From: adr <adr@SDF.ORG>
To: 9fans <9fans@9fans.net>
Subject: Re: [9fans] syscall silently kill processes
Date: Sat, 18 Jun 2022 09:22:41 +0000 (UTC) [thread overview]
Message-ID: <5e2f8566-da80-6c40-9718-3a9199434e7d@SDF.ORG> (raw)
In-Reply-To: <64a85bad-7ab-fb6-6517-acfafa819bc@SDF.ORG>
On Sat, 18 Jun 2022, adr wrote:
> On Sat, 18 Jun 2022, andrey100100100@gmail.com wrote:
>
>> ---------------------------------------------
>>
>> cpu% 6.out | grep end | wc -l
>> 33
>>
>>
>> Problem in unregistered handlers.
>
> But unregistered handlers shouldn't be a problem. The process is
> been killed when alarm sends the note. That's why the code worked
> removing the read statement, the alarm is set off and the note is
> not sent before the process ends. I just don't see why the process
> is been killed. The documentation describes another behavior. To
> me it smells like bug barbecue (corrupted onnote?). Maybe I got
> something wrong, bear with me.
>
>>> Note that you could register the handler in threadmain and avoid
>>> completely this issue, but as I said before, something seems wrong
>>> to me here.
>>
>> I'm don't understand how handler in threadmain would solve the problem.
>> I need in 'alarm' on per process basis.
>
> You need alarm() in every process, but you don't need to register the
> same handler 80 times!
>
> adr.
I think there is some confussion here, so I'll explain myself a
little more.
Lets change your last example to not use libthread:
#include <u.h>
#include <libc.h>
int
handler_alarm(void *, char *msg)
{
if(strstr(msg, "alarm")){
return 1;
}
return 0;
}
int
test(void)
{
if(atnotify(handler_alarm, 1) == 0){
fprint(1, "handler not registered\n");
}
alarm(10);
fprint(1, "start\n");
sleep(40);
fprint(1, "end\n");
alarm(0);
return 0;
}
void
main()
{
for(int i = 0; i < 80; i++){
test();
}
exits(nil);
}
You see, after the NFNth iteration of test(), onnot[NFN] in atnotify
will be full, the handlers wont be registered but the code will
work without any problem. It doesn't matter, the first handler in
onnot[] will be executed. I fact you only need one handler there, not
80, you should move atnotify to main.
The same should be happening with libthread. I'm really the only
one smelling a bug here?
adr.
------------------------------------------
9fans: 9fans
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next prev parent reply other threads:[~2022-06-18 9:23 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-17 9:37 andrey100100100
2022-06-17 13:46 ` Thaddeus Woskowiak
2022-06-17 14:11 ` Jacob Moody
2022-06-17 14:39 ` Thaddeus Woskowiak
2022-06-17 15:06 ` andrey100100100
2022-06-17 16:08 ` Skip Tavakkolian
2022-06-17 16:11 ` Skip Tavakkolian
2022-06-17 16:16 ` Skip Tavakkolian
2022-06-17 17:42 ` adr
2022-06-17 16:11 ` Jacob Moody
2022-06-17 18:48 ` andrey100100100
2022-06-17 19:28 ` Jacob Moody
2022-06-17 21:15 ` adr
2022-06-18 6:40 ` andrey100100100
2022-06-18 8:37 ` adr
2022-06-18 9:22 ` adr [this message]
2022-06-18 12:53 ` Jacob Moody
2022-06-18 22:03 ` andrey100100100
2022-06-19 5:54 ` adr
2022-06-19 6:13 ` Jacob Moody
2022-06-18 22:22 ` andrey100100100
2022-06-18 16:57 ` andrey100100100
2022-06-19 2:40 ` adr
2022-06-19 5:01 ` adr
2022-06-19 8:52 ` andrey100100100
2022-06-19 10:32 ` adr
2022-06-19 11:40 ` andrey100100100
2022-06-19 12:01 ` andrey100100100
2022-06-19 15:10 ` andrey100100100
2022-06-19 16:41 ` adr
2022-06-19 21:22 ` andrey100100100
2022-06-19 21:26 ` andrey100100100
2022-06-20 4:41 ` adr
2022-06-20 5:39 ` andrey100100100
2022-06-20 5:59 ` adr
2022-06-20 15:56 ` andrey100100100
2022-06-20 22:29 ` Skip Tavakkolian
2022-06-21 7:07 ` andrey100100100
2022-06-21 11:26 ` adr
2022-06-21 13:03 ` andrey100100100
2022-06-21 13:22 ` adr
2022-06-28 15:28 ` adr
2022-06-28 16:43 ` ori
2022-06-28 18:19 ` adr
2022-06-28 18:28 ` adr
2022-06-28 19:09 ` andrey100100100
2022-06-28 19:42 ` adr
2022-06-29 13:14 ` adr
2022-06-21 13:47 ` andrey100100100
2022-06-21 7:22 ` adr
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