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| author | Hui <hui.xie1990@gmail.com> | 2024-06-01 21:12:04 +0100 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2024-06-01 21:12:04 +0100 |
| commit | 6e22b538da4b09efb10a59582a3f43d8128ae7d1 (patch) | |
| tree | 5c163126046c57b38f8049d88032982e4c1a7eed /libcxx/src | |
| parent | 2b2ce50fe843b5b550806a0ab15b06cd5c405d48 (diff) | |
| download | llvm-6e22b538da4b09efb10a59582a3f43d8128ae7d1.zip llvm-6e22b538da4b09efb10a59582a3f43d8128ae7d1.tar.gz llvm-6e22b538da4b09efb10a59582a3f43d8128ae7d1.tar.bz2 | |
[libc++] Fix `std::atomic::wait` ulock wait UL_COMPARE_AND_WAIT64 (#92783)
in `atomic::wait`, when we call the platform wait ulock_wait , we are
using UL_COMPARE_AND_WAIT. But we should use UL_COMPARE_AND_WAIT64
instead as the address we are waiting for is a 64 bit integer.
fixes https://github.com/llvm/llvm-project/issues/85107
It is rather hard to test directly because in `atomic::wait`, before
calling into the platform wait, our c++ code has some poll logic which
checks the value not changing. Thus in this patch, the test is using the
internal function.
Diffstat (limited to 'libcxx/src')
| -rw-r--r-- | libcxx/src/atomic.cpp | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/libcxx/src/atomic.cpp b/libcxx/src/atomic.cpp index 44100d4..7142f38 100644 --- a/libcxx/src/atomic.cpp +++ b/libcxx/src/atomic.cpp @@ -69,17 +69,20 @@ extern "C" int __ulock_wait( uint32_t operation, void* addr, uint64_t value, uint32_t timeout); /* timeout is specified in microseconds */ extern "C" int __ulock_wake(uint32_t operation, void* addr, uint64_t wake_value); -# define UL_COMPARE_AND_WAIT 1 +// https://github.com/apple/darwin-xnu/blob/2ff845c2e033bd0ff64b5b6aa6063a1f8f65aa32/bsd/sys/ulock.h#L82 +# define UL_COMPARE_AND_WAIT64 5 # define ULF_WAKE_ALL 0x00000100 static void __libcpp_platform_wait_on_address(__cxx_atomic_contention_t const volatile* __ptr, __cxx_contention_t __val) { - __ulock_wait(UL_COMPARE_AND_WAIT, const_cast<__cxx_atomic_contention_t*>(__ptr), __val, 0); + static_assert(sizeof(__cxx_atomic_contention_t) == 8, "Waiting on 8 bytes value"); + __ulock_wait(UL_COMPARE_AND_WAIT64, const_cast<__cxx_atomic_contention_t*>(__ptr), __val, 0); } static void __libcpp_platform_wake_by_address(__cxx_atomic_contention_t const volatile* __ptr, bool __notify_one) { + static_assert(sizeof(__cxx_atomic_contention_t) == 8, "Waking up on 8 bytes value"); __ulock_wake( - UL_COMPARE_AND_WAIT | (__notify_one ? 0 : ULF_WAKE_ALL), const_cast<__cxx_atomic_contention_t*>(__ptr), 0); + UL_COMPARE_AND_WAIT64 | (__notify_one ? 0 : ULF_WAKE_ALL), const_cast<__cxx_atomic_contention_t*>(__ptr), 0); } #elif defined(__FreeBSD__) && __SIZEOF_LONG__ == 8 |