[vlc-devel] [PATCH] threads: rename vlc_addr_* following C++20 names

Steve Lhomme robux4 at ycbcr.xyz
Tue Feb 4 08:41:03 CET 2020


Looks OK to me.
I'm suprised these are only used by the core and don't have VLC_API. 
Shouldn't parts of the header be moved in the core then ? Or should 
these APIs be made available to anyone ?

On 2020-02-03 20:35, RĂ©mi Denis-Courmont wrote:
> Use C++20 draft-like names instead of custom neither-Linux-nor-Windows
> ones.
> 
> Note though that C++ has no timed variant for its atomic wait method.
> ---
>   include/vlc_threads.h | 20 +++++++++++---------
>   src/android/thread.c  |  2 +-
>   src/linux/thread.c    |  8 ++++----
>   src/misc/threads.c    | 10 +++++-----
>   src/win32/thread.c    | 10 +++++-----
>   5 files changed, 26 insertions(+), 24 deletions(-)
> 
> diff --git a/include/vlc_threads.h b/include/vlc_threads.h
> index 315729a097..8a39c61087 100644
> --- a/include/vlc_threads.h
> +++ b/include/vlc_threads.h
> @@ -688,19 +688,20 @@ VLC_API void *vlc_threadvar_get(vlc_threadvar_t);
>    *
>    * Puts the calling thread to sleep if a specific value is stored at a
>    * specified address. The thread will sleep until it is woken up by a call to
> - * vlc_addr_signal() or vlc_addr_broadcast() in another thread, or spuriously.
> + * vlc_atomic_notify_one() or vlc_atomic_notify_all() in another thread, or
> + * spuriously.
>    *
>    * If the value does not match, do nothing and return immediately.
>    *
>    * \param addr address to check for
>    * \param val value to match at the address
>    */
> -void vlc_addr_wait(void *addr, unsigned val);
> +void vlc_atomic_wait(void *addr, unsigned val);
>   
>   /**
>    * Waits on an address with a time-out.
>    *
> - * This function operates as vlc_addr_wait() but provides an additional
> + * This function operates as vlc_atomic_wait() but provides an additional
>    * time-out. If the time-out elapses, the thread resumes and the function
>    * returns.
>    *
> @@ -711,30 +712,31 @@ void vlc_addr_wait(void *addr, unsigned val);
>    * \return true if the function was woken up before the time-out,
>    * false if the time-out elapsed.
>    */
> -bool vlc_addr_timedwait(void *addr, unsigned val, vlc_tick_t delay);
> +bool vlc_atomic_timedwait(void *addr, unsigned val, vlc_tick_t delay);
>   
>   /**
>    * Wakes up one thread on an address.
>    *
>    * Wakes up (at least) one of the thread sleeping on the specified address.
>    * The address must be equal to the first parameter given by at least one
> - * thread sleeping within the vlc_addr_wait() or vlc_addr_timedwait()
> + * thread sleeping within the vlc_atomic_wait() or vlc_atomic_timedwait()
>    * functions. If no threads are found, this function does nothing.
>    *
>    * \param addr address identifying which threads may be woken up
>    */
> -void vlc_addr_signal(void *addr);
> +void vlc_atomic_notify_one(void *addr);
>   
>   /**
>    * Wakes up all thread on an address.
>    *
>    * Wakes up all threads sleeping on the specified address (if any).
> - * Any thread sleeping within a call to vlc_addr_wait() or vlc_addr_timedwait()
> - * with the specified address as first call parameter will be woken up.
> + * Any thread sleeping within a call to vlc_atomic_wait() or
> + * vlc_atomic_timedwait() with the specified address as first call parameter
> + * will be woken up.
>    *
>    * \param addr address identifying which threads to wake up
>    */
> -void vlc_addr_broadcast(void *addr);
> +void vlc_atomic_notify_all(void *addr);
>   
>   /**
>    * Creates and starts a new thread.
> diff --git a/src/android/thread.c b/src/android/thread.c
> index 0d9191592e..ca715418d4 100644
> --- a/src/android/thread.c
> +++ b/src/android/thread.c
> @@ -293,7 +293,7 @@ void vlc_cancel (vlc_thread_t thread_id)
>       if (addr != NULL)
>       {
>           atomic_fetch_or_explicit(addr, 1, memory_order_relaxed);
> -        vlc_addr_broadcast(addr);
> +        vlc_atomic_notify_all(addr);
>       }
>       vlc_mutex_unlock(&thread_id->wait.lock);
>   }
> diff --git a/src/linux/thread.c b/src/linux/thread.c
> index 7e9dab63bd..5a89cfa44a 100644
> --- a/src/linux/thread.c
> +++ b/src/linux/thread.c
> @@ -68,22 +68,22 @@ static int vlc_futex_wait(void *addr, unsigned val, const struct timespec *to)
>       return ret;
>   }
>   
> -void vlc_addr_signal(void *addr)
> +void vlc_atomic_notify_one(void *addr)
>   {
>       vlc_futex_wake(addr, 1);
>   }
>   
> -void vlc_addr_broadcast(void *addr)
> +void vlc_atomic_notify_all(void *addr)
>   {
>       vlc_futex_wake(addr, INT_MAX);
>   }
>   
> -void vlc_addr_wait(void *addr, unsigned val)
> +void vlc_atomic_wait(void *addr, unsigned val)
>   {
>       vlc_futex_wait(addr, val, NULL);
>   }
>   
> -bool vlc_addr_timedwait(void *addr, unsigned val, vlc_tick_t delay)
> +bool vlc_atomic_timedwait(void *addr, unsigned val, vlc_tick_t delay)
>   {
>       struct timespec ts = timespec_from_vlc_tick(delay);
>   
> diff --git a/src/misc/threads.c b/src/misc/threads.c
> index d267cc7344..501a17ac9b 100644
> --- a/src/misc/threads.c
> +++ b/src/misc/threads.c
> @@ -177,7 +177,7 @@ void (vlc_tick_wait)(vlc_tick_t deadline)
>   
>       while ((delay = (deadline - vlc_tick_now())) > 0)
>       {
> -        vlc_addr_timedwait(&value, 0, delay);
> +        vlc_atomic_timedwait(&value, 0, delay);
>           vlc_testcancel();
>       }
>   
> @@ -236,13 +236,13 @@ void vlc_cond_signal(vlc_cond_t *cond)
>        * - cnd_wait() sets the futex to the equal-or-next even value.
>        **/
>       atomic_fetch_or_explicit(vlc_cond_value(cond), 1, memory_order_relaxed);
> -    vlc_addr_signal(&cond->value);
> +    vlc_atomic_notify_one(&cond->value);
>   }
>   
>   void vlc_cond_broadcast(vlc_cond_t *cond)
>   {
>       atomic_fetch_or_explicit(vlc_cond_value(cond), 1, memory_order_relaxed);
> -    vlc_addr_broadcast(&cond->value);
> +    vlc_atomic_notify_all(&cond->value);
>   }
>   
>   void vlc_cond_wait(vlc_cond_t *cond, vlc_mutex_t *mutex)
> @@ -261,7 +261,7 @@ void vlc_cond_wait(vlc_cond_t *cond, vlc_mutex_t *mutex)
>       vlc_cancel_addr_prepare(&cond->value);
>       vlc_mutex_unlock(mutex);
>   
> -    vlc_addr_wait(&cond->value, value);
> +    vlc_atomic_wait(&cond->value, value);
>   
>       vlc_mutex_lock(mutex);
>       vlc_cancel_addr_finish(&cond->value);
> @@ -285,7 +285,7 @@ static int vlc_cond_wait_delay(vlc_cond_t *cond, vlc_mutex_t *mutex,
>       vlc_mutex_unlock(mutex);
>   
>       if (delay > 0)
> -        value = vlc_addr_timedwait(&cond->value, value, delay);
> +        value = vlc_atomic_timedwait(&cond->value, value, delay);
>       else
>           value = 0;
>   
> diff --git a/src/win32/thread.c b/src/win32/thread.c
> index d4fc433cae..07423af530 100644
> --- a/src/win32/thread.c
> +++ b/src/win32/thread.c
> @@ -424,12 +424,12 @@ static void WINAPI WakeByAddressFallback(void *addr)
>   }
>   #endif
>   
> -void vlc_addr_wait(void *addr, unsigned val)
> +void vlc_atomic_wait(void *addr, unsigned val)
>   {
>       WaitOnAddress(addr, &val, sizeof (val), -1);
>   }
>   
> -bool vlc_addr_timedwait(void *addr, unsigned val, vlc_tick_t delay)
> +bool vlc_atomic_timedwait(void *addr, unsigned val, vlc_tick_t delay)
>   {
>       delay = (delay + (1000-1)) / 1000;
>   
> @@ -442,12 +442,12 @@ bool vlc_addr_timedwait(void *addr, unsigned val, vlc_tick_t delay)
>       return WaitOnAddress(addr, &val, sizeof (val), delay);
>   }
>   
> -void vlc_addr_signal(void *addr)
> +void vlc_atomic_notify_one(void *addr)
>   {
>       WakeByAddressSingle(addr);
>   }
>   
> -void vlc_addr_broadcast(void *addr)
> +void vlc_atomic_notify_all(void *addr)
>   {
>       WakeByAddressAll(addr);
>   }
> @@ -585,7 +585,7 @@ void vlc_cancel (vlc_thread_t th)
>       if (th->wait.addr != NULL)
>       {
>           atomic_fetch_or_explicit(th->wait.addr, 1, memory_order_relaxed);
> -        vlc_addr_broadcast(th->wait.addr);
> +        vlc_atomic_notify_all(th->wait.addr);
>       }
>       LeaveCriticalSection(&th->wait.lock);
>   
> -- 
> 2.25.0
> 
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