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| author | Gabriel Schneider <[email protected]> | 2026-10-01 09:54:20 -0300 |
|---|---|---|
| committer | Gabriel Schneider <[email protected]> | 2026-10-01 10:16:45 -0300 |
| commit | caa8ed077e8b9b67d18f18b3ec46891bd8d310a7 (patch) | |
| tree | 05c09ee65e1a68aacffd90b137690d5b39ed9457 /docs | |
| parent | eda60572013d046d08e253e5847a0ba588c10339 (diff) | |
| download | pardes-caa8ed077e8b9b67d18f18b3ec46891bd8d310a7.tar.gz pardes-caa8ed077e8b9b67d18f18b3ec46891bd8d310a7.zip | |
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 <[email protected]>
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/typ/building.typ | 17 |
1 files changed, 8 insertions, 9 deletions
diff --git a/docs/typ/building.typ b/docs/typ/building.typ index 85f2dfbb..6a2758ad 100644 --- a/docs/typ/building.typ +++ b/docs/typ/building.typ @@ -229,15 +229,14 @@ use `.cloud9 = .{ .path = "../cloud9" }` while editing both. cloud9's own == Writes through a mount <writes-through-a-mount> A mount cuts a big write into pieces of at most one message (msize 65536, -less the header), and each command line runs once it is whole. A write -that does not fill its message is whole, so its last line runs even -without a newline (`printf Save > exec`), unless it is a multiple of 4096 -bytes: that is where a writer's buffer (stdio, a mount's page cache) -filled and cut a line, so its tail waits for the next write or the close. -A line held to the close (such a tail, or an `Edit` block never ended) -runs there, and its failure is only in the log, as its `err` record: the -close reports no error, and the write that sent it had already succeeded. -So a script that needs a line's result ends the write with a newline. +less the header), anywhere, and each command line runs once its newline +comes; nothing is read into a write's size. A last line with no newline +(`printf Save > exec`) runs when the file is closed, as does an `Edit` +block never ended, and its failure is then only in the log, as its `err` +record: the close reports no error, and the write that sent it had +already succeeded. So a script that needs a line's result ends it with a +newline. A line over 1 MiB is refused once, and the rest of it, through +its newline, is dropped. == Listeners <listeners> |