Re: Threads across programming languages

On 5/1/2024 10:20 PM, Chris M. Thomasson wrote:

On 5/1/2024 1:34 PM, Lawrence D'Oliveiro wrote:

On Wed, 1 May 2024 10:59:16 +0200, Bonita Montero wrote:
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Am 01.05.2024 um 10:53 schrieb Lawrence D'Oliveiro:
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On Wed, 1 May 2024 10:13:03 +0200, Bonita Montero wrote:
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Am 01.05.2024 um 09:10 schrieb Lawrence D'Oliveiro:
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On Wed, 1 May 2024 06:54:13 +0200, Bonita Montero wrote:
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Boost.ASIO does that all for you with a convenient interface.
If enabled it even uses io_uring or the Windows' pendant.

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How many languages does it support?

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Just C++ ...

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Not much use, then.

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System-level programming is mostly made with C++.

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No, it is actually mostly C, with Rust making inroads these days.
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And you don’t have to be doing “system-level” programming to be needing
event-driven paradigms.
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But functions and classes are not first-class objects in C++, ...

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Of course, since C++11.

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No they aren’t. You cannot easily define a C++ function that returns a
general function or class as a result, just for example.
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You cannot define function factories and class factories, like you can
in Python.

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Python is nothing for me since it is extremely slow.

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Remember, we’re talking about maximizing I/O throughput here, so CPU is
not the bottleneck.

 It can be if your thread synchronization scheme is sub par. I have actually seen code where an IOCP completion thread locks a global mutex. Something like this pseudo-code:
_________________
for (;;)
{
    iocp_overlapped& p = GQCS(INFINITE);
     lock_mutex(global);
     // process event...
     unlock_mutex(global);
}
_________________
This is really BAD! It will create a rather massive bottleneck under times of heavy load...

The global lock seems to work fine under light sporadic usage. However, when the server get under load, this mutex really messes things up.

Also, it creates a nasty condition where things can become deadlocked if processing the overlapped completion calls into unknown user code to do some work. I have had to debug some others code like this before. Not exactly fun...