 0000000..d40346d --- /dev/null +++ b/lib/libthr/thread/thr_pshared.c @@ -0,0 +1,223 @@ +/*- + * Copyright (c) 2015 The FreeBSD Foundation + * + * This software was developed by Konstantin Belousov + * under sponsorship from the FreeBSD Foundation. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/types.h> +#include <sys/mman.h> +#include <sys/queue.h> +#include "namespace.h" +#include <stdlib.h> +#include "un-namespace.h" + +#include "thr_private.h" + +struct psh { + LIST_ENTRY(psh) link; + void *key; + void *val; +}; + +LIST_HEAD(pshared_hash_head, psh); +#define HASH_SIZE 128 +static struct pshared_hash_head pshared_hash[HASH_SIZE]; +#define PSHARED_KEY_HASH(key) (((unsigned long)(key) >> 8) % HASH_SIZE) +/* XXXKIB: lock could be split to per-hash chain, if appears contested */ +static struct urwlock pshared_lock = DEFAULT_URWLOCK; + +void +__thr_pshared_init(void) +{ + int i; + + _thr_urwlock_init(&pshared_lock); + for (i = 0; i < HASH_SIZE; i++) + LIST_INIT(&pshared_hash[i]); +} + +static void +pshared_rlock(struct pthread *curthread) +{ + + curthread->locklevel++; + _thr_rwl_rdlock(&pshared_lock); +} + +static void +pshared_wlock(struct pthread *curthread) +{ + + curthread->locklevel++; + _thr_rwl_wrlock(&pshared_lock); +} + +static void +pshared_unlock(struct pthread *curthread) +{ + + _thr_rwl_unlock(&pshared_lock); + curthread->locklevel--; + _thr_ast(curthread); +} + +static void +pshared_gc(struct pthread *curthread) +{ + struct pshared_hash_head *hd; + struct psh *h, *h1; + int error, i; + + pshared_wlock(curthread); + for (i = 0; i < HASH_SIZE; i++) { + hd = &pshared_hash[i]; + LIST_FOREACH_SAFE(h, hd, link, h1) { + error = _umtx_op(NULL, UMTX_OP_SHM, UMTX_SHM_ALIVE, + h->val, NULL); + if (error == 0) + continue; + LIST_REMOVE(h, link); + munmap(h->val, PAGE_SIZE); + free(h); + } + } + pshared_unlock(curthread); +} + +static void * +pshared_lookup(void *key) +{ + struct pshared_hash_head *hd; + struct psh *h; + + hd = &pshared_hash[PSHARED_KEY_HASH(key)]; + LIST_FOREACH(h, hd, link) { + if (h->key == key) + return (h->val); + } + return (NULL); +} + +static int +pshared_insert(void *key, void **val) +{ + struct pshared_hash_head *hd; + struct psh *h; + + hd = &pshared_hash[PSHARED_KEY_HASH(key)]; + LIST_FOREACH(h, hd, link) { + if (h->key == key) { + if (h->val != *val) { + munmap(*val, PAGE_SIZE); + *val = h->val; + } + return (1); + } + } + + h = malloc(sizeof(*h)); + if (h == NULL) + return (0); + h->key = key; + h->val = *val; + LIST_INSERT_HEAD(hd, h, link); + return (1); +} + +static void * +pshared_remove(void *key) +{ + struct pshared_hash_head *hd; + struct psh *h; + void *val; + + hd = &pshared_hash[PSHARED_KEY_HASH(key)]; + LIST_FOREACH(h, hd, link) { + if (h->key == key) { + LIST_REMOVE(h, link); + val = h->val; + free(h); + return (val); + } + } + return (NULL); +} + +static void +pshared_clean(void *key, void *val) +{ + + if (val != NULL) + munmap(val, PAGE_SIZE); + _umtx_op(NULL, UMTX_OP_SHM, UMTX_SHM_DESTROY, key, NULL); +} + +void * +__thr_pshared_offpage(void *key, int doalloc) +{ + struct pthread *curthread; + void *res; + int fd, ins_done; + + curthread = _get_curthread(); + pshared_rlock(curthread); + res = pshared_lookup(key); + pshared_unlock(curthread); + if (res != NULL) + return (res); + fd = _umtx_op(NULL, UMTX_OP_SHM, doalloc ? UMTX_SHM_CREAT : + UMTX_SHM_LOOKUP, key, NULL); + if (fd == -1) + return (NULL); + res = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); + close(fd); + if (res == MAP_FAILED) + return (NULL); + pshared_wlock(curthread); + ins_done = pshared_insert(key, &res); + pshared_unlock(curthread); + if (!ins_done) { + pshared_clean(key, res); + res = NULL; + } + return (res); +} + +void +__thr_pshared_destroy(void *key) +{ + struct pthread *curthread; + void *val; + + curthread = _get_curthread(); + pshared_wlock(curthread); + val = pshared_remove(key); + pshared_unlock(curthread); + pshared_clean(key, val); + pshared_gc(curthread); +} |
