X-Git-Url: http://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Fio%2Fpoll.c;h=42ed67ad278a0c870c9c4a98baa015eb0ed4e60a;hp=fdff271c64f26e09f060b9e52e468dcf80d97696;hb=306b6b0e89957bc1f2faa0a9b30a8398d1f40dfc;hpb=a2dffefa5ef8d0cf71d99755c4640a8004679b1d diff --git a/ccan/io/poll.c b/ccan/io/poll.c index fdff271c..42ed67ad 100644 --- a/ccan/io/poll.c +++ b/ccan/io/poll.c @@ -1,4 +1,4 @@ -/* Licensed under BSD-MIT - see LICENSE file for details */ +/* Licensed under LGPLv2.1+ - see LICENSE file for details */ #include "io.h" #include "backend.h" #include @@ -6,10 +6,55 @@ #include #include #include +#include -static size_t num_fds = 0, max_fds = 0, num_next = 0, num_finished = 0; +static size_t num_fds = 0, max_fds = 0, num_closing = 0, num_waiting = 0; 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; + 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 + free(conn); +} +#else +static void io_loop_enter(void) +{ +} +static void io_loop_exit(void) +{ +} +static void free_conn(struct io_conn *conn) +{ + free(conn); +} +#endif static bool add_fd(struct fd *fd, short events) { @@ -29,12 +74,19 @@ static bool add_fd(struct fd *fd, short events) 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; } @@ -44,6 +96,8 @@ 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]; @@ -65,38 +119,73 @@ static void del_fd(struct fd *fd) bool add_listener(struct io_listener *l) { - return add_fd(&l->fd, POLLIN); + if (!add_fd(&l->fd, POLLIN)) + return false; + 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; + if (conn->duplex) { + int mask = conn->duplex->plan.pollflag; + /* 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++; } bool add_conn(struct io_conn *c) { - if (!add_fd(&c->fd, 0)) + if (!add_fd(&c->fd, c->plan.pollflag)) return false; - num_next++; + /* Immediate close is allowed. */ + if (!c->plan.next) + num_closing++; 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) { - if (conn->fd.finish) - conn->fd.finish(conn, conn->fd.finish_arg); + if (conn->finish) + conn->finish(conn, conn->finish_arg); + if (timeout_active(conn)) + backend_del_timeout(conn); + free(conn->timeout); if (conn->duplex) { /* In case fds[] pointed to the other one. */ 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--; } void del_listener(struct io_listener *l) @@ -104,89 +193,60 @@ void del_listener(struct io_listener *l) del_fd(&l->fd); } -static int pollmask(enum io_state state) +static void set_plan(struct io_conn *conn, struct io_plan plan) { - switch (state) { - case READ: - case READPART: - return POLLIN; - case WRITE: - case WRITEPART: - return POLLOUT; - default: - return 0; - } -} - -void backend_set_state(struct io_conn *conn, struct io_op *op) -{ - enum io_state state = from_ioop(op); - struct pollfd *pfd = &pollfds[conn->fd.backend_info]; - - pfd->events = pollmask(state); - if (conn->duplex) { - int mask = pollmask(conn->duplex->state); - /* You can't *both* read/write. */ - assert(!mask || pfd->events != mask); - pfd->events |= mask; - } - - 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->fd.next, l->fd.finish, l->fd.next_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 void finish_conns(void) { 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) { + if (!c->plan.next) { del_conn(c); - free(c); + free_conn(c); i--; - } else if (!finished_only && c->state == NEXT) { - backend_set_state(c, - c->fd.next(c, - c->fd.next_arg)); - num_next--; } } } } -static void ready(struct io_conn *c) +void backend_add_timeout(struct io_conn *conn, struct timespec duration) +{ + if (!timeouts.base) + timers_init(&timeouts, time_now()); + timer_add(&timeouts, &conn->timeout->timer, + time_add(time_now(), duration)); + conn->timeout->conn = conn; +} + +void backend_del_timeout(struct io_conn *conn) { - backend_set_state(c, do_ready(c)); + assert(conn->timeout->conn == conn); + timer_del(&timeouts, &conn->timeout->timer); + conn->timeout->conn = NULL; } /* This is the main loop. */ @@ -194,19 +254,56 @@ void *io_loop(void) { void *ret; + io_loop_enter(); + while (!io_loop_return) { - int i, r; + int i, r, timeout = INT_MAX; + struct timespec now; + bool some_timeouts = false; + + if (timeouts.base) { + struct timespec first; + struct list_head expired; + struct io_timeout *t; + + now = time_now(); + + /* Call functions for expired timers. */ + timers_expire(&timeouts, now, &expired); + while ((t = list_pop(&expired, struct io_timeout, timer.list))) { + struct io_conn *conn = t->conn; + /* Clear, in case timer re-adds */ + t->conn = NULL; + set_current(conn); + set_plan(conn, t->next(conn, t->next_arg)); + some_timeouts = true; + } - if (num_finished || num_next) { - finish_and_next(false); + /* Now figure out how long to wait for the next one. */ + if (timer_earliest(&timeouts, &first)) { + uint64_t f = time_to_msec(time_sub(first, now)); + if (f < INT_MAX) + timeout = f; + } + } + + if (num_closing) { + finish_conns(); /* Could have started/finished more. */ continue; } + /* debug can recurse on io_loop; anything can change. */ + if (doing_debug() && some_timeouts) + continue; + if (num_fds == 0) break; - r = poll(pollfds, num_fds, -1); + /* You can't tell them all to go to sleep! */ + assert(num_waiting); + + r = poll(pollfds, num_fds, timeout); if (r < 0) break; @@ -214,35 +311,51 @@ void *io_loop(void) struct io_conn *c = (void *)fds[i]; int events = pollfds[i].revents; + if (r == 0) + break; + if (fds[i]->listener) { - if (events & POLLIN) + if (events & POLLIN) { accept_conn((void *)c); + r--; + } } else if (events & (POLLIN|POLLOUT)) { + r--; if (c->duplex) { - int mask = pollmask(c->duplex->state); + int mask = c->duplex->plan.pollflag; if (events & mask) { - ready(c->duplex); + io_ready(c->duplex); events &= ~mask; + /* debug can recurse; + * anything can change. */ + if (doing_debug()) + break; if (!(events&(POLLIN|POLLOUT))) continue; } } - ready(c); - } else if (events & POLLHUP) { - backend_set_state(c, io_close(c, NULL)); - if (c->duplex) - backend_set_state(c->duplex, - io_close(c->duplex, - NULL)); + io_ready(c); + /* debug can recurse; anything can change. */ + if (doing_debug()) + break; + } else if (events & (POLLHUP|POLLNVAL|POLLERR)) { + r--; + set_current(c); + 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) + finish_conns(); ret = io_loop_return; io_loop_return = NULL; + + io_loop_exit(); return ret; }