[Spice-devel] [PATCH 02/11] worker: simplify process loops

[Frediano Ziglio]

It was not clear when req_cmd_notification was called.
This code reproduce just the old behavior but is easier to read.

Steps are:

// original

if (worker->display_poll_tries < CMD_RING_POLL_RETRIES) {
    worker->display_poll_tries++;
    worker->event_timeout = MIN(worker->event_timeout, CMD_RING_POLL_TIMEOUT);
    return n;
}
if (worker->display_poll_tries > CMD_RING_POLL_RETRIES ||
             worker->qxl->st->qif->req_cmd_notification(worker->qxl)) {
    worker->display_poll_tries++;
    return n;
}
continue;

// split if

if (worker->display_poll_tries < CMD_RING_POLL_RETRIES) {
    worker->display_poll_tries++;
    worker->event_timeout = MIN(worker->event_timeout, CMD_RING_POLL_TIMEOUT);
    return n;
}
if (worker->display_poll_tries > CMD_RING_POLL_RETRIES) {
    worker->display_poll_tries++;
    return n;
}
if (worker->qxl->st->qif->req_cmd_notification(worker->qxl)) {
    worker->display_poll_tries++;
    return n;
}
continue;

// order inside if

if (worker->display_poll_tries < CMD_RING_POLL_RETRIES) {
    worker->event_timeout = MIN(worker->event_timeout, CMD_RING_POLL_TIMEOUT);
    worker->display_poll_tries++;
    return n;
}
if (worker->display_poll_tries > CMD_RING_POLL_RETRIES) {
    worker->display_poll_tries++;
    return n;
}
if (worker->qxl->st->qif->req_cmd_notification(worker->qxl)) {
    worker->display_poll_tries++;
    return n;
}
continue;

// consider cases

if (worker->display_poll_tries < CMD_RING_POLL_RETRIES) {
    worker->event_timeout = MIN(worker->event_timeout, CMD_RING_POLL_TIMEOUT);
    worker->display_poll_tries++;
    return n;
}
if (worker->display_poll_tries > CMD_RING_POLL_RETRIES) {
    worker->display_poll_tries++;
    return n;
}
if (worker->display_poll_tries == CMD_RING_POLL_RETRIES) {
    if (worker->qxl->st->qif->req_cmd_notification(worker->qxl)) {
        worker->display_poll_tries++;
        return n;
    }
    continue;
}
// unreachable

// invert if

if (worker->display_poll_tries < CMD_RING_POLL_RETRIES) {
    worker->event_timeout = MIN(worker->event_timeout, CMD_RING_POLL_TIMEOUT);
    worker->display_poll_tries++;
    return n;
}
if (worker->display_poll_tries > CMD_RING_POLL_RETRIES) {
    worker->display_poll_tries++;
    return n;
}
if (worker->display_poll_tries == CMD_RING_POLL_RETRIES) {
    if (!worker->qxl->st->qif->req_cmd_notification(worker->qxl)) {
        continue;
    }
    worker->display_poll_tries++;
    return n;
}
// unreachable

// reuse code

if (worker->display_poll_tries < CMD_RING_POLL_RETRIES) {
    worker->event_timeout = MIN(worker->event_timeout, CMD_RING_POLL_TIMEOUT);
} else if (worker->display_poll_tries > CMD_RING_POLL_RETRIES) {
} else if (worker->display_poll_tries == CMD_RING_POLL_RETRIES) {
    if (!worker->qxl->st->qif->req_cmd_notification(worker->qxl)) {
        continue;
    }
}
worker->display_poll_tries++;
return n;

// remove empty if

if (worker->display_poll_tries < CMD_RING_POLL_RETRIES) {
    worker->event_timeout = MIN(worker->event_timeout, CMD_RING_POLL_TIMEOUT);
} else if (worker->display_poll_tries == CMD_RING_POLL_RETRIES) {
    if (!worker->qxl->st->qif->req_cmd_notification(worker->qxl)) {
        continue;
    }
}
worker->display_poll_tries++;
return n;

// collapse two conditions

if (worker->display_poll_tries < CMD_RING_POLL_RETRIES) {
    worker->event_timeout = MIN(worker->event_timeout, CMD_RING_POLL_TIMEOUT);
} else if (worker->display_poll_tries == CMD_RING_POLL_RETRIES &&
           !worker->qxl->st->qif->req_cmd_notification(worker->qxl)) {
    continue;
}
worker->display_poll_tries++;
return n;

Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
---
 server/red-worker.c | 26 ++++++++++----------------
 1 file changed, 10 insertions(+), 16 deletions(-)

diff --git a/server/red-worker.c b/server/red-worker.c
index e70c9df..ba37b6c 100644
--- a/server/red-worker.c
+++ b/server/red-worker.c
@@ -167,16 +167,13 @@ static int red_process_cursor(RedWorker *worker, int *ring_is_empty)
         if (!worker->qxl->st->qif->get_cursor_command(worker->qxl, &ext_cmd)) {
             *ring_is_empty = TRUE;
             if (worker->cursor_poll_tries < CMD_RING_POLL_RETRIES) {
-                worker->cursor_poll_tries++;
                 worker->event_timeout = MIN(worker->event_timeout, CMD_RING_POLL_TIMEOUT);
-                return n;
+            } else if (worker->cursor_poll_tries == CMD_RING_POLL_RETRIES &&
+                       !worker->qxl->st->qif->req_cursor_notification(worker->qxl)) {
+                continue;
             }
-            if (worker->cursor_poll_tries > CMD_RING_POLL_RETRIES ||
-                worker->qxl->st->qif->req_cursor_notification(worker->qxl)) {
-                worker->cursor_poll_tries++;
-                return n;
-            }
-            continue;
+            worker->cursor_poll_tries++;
+            return n;
         }
         worker->cursor_poll_tries = 0;
         switch (ext_cmd.cmd.type) {
@@ -228,16 +225,13 @@ static int red_process_display(RedWorker *worker, int *ring_is_empty)
         if (!worker->qxl->st->qif->get_command(worker->qxl, &ext_cmd)) {
             *ring_is_empty = TRUE;
             if (worker->display_poll_tries < CMD_RING_POLL_RETRIES) {
-                worker->display_poll_tries++;
                 worker->event_timeout = MIN(worker->event_timeout, CMD_RING_POLL_TIMEOUT);
-                return n;
+            } else if (worker->display_poll_tries == CMD_RING_POLL_RETRIES &&
+                       !worker->qxl->st->qif->req_cmd_notification(worker->qxl)) {
+                continue;
             }
-            if (worker->display_poll_tries > CMD_RING_POLL_RETRIES ||
-                         worker->qxl->st->qif->req_cmd_notification(worker->qxl)) {
-                worker->display_poll_tries++;
-                return n;
-            }
-            continue;
+            worker->display_poll_tries++;
+            return n;
         }
 
         if (worker->record_fd)
-- 
2.5.0