Re: stalls with concurrent host name resolvers

Hi Arvid,

Arvid Norberg <arvid-M9ekpT6mRt2zQB+pC5nmwQ@xxxxxxxxxxxxxxxx> wrote:
> On Nov 16, 2006, at 03:24, Christopher Kohlhoff wrote:
>> Arvid Norberg <arvid-M9ekpT6mRt2zQB+pC5nmwQ@xxxxxxxxxxxxxxxx> wrote:
>>> I discovered that if I have many (say, 50) io_services, and
>>> all of  them perform a name lookup at (more or less) the same
>>> time, some of the handlers will  stall for about 1 minute.
>>> Initially I thought the handlers were never called. All host
>>> name resolvers resolves the same host name, so only  the first
>>> one should stall (assuming the OS caches host names).
>>
>> Thanks, I'll take a look. What version of Mac OS are you
>> running?
>
> 10.4.8 PPC

Hmm, same as me. I managed to get it to happen very
occasionally, but when I tried to debug it using gdb it locked
up my ssh session. It makes me think that it's something to do
with the OS, but I can't say for certain. Or perhaps some asio
code is assuming that an OS function is thread safe when it
isn't. If you're able to get a call stack when the thing
deadlocks that would be most useful.

Cheers,
Chris



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