https://issues.dlang.org/show_bug.cgi?id=19481

kinke@gmx.net changed:

           What    |Removed                     |Added
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                 CC|                            |kinke@gmx.net

--- Comment #1 from kinke@gmx.net ---
`Mutex.m_hndl.alignof` (as it's a CRITICAL_SECTION for Windows) doesn't work,
as it's private.

There's no way to get the class instance alignment, is there? Plus anything > 16 bytes isn't guaranteed by the GC either AFAIK. So class alignments seem a bit problematic in general.

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https://issues.dlang.org/show_bug.cgi?id=19481

Iain Buclaw <ibuclaw@gdcproject.org> changed:

           What    |Removed                     |Added
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                 CC|                            |ibuclaw@gdcproject.org

--- Comment #2 from Iain Buclaw <ibuclaw@gdcproject.org> ---
(In reply to kinke from comment #1)
> `Mutex.m_hndl.alignof` (as it's a CRITICAL_SECTION for Windows) doesn't
> work, as it's private.
> 

I was thinking of just doing as a quick hack.

---
version (Windows)
{
    import core.sys.windows.winbase : CRITICAL_SECTION;
    enum Mutex_alignof = CRITICAL_SECTION.alignof;
}
else version (Posix)
{
    import core.sys.posix.sys.types : pthread_mutex_t;
    enum Mutex_alignof = pthread_mutex_t.alignof;
}
---


Alternatively...

class Mutex
{
  enum alignsize = Mutex.m_hndl.alignof;
  // ...
}


> There's no way to get the class instance alignment, is there? Plus anything
> > 16 bytes isn't guaranteed by the GC either AFAIK. So class alignments seem
> a bit problematic in general.

No, there isn't a way to do that.  I'm currently waiting to hear back if explicitly setting the alignment to 8 fixes the failure on SPARC/Solaris.

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https://issues.dlang.org/show_bug.cgi?id=19481

--- Comment #3 from Iain Buclaw <ibuclaw@gdcproject.org> ---
According to response, the alignment of _locks[0] is fine, _locks[1] is the problem.


>>>

Unfortunately, this doesn't work: the first time through, _locks[0] was already 8-byte aligned and everything worked fine.  This remained when using align(8) instead.  However, Mutex is 44 bytes on 32-bit Solaris/x86, so again _locks[1] lands on a non-8 byte boundary and pthread_mutex_init fails.

I tried rouding up the size of the _locks array members to a multiple of 8, but that let the constructor already fail the first time through where _d_arraycopy checks that the right amount of data is copied:

_d_arraycopy -> rt.util.array.enforceRawArraysConformable -> rt.util.array._enforceSameLength

<<<

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https://issues.dlang.org/show_bug.cgi?id=19481

--- Comment #4 from kinke@gmx.net ---
Argh, it's an array, and class instances aren't padded... - the error stems from the manual initialization in `initLocks()`, right? That should be easily adaptable; the ctor only gets the `this` pointer and shouldn't have any idea about the actual size.

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https://issues.dlang.org/show_bug.cgi?id=19481

--- Comment #5 from Iain Buclaw <ibuclaw@gdcproject.org> ---
(In reply to kinke from comment #4)
> Argh, it's an array, and class instances aren't padded... - the error stems from the manual initialization in `initLocks()`, right? That should be easily adaptable; the ctor only gets the `this` pointer and shouldn't have any idea about the actual size.

Correct.

This line:

    __gshared align(Mutex.alignof) void[__traits(classInstanceSize, Mutex)][2]
_locks;


The size should be rounded up to a suitable align boundary, then this line:

    lock[] = typeid(Mutex).initializer[];

The slice assignment is adjusted to only initialize up to
__traits(classInstanceSize, Mutex).

So we end up with something that looks like:

---

version (Windows)
{
    import core.sys.windows.winbase : CRITICAL_SECTION;
    enum lockAlign = CRITICAL_SECTION.alignof;
}
else version (Posix)
{
    import core.sys.posix.sys.types : pthread_mutex_t;
    enum lockAlign = pthread_mutex_t.alignof;
}

enum mutexInstanceSize = __traits(classInstanceSize, Mutex)
enum lockAlignedSize = (mutexInstanceSize + lockAlign - 1) & ~(lockAlign - 1);

__gshared align(lockAlign) void[lockAlignedSize][2] _locks;

static void initLocks() @nogc
{
    foreach (ref lock; _locks)
    {
        lock[0 .. mutexInstanceSize] = typeid(Mutex).initializer[];
        (cast(Mutex)lock.ptr).__ctor();
    }
}

---

I don't think `align(lockAlign)` is really necessary based on feedback, but it covers us "just incase".

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https://issues.dlang.org/show_bug.cgi?id=19481

--- Comment #6 from kinke@gmx.net ---
Yep, looks fine, and definitely keep the `align(mutexAlign)`. :) - You could
get away with a single `alignedMutexInstanceSize` enum (and no
`mutexInstanceSize`) by using `const init = typeid(Mutex).initializer; lock[0
.. init.length] = init[];`.

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https://issues.dlang.org/show_bug.cgi?id=19481

Dlang Bot <dlang-bot@dlang.rocks> changed:

           What    |Removed                     |Added
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           Keywords|                            |pull

--- Comment #7 from Dlang Bot <dlang-bot@dlang.rocks> ---
@ibuclaw updated dlang/druntime pull request #2411 "Fix Issue 19481: mutex.d(95) Error: pthread_mutex_init failed" fixing this issue:

- Fix Issue 19481: mutex.d(95) Error: pthread_mutex_init failed

https://github.com/dlang/druntime/pull/2411

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https://issues.dlang.org/show_bug.cgi?id=19481

--- Comment #8 from Dlang Bot <dlang-bot@dlang.rocks> ---
@ibuclaw created dlang/druntime pull request #2534 "[dmd-cxx] Fix Issue 19481: mutex.d(95) Error: pthread_mutex_init failed" fixing this issue:

- Fix Issue 19481: mutex.d(95) Error: pthread_mutex_init failed

https://github.com/dlang/druntime/pull/2534

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https://issues.dlang.org/show_bug.cgi?id=19481

Dlang Bot <dlang-bot@dlang.rocks> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |FIXED

--- Comment #9 from Dlang Bot <dlang-bot@dlang.rocks> ---
dlang/druntime pull request #2534 "[dmd-cxx] Fix Issue 19481: mutex.d(95) Error: pthread_mutex_init failed" was merged into dmd-cxx:

- 505e88f5b2983ffc286ed7c66442480433db3c9e by Iain Buclaw:
  Fix Issue 19481: mutex.d(95) Error: pthread_mutex_init failed

https://github.com/dlang/druntime/pull/2534

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https://issues.dlang.org/show_bug.cgi?id=19481

Iain Buclaw <ibuclaw@gdcproject.org> changed:

           What    |Removed                     |Added
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             Status|RESOLVED                    |REOPENED
         Resolution|FIXED                       |---

--- Comment #10 from Iain Buclaw <ibuclaw@gdcproject.org> ---
Not fixed, as patch still not in master.

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