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Diffstat (limited to 'docs/fs.md')
| -rw-r--r-- | docs/fs.md | 27 |
1 files changed, 18 insertions, 9 deletions
@@ -106,15 +106,24 @@ at the cost of acme's one-step `new/body`. Nothing in the tree is created by list, stat, walk or read; only that one open. Every other name in `/pane` is a serial. -A session cannot open its own tree through a mount. Looking at -`/mnt/9p/pardes/<me>/anything` from inside that very editor used to hang it -outright: the realpath, the stat and the read all leave through the mount and -come back as 9P requests only that editor's loop can answer, while the loop is -blocked making them, and the filesystem then stops answering anybody. Such a -path is now refused by name before any syscall runs, because the syscall is the -thing that never returns. Address your own tree as `/n/self/...`, which the -editor serves from memory without leaving the process. Another session's mount -is perfectly fine to open. +A session can open its own tree through a mount: a Look at +`/mnt/9p/pardes/<me>/pane/2/body` from inside that very editor opens it, and +a Save of that pane writes back through the mount into pane 2. Requests on +the Unix and TCP listeners are answered on the 9P connection's own task, not +by the editor's loop, so the realpath, the stat and the read the editor makes +out through the mount come back while it waits for them. The one rule is +whose turn it is with the core (`pardes.turn`): the editor has it, and gives +it up while it waits for input and while a step of it is out in a syscall. A +step of a connection task's own -- a Look written to `look` -- goes out the +same way, and the editor waits for it to return before it takes a step of +its own. While any step is out, a request that would change a pane (a write, +a truncation, an rmdir) parks in the engine until none is; everything else, +opening `pane/new` and `screen` included, is answered at once, which is why a +Look at any path in the tree comes back. A write into the tree from the +editor itself only ever happens between steps (a Save), so nothing it waits +on out there is a request that has to park. QUIC is still served on the +editor's loop, so through QUIC the old hang remains. `/n/self/...` names the +same tree without leaving the process. `/look` and `/exec` are the editor's two clicks, one per line of a write: |