POSIXMQ-RECV takes option o-nonblock

CHANGES

@@ -41,6 +41,10 @@ Corrections:
 	input lines. Changed Socat to explicitly print the newline in this
 	case.
 
+Features:
+	POSIXMQ-RECV now takes option o-nonblock; this, in combination with -T,
+	makes it possible to terminate Socat in case the queue is empty.
+
 Building:
 	Disabling certain features during configure could break build process.
 

doc/socat.yo

@@ -332,7 +332,7 @@ label(ADDRESS_DCCP_CONNECT)dit(bf(tt(DCCP-CONNECT:<host>:<port>)) (bf(tt(DCCP:<h
    link(connect-timeout)(OPTION_CONNECT_TIMEOUT),
    link(tos)(OPTION_TOS),
    link(dccp-set-ccid)(OPTION_DCCP_SET_CCID),
-   link(nonblock)(OPTION_NONBLOCK),
+   link(nonblock)(OPTION_O_NONBLOCK),
    link(sourceport)(OPTION_SOURCEPORT),
    link(retry)(OPTION_RETRY),
    link(readbytes)(OPTION_READBYTES)nl()
@@ -747,7 +747,7 @@ label(ADDRESS_NAMED_PIPE)dit(bf(tt(PIPE:<filename>)))
    Option groups: link(FD)(GROUP_FD),link(NAMED)(GROUP_NAMED),link(OPEN)(GROUP_OPEN) nl()
    Useful options:
    link(rdonly)(OPTION_RDONLY),
-   link(nonblock)(OPTION_NONBLOCK),
+   link(nonblock)(OPTION_O_NONBLOCK),
    link(group)(OPTION_GROUP),
    link(user)(OPTION_USER),
    link(mode)(OPTION_MODE),
@@ -784,7 +784,8 @@ label(ADDRESS_POSIXMQ_READ)dit(bf(tt(POSIXMQ-READ:/<mqueue>)))
    Useful options:
    link(posixmq-priority)(OPTION_POSIXMQ_PRIORITY),
    link(unlink-early)(OPTION_UNLINK_EARLY),
-   link(unlink-close)(OPTION_UNLINK_CLOSE)
+   link(unlink-close)(OPTION_UNLINK_CLOSE),
+   link(o-nonblock)(OPTION_O_NONBLOCK)
 
 label(ADDRESS_POSIXMQ_RECEIVE)dit(bf(tt(POSIXMQ-RECEIVE:/<mqueue>)))
 dit(bf(tt(POSIXMQ-RECV:/<mqueue>)))
@@ -882,7 +883,7 @@ label(ADDRESS_SCTP_CONNECT)dit(bf(tt(SCTP-CONNECT:<host>:<port>)))
    link(mtudiscover)(OPTION_MTUDISCOVER),
    link(sctp-maxseg)(OPTION_SCTP_MAXSEG),
    link(sctp-nodelay)(OPTION_SCTP_NODELAY),
-   link(nonblock)(OPTION_NONBLOCK),
+   link(nonblock)(OPTION_O_NONBLOCK),
    link(sourceport)(OPTION_SOURCEPORT),
    link(retry)(OPTION_RETRY),
    link(readbytes)(OPTION_READBYTES)nl()
@@ -1234,7 +1235,7 @@ label(ADDRESS_TCP_CONNECT)dit(bf(tt(TCP:<host>:<port>)))
    link(mtudiscover)(OPTION_MTUDISCOVER),
    link(mss)(OPTION_MSS),
    link(nodelay)(OPTION_TCP_NODELAY),
-   link(nonblock)(OPTION_NONBLOCK),
+   link(nonblock)(OPTION_O_NONBLOCK),
    link(readbytes)(OPTION_READBYTES)nl()
    See also:
    link(TCP4)(ADDRESS_TCP4_CONNECT),
@@ -1853,7 +1854,7 @@ label(OPTION_APPEND)dit(bf(tt(append[=<bool>])))
    socat() uses the code(O_APPEND) flag with the code(open()) system call
    (link(example)(EXAMPLE_OPTION_APPEND)).
    Otherwise, socat() applies the code(fcntl(fd, F_SETFL, O_APPEND)) call.
-label(OPTION_NONBLOCK)dit(bf(tt(nonblock[=<bool>])))
+label(OPTION_O_NONBLOCK)dit(bf(tt(nonblock[=<bool>])))
    Tries to open or use file in nonblocking mode. Its only effects are that the
    code(connect()) call of TCP addresses does not block, and that opening a
    named pipe for reading does not block.
@@ -1988,7 +1989,7 @@ E.g., option `creat' sets the code(O_CREAT) flag. When the used address does
 not use code(open()) (e.g.STDIO), the code(fcntl(..., F_SETFL, ...)) call is
 used instead.nl()
 See also options link(append)(OPTION_APPEND) and
-link(nonblock)(OPTION_NONBLOCK).
+link(nonblock)(OPTION_O_NONBLOCK).
 startdit()
 label(OPTION_O_CREAT)dit(bf(tt(creat[=<bool>])))
    Creates the file if it does not exist (link(example)(EXAMPLE_OPTION_CREAT)).
@@ -3973,7 +3974,7 @@ prompts.
 label(EXAMPLE_ADDRESS_PTY)
 label(EXAMPLE_OPTION_SYMBOLIC_LINK)
 label(EXAMPLE_OPTION_WAIT_SLAVE)
-label(EXAMPLE_OPTION_NONBLOCK)
+label(EXAMPLE_OPTION_O_NONBLOCK)
 mancommand(\.LP)
 mancommand(\.nf)
 mancommand(\fBsocat \\)

xio-posixmq.c

@@ -45,6 +45,7 @@ static int xioopen_posixmq(
 	int dirs = addrdesc->arg1;
 	int oneshot = addrdesc->arg2;
 	bool opt_unlink_early = false;
+	bool nonblock;
 	int oflag;
 	bool opt_o_excl = false;
 	mode_t opt_mode = 0666;
@@ -113,6 +114,8 @@ static int xioopen_posixmq(
 	case XIO_RDONLY: oflag |= O_RDONLY; break;
 	case XIO_WRONLY: oflag |= O_WRONLY; break;
 	}
+	if (retropt_bool(opts, OPT_O_NONBLOCK, &nonblock) >= 0 && nonblock)
+		oflag |= O_NONBLOCK;
 
 	/* Now open the message queue */
 	Debug3("mq_open(\"%s\", %d, "F_mode", NULL)", name, oflag, opt_mode);
@@ -155,6 +158,8 @@ static int xioopen_posixmq(
 		do {
 			struct pollfd pollfd;
 
+			if (oflag & O_NONBLOCK)
+				break;
 			pollfd.fd = sfd->fd;
 			pollfd.events = (dirs==XIO_RDONLY?POLLIN:POLLOUT);
 			if (xiopoll(&pollfd, 1, NULL) > 0) {