diff options
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/cloud9.md | 13 | ||||
| -rw-r--r-- | docs/fs.md | 27 | ||||
| -rw-r--r-- | docs/v9fs.md | 6 |
3 files changed, 29 insertions, 17 deletions
diff --git a/docs/cloud9.md b/docs/cloud9.md index d030db1d..6eb76238 100644 --- a/docs/cloud9.md +++ b/docs/cloud9.md @@ -16,11 +16,14 @@ Mounting, Unix namespace discovery and permissions, the editor event loop, connection limits, and exported tree policy remain here. The Unix and TCP listeners run on cloud9's `serve.Runner` (`std.Io`: an accept task per listener, a reader and a writer task per connection, four slots); its handler -queues every backend request for the editor's thread, which answers them all -in `Listener.tick` after each editor update, retries parked reads there, and -has the runner ship the replies. `src/9p_quic.zig` selects the existing -`pardes-9p` ALPN for cloud9's optional OpenSSL transport; QUIC still runs on -the poll loop in `src/9p_io.zig`, since cloud9's QUIC adapter is +answers every backend request on the connection's task, taking the editor's +turn with the core (`pardes.turn`) while the editor waits for input or is out +in a syscall. A request that would change a pane while the editor is mid-step +is parked with `Status.again` -- the engine parks reads, writes, opens, +truncations, clunks and removes -- and retried by `Runner.wakeAll` when the +editor next rests. `src/9p_quic.zig` selects the existing `pardes-9p` ALPN for +cloud9's optional OpenSSL transport; QUIC still runs on the poll loop in +`src/9p_io.zig` on the editor's thread, since cloud9's QUIC adapter is nonblocking-descriptor based rather than `std.Io` based. The standalone protocol/GPIO tests import the same module. The separate `05-zig-p4` build also supplies cloud9 for the GPIO firmware entry. @@ -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: diff --git a/docs/v9fs.md b/docs/v9fs.md index cfbbd35b..a105fe06 100644 --- a/docs/v9fs.md +++ b/docs/v9fs.md @@ -72,9 +72,9 @@ remain available for subsequent explicit authentication. The launcher waits for forwards termination signals, and removes its empty temporary directory on exit. Namespace destruction releases the mount when its last process exits. -The core stays outside the mount namespace because its event loop serves 9P. -A blocking filesystem operation through its own mount could wait for a request -that the blocked event loop must service. Even pathname resolution may do this. +The core stays outside the mount namespace, which is the helper's private +one: a path under `$PARDES_MOUNT` names nothing in the editor's own namespace, +so a Look on one from that shell opens nothing. Each `Tty9p` currently creates its own mount and consumes a server connection; the session has four application connection slots across all transports. This |