[vlc-devel] [vlc-commits] compat: replace aligned_alloc() rather than posix_memalign()

remi at remlab.net remi at remlab.net
Tue Jun 20 11:53:28 CEST 2017


Repeating myself but this patch does not change the fallback logic, so it can't break anything.

And to paraphrase other devs "I don't care" about non-ISO toolchains.

Le 20 juin 2017 12:40:41 GMT+03:00, Steve Lhomme <robux4 at gmail.com> a écrit :
>On Tue, Jun 20, 2017 at 11:35 AM, Steve Lhomme <robux4 at gmail.com>
>wrote:
>> On Tue, Jun 20, 2017 at 11:28 AM,  <remi at remlab.net> wrote:
>>> The goal is to use aligned_alloc() instead of posix_memalign() since
>the
>>> earlier is required by ISO C and C++ (and slightly simpler to use).
>>>
>>> This patch only changes the behaviour on supported non-POSIX
>toolchains by
>>> removing the need for POSIX emulation code. If the toolchain is
>broken, then
>>> the fallback logic is unchanged: posix_memalign(), else memalign()
>else
>>> screw-you.
>>
>> There is no posix_memalign() or memalign() on Windows. So right now
>> VLC and libvlc cannot be used at all.
>>
>> Proper support requires using __mingw_aligned_malloc() or
>> _aligned_malloc(). But that means using __mingw_aligned_free() and
>> _aligned_free() as well.
>
>For the record, calling free() instead of these aligned free functions
>results in a crash.
>
>> Next time you may break the core, please submit patches for review
>first.
>>
>>> Le 20 juin 2017 12:07:38 GMT+03:00, Steve Lhomme <robux4 at gmail.com>
>a écrit
>>> :
>>>>
>>>> On Sat, Jun 17, 2017 at 2:35 PM, Rémi Denis-Courmont
><git at videolan.org>
>>>> wrote:
>>>>>
>>>>>  vlc | branch: master | Rémi Denis-Courmont <remi at remlab.net> |
>Sat Jun
>>>>> 17 15:27:16 2017 +0300| [34cd965645cb0246f3d74515bbd5e55367f7d884]
>|
>>>>> committer: Rémi Denis-Courmont
>>>>>
>>>>>  compat: replace aligned_alloc() rather than posix_memalign()
>>>>>
>>>>>>
>>>>>>
>http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=34cd965645cb0246f3d74515bbd5e55367f7d884
>>>>>
>>>>>  ---
>>>>>
>>>>>   compat/{posix_memalign.c => aligned_alloc.c} | 62
>>>>> ++++++++++++++--------------
>>>>>   configure.ac                                 |  4 +-
>>>>>   include/vlc_common.h                         |  8 +---
>>>>>   include/vlc_fixups.h                         |  6 +--
>>>>>   4 files changed, 36 insertions(+), 44 deletions(-)
>>>>>
>>>>>  diff --git a/compat/posix_memalign.c b/compat/aligned_alloc.c
>>>>>  similarity index 55%
>>>>>  rename from compat/posix_memalign.c
>>>>>  rename to compat/aligned_alloc.c
>>>>>  index 3c6ffdfe28..9a61c0010f 100644
>>>>>  --- a/compat/posix_memalign.c
>>>>>  +++ b/compat/aligned_alloc.c
>>>>>  @@ -1,7 +1,7 @@
>>>>>
>>>>>
>/*****************************************************************************
>>>>>  - * posix_memalign.c: POSIX posix_memalign() replacement
>>>>>  + * aligned_alloc.c: C11 aligned_alloc() replacement
>>>>>
>>>>>
>*****************************************************************************
>>>>>  - * Copyright © 2012 Rémi Denis-Courmont
>>>>>  + * Copyright © 2012, 2017 Rémi Denis-Courmont
>>>>>    *
>>>>>    * This program is free software; you can redistribute it and/or
>modify
>>>>> it
>>>>>    * under the terms of the GNU Lesser General Public License as
>>>>> published by
>>>>>  @@ -22,46 +22,44 @@
>>>>>   # include <config.h>
>>>>>   #endif
>>>>>
>>>>>  +#include <assert.h>
>>>>>   #include <stdlib.h>
>>>>>   #include <errno.h>
>>>>>  +#if !defined (HAVE_POSIX_MEMALIGN) && !defined (_WIN32) &&
>!defined
>>>>> (__APPLE__)
>>>>>  +# include <malloc.h>
>>>>>  +#endif
>>>>>
>>>>>  -static int check_align (size_t align)
>>>>>  +void *aligned_alloc(size_t align, size_t size)
>>>>>   {
>>>>>  -    for (size_t i = sizeof (void *); i != 0; i *= 2)
>>>>>  -        if (align == i)
>>>>>  -            return 0;
>>>>>  -    return EINVAL;
>>>>>  -}
>>>>>  -
>>>>>  -#if !defined (_WIN32) && !defined (__APPLE__)
>>>>>  -#include <malloc.h>
>>>>>  +    /* align must be a power of 2 */
>>>>>  +    /* size must be a multiple of align */
>>>>>  +    if ((align & (align - 1)) || (size & (align - 1)))
>>>>>  +    {
>>>>>  +        errno = EINVAL;
>>>>>  +        return NULL;
>>>>>  +    }
>>>>>
>>>>>  -int posix_memalign (void **ptr, size_t align, size_t size)
>>>>>  -{
>>>>>  -    if (check_align (align))
>>>>>  -        return EINVAL;
>>>>>  +#ifdef HAVE_POSIX_MEMALIGN
>>>>>  +    if (align < sizeof (void *)) /* POSIX does not allow small
>>>>> alignment */
>>>>>  +        align = sizeof (void *);
>>>>>
>>>>>  -    int saved_errno = errno;
>>>>>  -    void *p = memalign (align, size);
>>>>>  -    if (p == NULL)
>>>>>  +    void *ptr;
>>>>>  +    int err = posix_memalign(&ptr, align, size);
>>>>>  +    if (err)
>>>>>       {
>>>>>  -        errno = saved_errno;
>>>>>  -        return ENOMEM;
>>>>>  +        errno = err;
>>>>>  +        ptr = NULL;
>>>>>       }
>>>>>  +    return ptr;
>>>>>
>>>>>  -    *ptr = p;
>>>>>  -    return 0;
>>>>>  -}
>>>>>  +#elif !defined (_WIN32) && !defined (__APPLE__)
>>>>>
>>>>>  -#else
>>>>>  -
>>>>>  -int posix_memalign (void **ptr, size_t align, size_t size)
>>>>>  -{
>>>>>  -    if (check_align (align))
>>>>>  -        return EINVAL;
>>>>>  +   return memalign(align, size);
>>>>
>>>>
>>>> Is the goal that this code is never called for Windows and Apple
>OSes
>>>> ? Because it worked and this function always return NULL.
>>>>
>>>>>  -    *ptr = NULL;
>>>>>  -    return size ? ENOMEM : 0;
>>>>>  -}
>>>>>  +#else
>>>>>
>>>>>  +   if (size > 0)
>>>>>  +       errno = ENOMEM;
>>>>>  +   return NULL;
>>>>>   #endif
>>>>>  +}
>>>>>  diff --git a/configure.ac b/configure.ac
>>>>>  index b1883a18b7..67fc7deb1a 100644
>>>>>  --- a/configure.ac
>>>>>  +++ b/configure.ac
>>>>>  @@ -597,8 +597,8 @@ dnl Check for system libs needed
>>>>>   need_libc=false
>>>>>
>>>>>   dnl Check for usual libc functions
>>>>>  -AC_CHECK_FUNCS([daemon fcntl flock fstatvfs fork getenv
>getpwuid_r
>>>>> isatty lstat memalign mkostemp mmap open_memstream openat pread
>>>>> posix_fadvise posix_madvise setlocale stricmp strnicmp strptime
>tdestroy
>>>>> uselocale])
>>>>>  -AC_REPLACE_FUNCS([atof atoll dirfd fdopendir ffsll flockfile
>fsync
>>>>> getdelim getpid lldiv memrchr nrand48 poll posix_memalign recvmsg
>rewind
>>>>> sendmsg setenv strcasecmp strcasestr strdup strlcpy strndup
>strnlen strnstr
>>>>> strsep strtof strtok_r strtoll swab tfind timegm timespec_get
>strverscmp
>>>>> pathconf])
>>>>>  +AC_CHECK_FUNCS([daemon fcntl flock fstatvfs fork getenv
>getpwuid_r
>>>>> isatty lstat memalign mkostemp mmap open_memstream openat pread
>>>>> posix_fadvise posix_madvise posix_memalign setlocale stricmp
>strnicmp
>>>>> strptime tdestroy uselocale])
>>>>>  +AC_REPLACE_FUNCS([aligned_alloc atof atoll dirfd fdopendir ffsll
>>>>> flockfile fsync getdelim getpid lldiv memrchr nrand48 poll recvmsg
>rewind
>>>>> sendmsg setenv strcasecmp strcasestr strdup strlcpy strndup
>strnlen strnstr
>>>>> strsep strtof strtok_r strtoll swab tfind timegm timespec_get
>strverscmp
>>>>> pathconf])
>>>>>   AC_REPLACE_FUNCS([gettimeofday])
>>>>>   AC_CHECK_FUNC(fdatasync,,
>>>>>     [AC_DEFINE(fdatasync, fsync, [Alias fdatasync() to fsync() if
>>>>> missing.])
>>>>>  diff --git a/include/vlc_common.h b/include/vlc_common.h
>>>>>  index e1cf885379..0bfb1b9b04 100644
>>>>>  --- a/include/vlc_common.h
>>>>>  +++ b/include/vlc_common.h
>>>>>  @@ -854,13 +854,7 @@ VLC_API bool vlc_ureduce( unsigned *,
>unsigned *,
>>>>> uint64_t, uint64_t, uint64_t )
>>>>>   # define vlc_memalign(align, size) (_aligned_malloc(size,
>align))
>>>>>   # define vlc_free(base)            (_aligned_free(base))
>>>>>   #else
>>>>>  -static inline void *vlc_memalign(size_t align, size_t size)
>>>>>  -{
>>>>>  -    void *base;
>>>>>  -    if (unlikely(posix_memalign(&base, align, size)))
>>>>>  -        base = NULL;
>>>>>  -    return base;
>>>>>  -}
>>>>>  +# define vlc_memalign(align, size) aligned_alloc(align, size)
>>>>>   # define vlc_free(base) free(base)
>>>>>   #endif
>>>>>
>>>>>  diff --git a/include/vlc_fixups.h b/include/vlc_fixups.h
>>>>>  index 8bfb76888f..44b8426f2c 100644
>>>>>  --- a/include/vlc_fixups.h
>>>>>  +++ b/include/vlc_fixups.h
>>>>>  @@ -88,7 +88,7 @@ typedef struct
>>>>>   # include <stdio.h> /* FILE */
>>>>>   #endif
>>>>>
>>>>>  -#if !defined (HAVE_POSIX_MEMALIGN) || \
>>>>>  +#if !defined (HAVE_ALIGNED_ALLOC) || \
>>>>>       !defined (HAVE_MEMRCHR) || \
>>>>>       !defined (HAVE_STRLCPY) || \
>>>>>       !defined (HAVE_STRNDUP) || \
>>>>>  @@ -302,8 +302,8 @@ int setenv (const char *, const char *, int);
>>>>>   int unsetenv (const char *);
>>>>>   #endif
>>>>>
>>>>>  -#ifndef HAVE_POSIX_MEMALIGN
>>>>>  -int posix_memalign (void **, size_t, size_t);
>>>>>  +#ifndef HAVE_ALIGNED_ALLOC
>>>>>  +void *aligned_alloc(size_t, size_t);
>>>>>   #endif
>>>>>
>>>>>   #if defined(__native_client__) && defined(__cplusplus)
>>>>>
>>>>> ________________________________
>>>>>
>>>>>  vlc-commits mailing list
>>>>>  vlc-commits at videolan.org
>>>>>  https://mailman.videolan.org/listinfo/vlc-commits
>>>>
>>>> ________________________________
>>>>
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>>>
>>>
>>> --
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>excuser ma
>>> brièveté.
>>>
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-- 
Envoyé de mon appareil Android avec Courriel K-9 Mail. Veuillez excuser ma brièveté.
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