GuardType Struct Reference

Collaboration diagram for GuardType:

Public Attributes
std::atomic< uint64_t >	guard {0}
	原子守护变量：bit 0 = is_initialized, bit 8 = is_in_use

Static Public Attributes
static constexpr uint64_t	kInitializedMask = 0x01
static constexpr uint64_t	kInUseMask = 0x100

Detailed Description

if ( obj_guard.first_byte == 0 ) { if ( __cxa_guard_acquire(&obj_guard) ) { try { ... initialize the object ...; } catch (...) { __cxa_guard_abort(&obj_guard); throw; } ... queue object destructor with __cxa_atexit() ...; __cxa_guard_release(&obj_guard); } }

Note

根据 Itanium C++ ABI，守护变量必须是 64 位

See also

https://itanium-cxx-abi.github.io/cxx-abi/abi.html#once-ctor

Definition at line 111 of file kstd_libcxx.cpp.

Member Data Documentation

guard

std::atomic<uint64_t> GuardType::guard {0}

原子守护变量：bit 0 = is_initialized, bit 8 = is_in_use

Definition at line 113 of file kstd_libcxx.cpp.

{0};

kInitializedMask

constexpr uint64_t GuardType::kInitializedMask = 0x01

staticconstexpr

Definition at line 115 of file kstd_libcxx.cpp.

kInUseMask

constexpr uint64_t GuardType::kInUseMask = 0x100

staticconstexpr

Definition at line 116 of file kstd_libcxx.cpp.

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The documentation for this struct was generated from the following file:

• /workspaces/SimpleKernel/src/libcxx/kstd_libcxx.cpp