diff options
Diffstat (limited to 'cmd-wait-for.c')
-rw-r--r-- | cmd-wait-for.c | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/cmd-wait-for.c b/cmd-wait-for.c new file mode 100644 index 0000000..8a6aa25 --- /dev/null +++ b/cmd-wait-for.c @@ -0,0 +1,264 @@ +/* $OpenBSD$ */ + +/* + * Copyright (c) 2013 Nicholas Marriott <nicholas.marriott@gmail.com> + * Copyright (c) 2013 Thiago de Arruda <tpadilha84@gmail.com> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER + * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING + * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include <sys/types.h> + +#include <stdlib.h> +#include <string.h> + +#include "tmux.h" + +/* + * Block or wake a client on a named wait channel. + */ + +static enum cmd_retval cmd_wait_for_exec(struct cmd *, struct cmdq_item *); + +const struct cmd_entry cmd_wait_for_entry = { + .name = "wait-for", + .alias = "wait", + + .args = { "LSU", 1, 1, NULL }, + .usage = "[-L|-S|-U] channel", + + .flags = 0, + .exec = cmd_wait_for_exec +}; + +struct wait_item { + struct cmdq_item *item; + TAILQ_ENTRY(wait_item) entry; +}; + +struct wait_channel { + const char *name; + int locked; + int woken; + + TAILQ_HEAD(, wait_item) waiters; + TAILQ_HEAD(, wait_item) lockers; + + RB_ENTRY(wait_channel) entry; +}; +RB_HEAD(wait_channels, wait_channel); +static struct wait_channels wait_channels = RB_INITIALIZER(wait_channels); + +static int wait_channel_cmp(struct wait_channel *, struct wait_channel *); +RB_GENERATE_STATIC(wait_channels, wait_channel, entry, wait_channel_cmp); + +static int +wait_channel_cmp(struct wait_channel *wc1, struct wait_channel *wc2) +{ + return (strcmp(wc1->name, wc2->name)); +} + +static enum cmd_retval cmd_wait_for_signal(struct cmdq_item *, const char *, + struct wait_channel *); +static enum cmd_retval cmd_wait_for_wait(struct cmdq_item *, const char *, + struct wait_channel *); +static enum cmd_retval cmd_wait_for_lock(struct cmdq_item *, const char *, + struct wait_channel *); +static enum cmd_retval cmd_wait_for_unlock(struct cmdq_item *, const char *, + struct wait_channel *); + +static struct wait_channel *cmd_wait_for_add(const char *); +static void cmd_wait_for_remove(struct wait_channel *); + +static struct wait_channel * +cmd_wait_for_add(const char *name) +{ + struct wait_channel *wc; + + wc = xmalloc(sizeof *wc); + wc->name = xstrdup(name); + + wc->locked = 0; + wc->woken = 0; + + TAILQ_INIT(&wc->waiters); + TAILQ_INIT(&wc->lockers); + + RB_INSERT(wait_channels, &wait_channels, wc); + + log_debug("add wait channel %s", wc->name); + + return (wc); +} + +static void +cmd_wait_for_remove(struct wait_channel *wc) +{ + if (wc->locked) + return; + if (!TAILQ_EMPTY(&wc->waiters) || !wc->woken) + return; + + log_debug("remove wait channel %s", wc->name); + + RB_REMOVE(wait_channels, &wait_channels, wc); + + free((void *)wc->name); + free(wc); +} + +static enum cmd_retval +cmd_wait_for_exec(struct cmd *self, struct cmdq_item *item) +{ + struct args *args = cmd_get_args(self); + const char *name = args_string(args, 0); + struct wait_channel *wc, find; + + find.name = name; + wc = RB_FIND(wait_channels, &wait_channels, &find); + + if (args_has(args, 'S')) + return (cmd_wait_for_signal(item, name, wc)); + if (args_has(args, 'L')) + return (cmd_wait_for_lock(item, name, wc)); + if (args_has(args, 'U')) + return (cmd_wait_for_unlock(item, name, wc)); + return (cmd_wait_for_wait(item, name, wc)); +} + +static enum cmd_retval +cmd_wait_for_signal(__unused struct cmdq_item *item, const char *name, + struct wait_channel *wc) +{ + struct wait_item *wi, *wi1; + + if (wc == NULL) + wc = cmd_wait_for_add(name); + + if (TAILQ_EMPTY(&wc->waiters) && !wc->woken) { + log_debug("signal wait channel %s, no waiters", wc->name); + wc->woken = 1; + return (CMD_RETURN_NORMAL); + } + log_debug("signal wait channel %s, with waiters", wc->name); + + TAILQ_FOREACH_SAFE(wi, &wc->waiters, entry, wi1) { + cmdq_continue(wi->item); + + TAILQ_REMOVE(&wc->waiters, wi, entry); + free(wi); + } + + cmd_wait_for_remove(wc); + return (CMD_RETURN_NORMAL); +} + +static enum cmd_retval +cmd_wait_for_wait(struct cmdq_item *item, const char *name, + struct wait_channel *wc) +{ + struct client *c = cmdq_get_client(item); + struct wait_item *wi; + + if (c == NULL) { + cmdq_error(item, "not able to wait"); + return (CMD_RETURN_ERROR); + } + + if (wc == NULL) + wc = cmd_wait_for_add(name); + + if (wc->woken) { + log_debug("wait channel %s already woken (%p)", wc->name, c); + cmd_wait_for_remove(wc); + return (CMD_RETURN_NORMAL); + } + log_debug("wait channel %s not woken (%p)", wc->name, c); + + wi = xcalloc(1, sizeof *wi); + wi->item = item; + TAILQ_INSERT_TAIL(&wc->waiters, wi, entry); + + return (CMD_RETURN_WAIT); +} + +static enum cmd_retval +cmd_wait_for_lock(struct cmdq_item *item, const char *name, + struct wait_channel *wc) +{ + struct wait_item *wi; + + if (cmdq_get_client(item) == NULL) { + cmdq_error(item, "not able to lock"); + return (CMD_RETURN_ERROR); + } + + if (wc == NULL) + wc = cmd_wait_for_add(name); + + if (wc->locked) { + wi = xcalloc(1, sizeof *wi); + wi->item = item; + TAILQ_INSERT_TAIL(&wc->lockers, wi, entry); + return (CMD_RETURN_WAIT); + } + wc->locked = 1; + + return (CMD_RETURN_NORMAL); +} + +static enum cmd_retval +cmd_wait_for_unlock(struct cmdq_item *item, const char *name, + struct wait_channel *wc) +{ + struct wait_item *wi; + + if (wc == NULL || !wc->locked) { + cmdq_error(item, "channel %s not locked", name); + return (CMD_RETURN_ERROR); + } + + if ((wi = TAILQ_FIRST(&wc->lockers)) != NULL) { + cmdq_continue(wi->item); + TAILQ_REMOVE(&wc->lockers, wi, entry); + free(wi); + } else { + wc->locked = 0; + cmd_wait_for_remove(wc); + } + + return (CMD_RETURN_NORMAL); +} + +void +cmd_wait_for_flush(void) +{ + struct wait_channel *wc, *wc1; + struct wait_item *wi, *wi1; + + RB_FOREACH_SAFE(wc, wait_channels, &wait_channels, wc1) { + TAILQ_FOREACH_SAFE(wi, &wc->waiters, entry, wi1) { + cmdq_continue(wi->item); + TAILQ_REMOVE(&wc->waiters, wi, entry); + free(wi); + } + wc->woken = 1; + TAILQ_FOREACH_SAFE(wi, &wc->lockers, entry, wi1) { + cmdq_continue(wi->item); + TAILQ_REMOVE(&wc->lockers, wi, entry); + free(wi); + } + wc->locked = 0; + cmd_wait_for_remove(wc); + } +} |