mirror of
https://gitlab.labs.nic.cz/labs/bird.git
synced 2024-05-11 16:54:54 +00:00
Rewritten the I/O loop. All socket operations are now safe, meaning that
you can delete the socket from anywhere in the hooks and nothing should break. Also, the receive/transmit buffers are now regular xmalloc()'ed buffers, not separate resources which would need shuffling around between pools. sk_close() is gone, use rfree() instead.
This commit is contained in:
141
sysdep/unix/io.c
141
sysdep/unix/io.c
@@ -1,7 +1,7 @@
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/*
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* BIRD Internet Routing Daemon -- Unix I/O
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*
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* (c) 1998--2000 Martin Mares <mj@ucw.cz>
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* (c) 1998--2004 Martin Mares <mj@ucw.cz>
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* (c) 2004 Ondrej Filip <feela@network.cz>
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*
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* Can be freely distributed and used under the terms of the GNU GPL.
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@@ -30,7 +30,6 @@
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#include "lib/unix.h"
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#include "lib/sysio.h"
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#define LOCAL_DEBUG
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/*
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* Tracked Files
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*/
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@@ -394,7 +393,7 @@ tm_format_reltime(char *x, bird_clock_t t)
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* (@rx_hook), when the contents of the transmit buffer have been transmitted
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* (@tx_hook) and when an error or connection close occurs (@err_hook).
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*
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* You should not use rfree() from inside a socket hook, please use sk_close() instead.
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* Freeing of sockets from inside socket hooks is perfectly safe.
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*/
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#ifndef SOL_IP
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@@ -410,16 +409,34 @@ tm_format_reltime(char *x, bird_clock_t t)
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#endif
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static list sock_list;
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static struct birdsock *current_sock;
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static int sock_recalc_fdsets_p;
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static inline sock *
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sk_next(sock *s)
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{
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if (!s->n.next->next)
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return NULL;
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else
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return SKIP_BACK(sock, n, s->n.next);
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}
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static void
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sk_free(resource *r)
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{
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sock *s = (sock *) r;
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if (s->rbuf_alloc)
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xfree(s->rbuf_alloc);
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if (s->tbuf_alloc)
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xfree(s->tbuf_alloc);
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if (s->fd >= 0)
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{
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close(s->fd);
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if (s == current_sock)
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current_sock = sk_next(s);
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rem_node(&s->n);
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sock_recalc_fdsets_p = 1;
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}
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}
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@@ -474,12 +491,16 @@ sk_new(pool *p)
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s->tbsize = 0;
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s->err_hook = NULL;
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s->fd = -1;
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s->entered = 0;
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s->rbuf_alloc = s->tbuf_alloc = NULL;
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return s;
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}
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#define ERR(x) do { err = x; goto bad; } while(0)
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#define WARN(x) log(L_WARN "sk_setup: %s: %m", x)
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static void
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sk_insert(sock *s)
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{
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add_tail(&sock_list, &s->n);
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sock_recalc_fdsets_p = 1;
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}
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#ifdef IPV6
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@@ -534,6 +555,9 @@ get_sockaddr(struct sockaddr_in *sa, ip_addr *a, unsigned *port, int check)
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#endif
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#define ERR(x) do { err = x; goto bad; } while(0)
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#define WARN(x) log(L_WARN "sk_setup: %s: %m", x)
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static char *
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sk_setup(sock *s)
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{
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@@ -566,10 +590,10 @@ static void
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sk_alloc_bufs(sock *s)
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{
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if (!s->rbuf && s->rbsize)
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s->rbuf = mb_alloc(s->pool, s->rbsize);
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s->rbuf = s->rbuf_alloc = xmalloc(s->rbsize);
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s->rpos = s->rbuf;
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if (!s->tbuf && s->tbsize)
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s->tbuf = mb_alloc(s->pool, s->tbsize);
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s->tbuf = s->tbuf_alloc = xmalloc(s->tbsize);
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s->tpos = s->ttx = s->tbuf;
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}
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@@ -597,7 +621,7 @@ sk_passive_connected(sock *s, struct sockaddr *sa, int al, int type)
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t->tbsize = s->tbsize;
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if (type == SK_TCP)
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get_sockaddr((sockaddr *) sa, &t->daddr, &t->dport, 1);
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add_tail(&sock_list, &t->n);
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sk_insert(t);
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if (err = sk_setup(t))
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{
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log(L_ERR "Incoming connection: %s: %m", err);
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@@ -663,9 +687,8 @@ sk_open(sock *s)
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s->fd = fd;
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if (err = sk_setup(s))
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{
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goto bad;
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}
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switch (type)
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{
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case SK_UDP:
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@@ -769,7 +792,7 @@ sk_open(sock *s)
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#endif
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}
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add_tail(&sock_list, &s->n);
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sk_insert(s);
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return 0;
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bad:
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@@ -799,7 +822,7 @@ sk_open_unix(sock *s, char *name)
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ERR("bind");
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if (listen(fd, 8))
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ERR("listen");
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add_tail(&sock_list, &s->n);
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sk_insert(s);
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return 0;
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bad:
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@@ -809,23 +832,6 @@ bad:
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return -1;
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}
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/**
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* sk_close - close a socket
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* @s: a socket
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*
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* If sk_close() has been called from outside of any socket hook,
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* it translates to a rfree(), else it just marks the socket for
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* deletion as soon as the socket hook returns.
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*/
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void
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sk_close(sock *s)
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{
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if (s && s->entered)
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s->type = SK_DELETED;
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else
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rfree(s);
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}
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static int
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sk_maybe_write(sock *s)
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{
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@@ -954,15 +960,17 @@ sk_read(sock *s)
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{
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s->rpos += c;
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if (s->rx_hook(s, s->rpos - s->rbuf))
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s->rpos = s->rbuf;
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{
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/* We need to be careful since the socket could have been deleted by the hook */
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if (current_sock == s)
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s->rpos = s->rbuf;
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}
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return 1;
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}
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return 0;
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}
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case SK_MAGIC:
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return s->rx_hook(s, 0);
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case SK_DELETED:
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return 0;
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default:
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{
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sockaddr sa;
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@@ -983,7 +991,7 @@ sk_read(sock *s)
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}
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}
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static void
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static int
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sk_write(sock *s)
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{
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switch (s->type)
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@@ -996,13 +1004,15 @@ sk_write(sock *s)
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sk_tcp_connected(s);
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else if (errno != EINTR && errno != EAGAIN && errno != EINPROGRESS)
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s->err_hook(s, errno);
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break;
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return 0;
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}
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case SK_DELETED:
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return;
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default:
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while (s->ttx != s->tpos && sk_maybe_write(s) > 0)
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s->tx_hook(s);
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if (s->ttx != s->tpos && sk_maybe_write(s) > 0)
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{
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s->tx_hook(s);
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return 1;
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}
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return 0;
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}
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}
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@@ -1052,10 +1062,9 @@ io_loop(void)
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time_t tout;
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int hi, events;
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sock *s;
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node *n, *p;
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node *n;
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FD_ZERO(&rd);
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FD_ZERO(&wr);
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sock_recalc_fdsets_p = 1;
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for(;;)
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{
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events = ev_run_list(&global_event_list);
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@@ -1069,6 +1078,13 @@ io_loop(void)
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timo.tv_sec = events ? 0 : tout - now;
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timo.tv_usec = 0;
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if (sock_recalc_fdsets_p)
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{
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sock_recalc_fdsets_p = 0;
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FD_ZERO(&rd);
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FD_ZERO(&wr);
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}
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hi = 0;
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WALK_LIST(n, sock_list)
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{
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@@ -1079,12 +1095,16 @@ io_loop(void)
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if (s->fd > hi)
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hi = s->fd;
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}
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else
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FD_CLR(s->fd, &rd);
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if (s->tx_hook && s->ttx != s->tpos)
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{
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FD_SET(s->fd, &wr);
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if (s->fd > hi)
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hi = s->fd;
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}
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else
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FD_CLR(s->fd, &wr);
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}
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/*
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@@ -1122,24 +1142,29 @@ io_loop(void)
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}
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if (hi)
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{
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WALK_LIST_DELSAFE(n, p, sock_list)
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current_sock = SKIP_BACK(sock, n, HEAD(sock_list)); /* guaranteed to be non-empty */
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while (current_sock)
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{
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s = SKIP_BACK(sock, n, n);
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s->entered = 1;
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sock *s = current_sock;
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int e;
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if (FD_ISSET(s->fd, &rd))
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{
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FD_CLR(s->fd, &rd);
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while (sk_read(s))
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;
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}
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if (s->type != SK_DELETED && FD_ISSET(s->fd, &wr))
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{
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FD_CLR(s->fd, &wr);
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sk_write(s);
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}
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s->entered = 0;
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if (s->type == SK_DELETED)
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rfree(s);
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do
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{
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e = sk_read(s);
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if (s != current_sock)
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goto next;
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}
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while (e);
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if (FD_ISSET(s->fd, &wr))
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do
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{
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e = sk_write(s);
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if (s != current_sock)
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goto next;
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}
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while (e);
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current_sock = sk_next(s);
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next: ;
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}
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}
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}
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