> For the complete documentation index, see [llms.txt](https://docs.urbit.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.urbit.org/urbit-os/base/threads/examples/gall/stop-thread.md). # Stop Thread Gall agent example demonstrating how to stop running threads - Spider-stop pokes and thread lifecycle management. Here's an example agent with an extra card in `+on-poke` to stop the thread and a little extra in `+on-agent` to print things for demonstrative purposes. We run the thread by poking Spider directly because we need to know the thread ID in order to stop it. In this example we use a thread file, but an inline thread could also be used.

/app/thread-starter.hoon code

{% code title="/app/thread-starter.hoon" lineNumbers="true" %} ```hoon /+ default-agent, dbug =* card card:agent:gall %- agent:dbug ^- agent:gall |_ =bowl:gall +* this . def ~(. (default-agent this %|) bowl) :: ++ on-init on-init:def ++ on-save on-save:def ++ on-load on-load:def ++ on-poke |= [=mark =vase] ^- (quip card _this) ?+ mark (on-poke:def mark vase) %noun ?+ q.vase (on-poke:def mark vase) (pair term term) =/ tid `@ta`(cat 3 'thread_' (scot %uv (sham eny.bowl))) =/ ta-now `@ta`(scot %da now.bowl) =/ start-args [~ `tid byk.bowl(r da+now.bowl) p.q.vase !>(q.q.vase)] :_ this :~ [%pass /thread/[ta-now] %agent [our.bowl %spider] %watch /thread-result/[tid]] [%pass /thread/[ta-now] %agent [our.bowl %spider] %poke %spider-start !>(start-args)] [%pass /thread/updates/[ta-now] %agent [our.bowl %spider] %watch /thread/[tid]/updates] [%pass /thread-stop/[ta-now] %agent [our.bowl %spider] %poke %spider-stop !>([tid %.y])] == == == ++ on-watch on-watch:def ++ on-leave on-leave:def ++ on-peek on-peek:def ++ on-agent |= [=wire =sign:agent:gall] ^- (quip card _this) ?+ -.wire (on-agent:def wire sign) %thread ?+ -.sign (on-agent:def wire sign) %poke-ack ?~ p.sign %- (slog leaf+"Thread started successfully" ~) `this %- (slog leaf+"Thread failed to start" u.p.sign) `this :: %fact ?+ p.cage.sign (on-agent:def wire sign) %thread-fail =/ err !< (pair term tang) q.cage.sign %- (slog leaf+"Thread failed: {(trip p.err)}" q.err) `this %thread-done ?: =(*vase q.cage.sign) %- (slog leaf+"Thread cancelled nicely" ~) `this =/ res (trip !<(term q.cage.sign)) %- (slog leaf+"Result: {res}" ~) `this %update =/ msg !< tape q.cage.sign %- (slog leaf+msg ~) `this == == %thread-stop ?+ -.sign (on-agent:def wire sign) %poke-ack ?~ p.sign %- (slog leaf+"Thread cancelled successfully" ~) `this %- (slog leaf+"Thread failed to stop" u.p.sign) `this == == ++ on-arvo on-arvo:def ++ on-fail on-fail:def -- ``` {% endcode %}

We've added a `sleep` to the thread to keep it running for demonstration: {% code title="/ted/test-thread.hoon" lineNumbers="true" %} ```hoon /+ *strandio |= arg=vase =/ m (strand:rand ,vase) ^- form:m ;< =path bind:m take-watch ;< ~ bind:m (send-raw-card [%give %fact ~[path] %update !>("message 1")]) ;< ~ bind:m %- send-raw-cards :~ [%give %fact ~[path] %update !>("message 2")] [%give %fact ~[path] %update !>("message 3")] [%give %fact ~[path] %update !>("message 4")] == ;< ~ bind:m (send-raw-card [%give %kick ~[path] ~]) ;< ~ bind:m (sleep ~m1) |= strand-input:rand ?+ q.arg [~ %fail %not-foo ~] %foo [~ %done arg] == ``` {% endcode %} Save these, `|commit`, and run with `:thread-starter [%test-thread %foo]`. You should see: ``` Thread started successfully message 1 message 2 message 3 message 4 Thread cancelled successfully Thread cancelled nicely ``` Now, try changing the vase in our new card from `!>([tid %.y])` to `!>([tid %.n])`. Save, `|commit`, and run again. You should see: ``` Thread started successfully message 1 message 2 message 3 message 4 Thread cancelled successfully Thread failed: cancelled ``` ### Analysis The card we've added to our agent: ```hoon [%pass /thread-stop/[ta-now] %agent [our.bowl %spider] %poke %spider-stop !>([tid %.y])] ``` ...pokes spider with mark `%spider-stop` and a vase containing the tid of the thread we want to stop and a `?`. The `?` specifies whether to end it nicely or not. If `%.y` it will end with `%thread-done` and a `*vase` bunted vase. If `%.n` it will end with `%thread-fail` and a vase containing `[term tang]` where `$term` is `%cancelled` and `$tang` is `~`. You can see the difference in our tests above. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://docs.urbit.org/urbit-os/base/threads/examples/gall/stop-thread.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.