Concurrency support library

 

+C

语言

标题

发布类型支持

程序实用程序

Variadic函数支持

错误处理

动态内存管理

字符串库

算法

数字

日期和时间实用程序

输入/输出支持

本地化支持

Concurrency support (哋它亢11)

技术规格书

符号索引

 

Concurrency support library

Threads thrd_create thrd_equal thrd_current    thrd_sleep thrd_yield thrd_exit thrd_detach thrd_join thrd_successthrd_timedoutthrd_busythrd_nomemthrd_error    Atomic operations atomic_init ATOMIC_VAR_INIT (until 哋它亢23) ATOMIC_* * *_LOCK_FREE atomic_is_lock_free atomic_store atomic_load atomic_exchange atomic_compare_exchange atomic_fetch_add atomic_fetch_sub atomic_fetch_or atomic_fetch_xor atomic_fetch_and

Atomic flags atomic_flag ATOMIC_FLAG_INIT atomic_flag_test_and_set atomic_flag_clear Memory ordering memory_order kill_dependency atomic_thread_fence atomic_signal_fence Mutual exclusion mtx_init mtx_lock mtx_timedlock mtx_trylock call_once mtx_unlock mtx_destroy mtx_plainmtx_recursivemtx_timed Condition variables cnd_init cnd_signal cnd_broadcast cnd_wait cnd_timedwait cnd_destroy Thread-local storage thread_local TSS_DTOR_ITERATIONS    tss_create tss_get tss_set tss_delete

 

C包括对线程、原子操作、互斥、条件变量和线程特定存储的内置支持。

可选择提供以下功能：

• if the macro constant __STDC_NO_THREADS__ is defined by the compiler, the header <threads.h> and all of the names provided in it are not provided;
• if the macro constant __STDC_NO_ATOMICS__ is defined by the compiler, the header <stdatomic.h> and all of the names provided in it are not provided.

See also _Atomic type specifier and qualifier.

Threads

Defined in header <threads.h>
thrd_t	implementation-defined complete object type identifying a thread
thrd_create (哋它亢11)	creates a thread (function)
thrd_equal (哋它亢11)	checks if two identifiers refer to the same thread (function)
thrd_current (哋它亢11)	obtains the current thread identifier (function)
thrd_sleep (哋它亢11)	suspends execution of the calling thread for the given period of time (function)
thrd_yield (哋它亢11)	yields the current time slice (function)
thrd_exit (哋它亢11)	terminates the calling thread (function)
thrd_detach (哋它亢11)	detaches a thread (function)
thrd_join (哋它亢11)	blocks until a thread terminates (function)
thrd_successthrd_timedoutthrd_busythrd_nomemthrd_error (哋它亢11)	indicates a thread error status (constant)
thrd_start_t (哋它亢11)	a typedef of the function pointer type int(*)(void*), used by thrd_create (typedef)

Atomic operations

Defined in header <stdatomic.h>
Operations on atomic types
ATOMIC_BOOL_LOCK_FREEATOMIC_CHAR_LOCK_FREEATOMIC_CHAR16_T_LOCK_FREEATOMIC_CHAR32_T_LOCK_FREEATOMIC_WCHAR_T_LOCK_FREEATOMIC_SHORT_LOCK_FREEATOMIC_INT_LOCK_FREEATOMIC_LONG_LOCK_FREEATOMIC_LLONG_LOCK_FREEATOMIC_POINTER_LOCK_FREE (哋它亢11)	indicates that the given atomic type is lock-free (macro constant)
atomic_is_lock_free (哋它亢11)	indicates whether the atomic object is lock-free (function)
atomic_storeatomic_store_explicit (哋它亢11)	stores a value in an atomic object (function)
atomic_loadatomic_load_explicit (哋它亢11)	reads a value from an atomic object (function)
atomic_exchangeatomic_exchange_explicit (哋它亢11)	swaps a value with the value of an atomic object (function)
atomic_compare_exchange_strongatomic_compare_exchange_strong_explicitatomic_compare_exchange_weakatomic_compare_exchange_weak_explicit (哋它亢11)	swaps a value with an atomic object if the old value is what is expected, otherwise reads the old value (function)
atomic_fetch_addatomic_fetch_add_explicit (哋它亢11)	atomic addition (function)
atomic_fetch_subatomic_fetch_sub_explicit (哋它亢11)	atomic subtraction (function)
atomic_fetch_oratomic_fetch_or_explicit (哋它亢11)	atomic bitwise OR (function)
atomic_fetch_xoratomic_fetch_xor_explicit (哋它亢11)	atomic bitwise exclusive OR (function)
atomic_fetch_andatomic_fetch_and_explicit (哋它亢11)	atomic bitwise AND (function)
Flag type and operations
atomic_flag (哋它亢11)	lock-free atomic boolean flag (struct)
atomic_flag_test_and_setatomic_flag_test_and_set_explicit (哋它亢11)	sets an atomic_flag to true and returns the old value (function)
atomic_flag_clearatomic_flag_clear_explicit (哋它亢11)	sets an atomic_flag to false (function)
Initialization
atomic_init (哋它亢11)	initializes an existing atomic object (function)
ATOMIC_VAR_INIT (哋它亢11)(deprecated in 哋它亢17)(removed in 哋它亢23)	initializes a new atomic object (function macro)
ATOMIC_FLAG_INIT (哋它亢11)	initializes a new atomic_flag (macro constant)
Memory synchronization ordering
memory_order (哋它亢11)	defines memory ordering constraints (enum)
kill_dependency (哋它亢11)	breaks a dependency chain for memory_order_consume (function macro)
atomic_thread_fence (哋它亢11)	generic memory order-dependent fence synchronization primitive (function)
atomic_signal_fence (哋它亢11)	fence between a thread and a signal handler executed in the same thread (function)
Convenience type aliases
Typedef name	Full type name
atomic_bool(哋它亢11)	_Atomic _Bool
atomic_char(哋它亢11)	_Atomic char
atomic_schar(哋它亢11)	_Atomic signed char
atomic_uchar(哋它亢11)	_Atomic unsigned char
atomic_short(哋它亢11)	_Atomic short
atomic_ushort(哋它亢11)	_Atomic unsigned short
atomic_int(哋它亢11)	_Atomic int
atomic_uint(哋它亢11)	_Atomic unsigned int
atomic_long(哋它亢11)	_Atomic long
atomic_ulong(哋它亢11)	_Atomic unsigned long
atomic_llong(哋它亢11)	_Atomic long long
atomic_ullong(哋它亢11)	_Atomic unsigned long long
atomic_char8_t(哋它亢23)	_Atomic char8_t
atomic_char16_t(哋它亢11)	_Atomic char16_t
atomic_char32_t(哋它亢11)	_Atomic char32_t
atomic_wchar_t(哋它亢11)	_Atomic wchar_t
atomic_int_least8_t(哋它亢11)	_Atomic int_least8_t
atomic_uint_least8_t(哋它亢11)	_Atomic uint_least8_t
atomic_int_least16_t(哋它亢11)	_Atomic int_least16_t
atomic_uint_least16_t(哋它亢11)	_Atomic uint_least16_t
atomic_int_least32_t(哋它亢11)	_Atomic int_least32_t
atomic_uint_least32_t(哋它亢11)	_Atomic uint_least32_t
atomic_int_least64_t(哋它亢11)	_Atomic int_least64_t
atomic_uint_least64_t(哋它亢11)	_Atomic uint_least64_t
atomic_int_fast8_t(哋它亢11)	_Atomic int_fast8_t
atomic_uint_fast8_t(哋它亢11)	_Atomic uint_fast8_t
atomic_int_fast16_t(哋它亢11)	_Atomic int_fast16_t
atomic_uint_fast16_t(哋它亢11)	_Atomic uint_fast16_t
atomic_int_fast32_t(哋它亢11)	_Atomic int_fast32_t
atomic_uint_fast32_t(哋它亢11)	_Atomic uint_fast32_t
atomic_int_fast64_t(哋它亢11)	_Atomic int_fast64_t
atomic_uint_fast64_t(哋它亢11)	_Atomic uint_fast64_t
atomic_intptr_t(哋它亢11)	_Atomic intptr_t
atomic_uintptr_t(哋它亢11)	_Atomic uintptr_t
atomic_size_t(哋它亢11)	_Atomic size_t
atomic_ptrdiff_t(哋它亢11)	_Atomic ptrdiff_t
atomic_intmax_t(哋它亢11)	_Atomic intmax_t
atomic_uintmax_t(哋它亢11)	_Atomic uintmax_t

Mutual exclusion

Defined in header <threads.h>
mtx_t	mutex identifier
mtx_init (哋它亢11)	creates a mutex (function)
mtx_lock (哋它亢11)	blocks until locks a mutex (function)
mtx_timedlock (哋它亢11)	blocks until locks a mutex or times out (function)
mtx_trylock (哋它亢11)	locks a mutex or returns without blocking if already locked (function)
mtx_unlock (哋它亢11)	unlocks a mutex (function)
mtx_destroy (哋它亢11)	destroys a mutex (function)
mtx_plainmtx_recursivemtx_timed (哋它亢11)(哋它亢11)(哋它亢11)	defines the type of a mutex (enum)
Call once
call_once (哋它亢11)	calls a function exactly once (function)

Condition variables

Defined in header <threads.h>
cnd_t	condition variable identifier
cnd_init (哋它亢11)	creates a condition variable (function)
cnd_signal (哋它亢11)	unblocks one thread blocked on a condition variable (function)
cnd_broadcast (哋它亢11)	unblocks all threads blocked on a condition variable (function)
cnd_wait (哋它亢11)	blocks on a condition variable (function)
cnd_timedwait (哋它亢11)	blocks on a condition variable, with a timeout (function)
cnd_destroy (哋它亢11)	destroys a condition variable (function)

Thread-local storage

Defined in header <threads.h>
thread_local (哋它亢11)(removed in 哋它亢23)	convenience macro for storage-class specifier _Thread_local (keyword macro)
tss_t	thread-specific storage pointer
TSS_DTOR_ITERATIONS (哋它亢11)	maximum number of times destructors are called (macro constant)
tss_dtor_t (哋它亢11)	function pointer type void(*)(void*), used for TSS destructor (typedef)
tss_create (哋它亢11)	creates thread-specific storage pointer with a given destructor (function)
tss_get (哋它亢11)	reads from thread-specific storage (function)
tss_set (哋它亢11)	write to thread-specific storage (function)
tss_delete (哋它亢11)	releases the resources held by a given thread-specific pointer (function)

Reserved identifiers

在C标准的未来修订中：

• function names, type names, and enumeration constants that begin with either cnd_, mtx_, thrd_, or tss_, and a lowercase letter may be added to the declarations in the <threads.h> header;
• macros that begin with ATOMIC_ and an uppercase letter may be added to the macros defined in the <stdatomic.h> header;
• typedef names that begin with either atomic_ or memory_, and a lowercase letter may be added to the declarations in the <stdatomic.h> header;
• enumeration constants that begin with memory_order_ and a lowercase letter may be added to the definition of the memory_order type in the <stdatomic.h> header;
• function names that begin with atomic_ and a lowercase letter may be added to the declarations in the <stdatomic.h> header.

Identifiers reserved for functions names are always potentially(since 哋它亢23) reserved for use as identifiers with external linkage, while other identifiers list here are potentially(since 哋它亢23) reserved when <stdatomic.h> is included.

Declaring, defining, or #undefing such an identifier results in undefined behavior if it is provided by the standard or implementation(since 哋它亢23). Portable programs should not use those identifiers.

References

• 哋它亢23 standard (ISO/IEC 9899:2023):

• 7.17 Atomics <stdatomic.h> (p: TBD)

• 7.26 Threads <threads.h> (p: TBD)

• 7.31.8 Atomics <stdatomic.h> (p: TBD)

• 7.31.15 Threads <threads.h> (p: TBD)

• 哋它亢17 standard (ISO/IEC 9899:2018):

• 7.17 Atomics <stdatomic.h> (p: 200-209)

• 7.26 Threads <threads.h> (p: 274-283)

• 7.31.8 Atomics <stdatomic.h> (p: 332)

• 7.31.15 Threads <threads.h> (p: 333)

• 哋它亢11 standard (ISO/IEC 9899:2011):

• 7.17 Atomics <stdatomic.h> (p: 273-286)

• 7.26 Threads <threads.h> (p: 376-387)

• 7.31.8 Atomics <stdatomic.h> (p: 455-456)

• 7.31.15 Threads <threads.h> (p: 456)

External links

GNU GCC Libc手册： ISO C互斥体