diff options
Diffstat (limited to 'docs/fs.md')
| -rw-r--r-- | docs/fs.md | 23 |
1 files changed, 16 insertions, 7 deletions
@@ -161,7 +161,10 @@ it: a `lock` while another open holds it waits until that open writes `unlock` or closes (or the pane does), and nothing else is refused for it -- not a write to any other file, not the person at the keyboard. It belongs to the open that wrote it, so only that open's `unlock` is taken; a write on an -open that cannot write (or the editor's own, on none) cannot lock. +open that cannot write (or the editor's own, on none) cannot lock. From a +shell the lock needs an open held across the edit, since `echo lock > ctl` +closes, and so unlocks, at once: `exec 3>ctl; echo lock >&3; ...edits...; +exec 3>&-`. The three range files `addr`, `dot` and `limit` each read the pair of offsets they also accept, so copying one onto another is all that acme's `addr=dot`, @@ -207,11 +210,15 @@ A read with nothing to give yet -- a following `log`, `event`, `pty/data`, a `pty/run` before its answer -- is held, the way factotum holds its log's reads (security/auth/factotum/log.c) and acme an event read: the core keeps it, and whoever next has news for it (a record, output, a run's answer, the pane -closing, which answers "No such file or directory") answers it on the connection it -came on as the turn is given up. Nothing else parked is retried for it. A -read the client flushed meanwhile is dropped unanswered, so no record is -spent on it. An open waits with one read at a time, as acme's window keeps -one `eventx`. QUIC connections still retry their parked reads each tick. +closing, which answers acme's "window shut down") answers it on the +connection it came on as the turn is given up. Nothing else parked is +retried for it. The core keeps the ticket cloud9 gave the park +(`Conn.hold`) and answers only while that very park waits, so a read the +client flushed or whose fid it clunked meanwhile is dropped unanswered, no +record is spent on it, and a tag the client reuses is never answered with +what was meant for the old one. An open waits with one read at a time, as +acme's window keeps one `eventx`; a second read on it meanwhile fails with +"file in use". QUIC connections still retry their parked reads each tick. `pty/run` runs one line at a terminal's prompt and answers how it ended, on the same open (factotum's `rpc` shape): write the line, then read `exit N` @@ -226,7 +233,9 @@ printed before its PROMPT_COMMAND lands in the next run's output. Only its last 64 KiB are kept, from a line start, and the header then reads `exit N cut M` (M bytes left out). `exit N cut`, with no count, says the output's start is not there to read: it scrolled out of the history, the command -erased it (`clear`, a reset), a start or end mark came on the alternate +erased the screen (`clear`, `watch`, a full-screen program's redraw, a +reset -- so such a command's output may read as cut), a start or end mark +came on the alternate screen, or the command printed more than 8192 rows, of which only the last are read so that the answer costs the editor a bounded amount. `exit ?` is a command whose end mark carried no status, which is not a success; `error out |