Comments (14)
An aside - a quick check on my machine seems to indicate that using :term
SIGTERM instead of :int
SIGINT will have the desired effect.
EDIT: nevermind, it works trivially because sigint handler is never called.
from janet.
Looking into this some more, I think the issue is some undefined behavior of what happens when you called exit
in a program with pthread "detached" threads, of which all Janet's threads are. This is certainly an issue that needs some careful consideration - by default, calling exit will run atexit
registered functions in each thread. One "fix" for this issue is to replace exit
in janet's source code with _exit
, which bypasses this atexit functionality that pthread presumably uses for cleanup.
I'm not sure this is an ideal solution, though.
from janet.
a signal is send to a random thread of the process group.
use sigmask
on the other threads.
from janet.
How can I use sigmask?
from janet.
man sigprocmask
man sigwait
you can mask the selected signals on every thread, and use sigwait
to listen for new signals
from janet.
So, you are saying this isn't an issue? Or?
from janet.
There is definitely some improvement to be made here - we can probably have better behavior by default, and possibly expose sigprocmask for control over which threads handle signals. Regardless, the current behavior isn't great.
from janet.
some undefined behavior
On Linux, the process group is killed together. The atexit
is a libc feature.
Does janet use atexit
at all?
from janet.
I found another issue while playing around with signal handler.
During the signal handler, the process signal mask is not changed (deviation from the POSIX behavior). So if you send SIGINT inside the Janet signal handler, the expected behavior is to not intercept the program.
Current behavior:
Pressing Ctrl+C makes the following program go into a loop.
(import spork/sh)
(def kill (ffi/lookup (ffi/native) "kill"))
(def signature (ffi/signature :default :int :int :int))
(defn action []
(sh/rm "test")
(print "Handled SIGINT!")
(ffi/call kill signature 0 2)
(print "unreachable"))
(ev/spawn-thread
(let [server (net/listen :unix "test" :stream)]
(forever
(with [conn (net/accept server)]
(print (ev/read conn :all))))))
(ev/spawn-thread
(forever
(print (file/read stdin :line))))
(defn main [_]
(os/sigaction :int action)
(forever
(ev/sleep 1)))
from janet.
@amano-kenji here's a janky workaround you can use for now (on Linux)
(def kill (ffi/lookup (ffi/native) "kill"))
(def signature (ffi/signature :default :int :int :int))
(defn action []
(sh/rm "test")
(print "Handled SIGINT!")
(ffi/call kill signature 0 15))
from janet.
This has been fixed on the latest master with the addition of a force
argument to exit that calls _exit
instead. The cause of this is just that exit()
flushed stdio streams before exiting, as per the C standard, so this is not an issue with the interpreter.
from janet.
So since f6df8ff, os/exit
has the docstring:
(os/exit &opt x force)
Exit from janet with an exit code equal to x. If x is not an
integer, the exit with status equal the hash of x. If `force` is
truthy will exit immediately and skip cleanup code.
from janet.
skip cleanup code
Does this mean os/sigaction
will be skippped? Does this mean files and streams aren't closed?
from janet.
I just tested the latest commit.
(os/exit 1 true)
can be called in signal handlers, but (os/exit 1)
skips signal handlers.
from janet.
Related Issues (20)
- Proposal: Terse Chained Indices HOT 19
- Reimplement `slurp` with `os/open`. HOT 28
- A way to read standard input in the background without `file/read` in a thread. HOT 4
- `each` macro improper behavior? HOT 8
- `if-let` breaks tail call optimization. HOT 6
- false branch of `if-let` doesn't report the correct call stack information. HOT 4
- `ev/select` should not resume a dead task. HOT 4
- `try` and `defer` break tail call optimization. HOT 4
- `(= @"update" @"update")` is `false`. HOT 3
- `ev/select` still revives fibers.... HOT 3
- option to unbundle docstrings and potential consequences HOT 8
- splicing into structs/tables HOT 2
- Disasm/asm doesn't round-trip for function with unused argument HOT 1
- eventloop/networking gets stuck on musl HOT 11
- Consider making `module/paths` a dynamic variable HOT 6
- Can it run on iOS? Thank you. HOT 3
- `os/strftime` doesn't respect environment variables. HOT 3
- Re-integrate jpm into janet HOT 45
- recent change kinda breaks lexical scope with multiple modules HOT 2
- How to switch off spork/sh/copy message? HOT 2
Recommend Projects
-
React
A declarative, efficient, and flexible JavaScript library for building user interfaces.
-
Vue.js
🖖 Vue.js is a progressive, incrementally-adoptable JavaScript framework for building UI on the web.
-
Typescript
TypeScript is a superset of JavaScript that compiles to clean JavaScript output.
-
TensorFlow
An Open Source Machine Learning Framework for Everyone
-
Django
The Web framework for perfectionists with deadlines.
-
Laravel
A PHP framework for web artisans
-
D3
Bring data to life with SVG, Canvas and HTML. 📊📈🎉
-
Recommend Topics
-
javascript
JavaScript (JS) is a lightweight interpreted programming language with first-class functions.
-
web
Some thing interesting about web. New door for the world.
-
server
A server is a program made to process requests and deliver data to clients.
-
Machine learning
Machine learning is a way of modeling and interpreting data that allows a piece of software to respond intelligently.
-
Visualization
Some thing interesting about visualization, use data art
-
Game
Some thing interesting about game, make everyone happy.
Recommend Org
-
Facebook
We are working to build community through open source technology. NB: members must have two-factor auth.
-
Microsoft
Open source projects and samples from Microsoft.
-
Google
Google ❤️ Open Source for everyone.
-
Alibaba
Alibaba Open Source for everyone
-
D3
Data-Driven Documents codes.
-
Tencent
China tencent open source team.
from janet.