[FFmpeg-devel] [PATCH] compat/os2threads: support static mutexes

[wm4]

On Thu, 28 Dec 2017 22:03:56 +0900
KO Myung-Hun <komh78 at gmail.com> wrote:

> ---
>  compat/os2threads.h | 14 ++++++++------
>  1 file changed, 8 insertions(+), 6 deletions(-)
> 
> diff --git a/compat/os2threads.h b/compat/os2threads.h
> index 40a119ffe1..2177a033ec 100644
> --- a/compat/os2threads.h
> +++ b/compat/os2threads.h
> @@ -1,5 +1,5 @@
>  /*
> - * Copyright (c) 2011 KO Myung-Hun <komh at chollian.net>
> + * Copyright (c) 2011-2017 KO Myung-Hun <komh at chollian.net>
>   *
>   * This file is part of FFmpeg.
>   *
> @@ -46,9 +46,11 @@ typedef struct {
>  
>  typedef void pthread_attr_t;
>  
> -typedef HMTX pthread_mutex_t;
> +typedef _fmutex pthread_mutex_t;
>  typedef void pthread_mutexattr_t;
>  
> +#define PTHREAD_MUTEX_INITIALIZER _FMUTEX_INITIALIZER
> +
>  typedef struct {
>      HEV event_sem;
>      HEV ack_sem;
> @@ -98,28 +100,28 @@ static av_always_inline int pthread_join(pthread_t thread, void **value_ptr)
>  static av_always_inline int pthread_mutex_init(pthread_mutex_t *mutex,
>                                                 const pthread_mutexattr_t *attr)
>  {
> -    DosCreateMutexSem(NULL, (PHMTX)mutex, 0, FALSE);
> +    _fmutex_create(mutex, 0);
>  
>      return 0;
>  }
>  
>  static av_always_inline int pthread_mutex_destroy(pthread_mutex_t *mutex)
>  {
> -    DosCloseMutexSem(*(PHMTX)mutex);
> +    _fmutex_close(mutex);
>  
>      return 0;
>  }
>  
>  static av_always_inline int pthread_mutex_lock(pthread_mutex_t *mutex)
>  {
> -    DosRequestMutexSem(*(PHMTX)mutex, SEM_INDEFINITE_WAIT);
> +    _fmutex_request(mutex, 0);
>  
>      return 0;
>  }
>  
>  static av_always_inline int pthread_mutex_unlock(pthread_mutex_t *mutex)
>  {
> -    DosReleaseMutexSem(*(PHMTX)mutex);
> +    _fmutex_release(mutex);
>  
>      return 0;
>  }

LGTM. Does this actually switch to futex-like light weight mutexes? (I
don't know anything about OS/2, but it does sound like PHMTX was the
equivalent of a win32 HANDLE mutex kernel object, that required kernel
entry on each lock/unlock, while _fmutex is possibly like Vista+ SRWs.)