ccan/io: flatten debug callchain further.

[ccan] / ccan / io / io.c

diff --git a/ccan/io/io.c b/ccan/io/io.c
index a4489ee8855c5a67fce5d746672342b345c72dc5..ddcd502f367d3afdbbb3562b91f883be13072ece 100644 (file)
--- a/ccan/io/io.c
+++ b/ccan/io/io.c
@@ -24,24 +24,78 @@ bool io_debug_wakeup;
 
 struct io_plan io_debug(struct io_plan plan)
 {
+       struct io_conn *ready = NULL;
+
        if (io_plan_nodebug) {
                io_plan_nodebug = false;
                return plan;
        }
 
-       if (!io_debug_conn || !current)
-               return plan;
-
-       if (!io_debug_conn(current) && !io_debug_wakeup)
-               return plan;
+       if (!current || !doing_debug_on(current)) {
+               if (!io_debug_wakeup)
+                       return plan;
+       }
 
        io_debug_wakeup = false;
        current->plan = plan;
        backend_plan_changed(current);
 
        /* Call back into the loop immediately. */
-       io_loop_return = io_loop();
-       return plan;
+       io_loop_return = do_io_loop(&ready);
+
+       if (ready) {
+               set_current(ready);
+               if (!ready->plan.next) {
+                       /* Call finish function immediately. */
+                       if (ready->finish) {
+                               errno = ready->plan.u.close.saved_errno;
+                               ready->finish(ready, ready->finish_arg);
+                               ready->finish = NULL;
+                       }
+                       backend_del_conn(ready);
+               } else {
+                       /* Calls back in itself, via io_debug_io(). */
+                       if (ready->plan.io(ready->fd.fd, &ready->plan) != 2)
+                               abort();
+               }
+               set_current(NULL);
+       }
+
+       /* Return a do-nothing plan, so backend_plan_changed in
+        * io_ready doesn't do anything (it's already been called). */
+       return io_idle_();
+}
+
+int io_debug_io(int ret)
+{
+       /* Cache it for debugging; current changes. */
+       struct io_conn *conn = current;
+       int saved_errno = errno;
+
+       if (!doing_debug_on(conn))
+               return ret;
+
+       /* These will all go linearly through the io_debug() path above. */
+       switch (ret) {
+       case -1:
+               /* This will call io_debug above. */
+               errno = saved_errno;
+               io_close();
+               break;
+       case 0: /* Keep going with plan. */
+               io_debug(conn->plan);
+               break;
+       case 1: /* Done: get next plan. */
+               if (timeout_active(conn))
+                       backend_del_timeout(conn);
+               conn->plan.next(conn, conn->plan.next_arg);
+               break;
+       default:
+               abort();
+       }
+
+       /* Normally-invalid value, used for sanity check. */
+       return 2;
 }
 
 static void debug_io_wake(struct io_conn *conn)
@@ -173,11 +227,11 @@ static int do_write(int fd, struct io_plan *plan)
 {
        ssize_t ret = write(fd, plan->u.write.buf, plan->u.write.len);
        if (ret < 0)
-               return -1;
+               return io_debug_io(-1);
 
        plan->u.write.buf += ret;
        plan->u.write.len -= ret;
-       return (plan->u.write.len == 0);
+       return io_debug_io(plan->u.write.len == 0);
 }
 
 /* Queue some data to be written. */
@@ -202,11 +256,11 @@ static int do_read(int fd, struct io_plan *plan)
 {
        ssize_t ret = read(fd, plan->u.read.buf, plan->u.read.len);
        if (ret <= 0)
-               return -1;
+               return io_debug_io(-1);
 
        plan->u.read.buf += ret;
        plan->u.read.len -= ret;
-       return (plan->u.read.len == 0);
+       return io_debug_io(plan->u.read.len == 0);
 }
 
 /* Queue a request to read into a buffer. */
@@ -231,10 +285,10 @@ static int do_read_partial(int fd, struct io_plan *plan)
 {
        ssize_t ret = read(fd, plan->u.readpart.buf, *plan->u.readpart.lenp);
        if (ret <= 0)
-               return -1;
+               return io_debug_io(-1);
 
        *plan->u.readpart.lenp = ret;
-       return 1;
+       return io_debug_io(1);
 }
 
 /* Queue a partial request to read into a buffer. */
@@ -259,10 +313,10 @@ static int do_write_partial(int fd, struct io_plan *plan)
 {
        ssize_t ret = write(fd, plan->u.writepart.buf, *plan->u.writepart.lenp);
        if (ret < 0)
-               return -1;
+               return io_debug_io(-1);
 
        *plan->u.writepart.lenp = ret;
-       return 1;
+       return io_debug_io(1);
 }
 
 /* Queue a partial write request. */
@@ -313,23 +367,21 @@ void io_wake_(struct io_conn *conn, struct io_plan plan)
 
 void io_ready(struct io_conn *conn)
 {
+       set_current(conn);
        switch (conn->plan.io(conn->fd.fd, &conn->plan)) {
        case -1: /* Failure means a new plan: close up. */
-               set_current(conn);
                conn->plan = io_close();
                backend_plan_changed(conn);
-               set_current(NULL);
                break;
        case 0: /* Keep going with plan. */
                break;
        case 1: /* Done: get next plan. */
-               set_current(conn);
                if (timeout_active(conn))
                        backend_del_timeout(conn);
                conn->plan = conn->plan.next(conn, conn->plan.next_arg);
                backend_plan_changed(conn);
-               set_current(NULL);
        }
+       set_current(NULL);
 }
 
 /* Close the connection, we're done. */