ludic/docs/language/process/process-poll.md
Orkuncakilkaya 43d5eb5b88 feat(launcher): Process.*, Http.save_to/received/expected, App.window_hide/show
Process.spawn/poll/kill/free - non-blocking child processes with no shell: posix_spawn on
macOS (process.ll), CreateProcessW with MSVC-quoted arguments and no console window on
Windows (process_win.ll), linked only when a program uses Process.*.

Http.save_to streams a response body into a file (NSURLSession with a run-time delegate
class on macOS, the WinHTTP read loop on Windows); Http.received / Http.expected report
progress while it is pending. Freeing a pending request cancels it and parks the slot
until the worker has finished.

App.window_hide / App.window_show take the game's window off the screen and back without
closing it; the run goes on while hidden. Docs, examples, tests and a changeset.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-09-17 13:32:23 +03:00

32 lines
1.3 KiB
Markdown

---
id: process-poll
name: Process.poll
category: process
kind: namespace-method
tokens: Process.poll
sig: Process.poll(handle) -> int
tip: -1 while running, else the exit code.
order: 1
ns: Process
member: poll
---
Returns <code>-1</code> while the child is still running and its exit code once it has ended; it never waits. The code is kept, so asking again gives the same answer until <a href="process-free.html"><code>Process.free</code></a>.
A child ended by a signal (macOS) answers <code>128</code> plus the signal number, as a shell reports it — <code>137</code> after <a href="process-kill.html"><code>Process.kill</code></a>, on both platforms. On Windows the code is the child's DWORD exit code as an <code>int</code>, so a crash such as <code>0xC0000005</code> arrives as a negative number (test for <code>!= 0</code>, not <code>&gt; 0</code>); a code of <code>0xFFFFFFFF</code> is reported as <code>255</code> so that <code>-1</code> always means "still running". A handle that is not one answers <code>255</code>.
```ludic
program Demo {
var game: int = -1
handler Watch phase Update {
if game >= 0 {
let code = Process.poll(handle: game)
if code >= 0 or code < -1 {
if code != 0 { print("the game crashed") }
Process.free(handle: game)
game = -1
}
}
}
}
```