From caa8ed077e8b9b67d18f18b3ec46891bd8d310a7 Mon Sep 17 00:00:00 2001 From: Gabriel Schneider Date: Thu, 1 Oct 2026 09:54:20 -0300 Subject: A command line runs when its newline comes, or at its open's close, never because a write was short: a long line cut by a mount is one line A write shorter than its message, and not a multiple of 4096, was taken as whole, its tail a line. 9ns cuts a FUSE write of up to 512 KiB into 65512-byte Twrites, the last one short, so a 600 KiB `Edit ,c/.../` arrived cut and its tail ran as an unknown control message; the 1 MiB refusal failed the same way. Each open now holds a partial line until its newline, or its release, which ends the last line; an Edit block is whole when it closes, as before. A name write with a NUL still fails its write at once. selfmount writes a 600 KiB Edit line and a 1.1 MiB line through a real 9ns mount; building.typ says how lines are cut. Co-Authored-By: Claude Opus 5.5 --- test/selfmount.py | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'test/selfmount.py') diff --git a/test/selfmount.py b/test/selfmount.py index 6b9d8740..ddfb77dc 100644 --- a/test/selfmount.py +++ b/test/selfmount.py @@ -169,6 +169,19 @@ def run(binary): check(run(f'python3 -c "{maker}" > {mount}/pane/{scratch}/ctl\n'.encode()) == '0', 'a 50 KB Edit block written through the mount') body = client.read(f'/pane/{scratch}/body').decode().splitlines() check(body == ['line %05d of the block' % i for i in range(2500)], f'it ran once, whole ({len(body)} lines)') + # One 600 KiB line: 9ns sends it as 65512-byte Twrites, the last + # one short, and none is taken for a whole line by its size. + errs = client.read('/log').decode().count('\nerr ') + long_edit = "import sys; sys.stdout.write('Edit ,c/' + 'q' * 600000 + '/\\n')" + check(run(f'python3 -c "{long_edit}" > {mount}/pane/{scratch}/ctl\n'.encode()) == '0', 'a 600 KiB Edit line written through the mount') + check(client.read(f'/pane/{scratch}/body') == b'q' * 600000, 'it ran once, whole') + check(client.read('/log').decode().count('\nerr ') == errs, 'no piece of it was refused as a line of its own') + # Over 1 MiB: refused once, its tail dropped through its newline. + too_long = "import sys; sys.stdout.write('Msg ' + 'z' * 1150000 + '\\nMsg after-long\\n')" + run(f'python3 -c "{too_long}" > {mount}/exec\n'.encode()) + log = client.read('/log').decode() + check(log.count('over 1 MiB') == 1 and 'unknown control message' not in log and 'after-long' in log, + 'a 1.1 MiB line is refused once, its tail never a line, the next line runs') # Forty event reads held through the mount, a follower each, and # the mount still answers the rest: 9ns keeps workers past what # the editor holds (128), so `cat layout` is not queued behind -- cgit v1.3