/usr.bin/csup/fixups.c
https://bitbucket.org/freebsd/freebsd-head/ · C · 198 lines · 129 code · 24 blank · 45 comment · 19 complexity · 8d12971d744d43ee1f101ce780852330 MD5 · raw file
- /*-
- * Copyright (c) 2006, Maxime Henrion <mux@FreeBSD.org>
- * All rights reserved.
- *
- * 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.
- *
- * $FreeBSD$
- */
- #include <assert.h>
- #include <pthread.h>
- #include <stdlib.h>
- #include <string.h>
- #include "fixups.h"
- #include "misc.h"
- #include "queue.h"
- /*
- * A synchronized queue to implement fixups. The updater thread adds
- * fixup requests to the queue with fixups_put() when a checksum
- * mismatch error occurred. It then calls fixups_close() when he's
- * done requesting fixups. The detailer thread gets the fixups with
- * fixups_get() and then send the requests to the server.
- *
- * The queue is synchronized with a mutex and a condition variable.
- */
- struct fixups {
- pthread_mutex_t lock;
- pthread_cond_t cond;
- STAILQ_HEAD(, fixup) fixupq;
- struct fixup *cur;
- size_t size;
- int closed;
- };
- static void fixups_lock(struct fixups *);
- static void fixups_unlock(struct fixups *);
- static struct fixup *fixup_new(struct coll *, const char *);
- static void fixup_free(struct fixup *);
- static void
- fixups_lock(struct fixups *f)
- {
- int error;
- error = pthread_mutex_lock(&f->lock);
- assert(!error);
- }
- static void
- fixups_unlock(struct fixups *f)
- {
- int error;
- error = pthread_mutex_unlock(&f->lock);
- assert(!error);
- }
- static struct fixup *
- fixup_new(struct coll *coll, const char *name)
- {
- struct fixup *fixup;
- fixup = xmalloc(sizeof(struct fixup));
- fixup->f_name = xstrdup(name);
- fixup->f_coll = coll;
- return (fixup);
- }
- static void
- fixup_free(struct fixup *fixup)
- {
- free(fixup->f_name);
- free(fixup);
- }
- /* Create a new fixup queue. */
- struct fixups *
- fixups_new(void)
- {
- struct fixups *f;
- f = xmalloc(sizeof(struct fixups));
- f->size = 0;
- f->closed = 0;
- f->cur = NULL;
- STAILQ_INIT(&f->fixupq);
- pthread_mutex_init(&f->lock, NULL);
- pthread_cond_init(&f->cond, NULL);
- return (f);
- }
- /* Add a fixup request to the queue. */
- void
- fixups_put(struct fixups *f, struct coll *coll, const char *name)
- {
- struct fixup *fixup;
- int dosignal;
- dosignal = 0;
- fixup = fixup_new(coll, name);
- fixups_lock(f);
- assert(!f->closed);
- STAILQ_INSERT_TAIL(&f->fixupq, fixup, f_link);
- if (f->size++ == 0)
- dosignal = 1;
- fixups_unlock(f);
- if (dosignal)
- pthread_cond_signal(&f->cond);
- }
- /* Get a fixup request from the queue. */
- struct fixup *
- fixups_get(struct fixups *f)
- {
- struct fixup *fixup, *tofree;
- fixups_lock(f);
- while (f->size == 0 && !f->closed)
- pthread_cond_wait(&f->cond, &f->lock);
- if (f->closed && f->size == 0) {
- fixups_unlock(f);
- return (NULL);
- }
- assert(f->size > 0);
- fixup = STAILQ_FIRST(&f->fixupq);
- tofree = f->cur;
- f->cur = fixup;
- STAILQ_REMOVE_HEAD(&f->fixupq, f_link);
- f->size--;
- fixups_unlock(f);
- if (tofree != NULL)
- fixup_free(tofree);
- return (fixup);
- }
- /* Close the writing end of the queue. */
- void
- fixups_close(struct fixups *f)
- {
- int dosignal;
- dosignal = 0;
- fixups_lock(f);
- if (f->size == 0 && !f->closed)
- dosignal = 1;
- f->closed = 1;
- fixups_unlock(f);
- if (dosignal)
- pthread_cond_signal(&f->cond);
- }
- /* Free a fixups queue. */
- void
- fixups_free(struct fixups *f)
- {
- struct fixup *fixup, *fixup2;
- assert(f->closed);
- /*
- * Free any fixup that has been left on the queue.
- * This can happen if we have been aborted prematurely.
- */
- fixup = STAILQ_FIRST(&f->fixupq);
- while (fixup != NULL) {
- fixup2 = STAILQ_NEXT(fixup, f_link);
- fixup_free(fixup);
- fixup = fixup2;
- }
- if (f->cur != NULL)
- fixup_free(f->cur);
- pthread_cond_destroy(&f->cond);
- pthread_mutex_destroy(&f->lock);
- free(f);
- }