Implement socket timeouts.

* lib.c (timeout_error_s): New symbol variable.
(obj_init): Intern timeout-error, init new variable.

* lib.h (timeout_error_s): Declared.

* socket.c (sock_timeout, sock_send_timeout,
sock_recv_timeout): New static functions.
(sock_load_init): Register sock-send-timeout and
sock-recv-timeout intrinsics.

* stream.c (stdio_maybe_read_error, stdio_maybe_error):
Convert EAGAIN into timeout_error_s.

* txr.1: Documented.

1 files changed, 33 insertions, 0 deletions

diff --git a/txr.1 b/txr.1
index 19f1ba54..de3b5103 100644
--- a/txr.1
+++ b/txr.1
@@ -37990,6 +37990,39 @@ Shutting down in the reading direction is potentially abrupt. If it is executed
 before an "end of stream" indication is received from a peer, it results in an
 abortive close.
 
+.coNP Functions @ sock-recv-timeout and @ sock-send-timeout
+.synb
+.mets (sock-recv-timeout < sock << usec )
+.mets (sock-send-timeout < sock << usec )
+.syne
+.desc
+The
+.code sock-recv-timeout
+and
+.code sock-send-timeout
+functions configure, respectively, receive and send timeouts on socket
+.metn sock .
+
+The
+.meta usec
+parameter specifies the value, in microseconds. It must be a
+.code fixnum
+integer.
+
+When a receive timeout is configured on a socket, then an
+exception of type
+.code timeout-error
+is thrown when an input operation waits for at least
+.code usec
+microseconds without receiving input.
+
+Similarly, when a send timeout is configured, then an
+exception of type
+.code timeout-error
+is thrown when an output operation waits for at least
+.code usec
+microseconds for the availability of buffer space in the socket.
+
 .coNP Functions @ str-inaddr and @ str-in6addr
 .synb
 .mets (str-inaddr address <> [ port ])