From: Eyal Birger <eyal.birger@gmail.com>
Date: Mon, 20 Jun 2016 05:36:47 +0000 (+0300)
Subject: uloop: handle waker pipe write() return value
X-Git-Url: http://git.openwrt.org/?p=project%2Flibubox.git;a=commitdiff_plain;h=d197c8ffa3cc61a747f318fd0ecef1f6e39b3935

uloop: handle waker pipe write() return value

Recent glibc warns if result of read() or write() is unused.

Added a retry in case of EINTR, all other faults are silently discarded.

Signed-off-by: Eyal Birger <eyal.birger@gmail.com>

-----
- I was not able to reproduce the EINTR case, but it seems to be the right
  thing to do
- Retrying on EAGAIN in this case would be weird as there is no one to read
  from the other end of the pipe. We could call waker_consume() directly but
  since the size of the message is just one byte, I think this would be dead
  code
---

diff --git a/uloop.c b/uloop.c
index 0b75d4b..1c5bcee 100644
--- a/uloop.c
+++ b/uloop.c
@@ -387,7 +387,13 @@ static void uloop_handle_processes(void)
 
 static void uloop_signal_wake(void)
 {
-	write(waker_pipe, "w", 1);
+	do {
+		if (write(waker_pipe, "w", 1) < 0) {
+			if (errno == EINTR)
+				continue;
+		}
+		break;
+	} while (1);
 }
 
 static void uloop_handle_sigint(int signo)