https://issues.dlang.org/show_bug.cgi?id=14251

Johan Engelen <jbc.engelen@gmail.com> changed:

           What    |Removed                     |Added
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                 CC|                            |jbc.engelen@gmail.com

--- Comment #1 from Johan Engelen <jbc.engelen@gmail.com> ---
Another effect of the missing semantic on _d_monitorenter/exit is that this code compiles while I think it shouldn't (_d_monitorenter/exit will write to klass.__monitor):

void foo() {
    immutable Klass klass = new Klass;
    synchronized (klass)
    {
        // do smth
    }
}

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https://issues.dlang.org/show_bug.cgi?id=14251

--- Comment #2 from Johan Engelen <jbc.engelen@gmail.com> ---
Synchronizing inside a const method is done in a deprecated method in std.concurrency:

    // @@@DEPRECATED_2016-03@@@
    /++
        $(RED Deprecated. isClosed can't be used with a const MessageBox.
              It will be removed in March 2016).
      +/
        deprecated("isClosed can't be used with a const MessageBox")
        final @property bool isClosed() const
        {
            synchronized( m_lock )
            {
                return m_closed;
            }
        }

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https://issues.dlang.org/show_bug.cgi?id=14251

--- Comment #3 from Johan Engelen <jbc.engelen@gmail.com> ---
https://github.com/D-Programming-Language/dmd/pull/5564

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https://issues.dlang.org/show_bug.cgi?id=14251

--- Comment #4 from github-bugzilla@puremagic.com ---
Commit pushed to master at https://github.com/D-Programming-Language/phobos

https://github.com/D-Programming-Language/phobos/commit/4b74c5f687a06d95c4ffe6e8aefe10f88acc098b Remove deprecated `std.concurrency.MessageBox.isClosed() const`.

Within Phobos, this is the only occurrence of synchronizing on an immutable object. Removal of this deprecated function allows us to resolve Issue 14251.

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https://issues.dlang.org/show_bug.cgi?id=14251

ZombineDev <petar.p.kirov@gmail.com> changed:

           What    |Removed                     |Added
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           Keywords|                            |safe
                 CC|                            |petar.p.kirov@gmail.com

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https://issues.dlang.org/show_bug.cgi?id=14251

Walter Bright <bugzilla@digitalmars.com> changed:

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                 CC|                            |bugzilla@digitalmars.com

--- Comment #5 from Walter Bright <bugzilla@digitalmars.com> ---
I'm not convinced this is a bug. The _monitor field is one that is totally managed by the language, and it outside of its rules.

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https://issues.dlang.org/show_bug.cgi?id=14251

Lodovico Giaretta <lodovico@giaretart.net> changed:

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                 CC|                            |lodovico@giaretart.net

--- Comment #6 from Lodovico Giaretta <lodovico@giaretart.net> ---
(In reply to Walter Bright from comment #5)
> I'm not convinced this is a bug. The _monitor field is one that is totally managed by the language, and it outside of its rules.

That is true. But having "logically inexistent" fields with different attributes from "normal" fields means that these attributes can not be "physically" exploited, but only "logically" enforced.

E.g.: if an immutable object has a mutable mutex, than an immutable object cannot reside in read-only memory.

So it's a tradeoff, and it must be clearly defined what is D's way here.

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https://issues.dlang.org/show_bug.cgi?id=14251

--- Comment #7 from ZombineDev <petar.p.kirov@gmail.com> ---
The OP issue doesn't mention class monitors. The bug also affects raw sync primitives like core.sync.mutex and in general everything using Object.IMonitor.

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https://issues.dlang.org/show_bug.cgi?id=14251

--- Comment #8 from Walter Bright <bugzilla@digitalmars.com> ---
(In reply to ZombineDev from comment #7)
> The OP issue doesn't mention class monitors. The bug also affects raw sync primitives like core.sync.mutex and in general everything using Object.IMonitor.

'Klass' is a class, and so has a class monitor.

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https://issues.dlang.org/show_bug.cgi?id=14251

Walter Bright <bugzilla@digitalmars.com> changed:

           What    |Removed                     |Added
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           Keywords|                            |pull

--- Comment #9 from Walter Bright <bugzilla@digitalmars.com> ---
https://github.com/dlang/dmd/pull/6092

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