| Message ID | 20211118225840.19810-31-mwilck@suse.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | christophe varoqui |
| Headers | show |
| Series | multipathd: uxlsnr overhaul | expand |
On Thu, Nov 18, 2021 at 11:58:22PM +0100, mwilck@suse.com wrote: > From: Martin Wilck <mwilck@suse.com> > > The previous patches added the state machine and the timeout handling, > but there was no wakeup mechanism for the uxlsnr for cases where > client connections were waiting for the vecs lock. > > This patch uses the previously introduced wakeup mechanism of > struct mutex_lock for this purpose. Processes which unlock the > "global" vecs lock send an event in an eventfd which the uxlsnr > loop is polling for. > > As we are now woken up for servicing client handlers that don't > wait for input but for the lock, we need to set up the pollfds > differently, and iterate over all clients when handling events, > not only over the ones that are receiving. The hangup handling > is changed, too. We have to look at every client, even if one has > hung up. Note that I don't take client_lock for the loop in > uxsock_listen(), it's not necessary and will be removed elsewhere > in a follow-up patch. > > With this in place, the lock need not be taken in execute_handler() > any more. The uxlsnr only ever calls trylock() on the vecs lock, > avoiding any waiting for other threads to finish. > > Signed-off-by: Martin Wilck <mwilck@suse.com> > --- > multipathd/uxlsnr.c | 200 ++++++++++++++++++++++++++++---------------- > 1 file changed, 129 insertions(+), 71 deletions(-) > > diff --git a/multipathd/uxlsnr.c b/multipathd/uxlsnr.c > index 87134d5..bf9780d 100644 > --- a/multipathd/uxlsnr.c > +++ b/multipathd/uxlsnr.c > @@ -24,6 +24,7 @@ > #include <signal.h> > #include <stdbool.h> > #include <sys/inotify.h> > +#include <sys/eventfd.h> > #include "checkers.h" > #include "memory.h" > #include "debug.h" > @@ -70,6 +71,7 @@ struct client { > enum { > POLLFD_UX = 0, > POLLFD_NOTIFY, > + POLLFD_IDLE, > POLLFDS_BASE, > }; > > @@ -90,6 +92,7 @@ static LIST_HEAD(clients); > static pthread_mutex_t client_lock = PTHREAD_MUTEX_INITIALIZER; > static struct pollfd *polls; > static int notify_fd = -1; > +static int idle_fd = -1; > static char *watch_config_dir; > > static bool _socket_client_is_root(int fd) > @@ -187,6 +190,17 @@ void uxsock_cleanup(void *arg) > free_polls(); > } > > +void wakeup_cleanup(void *arg) > +{ > + struct mutex_lock *lck = arg; > + int fd = idle_fd; > + > + idle_fd = -1; > + set_wakeup_fn(lck, NULL); > + if (fd != -1) > + close(fd); > +} > + > struct watch_descriptors { > int conf_wd; > int dir_wd; > @@ -293,6 +307,18 @@ static void handle_inotify(int fd, struct watch_descriptors *wds) > > static const struct timespec ts_zero = { .tv_sec = 0, }; > > +/* call with clients lock held */ > +static bool __need_vecs_lock(void) > +{ > + struct client *c; > + > + list_for_each_entry(c, &clients, node) { > + if (c->state == CLT_WAIT_LOCK) > + return true; > + } > + return false; > +} > + > static int parse_cmd(struct client *c) > { > int r; > @@ -310,40 +336,31 @@ static int parse_cmd(struct client *c) > return r; > } > > -static int execute_handler(struct client *c, struct vectors *vecs, int timeout) > +static int execute_handler(struct client *c, struct vectors *vecs) > { > - int r; > - struct timespec tmo; > > - if (!c->handler) > + if (!c->handler || !c->handler->fn) > return -EINVAL; > > - if (clock_gettime(CLOCK_REALTIME, &tmo) == 0) { > - tmo.tv_sec += timeout; > - } else { > - tmo.tv_sec = 0; > - } > + return c->handler->fn(c->cmdvec, &c->reply, vecs); > +} > > - if (c->handler->locked) { > - int locked = 0; > +static void wakeup_listener(void) > +{ > + uint64_t one = 1; > > - pthread_cleanup_push(cleanup_lock, &vecs->lock); > - if (tmo.tv_sec) { > - r = timedlock(&vecs->lock, &tmo); > - } else { > - lock(&vecs->lock); > - r = 0; > - } > - if (r == 0) { > - locked = 1; > - pthread_testcancel(); > - r = c->handler->fn(c->cmdvec, &c->reply, vecs); > - } > - pthread_cleanup_pop(locked); > - } else > - r = c->handler->fn(c->cmdvec, &c->reply, vecs); > + if (idle_fd != -1 && > + write(idle_fd, &one, sizeof(one)) != sizeof(one)) > + condlog(1, "%s: failed", __func__); > +} > > - return r; > +static void drain_idle_fd(int fd) > +{ > + uint64_t val; > + int rc; > + > + rc = read(fd, &val, sizeof(val)); > + condlog(4, "%s: %d, %"PRIu64, __func__, rc, val); > } > > void default_reply(struct client *c, int r) > @@ -397,16 +414,19 @@ enum { > STM_BREAK, > }; > > -static int client_state_machine(struct client *c, struct vectors *vecs) > +static int client_state_machine(struct client *c, struct vectors *vecs, > + short revents) > { > ssize_t n; > const char *buf; > > - condlog(4, "%s: cli[%d] state=%d cmd=\"%s\" repl \"%s\"", __func__, > - c->fd, c->state, c->cmd, get_strbuf_str(&c->reply)); > + condlog(4, "%s: cli[%d] poll=%x state=%d cmd=\"%s\" repl \"%s\"", __func__, > + c->fd, revents, c->state, c->cmd, get_strbuf_str(&c->reply)); > > switch (c->state) { > case CLT_RECV: > + if (!(revents & POLLIN)) > + return STM_BREAK; > if (c->cmd_len == 0) { > /* > * We got POLLIN; assume that at least the length can > @@ -462,17 +482,30 @@ static int client_state_machine(struct client *c, struct vectors *vecs) > } > if (c->error) > set_client_state(c, CLT_SEND); > + else if (c->handler->locked) > + set_client_state(c, CLT_WAIT_LOCK); > else > set_client_state(c, CLT_WORK); > return STM_CONT; > > case CLT_WAIT_LOCK: It's not a big deal, but I would prefer a name like CLT_LOCKED_WORK instead of CLT_WAIT_LOCK, to make it obvious that these are alternate possibilites. > - /* tbd */ > - set_client_state(c, CLT_WORK); > - return STM_CONT; > + if (trylock(&vecs->lock) == 0) { > + /* don't use cleanup_lock(), lest we wakeup ourselves */ > + pthread_cleanup_push_cast(__unlock, &vecs->lock); > + c->error = execute_handler(c, vecs); > + pthread_cleanup_pop(1); > + condlog(4, "%s: cli[%d] grabbed lock", __func__, c->fd); > + free_keys(c->cmdvec); > + c->cmdvec = NULL; > + set_client_state(c, CLT_SEND); > + return STM_CONT; > + } else { > + condlog(4, "%s: cli[%d] waiting for lock", __func__, c->fd); > + return STM_BREAK; > + } > > case CLT_WORK: > - c->error = execute_handler(c, vecs, uxsock_timeout / 1000); > + c->error = execute_handler(c, vecs); > free_keys(c->cmdvec); > c->cmdvec = NULL; > set_client_state(c, CLT_SEND); > @@ -499,9 +532,14 @@ static int client_state_machine(struct client *c, struct vectors *vecs) > } > } > > -static void handle_client(struct client *c, struct vectors *vecs) > +static void handle_client(struct client *c, struct vectors *vecs, short revents) > { > - while (client_state_machine(c, vecs) == STM_CONT); > + if (revents & (POLLHUP|POLLERR)) { > + c->error = -ECONNRESET; > + return; > + } > + > + while (client_state_machine(c, vecs, revents) == STM_CONT); > } > > /* > @@ -514,6 +552,8 @@ void *uxsock_listen(long ux_sock, void *trigger_data) > /* conf->sequence_nr will be 1 when uxsock_listen is first called */ > unsigned int sequence_nr = 0; > struct watch_descriptors wds = { .conf_wd = -1, .dir_wd = -1 }; > + bool need_lock = false; > + struct vectors *vecs = trigger_data; > > condlog(3, "uxsock: startup listener"); > polls = MALLOC(max_pfds * sizeof(*polls)); > @@ -524,6 +564,14 @@ void *uxsock_listen(long ux_sock, void *trigger_data) > notify_fd = inotify_init1(IN_NONBLOCK); > if (notify_fd == -1) /* it's fine if notifications fail */ > condlog(3, "failed to start up configuration notifications"); > + > + pthread_cleanup_push(wakeup_cleanup, &vecs->lock); > + idle_fd = eventfd(0, EFD_NONBLOCK|EFD_CLOEXEC); > + if (idle_fd == -1) > + condlog(1, "failed to create idle fd"); If the idle_fd doesn't get correctly set, that seems like a fatal error to me. > + else > + set_wakeup_fn(&vecs->lock, wakeup_listener); > + > sigfillset(&mask); > sigdelset(&mask, SIGINT); > sigdelset(&mask, SIGTERM); > @@ -575,16 +623,30 @@ void *uxsock_listen(long ux_sock, void *trigger_data) > else > polls[POLLFD_NOTIFY].events = POLLIN; > > + need_lock = __need_vecs_lock(); > + polls[POLLFD_IDLE].fd = idle_fd; > + if (need_lock) > + polls[POLLFD_IDLE].events = POLLIN; > + else > + polls[POLLFD_IDLE].events = 0; > + > /* setup the clients */ > - i = POLLFDS_BASE; > - list_for_each_entry(c, &clients, node) { > - polls[i].fd = c->fd; > - polls[i].events = POLLIN; > - i++; > - if (i >= max_pfds) > - break; > - } > - n_pfds = i; > + i = POLLFDS_BASE; > + list_for_each_entry(c, &clients, node) { Nitpick: This would look clearer to me if, instead of a switch statement, it was just if (c->state != CLT_RECV) continue; polls[i].events = POLLIN; polls[i].fd = c->fd; ... -Ben > + switch(c->state) { > + case CLT_RECV: > + polls[i].events = POLLIN; > + break; > + default: > + /* don't poll for this client */ > + continue; > + } > + polls[i].fd = c->fd; > + i++; > + if (i >= max_pfds) > + break; > + } > + n_pfds = i; > pthread_cleanup_pop(1); > > /* most of our life is spent in this call */ > @@ -607,33 +669,28 @@ void *uxsock_listen(long ux_sock, void *trigger_data) > handle_signals(true); > continue; > } > + if (polls[POLLFD_IDLE].fd != -1 && > + polls[POLLFD_IDLE].revents & POLLIN) > + drain_idle_fd(idle_fd); > > - /* see if a client wants to speak to us */ > - for (i = POLLFDS_BASE; i < n_pfds; i++) { > - if (polls[i].revents & (POLLIN|POLLHUP|POLLERR)) { > - c = NULL; > - pthread_mutex_lock(&client_lock); > - list_for_each_entry(tmp, &clients, node) { > - if (tmp->fd == polls[i].fd) { > - c = tmp; > - break; > - } > - } > - pthread_mutex_unlock(&client_lock); > - if (!c) { > - condlog(4, "cli%d: new fd %d", > - i, polls[i].fd); > - continue; > - } > - if (polls[i].revents & (POLLHUP|POLLERR)) { > - condlog(4, "cli[%d]: Disconnected", > - c->fd); > - dead_client(c); > - continue; > - } > - handle_client(c, trigger_data); > - if (c->error == -ECONNRESET) > - dead_client(c); > + /* see if a client needs handling */ > + list_for_each_entry_safe(c, tmp, &clients, node) { > + short revents = 0; > + > + for (i = POLLFDS_BASE; i < n_pfds; i++) { > + if (polls[i].fd == c->fd) { > + revents = polls[i].revents; > + break; > + } > + } > + > + handle_client(c, trigger_data, revents); > + > + if (c->error == -ECONNRESET) { > + condlog(4, "cli[%d]: disconnected", c->fd); > + dead_client(c); > + if (i < n_pfds) > + polls[i].fd = -1; > } > } > /* see if we got a non-fatal signal */ > @@ -649,5 +706,6 @@ void *uxsock_listen(long ux_sock, void *trigger_data) > handle_inotify(notify_fd, &wds); > } > > + pthread_cleanup_pop(1); > return NULL; > } > -- > 2.33.1 -- dm-devel mailing list dm-devel@redhat.com https://listman.redhat.com/mailman/listinfo/dm-devel
On Wed, 2021-11-24 at 19:08 -0600, Benjamin Marzinski wrote: > On Thu, Nov 18, 2021 at 11:58:22PM +0100, mwilck@suse.com wrote: > > From: Martin Wilck <mwilck@suse.com> > > > > The previous patches added the state machine and the timeout > > handling, > > but there was no wakeup mechanism for the uxlsnr for cases where > > client connections were waiting for the vecs lock. > > > > This patch uses the previously introduced wakeup mechanism of > > struct mutex_lock for this purpose. Processes which unlock the > > "global" vecs lock send an event in an eventfd which the uxlsnr > > loop is polling for. > > > > As we are now woken up for servicing client handlers that don't > > wait for input but for the lock, we need to set up the pollfds > > differently, and iterate over all clients when handling events, > > not only over the ones that are receiving. The hangup handling > > is changed, too. We have to look at every client, even if one has > > hung up. Note that I don't take client_lock for the loop in > > uxsock_listen(), it's not necessary and will be removed elsewhere > > in a follow-up patch. > > > > With this in place, the lock need not be taken in execute_handler() > > any more. The uxlsnr only ever calls trylock() on the vecs lock, > > avoiding any waiting for other threads to finish. > > > > Signed-off-by: Martin Wilck <mwilck@suse.com> > > --- > > multipathd/uxlsnr.c | 200 ++++++++++++++++++++++++++++------------ > > ---- > > 1 file changed, 129 insertions(+), 71 deletions(-) > > > > diff --git a/multipathd/uxlsnr.c b/multipathd/uxlsnr.c > > index 87134d5..bf9780d 100644 > > --- a/multipathd/uxlsnr.c > > +++ b/multipathd/uxlsnr.c > > Nitpick: This would look clearer to me if, instead of a switch > statement, it was just > > if (c->state != CLT_RECV) > continue; > > polls[i].events = POLLIN; > polls[i].fd = c->fd; > ... That's true if you look at this patch in isolation. The reason I use a switch statement is that with patch 32, we get another case to treat here (CLT_SEND). At that point, the switch is at least on par wrt clarity, IMO. No? Martin -- dm-devel mailing list dm-devel@redhat.com https://listman.redhat.com/mailman/listinfo/dm-devel
On Fri, Nov 26, 2021 at 03:23:18PM +0100, Martin Wilck wrote: > On Wed, 2021-11-24 at 19:08 -0600, Benjamin Marzinski wrote: > > On Thu, Nov 18, 2021 at 11:58:22PM +0100, mwilck@suse.com wrote: > > > From: Martin Wilck <mwilck@suse.com> > > > > > > The previous patches added the state machine and the timeout > > > handling, > > > but there was no wakeup mechanism for the uxlsnr for cases where > > > client connections were waiting for the vecs lock. > > > > > > This patch uses the previously introduced wakeup mechanism of > > > struct mutex_lock for this purpose. Processes which unlock the > > > "global" vecs lock send an event in an eventfd which the uxlsnr > > > loop is polling for. > > > > > > As we are now woken up for servicing client handlers that don't > > > wait for input but for the lock, we need to set up the pollfds > > > differently, and iterate over all clients when handling events, > > > not only over the ones that are receiving. The hangup handling > > > is changed, too. We have to look at every client, even if one has > > > hung up. Note that I don't take client_lock for the loop in > > > uxsock_listen(), it's not necessary and will be removed elsewhere > > > in a follow-up patch. > > > > > > With this in place, the lock need not be taken in execute_handler() > > > any more. The uxlsnr only ever calls trylock() on the vecs lock, > > > avoiding any waiting for other threads to finish. > > > > > > Signed-off-by: Martin Wilck <mwilck@suse.com> > > > --- > > > multipathd/uxlsnr.c | 200 ++++++++++++++++++++++++++++------------ > > > ---- > > > 1 file changed, 129 insertions(+), 71 deletions(-) > > > > > > diff --git a/multipathd/uxlsnr.c b/multipathd/uxlsnr.c > > > index 87134d5..bf9780d 100644 > > > --- a/multipathd/uxlsnr.c > > > +++ b/multipathd/uxlsnr.c > > > > Nitpick: This would look clearer to me if, instead of a switch > > statement, it was just > > > > if (c->state != CLT_RECV) > > continue; > > > > polls[i].events = POLLIN; > > polls[i].fd = c->fd; > > ... > > That's true if you look at this patch in isolation. The reason I use a > switch statement is that with patch 32, we get another case to treat > here (CLT_SEND). At that point, the switch is at least on par wrt > clarity, IMO. > > No? Yep. I retrack my objection Reviewed-by: Benjamin Marzinski <bmarzins@redhat.com> > > Martin -- dm-devel mailing list dm-devel@redhat.com https://listman.redhat.com/mailman/listinfo/dm-devel
diff --git a/multipathd/uxlsnr.c b/multipathd/uxlsnr.c index 87134d5..bf9780d 100644 --- a/multipathd/uxlsnr.c +++ b/multipathd/uxlsnr.c @@ -24,6 +24,7 @@ #include <signal.h> #include <stdbool.h> #include <sys/inotify.h> +#include <sys/eventfd.h> #include "checkers.h" #include "memory.h" #include "debug.h" @@ -70,6 +71,7 @@ struct client { enum { POLLFD_UX = 0, POLLFD_NOTIFY, + POLLFD_IDLE, POLLFDS_BASE, }; @@ -90,6 +92,7 @@ static LIST_HEAD(clients); static pthread_mutex_t client_lock = PTHREAD_MUTEX_INITIALIZER; static struct pollfd *polls; static int notify_fd = -1; +static int idle_fd = -1; static char *watch_config_dir; static bool _socket_client_is_root(int fd) @@ -187,6 +190,17 @@ void uxsock_cleanup(void *arg) free_polls(); } +void wakeup_cleanup(void *arg) +{ + struct mutex_lock *lck = arg; + int fd = idle_fd; + + idle_fd = -1; + set_wakeup_fn(lck, NULL); + if (fd != -1) + close(fd); +} + struct watch_descriptors { int conf_wd; int dir_wd; @@ -293,6 +307,18 @@ static void handle_inotify(int fd, struct watch_descriptors *wds) static const struct timespec ts_zero = { .tv_sec = 0, }; +/* call with clients lock held */ +static bool __need_vecs_lock(void) +{ + struct client *c; + + list_for_each_entry(c, &clients, node) { + if (c->state == CLT_WAIT_LOCK) + return true; + } + return false; +} + static int parse_cmd(struct client *c) { int r; @@ -310,40 +336,31 @@ static int parse_cmd(struct client *c) return r; } -static int execute_handler(struct client *c, struct vectors *vecs, int timeout) +static int execute_handler(struct client *c, struct vectors *vecs) { - int r; - struct timespec tmo; - if (!c->handler) + if (!c->handler || !c->handler->fn) return -EINVAL; - if (clock_gettime(CLOCK_REALTIME, &tmo) == 0) { - tmo.tv_sec += timeout; - } else { - tmo.tv_sec = 0; - } + return c->handler->fn(c->cmdvec, &c->reply, vecs); +} - if (c->handler->locked) { - int locked = 0; +static void wakeup_listener(void) +{ + uint64_t one = 1; - pthread_cleanup_push(cleanup_lock, &vecs->lock); - if (tmo.tv_sec) { - r = timedlock(&vecs->lock, &tmo); - } else { - lock(&vecs->lock); - r = 0; - } - if (r == 0) { - locked = 1; - pthread_testcancel(); - r = c->handler->fn(c->cmdvec, &c->reply, vecs); - } - pthread_cleanup_pop(locked); - } else - r = c->handler->fn(c->cmdvec, &c->reply, vecs); + if (idle_fd != -1 && + write(idle_fd, &one, sizeof(one)) != sizeof(one)) + condlog(1, "%s: failed", __func__); +} - return r; +static void drain_idle_fd(int fd) +{ + uint64_t val; + int rc; + + rc = read(fd, &val, sizeof(val)); + condlog(4, "%s: %d, %"PRIu64, __func__, rc, val); } void default_reply(struct client *c, int r) @@ -397,16 +414,19 @@ enum { STM_BREAK, }; -static int client_state_machine(struct client *c, struct vectors *vecs) +static int client_state_machine(struct client *c, struct vectors *vecs, + short revents) { ssize_t n; const char *buf; - condlog(4, "%s: cli[%d] state=%d cmd=\"%s\" repl \"%s\"", __func__, - c->fd, c->state, c->cmd, get_strbuf_str(&c->reply)); + condlog(4, "%s: cli[%d] poll=%x state=%d cmd=\"%s\" repl \"%s\"", __func__, + c->fd, revents, c->state, c->cmd, get_strbuf_str(&c->reply)); switch (c->state) { case CLT_RECV: + if (!(revents & POLLIN)) + return STM_BREAK; if (c->cmd_len == 0) { /* * We got POLLIN; assume that at least the length can @@ -462,17 +482,30 @@ static int client_state_machine(struct client *c, struct vectors *vecs) } if (c->error) set_client_state(c, CLT_SEND); + else if (c->handler->locked) + set_client_state(c, CLT_WAIT_LOCK); else set_client_state(c, CLT_WORK); return STM_CONT; case CLT_WAIT_LOCK: - /* tbd */ - set_client_state(c, CLT_WORK); - return STM_CONT; + if (trylock(&vecs->lock) == 0) { + /* don't use cleanup_lock(), lest we wakeup ourselves */ + pthread_cleanup_push_cast(__unlock, &vecs->lock); + c->error = execute_handler(c, vecs); + pthread_cleanup_pop(1); + condlog(4, "%s: cli[%d] grabbed lock", __func__, c->fd); + free_keys(c->cmdvec); + c->cmdvec = NULL; + set_client_state(c, CLT_SEND); + return STM_CONT; + } else { + condlog(4, "%s: cli[%d] waiting for lock", __func__, c->fd); + return STM_BREAK; + } case CLT_WORK: - c->error = execute_handler(c, vecs, uxsock_timeout / 1000); + c->error = execute_handler(c, vecs); free_keys(c->cmdvec); c->cmdvec = NULL; set_client_state(c, CLT_SEND); @@ -499,9 +532,14 @@ static int client_state_machine(struct client *c, struct vectors *vecs) } } -static void handle_client(struct client *c, struct vectors *vecs) +static void handle_client(struct client *c, struct vectors *vecs, short revents) { - while (client_state_machine(c, vecs) == STM_CONT); + if (revents & (POLLHUP|POLLERR)) { + c->error = -ECONNRESET; + return; + } + + while (client_state_machine(c, vecs, revents) == STM_CONT); } /* @@ -514,6 +552,8 @@ void *uxsock_listen(long ux_sock, void *trigger_data) /* conf->sequence_nr will be 1 when uxsock_listen is first called */ unsigned int sequence_nr = 0; struct watch_descriptors wds = { .conf_wd = -1, .dir_wd = -1 }; + bool need_lock = false; + struct vectors *vecs = trigger_data; condlog(3, "uxsock: startup listener"); polls = MALLOC(max_pfds * sizeof(*polls)); @@ -524,6 +564,14 @@ void *uxsock_listen(long ux_sock, void *trigger_data) notify_fd = inotify_init1(IN_NONBLOCK); if (notify_fd == -1) /* it's fine if notifications fail */ condlog(3, "failed to start up configuration notifications"); + + pthread_cleanup_push(wakeup_cleanup, &vecs->lock); + idle_fd = eventfd(0, EFD_NONBLOCK|EFD_CLOEXEC); + if (idle_fd == -1) + condlog(1, "failed to create idle fd"); + else + set_wakeup_fn(&vecs->lock, wakeup_listener); + sigfillset(&mask); sigdelset(&mask, SIGINT); sigdelset(&mask, SIGTERM); @@ -575,16 +623,30 @@ void *uxsock_listen(long ux_sock, void *trigger_data) else polls[POLLFD_NOTIFY].events = POLLIN; + need_lock = __need_vecs_lock(); + polls[POLLFD_IDLE].fd = idle_fd; + if (need_lock) + polls[POLLFD_IDLE].events = POLLIN; + else + polls[POLLFD_IDLE].events = 0; + /* setup the clients */ - i = POLLFDS_BASE; - list_for_each_entry(c, &clients, node) { - polls[i].fd = c->fd; - polls[i].events = POLLIN; - i++; - if (i >= max_pfds) - break; - } - n_pfds = i; + i = POLLFDS_BASE; + list_for_each_entry(c, &clients, node) { + switch(c->state) { + case CLT_RECV: + polls[i].events = POLLIN; + break; + default: + /* don't poll for this client */ + continue; + } + polls[i].fd = c->fd; + i++; + if (i >= max_pfds) + break; + } + n_pfds = i; pthread_cleanup_pop(1); /* most of our life is spent in this call */ @@ -607,33 +669,28 @@ void *uxsock_listen(long ux_sock, void *trigger_data) handle_signals(true); continue; } + if (polls[POLLFD_IDLE].fd != -1 && + polls[POLLFD_IDLE].revents & POLLIN) + drain_idle_fd(idle_fd); - /* see if a client wants to speak to us */ - for (i = POLLFDS_BASE; i < n_pfds; i++) { - if (polls[i].revents & (POLLIN|POLLHUP|POLLERR)) { - c = NULL; - pthread_mutex_lock(&client_lock); - list_for_each_entry(tmp, &clients, node) { - if (tmp->fd == polls[i].fd) { - c = tmp; - break; - } - } - pthread_mutex_unlock(&client_lock); - if (!c) { - condlog(4, "cli%d: new fd %d", - i, polls[i].fd); - continue; - } - if (polls[i].revents & (POLLHUP|POLLERR)) { - condlog(4, "cli[%d]: Disconnected", - c->fd); - dead_client(c); - continue; - } - handle_client(c, trigger_data); - if (c->error == -ECONNRESET) - dead_client(c); + /* see if a client needs handling */ + list_for_each_entry_safe(c, tmp, &clients, node) { + short revents = 0; + + for (i = POLLFDS_BASE; i < n_pfds; i++) { + if (polls[i].fd == c->fd) { + revents = polls[i].revents; + break; + } + } + + handle_client(c, trigger_data, revents); + + if (c->error == -ECONNRESET) { + condlog(4, "cli[%d]: disconnected", c->fd); + dead_client(c); + if (i < n_pfds) + polls[i].fd = -1; } } /* see if we got a non-fatal signal */ @@ -649,5 +706,6 @@ void *uxsock_listen(long ux_sock, void *trigger_data) handle_inotify(notify_fd, &wds); } + pthread_cleanup_pop(1); return NULL; }