X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lib%2Fpoll-loop.c;h=0f45d983541792c48f439f6fdd0096a0506177fa;hb=7aaeab4df24b7e9460705b1dad1010eef0354c50;hp=ea00d265af1d87411af8fdf4ec621c7cade298e4;hpb=10a89ef04df5669c5cdd02f786150a7ab8454e01;p=sliver-openvswitch.git diff --git a/lib/poll-loop.c b/lib/poll-loop.c index ea00d265a..0f45d9835 100644 --- a/lib/poll-loop.c +++ b/lib/poll-loop.c @@ -25,45 +25,30 @@ #include "dynamic-string.h" #include "fatal-signal.h" #include "list.h" +#include "ovs-thread.h" #include "socket-util.h" #include "timeval.h" #include "vlog.h" -#undef poll_fd_wait -#undef poll_timer_wait -#undef poll_timer_wait_until -#undef poll_immediate_wake - VLOG_DEFINE_THIS_MODULE(poll_loop); COVERAGE_DEFINE(poll_fd_wait); COVERAGE_DEFINE(poll_zero_timeout); -/* An event that will wake the following call to poll_block(). */ -struct poll_waiter { - /* Set when the waiter is created. */ - struct list node; /* Element in global waiters list. */ - int fd; /* File descriptor. */ - short int events; /* Events to wait for (POLLIN, POLLOUT). */ - const char *where; /* Where the waiter was created. */ +struct poll_loop { + /* All active poll waiters. */ + struct pollfd *pollfds; /* Events to pass to poll(). */ + const char **where; /* Where each pollfd was created. */ + size_t n_waiters; /* Number of elems in 'where' and 'pollfds'. */ + size_t allocated_waiters; /* Allocated elems in 'where' and 'pollfds'. */ - /* Set only when poll_block() is called. */ - struct pollfd *pollfd; /* Pointer to element of the pollfds array. */ + /* Time at which to wake up the next call to poll_block(), LLONG_MIN to + * wake up immediately, or LLONG_MAX to wait forever. */ + long long int timeout_when; /* In msecs as returned by time_msec(). */ + const char *timeout_where; /* Where 'timeout_when' was set. */ }; -/* All active poll waiters. */ -static struct list waiters = LIST_INITIALIZER(&waiters); - -/* Time at which to wake up the next call to poll_block(), in milliseconds as - * returned by time_msec(), LLONG_MIN to wake up immediately, or LLONG_MAX to - * wait forever. */ -static long long int timeout_when = LLONG_MAX; - -/* Location where waiter created. */ -static const char *timeout_where; - -static struct poll_waiter *new_waiter(int fd, short int events, - const char *where); +static struct poll_loop *poll_loop(void); /* Registers 'fd' as waiting for the specified 'events' (which should be POLLIN * or POLLOUT or POLLIN | POLLOUT). The following call to poll_block() will @@ -73,13 +58,27 @@ static struct poll_waiter *new_waiter(int fd, short int events, * is affected. The event will need to be re-registered after poll_block() is * called if it is to persist. * - * Ordinarily the 'where' argument is supplied automatically; see poll-loop.h - * for more information. */ -struct poll_waiter * -poll_fd_wait(int fd, short int events, const char *where) + * ('where' is used in debug logging. Commonly one would use poll_fd_wait() to + * automatically provide the caller's source file and line number for + * 'where'.) */ +void +poll_fd_wait_at(int fd, short int events, const char *where) { + struct poll_loop *loop = poll_loop(); + COVERAGE_INC(poll_fd_wait); - return new_waiter(fd, events, where); + if (loop->n_waiters >= loop->allocated_waiters) { + loop->where = x2nrealloc(loop->where, &loop->allocated_waiters, + sizeof *loop->where); + loop->pollfds = xrealloc(loop->pollfds, + (loop->allocated_waiters + * sizeof *loop->pollfds)); + } + + loop->where[loop->n_waiters] = where; + loop->pollfds[loop->n_waiters].fd = fd; + loop->pollfds[loop->n_waiters].events = events; + loop->n_waiters++; } /* Causes the following call to poll_block() to block for no more than 'msec' @@ -90,10 +89,11 @@ poll_fd_wait(int fd, short int events, const char *where) * is affected. The timer will need to be re-registered after poll_block() is * called if it is to persist. * - * Ordinarily the 'where' argument is supplied automatically; see poll-loop.h - * for more information. */ + * ('where' is used in debug logging. Commonly one would use poll_timer_wait() + * to automatically provide the caller's source file and line number for + * 'where'.) */ void -poll_timer_wait(long long int msec, const char *where) +poll_timer_wait_at(long long int msec, const char *where) { long long int now = time_msec(); long long int when; @@ -109,7 +109,7 @@ poll_timer_wait(long long int msec, const char *where) when = LLONG_MAX; } - poll_timer_wait_until(when, where); + poll_timer_wait_until_at(when, where); } /* Causes the following call to poll_block() to wake up when the current time, @@ -121,26 +121,29 @@ poll_timer_wait(long long int msec, const char *where) * is affected. The timer will need to be re-registered after poll_block() is * called if it is to persist. * - * Ordinarily the 'where' argument is supplied automatically; see poll-loop.h - * for more information. */ + * ('where' is used in debug logging. Commonly one would use + * poll_timer_wait_until() to automatically provide the caller's source file + * and line number for 'where'.) */ void -poll_timer_wait_until(long long int when, const char *where) +poll_timer_wait_until_at(long long int when, const char *where) { - if (when < timeout_when) { - timeout_when = when; - timeout_where = where; + struct poll_loop *loop = poll_loop(); + if (when < loop->timeout_when) { + loop->timeout_when = when; + loop->timeout_where = where; } } /* Causes the following call to poll_block() to wake up immediately, without * blocking. * - * Ordinarily the 'where' argument is supplied automatically; see poll-loop.h - * for more information. */ + * ('where' is used in debug logging. Commonly one would use + * poll_immediate_wake() to automatically provide the caller's source file and + * line number for 'where'.) */ void -poll_immediate_wake(const char *where) +poll_immediate_wake_at(const char *where) { - poll_timer_wait(0, where); + poll_timer_wait_at(0, where); } /* Logs, if appropriate, that the poll loop was awakened by an event @@ -156,7 +159,6 @@ poll_immediate_wake(const char *where) static void log_wakeup(const char *where, const struct pollfd *pollfd, int timeout) { - static struct vlog_rate_limit trace_rl = VLOG_RATE_LIMIT_INIT(1, 1); static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(10, 10); enum vlog_level level; int cpu_usage; @@ -200,11 +202,6 @@ log_wakeup(const char *where, const struct pollfd *pollfd, int timeout) } if (cpu_usage >= 0) { ds_put_format(&s, " (%d%% CPU usage)", cpu_usage); - - if (!vlog_should_drop(THIS_MODULE, level, &trace_rl)) { - ds_put_char(&s, '\n'); - format_backtraces(&s, 2); - } } VLOG(level, "%s", ds_cstr(&s)); ds_destroy(&s); @@ -216,11 +213,7 @@ log_wakeup(const char *where, const struct pollfd *pollfd, int timeout) void poll_block(void) { - static struct pollfd *pollfds; - static size_t max_pollfds; - - struct poll_waiter *pw, *next; - int n_waiters, n_pollfds; + struct poll_loop *loop = poll_loop(); int elapsed; int retval; @@ -228,70 +221,62 @@ poll_block(void) * poll_block. */ fatal_signal_wait(); - n_waiters = list_size(&waiters); - if (max_pollfds < n_waiters) { - max_pollfds = n_waiters; - pollfds = xrealloc(pollfds, max_pollfds * sizeof *pollfds); - } - - n_pollfds = 0; - LIST_FOR_EACH (pw, node, &waiters) { - pw->pollfd = &pollfds[n_pollfds]; - pollfds[n_pollfds].fd = pw->fd; - pollfds[n_pollfds].events = pw->events; - pollfds[n_pollfds].revents = 0; - n_pollfds++; - } - - if (timeout_when == LLONG_MIN) { + if (loop->timeout_when == LLONG_MIN) { COVERAGE_INC(poll_zero_timeout); } - retval = time_poll(pollfds, n_pollfds, timeout_when, &elapsed); + + retval = time_poll(loop->pollfds, loop->n_waiters, + loop->timeout_when, &elapsed); if (retval < 0) { static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5); VLOG_ERR_RL(&rl, "poll: %s", ovs_strerror(-retval)); } else if (!retval) { - log_wakeup(timeout_where, NULL, elapsed); - } + log_wakeup(loop->timeout_where, NULL, elapsed); + } else if (get_cpu_usage() > 50 || VLOG_IS_DBG_ENABLED()) { + size_t i; - LIST_FOR_EACH_SAFE (pw, next, node, &waiters) { - if (pw->pollfd->revents) { - log_wakeup(pw->where, pw->pollfd, 0); + for (i = 0; i < loop->n_waiters; i++) { + if (loop->pollfds[i].revents) { + log_wakeup(loop->where[i], &loop->pollfds[i], 0); + } } - poll_cancel(pw); } - timeout_when = LLONG_MAX; - timeout_where = NULL; + loop->timeout_when = LLONG_MAX; + loop->timeout_where = NULL; + loop->n_waiters = 0; /* Handle any pending signals before doing anything else. */ fatal_signal_run(); } - -/* Cancels the file descriptor event registered with poll_fd_wait() using 'pw', - * the struct poll_waiter returned by that function. - * - * An event registered with poll_fd_wait() may be canceled from its time of - * registration until the next call to poll_block(). At that point, the event - * is automatically canceled by the system and its poll_waiter is freed. */ -void -poll_cancel(struct poll_waiter *pw) + +static void +free_poll_loop(void *loop_) { - if (pw) { - list_remove(&pw->node); - free(pw); - } + struct poll_loop *loop = loop_; + + free(loop->pollfds); + free(loop->where); + free(loop); } - -/* Creates and returns a new poll_waiter for 'fd' and 'events'. */ -static struct poll_waiter * -new_waiter(int fd, short int events, const char *where) + +static struct poll_loop * +poll_loop(void) { - struct poll_waiter *waiter = xzalloc(sizeof *waiter); - ovs_assert(fd >= 0); - waiter->fd = fd; - waiter->events = events; - waiter->where = where; - list_push_back(&waiters, &waiter->node); - return waiter; + static struct ovsthread_once once = OVSTHREAD_ONCE_INITIALIZER; + static pthread_key_t key; + struct poll_loop *loop; + + if (ovsthread_once_start(&once)) { + xpthread_key_create(&key, free_poll_loop); + ovsthread_once_done(&once); + } + + loop = pthread_getspecific(key); + if (!loop) { + loop = xzalloc(sizeof *loop); + pthread_setspecific(key, loop); + } + return loop; } +