Re: [PATCH 01/10] htl: Rename _pthread_mutex_init/destroy to __pthread_mutex_init/destroy

[Adhemerval Zanella <adhemerval dot zanella at linaro dot org>]

On 14/01/2020 15:52, Samuel Thibault wrote:
> ---
>  htl/Versions                              | 2 ++
>  htl/pt-initialize.c                       | 4 ++--
>  sysdeps/htl/pt-key.h                      | 2 +-
>  sysdeps/htl/pt-mutex-destroy.c            | 4 ++--
>  sysdeps/htl/pt-mutex-init.c               | 4 ++--
>  sysdeps/htl/pthreadP.h                    | 5 +++--
>  sysdeps/mach/hurd/htl/pt-mutex-destroy.c  | 4 ++--
>  sysdeps/mach/hurd/htl/pt-mutex-init.c     | 6 +++---
>  sysdeps/mach/hurd/i386/libpthread.abilist | 2 --
>  9 files changed, 17 insertions(+), 16 deletions(-)
> 
> diff --git a/htl/Versions b/htl/Versions
> index 77f7335b9c..3ae4b5c17d 100644
> --- a/htl/Versions
> +++ b/htl/Versions
> @@ -155,6 +155,8 @@ libpthread {
>      __pthread_setspecific;
>      __pthread_getattr_np;
>      __pthread_attr_getstack;
> +    __pthread_mutex_init;
> +    __pthread_mutex_destroy;
>      __pthread_mutex_timedlock;
>    }
>  }
> diff --git a/htl/pt-initialize.c b/htl/pt-initialize.c
> index d5a64f7cd9..89ed742422 100644
> --- a/htl/pt-initialize.c
> +++ b/htl/pt-initialize.c
> @@ -51,8 +51,8 @@ static const struct pthread_functions pthread_functions = {
>    .ptr___pthread_exit = __pthread_exit,
>    .ptr_pthread_getschedparam = __pthread_getschedparam,
>    .ptr_pthread_setschedparam = __pthread_setschedparam,
> -  .ptr_pthread_mutex_destroy = _pthread_mutex_destroy,
> -  .ptr_pthread_mutex_init = _pthread_mutex_init,
> +  .ptr_pthread_mutex_destroy = __pthread_mutex_destroy,
> +  .ptr_pthread_mutex_init = __pthread_mutex_init,
>    .ptr_pthread_mutex_lock = __pthread_mutex_lock,
>    .ptr_pthread_mutex_trylock = __pthread_mutex_trylock,
>    .ptr_pthread_mutex_unlock = __pthread_mutex_unlock,
> diff --git a/sysdeps/htl/pt-key.h b/sysdeps/htl/pt-key.h
> index bfaa19900a..b547e8ad29 100644
> --- a/sysdeps/htl/pt-key.h
> +++ b/sysdeps/htl/pt-key.h
> @@ -66,7 +66,7 @@ __pthread_key_lock_ready (void)
>      err = __pthread_mutexattr_settype (&attr, PTHREAD_MUTEX_RECURSIVE);
>      assert_perror (err);
>  
> -    err = _pthread_mutex_init (&__pthread_key_lock, &attr);
> +    err = __pthread_mutex_init (&__pthread_key_lock, &attr);
>      assert_perror (err);
>  
>      err = __pthread_mutexattr_destroy (&attr);
> diff --git a/sysdeps/htl/pt-mutex-destroy.c b/sysdeps/htl/pt-mutex-destroy.c
> index 3824e62dd4..796fc11b8d 100644
> --- a/sysdeps/htl/pt-mutex-destroy.c
> +++ b/sysdeps/htl/pt-mutex-destroy.c
> @@ -23,7 +23,7 @@
>  #include <pt-internal.h>
>  
>  int
> -_pthread_mutex_destroy (pthread_mutex_t *mutex)
> +__pthread_mutex_destroy (pthread_mutex_t *mutex)
>  {
>    if (mutex->__attr == __PTHREAD_ERRORCHECK_MUTEXATTR
>        || mutex->__attr == __PTHREAD_RECURSIVE_MUTEXATTR)
> @@ -35,4 +35,4 @@ _pthread_mutex_destroy (pthread_mutex_t *mutex)
>    return 0;
>  }
>  
> -strong_alias (_pthread_mutex_destroy, pthread_mutex_destroy);
> +strong_alias (__pthread_mutex_destroy, pthread_mutex_destroy);
> diff --git a/sysdeps/htl/pt-mutex-init.c b/sysdeps/htl/pt-mutex-init.c
> index c59bd8a3f5..77f041352e 100644
> --- a/sysdeps/htl/pt-mutex-init.c
> +++ b/sysdeps/htl/pt-mutex-init.c
> @@ -24,7 +24,7 @@
>  #include <pt-internal.h>
>  
>  int
> -_pthread_mutex_init (pthread_mutex_t *mutex, const pthread_mutexattr_t *attr)
> +__pthread_mutex_init (pthread_mutex_t *mutex, const pthread_mutexattr_t *attr)
>  {
>    *mutex = (pthread_mutex_t) __PTHREAD_MUTEX_INITIALIZER;
>  
> @@ -47,4 +47,4 @@ _pthread_mutex_init (pthread_mutex_t *mutex, const pthread_mutexattr_t *attr)
>    return 0;
>  }
>  
> -strong_alias (_pthread_mutex_init, pthread_mutex_init);
> +strong_alias (__pthread_mutex_init, pthread_mutex_init);

Why do we need both htl and Hurd implementation of pt-mutex-init.c
(same for pt-mutex-destroy)?

For Linux, some pthread implementation are at sysdeps folder
because either they issues syscalls directly (through
{INLINE,INTERNAL}_SYSCALL macros) or implement some arch-specific
facily (such as HLE or spinlocks).

> diff --git a/sysdeps/htl/pthreadP.h b/sysdeps/htl/pthreadP.h
> index affe7cdf53..c6ddf76fd4 100644
> --- a/sysdeps/htl/pthreadP.h
> +++ b/sysdeps/htl/pthreadP.h
> @@ -27,7 +27,8 @@ extern pthread_t __pthread_self (void);
>  extern int __pthread_kill (pthread_t threadid, int signo);
>  extern struct __pthread **__pthread_threads;
>  
> -extern int _pthread_mutex_init (pthread_mutex_t *mutex, const pthread_mutexattr_t *attr);
> +extern int __pthread_mutex_init (pthread_mutex_t *__mutex, const pthread_mutexattr_t *__attr);
> +extern int __pthread_mutex_destroy (pthread_mutex_t *__mutex);
>  extern int __pthread_mutex_lock (pthread_mutex_t *__mutex);
>  extern int __pthread_mutex_timedlock (pthread_mutex_t *__mutex,
>       const struct timespec *__abstime);
> @@ -73,7 +74,7 @@ struct __pthread_cancelation_handler **___pthread_get_cleanup_stack (void) attri
>  hidden_proto (__pthread_key_create)
>  hidden_proto (__pthread_getspecific)
>  hidden_proto (__pthread_setspecific)
> -hidden_proto (_pthread_mutex_init)
> +hidden_proto (__pthread_mutex_init)
>  #endif
>  
>  #define ASSERT_TYPE_SIZE(type, size) 					\
> diff --git a/sysdeps/mach/hurd/htl/pt-mutex-destroy.c b/sysdeps/mach/hurd/htl/pt-mutex-destroy.c
> index afab03234e..a8a0adc03f 100644
> --- a/sysdeps/mach/hurd/htl/pt-mutex-destroy.c
> +++ b/sysdeps/mach/hurd/htl/pt-mutex-destroy.c
> @@ -24,7 +24,7 @@
>  #include <hurdlock.h>
>  
>  int
> -_pthread_mutex_destroy (pthread_mutex_t *mtxp)
> +__pthread_mutex_destroy (pthread_mutex_t *mtxp)
>  {
>    atomic_read_barrier ();
>    if (*(volatile unsigned int *) &mtxp->__lock != 0)
> @@ -34,4 +34,4 @@ _pthread_mutex_destroy (pthread_mutex_t *mtxp)
>    return 0;
>  }
>  
> -strong_alias (_pthread_mutex_destroy, pthread_mutex_destroy)
> +strong_alias (__pthread_mutex_destroy, pthread_mutex_destroy)
> diff --git a/sysdeps/mach/hurd/htl/pt-mutex-init.c b/sysdeps/mach/hurd/htl/pt-mutex-init.c
> index 6b804116a5..7a2cc462f3 100644
> --- a/sysdeps/mach/hurd/htl/pt-mutex-init.c
> +++ b/sysdeps/mach/hurd/htl/pt-mutex-init.c
> @@ -32,7 +32,7 @@ static const pthread_mutexattr_t dfl_attr = {
>  };
>  
>  int
> -_pthread_mutex_init (pthread_mutex_t *mtxp, const pthread_mutexattr_t *attrp)
> +__pthread_mutex_init (pthread_mutex_t *mtxp, const pthread_mutexattr_t *attrp)
>  {
>    ASSERT_TYPE_SIZE (pthread_mutex_t, __SIZEOF_PTHREAD_MUTEX_T);
>  
> @@ -55,5 +55,5 @@ _pthread_mutex_init (pthread_mutex_t *mtxp, const pthread_mutexattr_t *attrp)
>    return 0;
>  }
>  
> -strong_alias (_pthread_mutex_init, pthread_mutex_init)
> -hidden_def (_pthread_mutex_init)
> +strong_alias (__pthread_mutex_init, pthread_mutex_init)
> +hidden_def (__pthread_mutex_init)
> diff --git a/sysdeps/mach/hurd/i386/libpthread.abilist b/sysdeps/mach/hurd/i386/libpthread.abilist
> index 0ede90859c..cda8755960 100644
> --- a/sysdeps/mach/hurd/i386/libpthread.abilist
> +++ b/sysdeps/mach/hurd/i386/libpthread.abilist
> @@ -14,8 +14,6 @@ GLIBC_2.12 _cthread_init_routine D 0x4
>  GLIBC_2.12 _cthreads_flockfile F
>  GLIBC_2.12 _cthreads_ftrylockfile F
>  GLIBC_2.12 _cthreads_funlockfile F
> -GLIBC_2.12 _pthread_mutex_destroy F
> -GLIBC_2.12 _pthread_mutex_init F
>  GLIBC_2.12 _pthread_mutex_lock F
>  GLIBC_2.12 _pthread_mutex_trylock F
>  GLIBC_2.12 _pthread_mutex_unlock F
> 

I understand this change is follow Linux internal implementation
and make mtx_init.c generic, but I don't think changing hurd 
libpthread exported symbols is the correct solution. 

Since the symbol won't be used anymore I think we can move to
a compat symbol, something like:

+strong_alias (__pthread_mutex_init, pthread_mutex_init);
+hidden_def (__pthread_mutex_init)
+#if SHLIB_COMPAT (libpthread, GLIBC_2_12, GLIBC_2_31)
+compat_symbol (libpthread, __pthread_mutex_init, _pthread_mutex_init, GLIBC_2_12);
+#endif