Re: [PATCH] Properly handle short writes in sigint handlers

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+From: Dmitry Kurochkin <dmitry.kurochkin@gmail.com>\r
+To: Austin Clements <amdragon@MIT.EDU>, notmuch@notmuchmail.org\r
+Subject: Re: [PATCH] Properly handle short writes in sigint handlers\r
+In-Reply-To: <1324584948-8009-1-git-send-email-amdragon@mit.edu>\r
+References: <20111222201553.GK10376@mit.edu>\r
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+Date: Fri, 23 Dec 2011 23:10:35 +0400\r
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+\r
+Hi Austin.\r
+\r
+On Thu, 22 Dec 2011 15:15:48 -0500, Austin Clements <amdragon@MIT.EDU> wrote:\r
+> Even if we don't care about errors from write(2), it's still necessary\r
+> to handle short writes in order to use write correctly.  Some versions\r
+> of glibc even mark write as warn_unused_result because of this, so our\r
+> previous usage would trigger compiler warnings.\r
+\r
+I think we should put the write loop into a separate function and reuse\r
+it.\r
+\r
+Also, does it make sense to add a retry counter to prevent infinite loop\r
+if write keeps returning 0?\r
+\r
+Regards,\r
+  Dmitry\r
+\r
+> ---\r
+>  notmuch-new.c |    5 ++++-\r
+>  notmuch-tag.c |    6 +++++-\r
+>  2 files changed, 9 insertions(+), 2 deletions(-)\r
+> \r
+> diff --git a/notmuch-new.c b/notmuch-new.c\r
+> index 3512de7..fc09bbb 100644\r
+> --- a/notmuch-new.c\r
+> +++ b/notmuch-new.c\r
+> @@ -66,8 +66,11 @@ static void\r
+>  handle_sigint (unused (int sig))\r
+>  {\r
+>      static char msg[] = "Stopping...         \n";\r
+> +    const char *pos = msg, *end = msg + sizeof (msg) - 1;\r
+> +    ssize_t c = 0;\r
+>  \r
+> -    (void) write(2, msg, sizeof(msg)-1);\r
+> +    for (; pos < end && c >= 0; pos += c)\r
+> +    c = write (2, pos, end - pos);\r
+>      interrupted = 1;\r
+>  }\r
+>  \r
+> diff --git a/notmuch-tag.c b/notmuch-tag.c\r
+> index 292c5da..0d4873d 100644\r
+> --- a/notmuch-tag.c\r
+> +++ b/notmuch-tag.c\r
+> @@ -26,7 +26,11 @@ static void\r
+>  handle_sigint (unused (int sig))\r
+>  {\r
+>      static char msg[] = "Stopping...         \n";\r
+> -    (void) write(2, msg, sizeof(msg)-1);\r
+> +    const char *pos = msg, *end = msg + sizeof (msg) - 1;\r
+> +    ssize_t c = 0;\r
+> +\r
+> +    for (; pos < end && c >= 0; pos += c)\r
+> +    c = write (2, pos, end - pos);\r
+>      interrupted = 1;\r
+>  }\r
+>  \r
+> -- \r
+> 1.7.7.3\r
+> \r
+> _______________________________________________\r
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