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author | Sam Gross <colesbury@gmail.com> | 2024-06-20 15:29:08 (GMT) |
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committer | GitHub <noreply@github.com> | 2024-06-20 15:29:08 (GMT) |
commit | 3af7263037de1d0ef63b070fc7bfc2cf042eaebe (patch) | |
tree | 3503239cf4a4ca885e53f9e943530aa9bf93ac5c /Include/internal/pycore_lock.h | |
parent | e8e151d4715839f785ff853c77594d7302b40266 (diff) | |
download | cpython-3af7263037de1d0ef63b070fc7bfc2cf042eaebe.zip cpython-3af7263037de1d0ef63b070fc7bfc2cf042eaebe.tar.gz cpython-3af7263037de1d0ef63b070fc7bfc2cf042eaebe.tar.bz2 |
gh-117511: Make PyMutex public in the non-limited API (#117731)
Diffstat (limited to 'Include/internal/pycore_lock.h')
-rw-r--r-- | Include/internal/pycore_lock.h | 68 |
1 files changed, 3 insertions, 65 deletions
diff --git a/Include/internal/pycore_lock.h b/Include/internal/pycore_lock.h index 882c488..8aa7394 100644 --- a/Include/internal/pycore_lock.h +++ b/Include/internal/pycore_lock.h @@ -13,48 +13,10 @@ extern "C" { # error "this header requires Py_BUILD_CORE define" #endif - -// A mutex that occupies one byte. The lock can be zero initialized. -// -// Only the two least significant bits are used. The remaining bits should be -// zero: -// 0b00: unlocked -// 0b01: locked -// 0b10: unlocked and has parked threads -// 0b11: locked and has parked threads -// -// Typical initialization: -// PyMutex m = (PyMutex){0}; -// -// Or initialize as global variables: -// static PyMutex m; -// -// Typical usage: -// PyMutex_Lock(&m); -// ... -// PyMutex_Unlock(&m); - -// NOTE: In Py_GIL_DISABLED builds, `struct _PyMutex` is defined in Include/object.h. -// The Py_GIL_DISABLED builds need the definition in Include/object.h for the -// `ob_mutex` field in PyObject. For the default (non-free-threaded) build, -// we define the struct here to avoid exposing it in the public API. -#ifndef Py_GIL_DISABLED -struct _PyMutex { uint8_t v; }; -#endif - -typedef struct _PyMutex PyMutex; - -#define _Py_UNLOCKED 0 -#define _Py_LOCKED 1 +//_Py_UNLOCKED is defined as 0 and _Py_LOCKED as 1 in Include/cpython/lock.h #define _Py_HAS_PARKED 2 #define _Py_ONCE_INITIALIZED 4 -// (private) slow path for locking the mutex -PyAPI_FUNC(void) _PyMutex_LockSlow(PyMutex *m); - -// (private) slow path for unlocking the mutex -PyAPI_FUNC(void) _PyMutex_UnlockSlow(PyMutex *m); - static inline int PyMutex_LockFast(uint8_t *lock_bits) { @@ -62,35 +24,11 @@ PyMutex_LockFast(uint8_t *lock_bits) return _Py_atomic_compare_exchange_uint8(lock_bits, &expected, _Py_LOCKED); } -// Locks the mutex. -// -// If the mutex is currently locked, the calling thread will be parked until -// the mutex is unlocked. If the current thread holds the GIL, then the GIL -// will be released while the thread is parked. -static inline void -PyMutex_Lock(PyMutex *m) -{ - uint8_t expected = _Py_UNLOCKED; - if (!_Py_atomic_compare_exchange_uint8(&m->v, &expected, _Py_LOCKED)) { - _PyMutex_LockSlow(m); - } -} - -// Unlocks the mutex. -static inline void -PyMutex_Unlock(PyMutex *m) -{ - uint8_t expected = _Py_LOCKED; - if (!_Py_atomic_compare_exchange_uint8(&m->v, &expected, _Py_UNLOCKED)) { - _PyMutex_UnlockSlow(m); - } -} - // Checks if the mutex is currently locked. static inline int PyMutex_IsLocked(PyMutex *m) { - return (_Py_atomic_load_uint8(&m->v) & _Py_LOCKED) != 0; + return (_Py_atomic_load_uint8(&m->_bits) & _Py_LOCKED) != 0; } // Re-initializes the mutex after a fork to the unlocked state. @@ -121,7 +59,7 @@ static inline void PyMutex_LockFlags(PyMutex *m, _PyLockFlags flags) { uint8_t expected = _Py_UNLOCKED; - if (!_Py_atomic_compare_exchange_uint8(&m->v, &expected, _Py_LOCKED)) { + if (!_Py_atomic_compare_exchange_uint8(&m->_bits, &expected, _Py_LOCKED)) { _PyMutex_LockTimed(m, -1, flags); } } |