X-Git-Url: http://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Fio%2Fpoll.c;h=d7b9eb56b950b5a1b4772525c86bb944b3a60c6f;hp=5982ef1535e363723ac4904729fa824e1d718855;hb=12ab811533406e22b78ce8b227474f1056375ae4;hpb=174fe59fdce127808420986f56987205ecab2858 diff --git a/ccan/io/poll.c b/ccan/io/poll.c index 5982ef15..d7b9eb56 100644 --- a/ccan/io/poll.c +++ b/ccan/io/poll.c @@ -7,11 +7,56 @@ #include #include #include +#include -static size_t num_fds = 0, max_fds = 0, num_next = 0, num_finished = 0, num_waiting = 0; +static size_t num_fds = 0, max_fds = 0, num_closing = 0, num_waiting = 0; +static bool some_always = false; static struct pollfd *pollfds = NULL; static struct fd **fds = NULL; static struct timers timeouts; +#ifdef DEBUG +static unsigned int io_loop_level; +static struct io_conn *free_later; +static void io_loop_enter(void) +{ + io_loop_level++; +} +static void io_loop_exit(void) +{ + io_loop_level--; + if (io_loop_level == 0) { + /* Delayed free. */ + while (free_later) { + struct io_conn *c = free_later; + free_later = c->finish_arg; + io_alloc.free(c); + } + } +} +static void free_conn(struct io_conn *conn) +{ + /* Only free on final exit: chain via finish. */ + if (io_loop_level > 1) { + struct io_conn *c; + for (c = free_later; c; c = c->finish_arg) + assert(c != conn); + conn->finish_arg = free_later; + free_later = conn; + } else + io_alloc.free(conn); +} +#else +static void io_loop_enter(void) +{ +} +static void io_loop_exit(void) +{ +} +static void free_conn(struct io_conn *conn) +{ + io_alloc.free(conn); +} +#endif static bool add_fd(struct fd *fd, short events) { @@ -20,23 +65,30 @@ static bool add_fd(struct fd *fd, short events) struct fd **newfds; size_t num = max_fds ? max_fds * 2 : 8; - newpollfds = realloc(pollfds, sizeof(*newpollfds) * num); + newpollfds = io_alloc.realloc(pollfds, sizeof(*newpollfds)*num); if (!newpollfds) return false; pollfds = newpollfds; - newfds = realloc(fds, sizeof(*newfds) * num); + newfds = io_alloc.realloc(fds, sizeof(*newfds) * num); if (!newfds) return false; fds = newfds; max_fds = num; } - pollfds[num_fds].fd = fd->fd; pollfds[num_fds].events = events; + /* In case it's idle. */ + if (!events) + pollfds[num_fds].fd = -fd->fd; + else + pollfds[num_fds].fd = fd->fd; pollfds[num_fds].revents = 0; /* In case we're iterating now */ fds[num_fds] = fd; fd->backend_info = num_fds; num_fds++; + if (events) + num_waiting++; + return true; } @@ -46,16 +98,26 @@ static void del_fd(struct fd *fd) assert(n != -1); assert(n < num_fds); + if (pollfds[n].events) + num_waiting--; if (n != num_fds - 1) { /* Move last one over us. */ pollfds[n] = pollfds[num_fds-1]; fds[n] = fds[num_fds-1]; assert(fds[n]->backend_info == num_fds-1); fds[n]->backend_info = n; + /* If that happens to be a duplex, move that too. */ + if (!fds[n]->listener) { + struct io_conn *c = (void *)fds[n]; + if (c->duplex) { + assert(c->duplex->fd.backend_info == num_fds-1); + c->duplex->fd.backend_info = n; + } + } } else if (num_fds == 1) { /* Free everything when no more fds. */ - free(pollfds); - free(fds); + io_alloc.free(pollfds); + io_alloc.free(fds); pollfds = NULL; fds = NULL; max_fds = 0; @@ -69,42 +131,81 @@ bool add_listener(struct io_listener *l) { if (!add_fd(&l->fd, POLLIN)) return false; - num_waiting++; return true; } +void backend_plan_changed(struct io_conn *conn) +{ + struct pollfd *pfd; + + /* This can happen with debugging and delayed free... */ + if (conn->fd.backend_info == -1) + return; + + pfd = &pollfds[conn->fd.backend_info]; + + if (pfd->events) + num_waiting--; + + pfd->events = conn->plan.pollflag & (POLLIN|POLLOUT); + if (conn->duplex) { + int mask = conn->duplex->plan.pollflag & (POLLIN|POLLOUT); + /* You can't *both* read/write. */ + assert(!mask || pfd->events != mask); + pfd->events |= mask; + } + if (pfd->events) { + num_waiting++; + pfd->fd = conn->fd.fd; + } else + pfd->fd = -conn->fd.fd; + + if (!conn->plan.next) + num_closing++; + + if (conn->plan.pollflag == POLLALWAYS) + some_always = true; +} + bool add_conn(struct io_conn *c) { - if (!add_fd(&c->fd, 0)) + if (!add_fd(&c->fd, c->plan.pollflag & (POLLIN|POLLOUT))) return false; - num_next++; + /* Immediate close is allowed. */ + if (!c->plan.next) + num_closing++; + if (c->plan.pollflag == POLLALWAYS) + some_always = true; return true; } bool add_duplex(struct io_conn *c) { c->fd.backend_info = c->duplex->fd.backend_info; - num_next++; + backend_plan_changed(c); return true; } -static void del_conn(struct io_conn *conn) +void backend_del_conn(struct io_conn *conn) { - if (conn->finish) + if (conn->finish) { + /* Saved by io_close */ + errno = conn->plan.u1.s; conn->finish(conn, conn->finish_arg); + } if (timeout_active(conn)) backend_del_timeout(conn); - free(conn->timeout); + io_alloc.free(conn->timeout); if (conn->duplex) { /* In case fds[] pointed to the other one. */ + assert(conn->duplex->fd.backend_info == conn->fd.backend_info); fds[conn->fd.backend_info] = &conn->duplex->fd; conn->duplex->duplex = NULL; + conn->fd.backend_info = -1; } else del_fd(&conn->fd); - if (conn->state == FINISHED) - num_finished--; - else if (conn->state == NEXT) - num_next--; + num_closing--; + free_conn(conn); } void del_listener(struct io_listener *l) @@ -112,78 +213,48 @@ void del_listener(struct io_listener *l) del_fd(&l->fd); } -void backend_set_state(struct io_conn *conn, struct io_plan *plan) +static void set_plan(struct io_conn *conn, struct io_plan plan) { - enum io_state state = from_ioplan(plan); - struct pollfd *pfd = &pollfds[conn->fd.backend_info]; - - if (pfd->events) - num_waiting--; - - pfd->events = conn->pollflag; - if (conn->duplex) { - int mask = conn->duplex->pollflag; - /* You can't *both* read/write. */ - assert(!mask || pfd->events != mask); - pfd->events |= mask; - } - if (pfd->events) - num_waiting++; - - if (state == NEXT) - num_next++; - else if (state == FINISHED) - num_finished++; - - conn->state = state; + conn->plan = plan; + backend_plan_changed(conn); } static void accept_conn(struct io_listener *l) { - struct io_conn *c; int fd = accept(l->fd.fd, NULL, NULL); /* FIXME: What to do here? */ if (fd < 0) return; - c = io_new_conn(fd, l->next, l->finish, l->conn_arg); - if (!c) { - close(fd); - return; - } + l->init(fd, l->arg); } /* It's OK to miss some, as long as we make progress. */ -static void finish_and_next(bool finished_only) +static bool finish_conns(struct io_conn **ready) { unsigned int i; for (i = 0; !io_loop_return && i < num_fds; i++) { struct io_conn *c, *duplex; - if (!num_finished) { - if (finished_only || num_next == 0) - break; - } + if (!num_closing) + break; + if (fds[i]->listener) continue; c = (void *)fds[i]; for (duplex = c->duplex; c; c = duplex, duplex = NULL) { - if (c->state == FINISHED) { - del_conn(c); - free(c); + if (!c->plan.next) { + if (doing_debug_on(c) && ready) { + *ready = c; + return true; + } + backend_del_conn(c); i--; - } else if (!finished_only && c->state == NEXT) { - backend_set_state(c, c->next(c, c->next_arg)); - num_next--; } } } -} - -static void ready(struct io_conn *c) -{ - backend_set_state(c, do_ready(c)); + return false; } void backend_add_timeout(struct io_conn *conn, struct timespec duration) @@ -202,14 +273,37 @@ void backend_del_timeout(struct io_conn *conn) conn->timeout->conn = NULL; } +static void handle_always(void) +{ + int i; + + some_always = false; + + for (i = 0; i < num_fds && !io_loop_return; i++) { + struct io_conn *c = (void *)fds[i]; + + if (fds[i]->listener) + continue; + + if (c->plan.pollflag == POLLALWAYS) + io_ready(c); + + if (c->duplex && c->duplex->plan.pollflag == POLLALWAYS) + io_ready(c->duplex); + } +} + /* This is the main loop. */ -void *io_loop(void) +void *do_io_loop(struct io_conn **ready) { void *ret; + io_loop_enter(); + while (!io_loop_return) { int i, r, timeout = INT_MAX; struct timespec now; + bool some_timeouts = false; if (timeouts.base) { struct timespec first; @@ -224,7 +318,9 @@ void *io_loop(void) struct io_conn *conn = t->conn; /* Clear, in case timer re-adds */ t->conn = NULL; - backend_set_state(conn, t->next(conn, t->next_arg)); + set_current(conn); + set_plan(conn, t->next(conn, t->next_arg)); + some_timeouts = true; } /* Now figure out how long to wait for the next one. */ @@ -235,12 +331,23 @@ void *io_loop(void) } } - if (num_finished || num_next) { - finish_and_next(false); + if (num_closing) { + /* If this finishes a debugging con, return now. */ + if (finish_conns(ready)) + return NULL; /* Could have started/finished more. */ continue; } + /* debug can recurse on io_loop; anything can change. */ + if (doing_debug() && some_timeouts) + continue; + + if (some_always) { + handle_always(); + continue; + } + if (num_fds == 0) break; @@ -266,30 +373,61 @@ void *io_loop(void) } else if (events & (POLLIN|POLLOUT)) { r--; if (c->duplex) { - int mask = c->duplex->pollflag; + int mask = c->duplex->plan.pollflag; if (events & mask) { - ready(c->duplex); + if (doing_debug_on(c->duplex) + && ready) { + *ready = c->duplex; + return NULL; + } + io_ready(c->duplex); events &= ~mask; - if (!(events&(POLLIN|POLLOUT))) + /* debug can recurse; + * anything can change. */ + if (doing_debug()) + break; + + /* If no events, or it closed + * the duplex, continue. */ + if (!(events&(POLLIN|POLLOUT)) + || !c->plan.next) continue; } } - ready(c); - } else if (events & POLLHUP) { + if (doing_debug_on(c) && ready) { + *ready = c; + return NULL; + } + io_ready(c); + /* debug can recurse; anything can change. */ + if (doing_debug()) + break; + } else if (events & (POLLHUP|POLLNVAL|POLLERR)) { r--; - backend_set_state(c, io_close(c, NULL)); - if (c->duplex) - backend_set_state(c->duplex, - io_close(c->duplex, - NULL)); + set_current(c); + errno = EBADF; + set_plan(c, io_close()); + if (c->duplex) { + set_current(c->duplex); + set_plan(c->duplex, io_close()); + } } } } - while (num_finished) - finish_and_next(true); + while (num_closing && !io_loop_return) { + if (finish_conns(ready)) + return NULL; + } ret = io_loop_return; io_loop_return = NULL; + + io_loop_exit(); return ret; } + +void *io_loop(void) +{ + return do_io_loop(NULL); +}