Thank you Vibhu That is exactly what I came up with, and it seems to work decently well. Only thing, I put a non-zero timeout. All the best Marco On Thu, Dec 18, 2025 at 10:18 AM Vibhu Mohindra <vibhu.mohindra@gmail.com> wrote:
-------- Forwarded Message -------- Subject: Re: READ-SEQUENCE and USOCKET Date: Thu, 18 Dec 2025 10:14:57 +0100 From: Vibhu Mohindra <vibhu.mohindra@gmail.com> To: pro@common-lisp.net
How are you doing Marco?
I'm looking at usocket-0.8.4. It may be worth exploring some of these aspects I see in its code: 1. option.lisp allows: (setf (socket-option mysocket :receive-timeout) ...) 2. usocket.lisp defines a generic socket-receive. It's only implemented for UDP sockets but I don't see why it shouldn't be implementable for stream-sockets too.
Otherwise I don't see a better solution in usocket than inefficiently checking for and reading a byte at a time, like this.
(defun read-available-vector (vector socket &key (start 0) (end nil)) "Reads whatever is presently available in SOCKET without hanging. SOCKET and VECTOR are assumed to have elts of type (unsigned-byte 8). Returns first unwritten position in VECTOR and whether at end-of-file." (when (null end) (setq end (length vector))) (assert (<= 0 start end (length vector))) (flet ((socket-readyp () (wait-for-input socket :timeout 0 :ready-only t))) (do ((i start (1+ i))) ((or (>= i end) (not (socket-readyp))) (values i nil)) (let ((b (read-byte (socket-stream stream) nil nil))) (unless b (return (values i t))) (setf (aref vector i) b)))))
-- Vibhu
-- Marco Antoniotti, Professor, Director tel. +39 - 02 64 48 79 01 DISCo, University of Milan-Bicocca U14 2043 http://dcb.disco.unimib.it Viale Sarca 336 I-20126 Milan (MI) ITALY REGAINS: https://regains.disco.unimib.it/
Marco, If this works for you, great. I've always avoided these higher-level wrappings of sockets, and try to use as close to the BSD interface as I can (which made SBCL a very good fit for me). It could be worth looking to see if LW has recv(2) directly exposed somewhere. Cheers, Thomas
Le 18/12/2025 11:39 CET, Marco Antoniotti <marco.antoniotti@unimib.it> a écrit :
Thank you Vibhu
That is exactly what I came up with, and it seems to work decently well. Only thing, I put a non-zero timeout.
All the best
Marco
On Thu, Dec 18, 2025 at 10:18 AM Vibhu Mohindra <vibhu.mohindra@gmail.com mailto:vibhu.mohindra@gmail.com> wrote:
-------- Forwarded Message -------- Subject: Re: READ-SEQUENCE and USOCKET Date: Thu, 18 Dec 2025 10:14:57 +0100 From: Vibhu Mohindra <vibhu.mohindra@gmail.com mailto:vibhu.mohindra@gmail.com> To: pro@common-lisp.net mailto:pro@common-lisp.net
How are you doing Marco?
I'm looking at usocket-0.8.4. It may be worth exploring some of these aspects I see in its code: 1. option.lisp allows: (setf (socket-option mysocket :receive-timeout) ...) 2. usocket.lisp defines a generic socket-receive. It's only implemented for UDP sockets but I don't see why it shouldn't be implementable for stream-sockets too.
Otherwise I don't see a better solution in usocket than inefficiently checking for and reading a byte at a time, like this.
(defun read-available-vector (vector socket &key (start 0) (end nil)) "Reads whatever is presently available in SOCKET without hanging. SOCKET and VECTOR are assumed to have elts of type (unsigned-byte 8). Returns first unwritten position in VECTOR and whether at end-of-file." (when (null end) (setq end (length vector))) (assert (<= 0 start end (length vector))) (flet ((socket-readyp () (wait-for-input socket :timeout 0 :ready-only t))) (do ((i start (1+ i))) ((or (>= i end) (not (socket-readyp))) (values i nil)) (let ((b (read-byte (socket-stream stream) nil nil))) (unless b (return (values i t))) (setf (aref vector i) b)))))
-- Vibhu
-- Marco Antoniotti, Professor, Director tel. +39 - 02 64 48 79 01 DISCo, University of Milan-Bicocca U14 2043 http://dcb.disco.unimib.it Viale Sarca 336 I-20126 Milan (MI) ITALY
REGAINS: https://regains.disco.unimib.it/
participants (2)
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Marco Antoniotti -
Thomas Burdick