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Pause a llama turn at once, and let Stop take the model with it

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A turn waits on three things that look nowhere at all: a permission
question, a tool call with a minute to run, and the completion itself,
which says nothing while the prompt is read -- tens of seconds on a long
conversation. Setting a flag left the turn exactly where it was until
whichever it was came back.

The wait is now what ends, not the work. Each of those runs on a thread of
its own and the interrupt answers the wait; the abandoned thread finishes
into a channel nobody is reading. 43ms to end a turn in every state,
measured against a real model -- including mid prompt-processing, which
used to be a twenty-second wait. That makes cancellation a token per turn
rather than a flag on the session: the abandoned thread wakes up some time
later, and a flag the next turn had reset would let it write into a
conversation it is no longer part of. The open thinking block moves to
Shared for the same reason -- the thread that knows one is open is no
longer the thread that ends the turn.

Stop, meanwhile, did nothing at all to a llama session: it signals the
session's recorded process and process::stop refuses a Shared one, which
is the whole point of that record -- so the session sat at idle. A Shared
record routes to the driver now, because what stopping means for a session
that borrows the machine's process is the driver's to say. It ends the
turn, says exited itself, and gives up its claim on the model; each live
session claims the model it is on, and the model is unloaded when the last
claim goes. A model another session is using stays where it is.
This commit is contained in:
iris-ai committed 2026-09-21 03:16:55 -04:00
1 parent 849c3b599f
commit 386c1c4def
6 files changed
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AGENTS.md
+30 -8
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@@ -511,14 +511,36 @@ written, and the fold uses that same predicate to decide a reply is settled.
reply, and the transcript keeps whatever arrived before it.
- **A cancel flag is only as prompt as the next place somebody looks.** A
llama turn waits on two things that look nowhere at all: a permission
question, and a tool call `llama-server` is running -- a shell command there
runs to its own timeout, up to a minute. Setting `cancel` left the turn
exactly where it was until that came back, so Pause did nothing on screen
for as long as the command took. `Shared::abandon_turn` sets the flag *and*
releases both waits, the tool call by answering its channel with
`tools::UNFINISHED` -- the call is left running over there, because nothing
in that protocol takes one back, and its answer is dropped.
llama turn waits on three things that look nowhere at all: a permission
question, a tool call `llama-server` is running (a shell command there runs
to its own timeout, up to a minute), and the completion itself, which says
nothing for as long as the prompt takes to read -- tens of seconds on a long
conversation. Setting `cancel` left the turn exactly where it was until
whichever it was came back, so Pause did nothing on screen for all of it.
**The wait is what ends, not the work**: `awaiting` runs each of those on a
thread of its own and `Shared::abandon_turn` answers the wait, so the turn
ends in milliseconds (measured 43ms in every state) and the abandoned thread
finishes into a channel nobody is reading. Nothing here can stop a shell
command or a model mid-reply, and pretending otherwise is what the old code
did.
**Which is why cancellation is a token per turn** (`Cancel`), not a flag on
the session: the abandoned thread wakes up some time later, and a flag the
next turn had reset would let it write into a conversation it is no longer
part of. Its own token stays set for ever, so it says nothing -- and the
open thinking block is closed by `Shared::abandon_turn` rather than by that
thread, since the one that knows is not the one that ends the turn.
- **Stop ends a llama session and takes the model with it, if nobody else
wants it** (2026-09-21). Until then Stop did *nothing at all* to one:
`stop_session` signals the session's recorded process, and `process::stop`
refuses a `Shared` record -- so the session sat at `idle` with no sign
anything had happened. A `Shared` record now routes to `Driver::stop`,
because what stopping means for a session that borrows somebody else's
process is the driver's to say. The llama driver ends the turn, says
`exited` itself (nothing else will -- there is no process of its own to
die), and asks `Router::release`: each live session claims the model it is
on, and the model comes out of memory only when the last claim goes. A model
another session is using stays.
- **A path is stored as it was typed, and `~` is expanded where it is used.**
`~/repos/x` and `/home/someone/repos/x` are a path and a snapshot of where it
PLAN.md
+24
View File
@@ -477,6 +477,30 @@ deliberate and easy to undo by accident:
only a turn whose model was changed under it. The conversation is read
*before* the message is announced, which is what makes "everything before
this message" true rather than a race against the pump.
- **An interrupt ends the wait, not the work** (2026-09-21, `awaiting`,
`Cancel`). Everything a llama turn waits on is on the far side of something
that cannot be told to stop -- a permission nobody has answered, a shell
command with a minute to run, a completion that says nothing until the
prompt has been read. Each now runs on a thread of its own and the
interrupt answers the *wait*; the abandoned thread finishes into a channel
nobody is reading. Measured at 43ms to end a turn in every state, against
up to a minute before. Two things fall out of it. Cancellation is a **token
per turn** rather than a flag on the session, because the abandoned thread
wakes later and a flag the next turn had reset would let it speak into a
conversation it is no longer part of. And the open thinking block is closed
by the interrupt, not by that thread, since the thread that knows is not
the one that ends the turn.
- **Stop takes the model with it when nobody else wants it** (2026-09-21).
Stop did nothing to a llama session at all: `stop_session` signals the
session's own recorded process and refuses a `Shared` one, which is the
whole point of that record -- so the session sat at `idle`. A `Shared`
record routes to `Driver::stop` now, because what stopping means for a
session that borrows the machine's process is the driver's to say. Each
live session claims the model it is on (`Router::claim`) and the model is
unloaded when the last claim goes, which is the honest reading of "give me
my GPU back": a model another session is on is nobody's to take. Rejected:
unloading unconditionally, which is the thing the shared router exists to
prevent.
- **A wait that can be measured says how far along it is** (2026-09-21,
`GET /sessions/{id}/progress`, `Driver::progress`). Both of this
driver's waits have a real number behind them and neither used to reach
TODO.md
+27
View File
@@ -22,6 +22,33 @@ one in place when it turns out to need a decision.
## Session settings
Asked for by Bryan on 2026-09-21, in one run while other work was in flight.
The first two are one change; the rest can land separately.
- [ ] **A screen, not a modal.** The settings dialog has outgrown one: it
scrolls inside itself and covers the session it is about.
- [ ] **Two tabs on that screen, the way the main screen has three.** One is
the session's own settings; the other is *the same provider screen*
reached from the machines tab (`ProviderScreen`), for this session's
provider -- two ways in, one screen, no second copy of the truth.
- [ ] **Compact fields everywhere.** The label goes above the box rather than
floating inside it, and the padding around the value comes down. The
value's own text size does not change: what is costing a row its height
is the framing, not the text.
- [ ] **A system prompt per session.** For llama.cpp it is a `system` message
on each request, so it is one entry in `DriverKind::params` and no app
change; whether the CLI drivers get one (`--append-system-prompt`) is a
separate question.
- [ ] **Stop unloads the model where nothing else is using it.** Today
`Driver::stop` deliberately leaves it in memory, because the server is
the machine's and another session may be on the same model. The answer
is a claim per live session on the router, and an unload when the last
one goes -- not an unconditional unload.
- [ ] Autocompact belongs in session settings; empty disables it, which is the
default. Iris chose "hand it to the driver" — only where a driver has
auto-compaction of its own. **That option was offered on a false premise
server/src/session/llama/mod.rs
+275 -125
View File
@@ -280,6 +280,7 @@ impl Call {
}
/// What one completion produced.
#[derive(Default)]
struct Reply {
text: String,
calls: Vec<Call>,
@@ -370,6 +371,20 @@ struct Respawn {
router: Arc<Router>,
}
/// One turn's cancellation, and what decides whether a thread still belongs to
/// the turn that is running now.
///
/// A token per turn rather than one flag on the session, because an interrupt
/// abandons the *wait* and leaves the work running: the abandoned thread wakes
/// some time later, and a flag the next turn had reset would let it write into
/// a conversation it is no longer part of. Its own token stays set for ever,
/// so it cannot.
type Cancel = Arc<AtomicBool>;
/// How one abandoned wait is answered. Held by [`Shared::abandonable`] and
/// called by [`Shared::abandon_turn`]; see [`awaiting`].
type Canceller = Box<dyn FnOnce() + Send>;
/// Everything the driver's own threads need, which is nearly all of it: a turn
/// runs on a thread of its own and outlives any borrow of the driver.
struct Shared {
@@ -389,11 +404,17 @@ struct Shared {
/// `~`. `None` leaves the directory to `llama-server`, which is the honest
/// answer rather than a guess at one.
cwd: Option<String>,
/// Set by [`Shared::abandon_turn`]; the streaming loop and the tool loop
/// both check it, leaving what was produced in the transcript. A flag is
/// only as prompt as the next place somebody looks, which is why the two
/// waits that look nowhere are released by hand there as well.
cancel: AtomicBool,
/// The running turn's cancellation -- see [`Cancel`]. Replaced at the
/// start of every turn; [`Shared::abandon_turn`] sets whichever one is
/// current.
cancel: Mutex<Cancel>,
/// The open thinking block, if the model is in one: when it started.
///
/// Here rather than in [`generate`]'s own frame because a turn can be
/// let go of while a block is open, and then the thread that knows is not
/// the thread that ends the turn -- see [`Shared::done_thinking`]. Without
/// it the card on the phone spins for ever.
thinking_since: Mutex<Option<std::time::Instant>>,
/// Whether a turn is running, and what is waiting behind it.
///
/// One lock over both, because the two decide each other: with a flag and
@@ -426,9 +447,10 @@ struct Shared {
/// is only ever about the wait the session is in now -- see
/// [`SessionStatus::Reading`].
reading: Mutex<Option<(u64, u64)>>,
/// Tool calls a turn is blocked on, by the call's id, so that an
/// interrupt can let go of one rather than sit out whatever it is doing.
running_tools: Mutex<HashMap<String, std::sync::mpsc::Sender<String>>>,
/// Waits an interrupt can end, by the id of what is being waited on --
/// see [`awaiting`]. Each entry answers its own wait; nothing here stops
/// the work, which goes on wherever it is until it notices.
abandonable: Mutex<HashMap<String, Canceller>>,
/// Which of the machine's tools this session offers its model. Live like
/// the sampling settings and for the same reason -- it is applied to the
/// next request rather than to anything that was started.
@@ -516,7 +538,8 @@ impl LlamaDriver {
session_dir: session_dir.to_path_buf(),
sampling: Mutex::new(sampling),
cwd,
cancel: AtomicBool::new(false),
cancel: Mutex::new(Arc::new(AtomicBool::new(false))),
thinking_since: Mutex::new(None),
turns: Mutex::new(Turns::default()),
serving: Mutex::new(Serving::Loading(meta.model.clone().unwrap_or_default())),
settled: Condvar::new(),
@@ -533,7 +556,7 @@ impl LlamaDriver {
allowed: Mutex::new(allowances(transcript)),
asked: Mutex::new(HashMap::new()),
reading: Mutex::new(None),
running_tools: Mutex::new(HashMap::new()),
abandonable: Mutex::new(HashMap::new()),
tools_wanted: Mutex::new(Chosen::from(meta.params.get(TOOLS).map(String::as_str))),
watching: AtomicBool::new(false),
thinking: Mutex::new(chosen_thinking(&meta.params)),
@@ -656,6 +679,10 @@ impl LlamaDriver {
shared.emit(Event::Images {
images: shared.images(),
});
// This session is on this model now, which is what
// decides whether stopping it can take the model out of
// memory -- see `Router::release`.
router.claim(&session, &model);
Serving::Ready {
serves,
tools: Arc::new(tools),
@@ -844,37 +871,80 @@ impl Shared {
}
}
/// Lets go of every tool call this session is waiting on, telling the
/// model what a call that never came back was.
///
/// The call itself is not stopped: `llama-server` does not take one back
/// once it has started it, so the thread that asked is left to collect an
/// answer nobody reads. What ends here is the *waiting*, which is what a
/// turn is actually made of.
fn abandon_tools(&self) {
for (_, finished) in std::mem::take(
&mut *self
.running_tools
/// The running turn's cancellation, for a thread that is about to act on
/// behalf of it.
fn cancel(&self) -> Cancel {
Arc::clone(
&self
.cancel
.lock()
.unwrap_or_else(std::sync::PoisonError::into_inner),
) {
let _ = finished.send(tools::UNFINISHED.to_string());
)
}
/// Opens a turn: a token of its own, which is what makes everything the
/// last turn left running unable to speak into this one.
fn open_turn(&self) -> Cancel {
let fresh: Cancel = Arc::new(AtomicBool::new(false));
*self
.cancel
.lock()
.unwrap_or_else(std::sync::PoisonError::into_inner) = Arc::clone(&fresh);
fresh
}
/// Closes the open thinking block, saying how long it was open for.
///
/// Exactly once, whoever gets here first: the stream's next fragment, the
/// end of the reply, or the reader ending the turn from another thread.
fn done_thinking(&self) {
let started = self
.thinking_since
.lock()
.unwrap_or_else(std::sync::PoisonError::into_inner)
.take();
if let Some(started) = started {
self.emit(Event::ThinkingDone {
ms: started.elapsed().as_millis() as u64,
});
}
}
/// Ends the running turn: the flag, and everything blocked on something
/// Lets go of everything this turn is waiting on, telling whatever was
/// waiting what a thing that never came back is.
///
/// None of it is *stopped*: a tool call runs to `llama-server`'s own
/// timeout, a completion generates until its connection is dropped, and
/// neither takes an instruction to stop. So each abandoned thread is left
/// to finish and find nobody there -- and it finds its turn's token set,
/// which is what keeps it silent.
fn abandon_waits(&self) {
for (_, abandon) in std::mem::take(
&mut *self
.abandonable
.lock()
.unwrap_or_else(std::sync::PoisonError::into_inner),
) {
abandon();
}
}
/// Ends the running turn: the token, and everything blocked on something
/// that will not read it.
///
/// Both of those waits are on another thread with no deadline a reader
/// would sit through -- a permission nobody is going to answer, and a tool
/// call running a shell command, which is up to a minute of `llama-server`
/// not being asked anything. Setting the flag alone left the turn exactly
/// where it was until that came back, which on screen was a Pause button
/// that did nothing at all.
/// Every one of those waits is on another thread with no deadline a reader
/// would sit through -- a permission nobody is going to answer, a shell
/// command that has a minute to run, a model that has said nothing yet and
/// will not for another twenty seconds. Setting the flag alone left the
/// turn exactly where it was until that came back, which on screen was a
/// Pause button that did nothing at all.
fn abandon_turn(&self) {
self.cancel.store(true, Ordering::SeqCst);
self.cancel().store(true, Ordering::SeqCst);
self.abandon_questions();
self.abandon_tools();
self.abandon_waits();
// The block the model had open is over, and the thread that was
// watching it is not coming back to say so.
self.done_thinking();
}
fn emit(&self, event: Event) {
@@ -1103,7 +1173,7 @@ impl LlamaDriver {
) {
let shared = Arc::clone(shared);
std::thread::spawn(move || {
shared.cancel.store(false, Ordering::SeqCst);
let cancel = shared.open_turn();
// Everything before this message is read here, before the
// message is announced: the record is written behind us, so a
// conversation read after the announcement can already contain
@@ -1142,7 +1212,7 @@ impl LlamaDriver {
text,
image_parts(&shared.session_dir, &images),
));
if let Err(err) = converse(&shared, &serves, &tools, messages) {
if let Err(err) = converse(&shared, &serves, &tools, messages, &cancel) {
shared.emit(Event::Error {
message: format!("{err:#}"),
});
@@ -1180,15 +1250,34 @@ fn converse(
serves: &Serves,
tools: &Arc<Tools>,
mut messages: Vec<Message>,
cancel: &Cancel,
) -> Result<()> {
for _ in 0..MAX_STEPS {
if shared.cancel.load(Ordering::SeqCst) {
if cancel.load(Ordering::SeqCst) {
return Ok(());
}
// Read per call rather than per turn, so a sampling change made while
// a long turn is running reaches the rest of it.
let sampling = shared.sampling.lock().unwrap().clone();
let reply = generate(serves, &messages, tools, &sampling, shared)?;
// The conversation is handed *to* the thread that generates and
// handed back with the reply, rather than borrowed: the request can
// be abandoned, and what a thread with no borrow to honour leaves
// behind is nothing at all. It is also the whole prompt, which is not
// a thing to copy once a turn.
let asked = std::mem::take(&mut messages);
let generated = awaiting(shared, GENERATING, cancel, {
let shared = Arc::clone(shared);
let serves = serves.clone();
let tools = Arc::clone(tools);
let cancel = Arc::clone(cancel);
move || generate(&serves, asked, &tools, &sampling, &shared, &cancel)
});
// Let go of mid-request: the reader ended the turn, and what arrived
// before that is already in the transcript.
let Some((asked, reply)) = generated.transpose()? else {
return Ok(());
};
messages = asked;
let calls = reply.calls;
messages.push(Message {
tool_calls: calls.iter().map(Call::wire).collect(),
@@ -1198,10 +1287,10 @@ fn converse(
return Ok(());
}
for call in &calls {
let output = run_call(shared, tools, call);
let output = run_call(shared, tools, call, cancel);
messages.push(Message::result_of(&call.id, output));
}
take_steers(shared, &mut messages);
take_steers(shared, &mut messages, cancel);
}
// Said rather than left as a turn that simply stopped: a reply that ends
// here and one that ends because the model was finished look identical on
@@ -1235,11 +1324,11 @@ fn converse(
/// the next turn, which rebuilds the conversation out of the transcript --
/// which is what the note says anyway, since by then the turn it was typed
/// into is over.
fn take_steers(shared: &Arc<Shared>, messages: &mut Vec<Message>) {
fn take_steers(shared: &Arc<Shared>, messages: &mut Vec<Message>, cancel: &Cancel) {
// An interrupted turn takes nothing: this request is not going out, so a
// message taken here would be recorded as read and then never answered.
// Left in the queue it opens the next turn instead.
if shared.cancel.load(Ordering::SeqCst) {
if cancel.load(Ordering::SeqCst) {
return;
}
let waiting = std::mem::take(&mut shared.turns.lock().unwrap().waiting);
@@ -1270,7 +1359,7 @@ fn take_steers(shared: &Arc<Shared>, messages: &mut Vec<Message>) {
/// refused or interrupted. A call with no result is a conversation a chat
/// template cannot render -- see [`tools::UNFINISHED`] -- so there is no path
/// out of here that leaves one.
fn run_call(shared: &Arc<Shared>, tools: &Arc<Tools>, call: &Call) -> String {
fn run_call(shared: &Arc<Shared>, tools: &Arc<Tools>, call: &Call, cancel: &Cancel) -> String {
let arguments = call.arguments();
shared.emit(Event::ToolStart {
id: call.id.clone(),
@@ -1284,12 +1373,12 @@ fn run_call(shared: &Arc<Shared>, tools: &Arc<Tools>, call: &Call) -> String {
"There is no tool called {}. Use one of the tools you were given.",
call.name
)
} else if shared.cancel.load(Ordering::SeqCst) {
} else if cancel.load(Ordering::SeqCst) {
tools::UNFINISHED.to_string()
} else if !permitted(shared, call) {
tools::REFUSED.to_string()
} else {
run_tool(shared, tools, call, arguments)
run_tool(shared, tools, call, arguments, cancel)
};
shared.emit(Event::ToolEnd {
id: call.id.clone(),
@@ -1298,56 +1387,89 @@ fn run_call(shared: &Arc<Shared>, tools: &Arc<Tools>, call: &Call) -> String {
output
}
/// Runs one tool on a thread of its own, and waits for it in a way an
/// interrupt can reach.
/// Runs one tool where an interrupt can let go of it.
///
/// The wait is a channel with two writers -- the call's own thread and
/// [`Shared::abandon_tools`] -- and whichever speaks first is what the model
/// is told. A call is the one part of a turn this server can neither hurry
/// nor take back: `llama-server` runs it to its own timeout, up to a minute
/// for a shell command, and nothing in the protocol says "stop that one". So
/// an interrupt leaves it running over there and drops its answer, which is
/// what makes Pause end the turn when it is pressed rather than when the
/// command it happened to be running is over.
fn run_tool(shared: &Arc<Shared>, tools: &Arc<Tools>, call: &Call, arguments: Value) -> String {
let (finished, waiting) = std::sync::mpsc::channel();
shared
.running_tools
.lock()
.unwrap()
.insert(call.id.clone(), finished.clone());
// Checked after registering, not before: the flag is set ahead of the
// drain, so a call that registered after that drain would be waiting on a
// wake-up already given out. Either the insert beat the drain and this
// will be released, or it did not and the flag is already true.
if shared.cancel.load(Ordering::SeqCst) {
shared.running_tools.lock().unwrap().remove(&call.id);
return tools::UNFINISHED.to_string();
/// A call is the one part of a turn this server can neither hurry nor take
/// back: `llama-server` runs it to its own timeout, up to a minute for a
/// shell command, and nothing in the protocol says "stop that one". So an
/// interrupt leaves it running over there and drops its answer, which is what
/// makes Pause end the turn when it is pressed rather than when the command
/// it happened to be running is over.
fn run_tool(
shared: &Arc<Shared>,
tools: &Arc<Tools>,
call: &Call,
arguments: Value,
cancel: &Cancel,
) -> String {
let tools = Arc::clone(tools);
let name = call.name.clone();
let cwd = shared.cwd.clone();
// Read here rather than in the thread: the filter is live, and this is the
// call it applies to.
let chosen = shared.tools_wanted.lock().unwrap().clone();
awaiting(shared, &call.id, cancel, move || {
match tools.execute(&name, &arguments, cwd.as_deref(), &chosen) {
Ok(output) => output,
// Reaching the tool failed, which is this server's problem and not
// the model's work going wrong -- but the model is still what has
// to carry on, so it is told in the result rather than only in the
// log.
Err(err) => format!("This tool could not be run: {err:#}"),
}
})
.unwrap_or_else(|| tools::UNFINISHED.to_string())
}
/// The id [`awaiting`] registers a completion under. One name is enough: a
/// session runs one turn at a time, and an abandoned turn's entry is taken by
/// the abandoning.
const GENERATING: &str = "generating";
/// Runs `work` on a thread of its own and waits for it in a way an interrupt
/// can reach, answering `None` where one arrived first.
///
/// What this buys is that **the wait is what ends, not the work**: nothing
/// here can stop a shell command or a model mid-reply, and pretending
/// otherwise would mean holding the turn open until whatever it was doing
/// finished -- a minute for a command, twenty seconds for a long prompt, all
/// of it with a Pause button that had visibly done nothing. The abandoned
/// thread finishes into a channel nobody is reading, finds its turn's
/// [`Cancel`] set, and says nothing.
fn awaiting<T: Send + 'static>(
shared: &Arc<Shared>,
id: &str,
cancel: &Cancel,
work: impl FnOnce() -> T + Send + 'static,
) -> Option<T> {
let (done, waiting) = std::sync::mpsc::channel();
let interrupt = done.clone();
shared.abandonable.lock().unwrap().insert(
id.to_string(),
Box::new(move || {
let _ = interrupt.send(None);
}),
);
// Registered before the token is read, not after: an interrupt sets it and
// *then* takes the entries, so anything registering after that would be
// waiting on a wake-up already given out. Either this got in before, or
// the token is set and this answers itself with the same entry.
if cancel.load(Ordering::SeqCst) {
if let Some(abandon) = shared.abandonable.lock().unwrap().remove(id) {
abandon();
}
// Whichever of this and the interrupt took the entry has called it, so
// there is an answer waiting either way.
return waiting.recv().ok().flatten();
}
{
let tools = Arc::clone(tools);
let name = call.name.clone();
let cwd = shared.cwd.clone();
// Read here rather than in the thread, which is where it was read
// before: the filter is live, and this is the call it applies to.
let chosen = shared.tools_wanted.lock().unwrap().clone();
std::thread::spawn(move || {
let output = match tools.execute(&name, &arguments, cwd.as_deref(), &chosen) {
Ok(output) => output,
// Reaching the tool failed, which is this server's problem and
// not the model's work going wrong -- but the model is still
// what has to carry on, so it is told in the result rather
// than only in the log.
Err(err) => format!("This tool could not be run: {err:#}"),
};
let _ = finished.send(output);
});
}
let output = waiting
.recv()
.unwrap_or_else(|_| tools::UNFINISHED.to_string());
shared.running_tools.lock().unwrap().remove(&call.id);
output
std::thread::spawn(move || {
let _ = done.send(Some(work()));
});
// `Err` is the working thread having panicked, which says the same thing
// an interrupt does: nothing is coming.
let answer = waiting.recv().ok().flatten();
shared.abandonable.lock().unwrap().remove(id);
answer
}
/// Whether this call may go ahead, asking whoever is reading if it has to.
@@ -1605,8 +1727,9 @@ impl Driver for LlamaDriver {
});
return;
}
self.shared.cancel.store(true, Ordering::SeqCst);
self.shared.cancel.store(false, Ordering::SeqCst);
// A token of its own for whatever comes next, so nothing left over
// from the last turn is holding the one this model will answer.
self.shared.open_turn();
match self.start(model) {
// Reported when it is true and not before: `start` has put the
// session into `Loading`, and the model it is loading is this one.
@@ -1659,15 +1782,44 @@ impl Driver for LlamaDriver {
self.shared.abandon_turn();
}
/// Ends this session's claim on the model and nothing else.
/// Ends this session's turn and its claim on the model, and takes the
/// model out of memory if this session was the last thing using it.
///
/// The server holding it is the machine's, shared with every other session
/// on it, so stopping one session unloads nothing -- see
/// [`process::Detail::Shared`], which is what makes that structural rather
/// than a rule to remember. A model is taken out of memory from the
/// machine's provider settings, where what it costs everybody is visible.
/// The server itself stays: it is the machine's, shared with every other
/// session on it, and `process::stop` refuses to signal a
/// [`process::Detail::Shared`] record -- which is what makes that
/// structural rather than a rule to remember. What Stop can honestly do
/// is give back the memory *this* session was the reason for, and a model
/// somebody else is on is not that; see [`Router::release`], which
/// answers with the model only when nobody else holds it.
///
/// On a thread because it is an HTTP round trip to the serving machine,
/// and stopping a session should not wait on one: the session is stopped
/// either way, and a model that could not be unloaded is a message in the
/// log rather than a failure to report.
fn stop(&self) {
self.shared.abandon_turn();
// Said here because nothing else will: a session whose process is the
// machine's shared server has no process of its own to die and be
// noticed. Without it the session sits at `idle` after Stop, with no
// Start button and no sign anything happened.
self.shared.emit(Event::Status {
state: SessionStatus::Exited,
});
// Anything waiting on this model is waiting on a session that has
// stopped, and nothing else will wake it.
self.shared
.settle(Serving::Failed("this session was stopped.".to_string()));
if let Some(model) = self.respawn.router.release(&self.respawn.meta.id) {
let router = Arc::clone(&self.respawn.router);
std::thread::spawn(move || {
if let Err(err) = router.unload(&model) {
tracing::warn!("could not unload {model}: {err:#}");
} else {
tracing::info!("unloaded {model}, which nothing else was using");
}
});
}
process::clear(&self.shared.session_dir);
}
}
@@ -2168,11 +2320,12 @@ fn thinking_kwargs(shared: &Shared) -> Option<Value> {
/// how long it thought for.
fn generate(
serves: &Serves,
messages: &[Message],
messages: Vec<Message>,
tools: &Tools,
sampling: &serde_json::Map<String, Value>,
shared: &Shared,
) -> Result<Reply> {
cancel: &Cancel,
) -> Result<(Vec<Message>, Reply)> {
let mut body = json!({
// Which model, because one `llama-server` is serving every model this
// machine has loaded and this is how a request says which it means.
@@ -2238,11 +2391,6 @@ fn generate(
// worst direction for a figure somebody is watching to see how much room
// is left.
let mut context = None;
// The open thinking block: when it started, so its duration is measured
// where the deltas actually arrive rather than worked out later from two
// timestamps. `None` between blocks -- a turn can think, speak, call a
// tool and think again.
let mut thinking: Option<std::time::Instant> = None;
// Whether the model has produced anything at all yet; until it has, this
// turn is still reading its prompt.
let mut speaking = false;
@@ -2259,17 +2407,8 @@ fn generate(
// server's own account of prompt processing, and a prompt it had cached is
// a small number rather than a missing one.
let mut prefill = None;
// Closes the open block, which is anything the model says that is not more
// working: the first word of the reply, or a tool call.
let done_thinking = |thinking: &mut Option<std::time::Instant>| {
if let Some(started) = thinking.take() {
shared.emit(Event::ThinkingDone {
ms: started.elapsed().as_millis() as u64,
});
}
};
for line in std::io::BufRead::lines(reader) {
if shared.cancel.load(Ordering::SeqCst) {
if cancel.load(Ordering::SeqCst) {
break;
}
let line = line.context("reading the generation stream")?;
@@ -2289,7 +2428,7 @@ fn generate(
// `refusal` never sees it. Skipped as an unrecognised chunk, it ended
// the turn with nothing said at all.
if let Some(why) = chunk.pointer("/error/message").and_then(Value::as_str) {
done_thinking(&mut thinking);
shared.done_thinking();
bail!("llama-server stopped generating: {why}");
}
// One figure answering both questions, which for this dialect it
@@ -2335,7 +2474,11 @@ fn generate(
if let Some(fragment) = delta.get("reasoning_content").and_then(Value::as_str)
&& !fragment.is_empty()
{
thinking.get_or_insert_with(std::time::Instant::now);
shared
.thinking_since
.lock()
.unwrap()
.get_or_insert_with(std::time::Instant::now);
shared.emit(Event::Thinking {
delta: fragment.to_string(),
});
@@ -2343,7 +2486,7 @@ fn generate(
if let Some(fragment) = delta.get("content").and_then(Value::as_str)
&& !fragment.is_empty()
{
done_thinking(&mut thinking);
shared.done_thinking();
text.push_str(fragment);
shared.emit(Event::AssistantText {
delta: fragment.to_string(),
@@ -2355,7 +2498,7 @@ fn generate(
.into_iter()
.flatten()
{
done_thinking(&mut thinking);
shared.done_thinking();
absorb(&mut calls, fragment);
}
}
@@ -2364,15 +2507,22 @@ fn generate(
// ever having spoken.
*shared.reading.lock().unwrap() = None;
// A block left open by the end of the stream -- a model that thought and
// then said nothing, or a turn the reader cancelled -- is still a block
// that ended. Without this its card spins for ever.
done_thinking(&mut thinking);
// then said nothing -- is still a block that ended. Without this its card
// spins for ever. The interrupted case is closed by the interrupt itself,
// which is the thread that ends that turn.
shared.done_thinking();
// Said before anything else is reported, because what arrived is a partial
// reply rather than a reply. A cancelled turn leaves the same stream
// unfinished and is not a failure: it is what the reader asked for.
if !finished && !shared.cancel.load(Ordering::SeqCst) {
if !finished && !cancel.load(Ordering::SeqCst) {
bail!("llama-server stopped sending this reply before it was finished");
}
// Nothing more is said into a turn somebody ended. This thread is here
// only to notice that the stream stopped, and what it has left to report
// is about a turn that is over -- see `awaiting`.
if cancel.load(Ordering::SeqCst) {
return Ok((messages, Reply::default()));
}
if tokens > 0 {
shared.emit(Event::UsageDelta {
tokens,
@@ -2385,7 +2535,7 @@ fn generate(
// is cut mid-fragment, and running it would mean inventing what was asked
// for.
calls.retain(|call| !call.name.is_empty());
Ok(Reply { text, calls })
Ok((messages, Reply { text, calls }))
}
/// Whether a delta carries anything the model produced, of any kind.
server/src/session/llama/router.rs
+33
View File
@@ -146,6 +146,7 @@ impl Routers {
gate: Mutex::new(()),
loading: Arc::new(Mutex::new(HashMap::new())),
watching: Arc::new(AtomicBool::new(false)),
claims: Mutex::new(HashMap::new()),
})
});
*router.spec.lock().unwrap_or_else(|e| e.into_inner()) = spec;
@@ -180,6 +181,16 @@ pub struct Router {
/// is enough, and every load asks -- an adopted router has none until
/// somebody wants a model from it.
watching: Arc<AtomicBool>,
/// Which model each live session on this router is holding, so that the
/// last session to let go of one is the one that can take it out of
/// memory -- see [`release`](Self::release).
///
/// One model per session because that is what a session has: claiming a
/// new one is how the old claim ends, which is what a model change is.
/// Only sessions *this* backend has running are in here, which is the
/// right set: a stopped session is not using a model, whatever it is
/// configured with.
claims: Mutex<HashMap<String, String>>,
}
/// Where one model's load has got to, as the router last said.
@@ -361,6 +372,28 @@ impl Router {
.unwrap_or_default()
}
/// Records that `session` is on `model`, which is also how its claim on
/// whatever it was on before ends.
pub fn claim(&self, session: &str, model: &str) {
self.claims
.lock()
.unwrap_or_else(|e| e.into_inner())
.insert(session.to_string(), model.to_string());
}
/// Lets go of `session`'s model, answering with it when no other session
/// is on it -- which is to say, when taking it out of memory would cost
/// nobody anything.
///
/// `None` for a session that had no claim, and for one whose model
/// somebody else is still using. Both of those are the same instruction:
/// leave it where it is.
pub fn release(&self, session: &str) -> Option<String> {
let mut claims = self.claims.lock().unwrap_or_else(|e| e.into_inner());
let model = claims.remove(session)?;
(!claims.values().any(|held| *held == model)).then_some(model)
}
/// Takes one model out of memory, leaving the router and every other model
/// alone.
pub fn unload(&self, key: &str) -> Result<()> {
server/src/session/mod.rs
+30 -4
View File
@@ -2040,10 +2040,19 @@ impl SessionManager {
/// ahead of the measurement, and wrong for the grace period a process
/// that ignores SIGTERM keeps running.
///
/// Deliberately not routed through the driver: the record is the
/// session's rather than any dialect's, so asking it here stops a
/// session whose driver is in no state to be asked, and adds no method a
/// new driver could implement wrongly.
/// Deliberately not routed through the driver *where the process is the
/// session's own*: the record is the session's rather than any dialect's,
/// so asking it here stops a session whose driver is in no state to be
/// asked, and adds no method a new driver could implement wrongly.
///
/// A [`process::Detail::Shared`] record is the exception, and it is one
/// this rule could not have anticipated: the process is the machine's
/// llama-server, shared with every other session on it, so `process::stop`
/// refuses to signal it -- and Stop therefore did nothing at all, leaving
/// the session sitting at `idle`. What stopping means for a session that
/// borrows somebody else's process is the driver's to say, and only it
/// can say it: it is the half that knows whether the model is still
/// wanted by anybody else.
pub fn stop_session(&self, id: &str) -> Result<()> {
if !self
.inner
@@ -2072,6 +2081,23 @@ impl SessionManager {
};
tracing::info!("stopping session {id} (pid {})", record.pid);
process::mark_stopping(&self.data_dir.join(id))?;
if let process::Detail::Shared { .. } = record.detail {
let driver = self
.inner
.read()
.unwrap()
.live
.get(id)
.and_then(|session| session.driver());
match driver {
Some(driver) => driver.stop(),
// A borrowed process and no driver to ask: the record is all
// there is, and clearing it is what says this session is not
// using that server any more.
None => process::clear(&self.data_dir.join(id)),
}
return Ok(());
}
process::stop(&record, process::STOP_GRACE);
Ok(())
}