AMD-GFX Archive on lore.kernel.org
 help / color / mirror / Atom feed
From: jimqu <Jim.Qu-5C7GfCeVMHo@public.gmane.org>
To: amd-gfx-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org
Cc: jimqu <Jim.Qu-5C7GfCeVMHo@public.gmane.org>
Subject: [PATCH] udev_monitor_receive_device() will block when hotplug monitor
Date: Tue, 13 Dec 2016 16:33:26 +0800	[thread overview]
Message-ID: <1481618006-29239-1-git-send-email-Jim.Qu@amd.com> (raw)

udev_monitor_receive_device() will block and wait for the event of udev
use select() to ensure that this will not block.

Change-Id: I4e8f4629580222e94f55a4c03070741bf5f4024c
Signed-off-by: JimQu <Jim.Qu@amd.com>
---
 src/drmmode_display.c | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/src/drmmode_display.c b/src/drmmode_display.c
index 79c9390..a5b4345 100644
--- a/src/drmmode_display.c
+++ b/src/drmmode_display.c
@@ -2528,10 +2528,26 @@ static void drmmode_handle_uevents(int fd, void *closure)
 	ScrnInfoPtr scrn = drmmode->scrn;
 	struct udev_device *dev;
 	Bool received = FALSE;
+	struct timeval tv;
+	fd_set readfd;
+	int ret;
+
+	FD_ZERO(&readfd);
+	FD_SET(fd, &readfd);
+	tv.tv_sec = 0;
+	tv.tv_usec = 0;
 
-	while ((dev = udev_monitor_receive_device(drmmode->uevent_monitor))) {
-		udev_device_unref(dev);
-		received = TRUE;
+	while (1) {
+		ret = select(fd + 1, &readfd, NULL, NULL, &tv);
+		/* Check if our file descriptor has received data. */
+		if (!(ret > 0 && FD_ISSET(fd, &readfd)))
+			break;
+		/* Make the call to receive device. select() ensured that this will not be blocked. */
+		dev = udev_monitor_receive_device(drmmode->uevent_monitor);
+		if (dev) {
+			udev_device_unref(dev);
+			received = TRUE;
+		}
 	}
 
 	if (received)
-- 
1.9.1

_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx

             reply	other threads:[~2016-12-13  8:33 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-12-13  8:33 jimqu [this message]
     [not found] ` <1481618006-29239-1-git-send-email-Jim.Qu-5C7GfCeVMHo@public.gmane.org>
2016-12-13 23:45   ` 答复: [PATCH] udev_monitor_receive_device() will block when hotplug monitor Qu, Jim
2016-12-14  3:03   ` Michel Dänzer
     [not found]     ` <056cefae-e2c6-7cd7-c7fd-461e1cb8bf25-otUistvHUpPR7s880joybQ@public.gmane.org>
2016-12-14  3:33       ` 答复: " Qu, Jim

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1481618006-29239-1-git-send-email-Jim.Qu@amd.com \
    --to=jim.qu-5c7gfcevmho@public.gmane.org \
    --cc=amd-gfx-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox