场景
vlc-3.0.11源码升级到vlc-3.0.21
范式_Generic
static inline void *vlc_alloc(size_t count, size_t size)
{
//return mul_overflow(count, size, &size) ? NULL : malloc(size);
return umull_overflow(count, size, &size) ? NULL : malloc(size);
}//#if !defined(__cplusplus)
// # define VLC_OBJECT(x) \
// _Generic((x)->obj, \
// struct vlc_common_members: (vlc_object_t *)(&(x)->obj), \
// const struct vlc_common_members: (const vlc_object_t *)(&(x)->obj) \
// )
// #else
# define VLC_OBJECT( x ) ((vlc_object_t *)&(x)->obj)
//#endif#ifndef __cplusplus
// # define vlc_array_item_at_index(ar, idx) \
// _Generic((ar), \
// const vlc_array_t *: ((ar)->pp_elems[idx]), \
// vlc_array_t *: ((ar)->pp_elems[idx]))
// #else
// static inline void *vlc_array_item_at_index( vlc_array_t *ar, size_t idx )
// {
// return ar->pp_elems[idx];
// }
static inline const void *vlc_array_item_at_index( const vlc_array_t *ar,
size_t idx )
{
return ar->pp_elems[idx];
}
#endifatomic原子锁
/*****************************************************************************
* vlc_atomic.h:
*****************************************************************************
* Copyright (C) 2010 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
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
*****************************************************************************/
#ifndef VLC_ATOMIC_H
# define VLC_ATOMIC_H
/**
* \file
* Atomic operations do not require locking, but they are not very powerful.
*/
/* Clang older versions support atomics but lacks the stdatomic.h header */
#if defined(__clang__)
# if !defined(__has_include) || !__has_include(<stdatomic.h>)
# define __STDC_NO_ATOMICS__ 1
# endif
#endif
# ifndef __cplusplus
# if !defined (__STDC_NO_ATOMICS__)
/*** Native C11 atomics ***/
# include "stdatomic.h"
# else
# define ATOMIC_FLAG_INIT false
# define ATOMIC_VAR_INIT(value) (value)
# define atomic_init(obj, value) \
do { *(obj) = (value); } while(0)
# define kill_dependency(y) \
((void)0)
# define atomic_thread_fence(order) \
__sync_synchronize()
# define atomic_signal_fence(order) \
((void)0)
# define atomic_is_lock_free(obj) \
false
/* In principles, __sync_*() only supports int, long and long long and their
* unsigned equivalents, i.e. 4-bytes and 8-bytes types, although GCC also
* supports 1 and 2-bytes types. Some non-x86 architectures do not support
* 8-byte atomic types (or not efficiently). */
# if defined (_MSC_VER)
/* Some atomic operations of the Interlocked API are only
available for desktop apps. Thus we define the atomic types to
be at least 32 bits wide. */
typedef int_least32_t atomic_flag;
typedef int_least32_t atomic_bool;
typedef int_least32_t atomic_char;
typedef int_least32_t atomic_schar;
typedef uint_least32_t atomic_uchar;
typedef int_least32_t atomic_short;
typedef uint_least32_t atomic_ushort;
# else
typedef bool atomic_flag;
typedef bool atomic_bool;
typedef char atomic_char;
typedef signed char atomic_schar;
typedef unsigned char atomic_uchar;
typedef short atomic_short;
typedef unsigned short atomic_ushort;
#endif
typedef int atomic_int;
typedef unsigned int atomic_uint;
typedef long atomic_long;
typedef unsigned long atomic_ulong;
typedef long long atomic_llong;
typedef unsigned long long atomic_ullong;
//typedef char16_t atomic_char16_t;
//typedef char32_t atomic_char32_t;
typedef wchar_t atomic_wchar_t;
typedef int_least8_t atomic_int_least8_t;
typedef uint_least8_t atomic_uint_least8_t;
typedef int_least16_t atomic_int_least16_t;
typedef uint_least16_t atomic_uint_least16_t;
typedef int_least32_t atomic_int_least32_t;
typedef uint_least32_t atomic_uint_least32_t;
typedef int_least64_t atomic_int_least64_t;
typedef uint_least64_t atomic_uint_least64_t;
typedef int_fast8_t atomic_int_fast8_t;
typedef uint_fast8_t atomic_uint_fast8_t;
typedef int_fast16_t atomic_int_fast16_t;
typedef uint_fast16_t atomic_uint_fast16_t;
typedef int_fast32_t atomic_int_fast32_t;
typedef uint_fast32_t atomic_uint_fast32_t;
typedef int_fast64_t atomic_int_fast64_t;
typedef uint_fast64_t atomic_uint_fast64_t;
typedef intptr_t atomic_intptr_t;
typedef uintptr_t atomic_uintptr_t;
typedef size_t atomic_size_t;
typedef ptrdiff_t atomic_ptrdiff_t;
typedef intmax_t atomic_intmax_t;
typedef uintmax_t atomic_uintmax_t;
# if defined (__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4) || (defined (__clang__) && (defined (__x86_64__) || defined (__i386__)))
/*** Intel/GCC atomics ***/
# define atomic_store(object,desired) \
do { \
*(object) = (desired); \
__sync_synchronize(); \
} while (0)
# define atomic_store_explicit(object,desired,order) \
atomic_store(object,desired)
# define atomic_load(object) \
(__sync_synchronize(), *(object))
# define atomic_load_explicit(object,order) \
atomic_load(object)
# define atomic_exchange(object,desired) \
({ \
typeof (object) _obj = (object); \
typeof (*object) _old; \
do \
_old = atomic_load(_obj); \
while (!__sync_bool_compare_and_swap(_obj, _old, (desired))); \
_old; \
})
# define atomic_exchange_explicit(object,desired,order) \
atomic_exchange(object,desired)
# define atomic_compare_exchange(object,expected,desired) \
({ \
typeof (object) _exp = (expected); \
typeof (*object) _old = *_exp; \
*_exp = __sync_val_compare_and_swap((object), _old, (desired)); \
*_exp == _old; \
})
# define atomic_compare_exchange_strong(object,expected,desired) \
atomic_compare_exchange(object, expected, desired)
# define atomic_compare_exchange_strong_explicit(object,expected,desired,order,order_different) \
atomic_compare_exchange_strong(object, expected, desired)
# define atomic_compare_exchange_weak(object,expected,desired) \
atomic_compare_exchange(object, expected, desired)
# define atomic_compare_exchange_weak_explicit(object,expected,desired,order_equal,order_different) \
atomic_compare_exchange_weak(object, expected, desired)
# define atomic_fetch_add(object,operand) \
__sync_fetch_and_add(object, operand)
# define atomic_fetch_add_explicit(object,operand,order) \
atomic_fetch_add(object,operand)
# define atomic_fetch_sub(object,operand) \
__sync_fetch_and_sub(object, operand)
# define atomic_fetch_sub_explicit(object,operand,order) \
atomic_fetch_sub(object,operand)
# define atomic_fetch_or(object,operand) \
__sync_fetch_and_or(object, operand)
# define atomic_fetch_or_explicit(object,operand,order) \
atomic_fetch_or(object,operand)
# define atomic_fetch_xor(object,operand) \
__sync_fetch_and_sub(object, operand)
# define atomic_fetch_xor_explicit(object,operand,order) \
atomic_fetch_sub(object,operand)
# define atomic_fetch_and(object,operand) \
__sync_fetch_and_and(object, operand)
# define atomic_fetch_and_explicit(object,operand,order) \
atomic_fetch_and(object,operand)
# define atomic_flag_test_and_set(object) \
atomic_exchange(object, true)
# define atomic_flag_test_and_set_explicit(object,order) \
atomic_flag_test_and_set(object)
# define atomic_flag_clear(object) \
atomic_store(object, false)
# define atomic_flag_clear_explicit(object,order) \
atomic_flag_clear(object)
# elif defined (__GNUC__)
/*** No atomics ***/
# define atomic_store(object,desired) \
do { \
typeof (object) _obj = (object); \
typeof (*object) _des = (desired); \
vlc_global_lock(VLC_ATOMIC_MUTEX); \
*_obj = _des; \
vlc_global_unlock(VLC_ATOMIC_MUTEX); \
} while (0)
# define atomic_store_explicit(object,desired,order) \
atomic_store(object,desired)
# define atomic_load(object) \
({ \
typeof (object) _obj = (object); \
typeof (*object) _old; \
vlc_global_lock(VLC_ATOMIC_MUTEX); \
_old = *_obj; \
vlc_global_unlock(VLC_ATOMIC_MUTEX); \
_old; \
})
# define atomic_load_explicit(object,order) \
atomic_load(object)
# define atomic_exchange(object,desired) \
({ \
typeof (object) _obj = (object); \
typeof (*object) _des = (desired); \
typeof (*object) _old; \
vlc_global_lock(VLC_ATOMIC_MUTEX); \
_old = *_obj; \
*_obj = _des; \
vlc_global_unlock(VLC_ATOMIC_MUTEX); \
_old; \
})
# define atomic_exchange_explicit(object,desired,order) \
atomic_exchange(object,desired)
# define atomic_compare_exchange_strong(object,expected,desired) \
({ \
typeof (object) _obj = (object); \
typeof (object) _exp = (expected); \
typeof (*object) _des = (desired); \
bool ret; \
vlc_global_lock(VLC_ATOMIC_MUTEX); \
ret = *_obj == *_exp; \
if (ret) \
*_obj = _des; \
else \
*_exp = *_obj; \
vlc_global_unlock(VLC_ATOMIC_MUTEX); \
ret; \
})
# define atomic_compare_exchange_strong_explicit(object,expected,desired,order) \
atomic_compare_exchange_strong(object, expected, desired)
# define atomic_compare_exchange_weak(object,expected,desired) \
atomic_compare_exchange_strong(object, expected, desired)
# define atomic_compare_exchange_weak_explicit(object,expected,desired,order) \
atomic_compare_exchange_weak(object, expected, desired)
# define atomic_fetch_OP(object,desired,op) \
({ \
typeof (object) _obj = (object); \
typeof (*object) _des = (desired); \
typeof (*object) _old; \
vlc_global_lock(VLC_ATOMIC_MUTEX); \
_old = *_obj; \
*_obj = (*_obj) op (_des); \
vlc_global_unlock(VLC_ATOMIC_MUTEX); \
_old; \
})
# define atomic_fetch_add(object,operand) \
atomic_fetch_OP(object,operand,+)
# define atomic_fetch_add_explicit(object,operand,order) \
atomic_fetch_add(object,operand)
# define atomic_fetch_sub(object,operand) \
atomic_fetch_OP(object,operand,-)
# define atomic_fetch_sub_explicit(object,operand,order) \
atomic_fetch_sub(object,operand)
# define atomic_fetch_or(object,operand) \
atomic_fetch_OP(object,operand,|)
# define atomic_fetch_or_explicit(object,operand,order) \
atomic_fetch_or(object,operand)
# define atomic_fetch_xor(object,operand) \
atomic_fetch_OP(object,operand,^)
# define atomic_fetch_xor_explicit(object,operand,order) \
atomic_fetch_sub(object,operand)
# define atomic_fetch_and(object,operand) \
atomic_fetch_OP(object,operand,&)
# define atomic_fetch_and_explicit(object,operand,order) \
atomic_fetch_and(object,operand)
# define atomic_flag_test_and_set(object) \
atomic_exchange(object, true)
# define atomic_flag_test_and_set_explicit(object,order) \
atomic_flag_test_and_set(object)
# define atomic_flag_clear(object) \
atomic_store(object, false)
# define atomic_flag_clear_explicit(object,order) \
atomic_flag_clear(object)
# elif defined (_MSC_VER)
# include <windows.h>
/*** Use the Interlocked API. ***/
/* Define macros in order to dispatch to the correct function depending on the type.
Several ranges are need because some operations are not implemented for all types. */
# define atomic_type_dispatch_32_64(operation, object, ...) \
(sizeof(*object) == 4 ? operation((LONG *)object, __VA_ARGS__) : \
sizeof(*object) == 8 ? operation##64((LONGLONG *)object, __VA_ARGS__) : \
(abort(), 0))
# define atomic_type_dispatch_16_64(operation, object, ...) \
(sizeof(*object) == 2 ? operation##16((short *)object, __VA_ARGS__) : \
atomic_type_dispatch_32_64(operation, object, __VA_ARGS__))
# define atomic_type_dispatch_8_64(operation, object, ...) \
(sizeof(*object) == 1 ? operation##8((char *)object, __VA_ARGS__) : \
atomic_type_dispatch_16_64(operation, object, __VA_ARGS__))
# define atomic_store(object,desired) \
atomic_type_dispatch_16_64(InterlockedExchange, object, desired)
# define atomic_store_explicit(object,desired,order) \
atomic_store(object, desired)
# define atomic_load(object) \
atomic_type_dispatch_16_64(InterlockedCompareExchange, object, 0, 0)
# define atomic_load_explicit(object,order) \
atomic_load(object)
# define atomic_exchange(object,desired) \
atomic_type_dispatch_16_64(InterlockedExchange, object, desired)
# define atomic_exchange_explicit(object,desired,order) \
atomic_exchange(object, desired)
# define atomic_compare_exchange_strong(object,expected,desired) \
atomic_type_dispatch_16_64(InterlockedCompareExchange, object, desired, *expected) == *expected
# define atomic_compare_exchange_strong_explicit(object,expected,desired,order) \
atomic_compare_exchange_strong(object, expected, desired)
# define atomic_compare_exchange_weak(object,expected,desired) \
atomic_compare_exchange_strong(object, expected, desired)
# define atomic_compare_exchange_weak_explicit(object,expected,desired,order,order_different) \
atomic_compare_exchange_weak(object, expected, desired)
# define atomic_fetch_add(object,operand) \
atomic_type_dispatch_32_64(InterlockedExchangeAdd, object, operand)
# define atomic_fetch_add_explicit(object,operand,order) \
atomic_fetch_add(object, operand)
# define atomic_fetch_sub(object,operand) \
atomic_type_dispatch_32_64(InterlockedExchangeAdd, object, -(LONGLONG)operand)
# define atomic_fetch_sub_explicit(object,operand,order) \
atomic_fetch_sub(object, operand)
# define atomic_fetch_or(object,operand) \
atomic_type_dispatch_8_64(InterlockedOr, object, operand)
# define atomic_fetch_or_explicit(object,operand,order) \
atomic_fetch_or(object, operand)
# define atomic_fetch_xor(object,operand) \
atomic_type_dispatch_8_64(InterlockedXor, object, operand)
# define atomic_fetch_xor_explicit(object,operand,order) \
atomic_fetch_sub(object, operand)
# define atomic_fetch_and(object,operand) \
atomic_type_dispatch_8_64(InterlockedAnd, object, operand)
# define atomic_fetch_and_explicit(object,operand,order) \
atomic_fetch_and(object, operand)
# define atomic_flag_test_and_set(object) \
atomic_exchange(object, true)
# define atomic_flag_test_and_set_explicit(object,order) \
atomic_flag_test_and_set(object)
# define atomic_flag_clear(object) \
atomic_store(object, false)
# define atomic_flag_clear_explicit(object,order) \
atomic_flag_clear(object)
# else
# error FIXME: implement atomic operations for this compiler.
# endif
# endif /* !C11 */
typedef atomic_uint_least32_t vlc_atomic_float;
static inline void vlc_atomic_init_float(vlc_atomic_float *var, float f)
{
union { float f; uint32_t i; } u;
u.f = f;
atomic_init(var, u.i);
}
/** Helper to retrieve a single precision from an atom. */
static inline float vlc_atomic_load_float(vlc_atomic_float *atom)
{
union { float f; uint32_t i; } u;
u.i = atomic_load(atom);
return u.f;
}
/** Helper to store a single precision into an atom. */
static inline void vlc_atomic_store_float(vlc_atomic_float *atom, float f)
{
union { float f; uint32_t i; } u;
u.f = f;
atomic_store(atom, u.i);
}
# else /* C++ */
/*** Native C++11 atomics ***/
# include <atomic>
# endif /* C++ */
#endif
数组
int config_CreateDir( vlc_object_t *p_this, const char *psz_dirname )
{
if( !psz_dirname || !*psz_dirname ) return -1;
if( vlc_mkdir( psz_dirname, 0700 ) == 0 )
return 0;
switch( errno )
{
case EEXIST:
return 0;
case ENOENT:
{
/* Let's try to create the parent directory */
char* psz_end;
#ifdef __STDC_NO_VLA__
char* psz_parent = (char*)malloc(strlen(psz_dirname) + 1);
#else
char psz_parent[strlen(psz_dirname) + 1];
#endif
strcpy( psz_parent, psz_dirname );
psz_end = strrchr( psz_parent, DIR_SEP_CHAR );
if( psz_end && psz_end != psz_parent )
{
*psz_end = '\0';
if( config_CreateDir( p_this, psz_parent ) == 0 )
{
if (!vlc_mkdir(psz_dirname, 0700))
{
#ifdef __STDC_NO_VLA__
free(psz_parent);
#endif
return 0;
}
}
}
#ifdef __STDC_NO_VLA__
free(psz_parent);
#endif
}
}
msg_Warn( p_this, "could not create %s: %s", psz_dirname,
vlc_strerror_c(errno) );
return -1;
}#warning
//#warning "input_clock_SetJitter needs more work"
#pragma message("warning:input_clock_SetJitter needs more work"){}
//vlc_viewpoint_t vp = {};
vlc_viewpoint_t vp;使用了未初始化
const char *psz_es = NULL;
const char *psz_forced_demux = NULL;
vlc_viewpoint_t vp = { 0 };SIZE_MAX替代SSIZE_MAX
字节对齐
struct vlc_object_internals
{
//alignas (max_align_t) /* ensure vlc_externals() is maximally aligned */
