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	Thu, 30 May 2024 03:28:20 -0700 (PDT)
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Date:	Thu, 30 May 2024 12:28:16 +0200
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Subject:	Re: [PATCH v2] Cygwin: pthread: Fix a race issue introduced by the
	commit 2c5433e5da82
To:	Bruno Haible <bruno AT clisp DOT org>, Takashi Yano <takashi DOT yano AT nifty DOT ne DOT jp>,
	cygwin AT cygwin DOT com
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From:	Noel Grandin via Cygwin <cygwin AT cygwin DOT com>
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On 5/30/2024 11:15 AM, Bruno Haible wrote:
> 
> Still: Does ReleaseSRWLockExclusive notify other threads?
> 

Of course? How else would a lock work, it must release other waiters?

It might not be a fair lock though, which is not a problem for this situation, which does not require fair locking.


> Functionally, the INIT_ONCE looks interesting. But, like Takashi Yano mentioned,
> how would you make it fit into a pthread_once_t that is defined as
>    struct { pthread_mutex_t mutex; int state; }
> ?

Something like:

struct once {
    union {
       pthread_mutex_t old_mutex_field_for_size_compatibility;
       SRWLOCK lock = SRWLOCK_INIT;
     };
     int state;
};

Regards, Noel Grandin

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