Commit f7ab2c65 authored by Rusty Russell's avatar Rusty Russell

io: change io_idle() to io_wait()

Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent cdf62dce
......@@ -25,76 +25,74 @@
* #include <signal.h>
* #include <sys/types.h>
* #include <sys/wait.h>
* #include <string.h>
*
* struct buffer {
* size_t max, off, rlen;
* char *buf;
* bool finished;
* size_t start, end, rlen, wlen;
* char buf[4096];
* };
*
* struct stdin_buffer {
* struct io_conn *reader, *writer;
* size_t len;
* char inbuf[4096];
* };
*
* // This reads from stdin.
* static struct io_plan wake_writer(struct io_conn *, struct stdin_buffer *);
* // This writes the stdin buffer to the child.
* static struct io_plan wake_reader(struct io_conn *, struct stdin_buffer *);
*
* static struct io_plan wake_writer(struct io_conn *c, struct stdin_buffer *b)
* static void finish(struct io_conn *c, struct buffer *b)
* {
* assert(c == b->reader);
* io_wake(b->writer, io_write(b->inbuf, b->len, wake_reader, b));
* return io_idle();
* // Mark us finished.
* b->finished = true;
* // Wake writer just in case it's asleep.
* io_wake(b);
* }
*
* static void reader_exit(struct io_conn *c, struct stdin_buffer *b)
* static struct io_plan read_in(struct io_conn *c, struct buffer *b)
* {
* assert(c == b->reader);
* io_wake(b->writer, io_close());
* b->reader = NULL;
* }
* // Add what we just read.
* b->end += b->rlen;
* assert(b->end <= sizeof(b->buf));
*
* static struct io_plan wake_reader(struct io_conn *c, struct stdin_buffer *b)
* {
* assert(c == b->writer);
* if (!b->reader)
* return io_close();
* b->len = sizeof(b->inbuf);
* io_wake(b->reader, io_read_partial(b->inbuf, &b->len, wake_writer, b));
* return io_idle();
* }
* // If we just read something, wake writer.
* if (b->rlen != 0)
* io_wake(b);
*
* static void fail_child_write(struct io_conn *conn, struct stdin_buffer *b)
* {
* if (b->reader)
* err(1, "Failed writing to child.");
* // If buffer is empty, return to start.
* if (b->start == b->end)
* b->start = b->end = 0;
*
* // Read in some of the rest.
* b->rlen = sizeof(b->buf) - b->end;
*
* // No room? Wait for writer
* if (b->rlen == 0)
* return io_wait(b, read_in, b);
*
* return io_read_partial(b->buf + b->end, &b->rlen, read_in, b);
* }
*
* // This reads from the child and saves it into buffer.
* static struct io_plan read_from_child(struct io_conn *conn,
* struct buffer *b)
* static struct io_plan write_out(struct io_conn *c, struct buffer *b)
* {
* b->off += b->rlen;
*
* if (b->off == b->max)
* b->buf = realloc(b->buf, b->max *= 2);
* // Remove what we just wrote.
* b->start += b->wlen;
* assert(b->start <= sizeof(b->buf));
*
* // If we wrote somthing, wake writer.
* if (b->wlen != 0)
* io_wake(b);
*
* b->wlen = b->end - b->start;
* // Nothing to write? Wait for reader.
* if (b->wlen == 0) {
* if (b->finished)
* return io_close();
* return io_wait(b, write_out, b);
* }
*
* b->rlen = b->max - b->off;
* return io_read_partial(b->buf + b->off, &b->rlen, read_from_child, b);
* return io_write_partial(b->buf + b->start, &b->wlen, write_out, b);
* }
*
* // Feed a program our stdin, gather its stdout, print that at end.
* int main(int argc, char *argv[])
* {
* int tochild[2], fromchild[2];
* struct buffer out;
* struct stdin_buffer sbuf;
* struct buffer to, from;
* int status;
* size_t off;
* ssize_t ret;
* struct io_conn *from_child;
* struct io_conn *reader;
*
* if (argc == 1)
* errx(1, "Usage: runner <cmdline>...");
......@@ -117,35 +115,20 @@
* close(fromchild[1]);
* signal(SIGPIPE, SIG_IGN);
*
* sbuf.len = sizeof(sbuf.inbuf);
* sbuf.reader = io_new_conn(STDIN_FILENO,
* io_read_partial(sbuf.inbuf, &sbuf.len,
* wake_writer, &sbuf));
* sbuf.writer = io_new_conn(tochild[1], io_idle());
*
* out.max = 128;
* out.off = 0;
* out.rlen = 128;
* out.buf = malloc(out.max);
* from_child = io_new_conn(fromchild[0],
* io_read_partial(out.buf, &out.rlen,
* read_from_child, &out));
* if (!sbuf.reader || !sbuf.writer || !from_child)
* err(1, "Allocating connections");
*
* io_set_finish(sbuf.reader, reader_exit, &sbuf);
* io_set_finish(sbuf.writer, fail_child_write, &sbuf);
* // Read from stdin, write to child.
* memset(&to, 0, sizeof(to));
* reader = io_new_conn(STDIN_FILENO, read_in(NULL, &to));
* io_set_finish(reader, finish, &to);
* io_new_conn(tochild[1], write_out(NULL, &to));
*
* // Read from child, write to stdout.
* reader = io_new_conn(fromchild[0], read_in(NULL, &from));
* io_set_finish(reader, finish, &from);
* io_new_conn(STDOUT_FILENO, write_out(NULL, &from));
*
* io_loop();
* wait(&status);
*
* for (off = 0; off < out.off; off += ret) {
* ret = write(STDOUT_FILENO, out.buf+off, out.off-off);
* if (ret < 0)
* err(1, "Writing stdout");
* }
* free(out.buf);
*
* return WIFEXITED(status) ? WEXITSTATUS(status) : 2;
* }
*
......
......@@ -91,6 +91,7 @@ bool add_conn(struct io_conn *c);
bool add_duplex(struct io_conn *c);
void del_listener(struct io_listener *l);
void backend_plan_changed(struct io_conn *conn);
void backend_wait_changed(const void *wait);
void backend_add_timeout(struct io_conn *conn, struct timespec ts);
void backend_del_timeout(struct io_conn *conn);
void backend_del_conn(struct io_conn *conn);
......
......@@ -24,8 +24,6 @@ bool io_plan_nodebug;
struct io_conn *current;
/* User-defined function to select which connection(s) to debug. */
bool (*io_debug_conn)(struct io_conn *conn);
/* Set when we wake up an connection we are debugging. */
bool io_debug_wakeup;
struct io_plan io_debug(struct io_plan plan)
{
......@@ -36,12 +34,9 @@ struct io_plan io_debug(struct io_plan plan)
return plan;
}
if (!current || !doing_debug_on(current)) {
if (!io_debug_wakeup)
if (!current || !doing_debug_on(current))
return plan;
}
io_debug_wakeup = false;
current->plan = plan;
backend_plan_changed(current);
......@@ -68,7 +63,7 @@ struct io_plan io_debug(struct io_plan plan)
/* Return a do-nothing plan, so backend_plan_changed in
* io_ready doesn't do anything (it's already been called). */
return io_idle_();
return io_wait_(NULL, (void *)1, NULL);
}
int io_debug_io(int ret)
......@@ -107,22 +102,12 @@ int io_debug_io(int ret)
return 2;
}
static void debug_io_wake(struct io_conn *conn)
{
/* We want linear if we wake a debugged connection, too. */
if (io_debug_conn && io_debug_conn(conn))
io_debug_wakeup = true;
}
/* Counterpart to io_plan_no_debug(), called in macros in io.h */
static void io_plan_debug_again(void)
{
io_plan_nodebug = false;
}
#else
static void debug_io_wake(struct io_conn *conn)
{
}
static void io_plan_debug_again(void)
{
}
......@@ -436,37 +421,26 @@ struct io_plan io_connect_(int fd, const struct addrinfo *addr,
return plan;
}
struct io_plan io_idle_(void)
struct io_plan io_wait_(const void *wait,
struct io_plan (*cb)(struct io_conn *, void*),
void *arg)
{
struct io_plan plan;
assert(cb);
plan.pollflag = 0;
plan.io = NULL;
/* Never called (overridden by io_wake), but NULL means closing */
plan.next = (void *)io_idle_;
plan.next = cb;
plan.next_arg = arg;
return plan;
}
plan.u1.const_vp = wait;
bool io_is_idle(const struct io_conn *conn)
{
return conn->plan.io == NULL;
return plan;
}
void io_wake_(struct io_conn *conn, struct io_plan plan)
void io_wake(const void *wait)
{
io_plan_debug_again();
/* It might be closing, but we haven't called its finish() yet. */
if (!conn->plan.next)
return;
/* It was idle, right? */
assert(!conn->plan.io);
conn->plan = plan;
backend_plan_changed(conn);
debug_io_wake(conn);
backend_wait_changed(wait);
}
void io_ready(struct io_conn *conn)
......
......@@ -314,6 +314,7 @@ struct io_plan io_write_partial_(const void *data, size_t *len,
struct io_plan io_always_(struct io_plan (*cb)(struct io_conn *, void *),
void *arg);
/**
* io_connect - plan to connect to a listening socket.
* @fd: file descriptor.
......@@ -360,19 +361,32 @@ struct io_plan io_connect_(int fd, const struct addrinfo *addr,
void *arg);
/**
* io_idle - plan to do nothing.
* io_wait - plan to wait for something.
* @wait: the address to wait on.
* @cb: function to call after waiting.
* @arg: @cb argument
*
* This indicates the connection is idle: io_wake() will be called later do
* give the connection a new plan.
* This indicates the connection is idle: io_wake() will be called later to
* restart the connection.
*
* Example:
* struct io_conn *sleeper;
* sleeper = io_new_conn(open("/dev/null", O_RDONLY), io_idle());
* unsigned int counter = 0;
* sleeper = io_new_conn(open("/dev/null", O_RDONLY),
* io_wait(&counter, io_close_cb, NULL));
* if (!sleeper)
* exit(1);
*/
#define io_idle() io_debug(io_idle_())
struct io_plan io_idle_(void);
#define io_wait(wait, cb, arg) \
io_debug(io_wait_(wait, \
typesafe_cb_preargs(struct io_plan, void *, \
(cb), (arg), \
struct io_conn *), \
(arg)))
struct io_plan io_wait_(const void *wait,
struct io_plan (*cb)(struct io_conn *, void *),
void *arg);
/**
* io_timeout - set timeout function if the callback doesn't complete.
......@@ -440,35 +454,18 @@ bool io_timeout_(struct io_conn *conn, struct timespec ts,
struct io_conn *io_duplex_(struct io_conn *conn, struct io_plan plan);
/**
* io_wake - wake up an idle connection.
* @conn: an idle connection.
* @plan: the next I/O plan for @conn.
*
* This makes @conn ready to do I/O the next time around the io_loop().
* io_wake - wake up any connections waiting on @wait
* @wait: the address to trigger.
*
* Example:
* struct io_conn *sleeper;
* sleeper = io_new_conn(open("/dev/null", O_RDONLY), io_idle());
* unsigned int wait;
*
* io_wake(sleeper, io_write("junk", 4, io_close_cb, NULL));
*/
#define io_wake(conn, plan) (io_plan_no_debug(), io_wake_((conn), (plan)))
void io_wake_(struct io_conn *conn, struct io_plan plan);
/**
* io_is_idle - is a connection idle?
*
* This can be useful for complex protocols, eg. where you want a connection
* to send something, so you queue it and wake it if it's idle.
*
* Example:
* struct io_conn *sleeper;
* sleeper = io_new_conn(open("/dev/null", O_RDONLY), io_idle());
* io_new_conn(open("/dev/null", O_RDONLY),
* io_wait(&wait, io_close_cb, NULL));
*
* assert(io_is_idle(sleeper));
* io_wake(sleeper, io_write("junk", 4, io_close_cb, NULL));
* io_wake(&wait);
*/
bool io_is_idle(const struct io_conn *conn);
void io_wake(const void *wait);
/**
* io_break - return from io_loop()
......
......@@ -167,6 +167,34 @@ void backend_plan_changed(struct io_conn *conn)
some_always = true;
}
void backend_wait_changed(const void *wait)
{
unsigned int i;
for (i = 0; i < num_fds; i++) {
struct io_conn *c, *duplex;
/* Ignore listeners */
if (fds[i]->listener)
continue;
c = (void *)fds[i];
for (duplex = c->duplex; c; c = duplex, duplex = NULL) {
/* Ignore closing. */
if (!c->plan.next)
continue;
/* Not idle? */
if (c->plan.io)
continue;
/* Waiting on something else? */
if (c->plan.u1.const_vp != wait)
continue;
/* Make it do the next thing. */
c->plan = io_always_(c->plan.next, c->plan.next_arg);
backend_plan_changed(c);
}
}
}
bool add_conn(struct io_conn *c)
{
if (!add_fd(&c->fd, c->plan.pollflag & (POLLIN|POLLOUT)))
......
......@@ -29,8 +29,7 @@ static struct io_plan read_done(struct io_conn *conn, struct data *d)
static void finish_waker(struct io_conn *conn, struct data *d)
{
ok1(io_is_idle(idler));
io_wake(idler, io_read(d->buf, sizeof(d->buf), read_done, d));
io_wake(d);
ok1(d->state == 1);
d->state++;
}
......@@ -47,13 +46,18 @@ static struct io_plan never(struct io_conn *conn, void *arg)
abort();
}
static struct io_plan read_buf(struct io_conn *conn, struct data *d)
{
return io_read(d->buf, sizeof(d->buf), read_done, d);
}
static void init_conn(int fd, struct data *d)
{
int fd2;
ok1(d->state == 0);
d->state++;
idler = io_new_conn(fd, io_idle());
idler = io_new_conn(fd, io_wait(d, read_buf, d));
io_set_finish(idler, finish_idle, d);
/* This will wake us up, as read will fail. */
......@@ -103,7 +107,7 @@ int main(void)
int fd, status;
/* This is how many tests you plan to run */
plan_tests(14);
plan_tests(13);
d->state = 0;
fd = make_listen_fd(PORT, &addrinfo);
ok1(fd >= 0);
......
......@@ -15,6 +15,11 @@ static struct io_plan timeout_wakeup(struct io_conn *conn, char *buf)
return io_read(buf, 16, io_close_cb, NULL);
}
static struct io_plan never(struct io_conn *conn, void *unused)
{
abort();
}
int main(void)
{
int fds[2];
......@@ -28,7 +33,7 @@ int main(void)
/* Write then close. */
io_new_conn(fds[1], io_write("hello there world", 16,
io_close_cb, NULL));
conn = io_new_conn(fds[0], io_idle());
conn = io_new_conn(fds[0], io_wait(buf, never, NULL));
/* To avoid assert(num_waiting) */
ok1(pipe(fds2) == 0);
......
......@@ -11,10 +11,15 @@ static char inbuf[8];
static struct io_plan wake_it(struct io_conn *conn, struct io_conn *reader)
{
io_wake(reader, io_read(inbuf, 8, io_close_cb, NULL));
io_wake(inbuf);
return io_close();
}
static struct io_plan read_buf(struct io_conn *conn, void *unused)
{
return io_read(inbuf, 8, io_close_cb, NULL);
}
int main(void)
{
int fds[2];
......@@ -23,7 +28,7 @@ int main(void)
plan_tests(3);
ok1(pipe(fds) == 0);
conn = io_new_conn(fds[0], io_idle());
conn = io_new_conn(fds[0], io_wait(inbuf, read_buf, NULL));
io_new_conn(fds[1], io_write("EASYTEST", 8, wake_it, conn));
ok1(io_loop() == NULL);
......
......@@ -16,6 +16,12 @@ struct buffer {
};
static struct io_plan poke_reader(struct io_conn *conn, struct buffer *buf);
static struct io_plan poke_writer(struct io_conn *conn, struct buffer *buf);
static struct io_plan read_buf(struct io_conn *conn, struct buffer *buf)
{
return io_read(&buf->buf, sizeof(buf->buf), poke_writer, buf);
}
static struct io_plan poke_writer(struct io_conn *conn, struct buffer *buf)
{
......@@ -25,25 +31,28 @@ static struct io_plan poke_writer(struct io_conn *conn, struct buffer *buf)
return io_close();
/* You write. */
io_wake(buf->writer,
io_write(&buf->buf, sizeof(buf->buf), poke_reader, buf));
io_wake(&buf->writer);
/* I'll wait until you wake me. */
return io_idle();
return io_wait(&buf->reader, read_buf, buf);
}
static struct io_plan write_buf(struct io_conn *conn, struct buffer *buf)
{
return io_write(&buf->buf, sizeof(buf->buf), poke_reader, buf);
}
static struct io_plan poke_reader(struct io_conn *conn, struct buffer *buf)
{
assert(conn == buf->writer);
/* You read. */
io_wake(buf->reader,
io_read(&buf->buf, sizeof(buf->buf), poke_writer, buf));
io_wake(&buf->reader);
if (++buf->iters == NUM_ITERS)
return io_close();
/* I'll wait until you tell me to write. */
return io_idle();
return io_wait(&buf->writer, write_buf, buf);
}
static struct buffer buf[NUM];
......@@ -66,13 +75,12 @@ int main(void)
sprintf(buf[i].buf, "%i-%i", i, i);
/* Wait for writer to tell us to read. */
buf[i].reader = io_new_conn(last_read, io_idle());
buf[i].reader = io_new_conn(last_read,
io_wait(&buf[i].reader, read_buf,
&buf[i]));
if (!buf[i].reader)
break;
buf[i].writer = io_new_conn(fds[1],
io_write(&buf[i].buf,
sizeof(buf[i].buf),
poke_reader, &buf[i]));
buf[i].writer = io_new_conn(fds[1], write_buf(NULL, &buf[i]));
if (!buf[i].writer)
break;
last_read = fds[0];
......@@ -83,11 +91,10 @@ int main(void)
/* Last one completes the cirle. */
i = 0;
sprintf(buf[i].buf, "%i-%i", i, i);
buf[i].reader = io_new_conn(last_read, io_idle());
buf[i].reader = io_new_conn(last_read,
io_wait(&buf[i].reader, read_buf, &buf[i]));
ok1(buf[i].reader);
buf[i].writer = io_new_conn(last_write,
io_write(&buf[i].buf, sizeof(buf[i].buf),
poke_reader, &buf[i]));
buf[i].writer = io_new_conn(last_write, write_buf(NULL, &buf[i]));
ok1(buf[i].writer);
/* They should eventually exit */
......
......@@ -17,7 +17,7 @@ int main(void)
int fds[2];
ok1(pipe(fds) == 0);
io_new_conn(fds[0], io_idle());
io_new_conn(fds[0], io_wait(&status, io_close_cb, NULL));
io_loop();
exit(1);
}
......
......@@ -28,7 +28,7 @@ static void finish_ok(struct io_conn *conn, struct data *d)
static struct io_plan write_done(struct io_conn *conn, struct data *d)
{
d->state++;
return io_idle();
return io_wait(d, io_close_cb, NULL);
}
static struct io_plan read_done(struct io_conn *conn, struct data *d)
......
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