X-Git-Url: https://git.ozlabs.org/?a=blobdiff_plain;f=ccan%2Fio%2Fpoll.c;h=31a56600fe487b836e8bf1b8bdb88ecfa75953e0;hb=641b511049e5c03d45ada0c3fd829691b173e5d1;hp=46b2334e7e03ef481cd8ff74d047ce443d5cddc8;hpb=109f8003b603675aec35e5b1fc678ee363e2f30c;p=ccan diff --git a/ccan/io/poll.c b/ccan/io/poll.c index 46b2334e..31a56600 100644 --- a/ccan/io/poll.c +++ b/ccan/io/poll.c @@ -7,11 +7,55 @@ #include #include #include +#include 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) { @@ -31,8 +75,12 @@ 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; @@ -77,9 +125,15 @@ bool add_listener(struct io_listener *l) return true; } -static void update_pollevents(struct io_conn *conn) +void backend_plan_changed(struct io_conn *conn) { - struct pollfd *pfd = &pollfds[conn->fd.backend_info]; + 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--; @@ -91,8 +145,11 @@ static void update_pollevents(struct io_conn *conn) assert(!mask || pfd->events != mask); pfd->events |= mask; } - if (pfd->events) + if (pfd->events) { num_waiting++; + pfd->fd = conn->fd.fd; + } else + pfd->fd = -conn->fd.fd; if (!conn->plan.next) num_closing++; @@ -111,14 +168,16 @@ bool add_conn(struct io_conn *c) bool add_duplex(struct io_conn *c) { c->fd.backend_info = c->duplex->fd.backend_info; - update_pollevents(c); + 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) { + errno = conn->plan.u.close.saved_errno; conn->finish(conn, conn->finish_arg); + } if (timeout_active(conn)) backend_del_timeout(conn); free(conn->timeout); @@ -126,9 +185,11 @@ static void del_conn(struct io_conn *conn) /* 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); num_closing--; + free_conn(conn); } void del_listener(struct io_listener *l) @@ -136,15 +197,10 @@ void del_listener(struct io_listener *l) del_fd(&l->fd); } -static void backend_set_state(struct io_conn *conn, struct io_plan plan) +static void set_plan(struct io_conn *conn, struct io_plan plan) { conn->plan = plan; - update_pollevents(conn); -} - -void backend_wakeup(struct io_conn *conn) -{ - update_pollevents(conn); + backend_plan_changed(conn); } static void accept_conn(struct io_listener *l) @@ -158,7 +214,7 @@ static void accept_conn(struct io_listener *l) } /* It's OK to miss some, as long as we make progress. */ -static void finish_conns(void) +static bool finish_conns(struct io_conn **ready) { unsigned int i; @@ -173,17 +229,16 @@ static void finish_conns(void) c = (void *)fds[i]; for (duplex = c->duplex; c; c = duplex, duplex = NULL) { if (!c->plan.next) { - del_conn(c); - free(c); + if (doing_debug_on(c) && ready) { + *ready = c; + return true; + } + backend_del_conn(c); i--; } } } -} - -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) @@ -203,13 +258,16 @@ void backend_del_timeout(struct io_conn *conn) } /* 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 +282,9 @@ 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. */ @@ -236,11 +296,17 @@ void *io_loop(void) } if (num_closing) { - finish_conns(); + /* 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 (num_fds == 0) break; @@ -268,28 +334,55 @@ void *io_loop(void) if (c->duplex) { 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; + /* debug can recurse; + * anything can change. */ + if (doing_debug()) + break; if (!(events&(POLLIN|POLLOUT))) 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_closing) - finish_conns(); + 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); +}