SWAMPy

✎ CARVE FLESH

EDITING: pycore_critical_section.h

#ifndef Py_INTERNAL_CRITICAL_SECTION_H
#define Py_INTERNAL_CRITICAL_SECTION_H

#ifndef Py_BUILD_CORE
#  error "this header requires Py_BUILD_CORE define"
#endif

#include "pycore_lock.h"        // PyMutex
#include "pycore_pystate.h"     // _PyThreadState_GET()
#include <stdint.h>

#ifdef __cplusplus
extern "C" {
#endif

// Tagged pointers to critical sections use the two least significant bits to
// mark if the pointed-to critical section is inactive and whether it is a
// PyCriticalSection2 object.
#define _Py_CRITICAL_SECTION_INACTIVE       0x1
#define _Py_CRITICAL_SECTION_TWO_MUTEXES    0x2
#define _Py_CRITICAL_SECTION_MASK           0x3

#ifdef Py_GIL_DISABLED
# define Py_BEGIN_CRITICAL_SECTION_MUT(mutex)                           \
    {                                                                   \
        PyCriticalSection _py_cs;                                       \
        _PyCriticalSection_BeginMutex(&_py_cs, mutex)

# define Py_BEGIN_CRITICAL_SECTION2_MUT(m1, m2)                         \
    {                                                                   \
        PyCriticalSection2 _py_cs2;                                     \
        _PyCriticalSection2_BeginMutex(&_py_cs2, m1, m2)

// Specialized version of critical section locking to safely use
// PySequence_Fast APIs without the GIL. For performance, the argument *to*
// PySequence_Fast() is provided to the macro, not the *result* of
// PySequence_Fast(), which would require an extra test to determine if the
// lock must be acquired.
# define Py_BEGIN_CRITICAL_SECTION_SEQUENCE_FAST(original)              \
    {                                                                   \
        PyObject *_orig_seq = _PyObject_CAST(original);                 \
        const bool _should_lock_cs = PyList_CheckExact(_orig_seq);      \
        PyCriticalSection _cs;                                          \
        if (_should_lock_cs) {                                          \
            _PyCriticalSection_Begin(&_cs, _orig_seq);                  \
        }

# define Py_END_CRITICAL_SECTION_SEQUENCE_FAST()                        \
        if (_should_lock_cs) {                                          \
            PyCriticalSection_End(&_cs);                                \
        }                                                               \
    }

// Asserts that the mutex is locked.  The mutex must be held by the
// top-most critical section otherwise there's the possibility
// that the mutex would be swalled out in some code paths.
#define _Py_CRITICAL_SECTION_ASSERT_MUTEX_LOCKED(mutex) \
    _PyCriticalSection_AssertHeld(mutex)

// Asserts that the mutex for the given object is locked. The mutex must
// be held by the top-most critical section otherwise there's the
// possibility that the mutex would be swalled out in some code paths.
#ifdef Py_DEBUG

# define _Py_CRITICAL_SECTION_ASSERT_OBJECT_LOCKED(op)                           \
    if (Py_REFCNT(op) != 1) {                                                    \
        _Py_CRITICAL_SECTION_ASSERT_MUTEX_LOCKED(&_PyObject_CAST(op)->ob_mutex); \
    }

#else   /* Py_DEBUG */

# define _Py_CRITICAL_SECTION_ASSERT_OBJECT_LOCKED(op)

#endif  /* Py_DEBUG */

#else  /* !Py_GIL_DISABLED */
// The critical section APIs are no-ops with the GIL.
# define Py_BEGIN_CRITICAL_SECTION_MUT(mut) {
# define Py_BEGIN_CRITICAL_SECTION2_MUT(m1, m2) {
# define Py_BEGIN_CRITICAL_SECTION_SEQUENCE_FAST(original) {
# define Py_END_CRITICAL_SECTION_SEQUENCE_FAST() }
# define _Py_CRITICAL_SECTION_ASSERT_MUTEX_LOCKED(mutex)
# define _Py_CRITICAL_SECTION_ASSERT_OBJECT_LOCKED(op)
#endif  /* !Py_GIL_DISABLED */

// Resumes the top-most critical section.
PyAPI_FUNC(void)
_PyCriticalSection_Resume(PyThreadState *tstate);

// (private) slow path for locking the mutex
PyAPI_FUNC(void)
_PyCriticalSection_BeginSlow(PyCriticalSection *c, PyMutex *m);

PyAPI_FUNC(void)
_PyCriticalSection2_BeginSlow(PyCriticalSection2 *c, PyMutex *m1, PyMutex *m2,
                             int is_m1_locked);

PyAPI_FUNC(void)
_PyCriticalSection_SuspendAll(PyThreadState *tstate);

#ifdef Py_GIL_DISABLED

static inline int
_PyCriticalSection_IsActive(uintptr_t tag)
{
    return tag != 0 && (tag & _Py_CRITICAL_SECTION_INACTIVE) == 0;
}

static inline void
_PyCriticalSection_BeginMutex(PyCriticalSection *c, PyMutex *m)
{
    if (PyMutex_LockFast(&m->_bits)) {
        PyThreadState *tstate = _PyThreadState_GET();
        c->_cs_mutex = m;
        c->_cs_prev = tstate->critical_section;
        tstate->critical_section = (uintptr_t)c;
    }
    else {
        _PyCriticalSection_BeginSlow(c, m);
    }
}

static inline void
_PyCriticalSection_Begin(PyCriticalSection *c, PyObject *op)
{
    _PyCriticalSection_BeginMutex(c, &op->ob_mutex);
}
#define PyCriticalSection_Begin _PyCriticalSection_Begin

// Removes the top-most critical section from the thread's stack of critical
// sections. If the new top-most critical section is inactive, then it is
// resumed.
static inline void
_PyCriticalSection_Pop(PyCriticalSection *c)
{
    PyThreadState *tstate = _PyThreadState_GET();
    uintptr_t prev = c->_cs_prev;
    tstate->critical_section = prev;

if ((prev & _Py_CRITICAL_SECTION_INACTIVE) != 0) {
        _PyCriticalSection_Resume(tstate);
    }
}

static inline void
_PyCriticalSection_End(PyCriticalSection *c)
{
    PyMutex_Unlock(c->_cs_mutex);
    _PyCriticalSection_Pop(c);
}
#define PyCriticalSection_End _PyCriticalSection_End

static inline void
_PyCriticalSection2_BeginMutex(PyCriticalSection2 *c, PyMutex *m1, PyMutex *m2)
{
    if (m1 == m2) {
        // If the two mutex arguments are the same, treat this as a critical
        // section with a single mutex.
        c->_cs_mutex2 = NULL;
        _PyCriticalSection_BeginMutex(&c->_cs_base, m1);
        return;
    }

if ((uintptr_t)m2 < (uintptr_t)m1) {
        // Sort the mutexes so that the lower address is locked first.
        // The exact order does not matter, but we need to acquire the mutexes
        // in a consistent order to avoid lock ordering deadlocks.
        PyMutex *tmp = m1;
        m1 = m2;
        m2 = tmp;
    }

if (PyMutex_LockFast(&m1->_bits)) {
        if (PyMutex_LockFast(&m2->_bits)) {
            PyThreadState *tstate = _PyThreadState_GET();
            c->_cs_base._cs_mutex = m1;
            c->_cs_mutex2 = m2;
            c->_cs_base._cs_prev = tstate->critical_section;

uintptr_t p = (uintptr_t)c | _Py_CRITICAL_SECTION_TWO_MUTEXES;
            tstate->critical_section = p;
        }
        else {
            _PyCriticalSection2_BeginSlow(c, m1, m2, 1);
        }
    }
    else {
        _PyCriticalSection2_BeginSlow(c, m1, m2, 0);
    }
}

static inline void
_PyCriticalSection2_Begin(PyCriticalSection2 *c, PyObject *a, PyObject *b)
{
    _PyCriticalSection2_BeginMutex(c, &a->ob_mutex, &b->ob_mutex);
}
#define PyCriticalSection2_Begin _PyCriticalSection2_Begin

static inline void
_PyCriticalSection2_End(PyCriticalSection2 *c)
{
    if (c->_cs_mutex2) {
        PyMutex_Unlock(c->_cs_mutex2);
    }
    PyMutex_Unlock(c->_cs_base._cs_mutex);
    _PyCriticalSection_Pop(&c->_cs_base);
}
#define PyCriticalSection2_End _PyCriticalSection2_End

static inline void
_PyCriticalSection_AssertHeld(PyMutex *mutex)
{
#ifdef Py_DEBUG
    PyThreadState *tstate = _PyThreadState_GET();
    uintptr_t prev = tstate->critical_section;
    if (prev & _Py_CRITICAL_SECTION_TWO_MUTEXES) {
        PyCriticalSection2 *cs = (PyCriticalSection2 *)(prev & ~_Py_CRITICAL_SECTION_MASK);
        assert(cs != NULL && (cs->_cs_base._cs_mutex == mutex || cs->_cs_mutex2 == mutex));
    }
    else {
        PyCriticalSection *cs = (PyCriticalSection *)(tstate->critical_section & ~_Py_CRITICAL_SECTION_MASK);
        assert(cs != NULL && cs->_cs_mutex == mutex);
    }

#endif
}

#endif /* Py_GIL_DISABLED */

#ifdef __cplusplus
}
#endif
#endif /* !Py_INTERNAL_CRITICAL_SECTION_H */

CANCEL

Name	Type	Size	Modified	Actions
↩ ..	DIR	—	—
📁 mimalloc/	DIR	—	2026-10-27 23:40
📄 pycore_abstract.h	H	1.9 KB	2026-10-25 18:31	EDIT
📄 pycore_asdl.h	H	3 KB	2026-10-25 18:31	EDIT
📄 pycore_ast.h	H	30.8 KB	2026-10-25 18:31	EDIT
📄 pycore_ast_state.h	H	6.6 KB	2026-10-25 18:31	EDIT
📄 pycore_atexit.h	H	1.4 KB	2026-10-25 18:31	EDIT
📄 pycore_backoff.h	H	3.9 KB	2026-10-25 18:31	EDIT
📄 pycore_bitutils.h	H	5.9 KB	2026-10-25 18:31	EDIT
📄 pycore_blocks_output_buffer.h	H	8.6 KB	2026-10-25 18:31	EDIT
📄 pycore_brc.h	H	2.1 KB	2026-10-25 18:31	EDIT
📄 pycore_bytes_methods.h	H	3.8 KB	2026-10-25 18:31	EDIT
📄 pycore_bytesobject.h	H	5 KB	2026-10-25 18:31	EDIT
📄 pycore_call.h	H	6 KB	2026-10-25 18:31	EDIT
📄 pycore_capsule.h	H	397 B	2026-10-25 18:31	EDIT
📄 pycore_cell.h	H	1 KB	2026-10-25 18:31	EDIT
📄 pycore_ceval.h	H	11.1 KB	2026-10-25 18:31	EDIT
📄 pycore_ceval_state.h	H	3.9 KB	2026-10-25 18:31	EDIT
📄 pycore_code.h	H	19.8 KB	2026-10-25 18:31	EDIT
📄 pycore_codecs.h	H	2.4 KB	2026-10-25 18:31	EDIT
📄 pycore_compile.h	H	3.7 KB	2026-10-25 18:31	EDIT
📄 pycore_complexobject.h	H	588 B	2026-10-25 18:31	EDIT
📄 pycore_condvar.h	H	2.6 KB	2026-10-25 18:31	EDIT
📄 pycore_context.h	H	1.2 KB	2026-10-25 18:31	EDIT
📄 pycore_critical_section.h	H	7.8 KB	2026-10-25 18:31	EDIT
📄 pycore_crossinterp.h	H	11.8 KB	2026-10-25 18:31	EDIT
📄 pycore_descrobject.h	H	543 B	2026-10-25 18:31	EDIT
📄 pycore_dict.h	H	12 KB	2026-10-25 18:31	EDIT
📄 pycore_dict_state.h	H	732 B	2026-10-25 18:31	EDIT
📄 pycore_dtoa.h	H	1.7 KB	2026-10-25 18:31	EDIT
📄 pycore_emscripten_signal.h	H	685 B	2026-10-25 18:31	EDIT
📄 pycore_emscripten_trampoline.h	H	3.1 KB	2026-10-25 18:31	EDIT
📄 pycore_exceptions.h	H	900 B	2026-10-25 18:31	EDIT
📄 pycore_faulthandler.h	H	2.2 KB	2026-10-25 18:31	EDIT
📄 pycore_fileutils.h	H	9.2 KB	2026-10-25 18:31	EDIT
📄 pycore_fileutils_windows.h	H	2.6 KB	2026-10-25 18:31	EDIT
📄 pycore_floatobject.h	H	1.5 KB	2026-10-25 18:31	EDIT
📄 pycore_flowgraph.h	H	1.5 KB	2026-10-25 18:31	EDIT
📄 pycore_format.h	H	480 B	2026-10-25 18:31	EDIT
📄 pycore_frame.h	H	12.1 KB	2026-10-25 18:31	EDIT
📄 pycore_freelist.h	H	4.7 KB	2026-10-25 18:31	EDIT
📄 pycore_function.h	H	1.5 KB	2026-10-25 18:31	EDIT
📄 pycore_gc.h	H	12.7 KB	2026-10-25 18:31	EDIT
📄 pycore_genobject.h	H	859 B	2026-10-25 18:31	EDIT
📄 pycore_getopt.h	H	490 B	2026-10-25 18:31	EDIT
📄 pycore_gil.h	H	2.1 KB	2026-10-25 18:31	EDIT
📄 pycore_global_objects.h	H	3 KB	2026-10-25 18:31	EDIT
📄 pycore_global_objects_fini_generated.h	H	115 KB	2026-10-25 18:31	EDIT
📄 pycore_global_strings.h	H	26.1 KB	2026-10-25 18:31	EDIT
📄 pycore_hamt.h	H	3.7 KB	2026-10-25 18:31	EDIT
📄 pycore_hashtable.h	H	4.3 KB	2026-10-25 18:31	EDIT
📄 pycore_identifier.h	H	515 B	2026-10-25 18:31	EDIT
📄 pycore_import.h	H	7.5 KB	2026-10-25 18:31	EDIT
📄 pycore_importdl.h	H	4 KB	2026-10-25 18:31	EDIT
📄 pycore_initconfig.h	H	6.2 KB	2026-10-25 18:31	EDIT
📄 pycore_instruction_sequence.h	H	2.1 KB	2026-10-25 18:31	EDIT
📄 pycore_instruments.h	H	2.3 KB	2026-10-25 18:31	EDIT
📄 pycore_interp.h	H	14.7 KB	2026-10-25 18:31	EDIT
📄 pycore_intrinsics.h	H	1.7 KB	2026-10-25 18:31	EDIT
📄 pycore_jit.h	H	527 B	2026-10-25 18:31	EDIT
📄 pycore_list.h	H	1.8 KB	2026-10-25 18:31	EDIT
📄 pycore_llist.h	H	2.4 KB	2026-10-25 18:31	EDIT
📄 pycore_lock.h	H	8.3 KB	2026-10-25 18:31	EDIT
📄 pycore_long.h	H	10.5 KB	2026-10-25 18:31	EDIT
📄 pycore_memoryobject.h	H	427 B	2026-10-25 18:31	EDIT
📄 pycore_mimalloc.h	H	1.6 KB	2026-10-25 18:31	EDIT
📄 pycore_modsupport.h	H	3.3 KB	2026-10-25 18:31	EDIT
📄 pycore_moduleobject.h	H	1.5 KB	2026-10-25 18:31	EDIT
📄 pycore_namespace.h	H	435 B	2026-10-25 18:31	EDIT
📄 pycore_object.h	H	27.3 KB	2026-10-25 18:31	EDIT
📄 pycore_object_alloc.h	H	2.1 KB	2026-10-25 18:31	EDIT
📄 pycore_object_stack.h	H	2.3 KB	2026-10-25 18:31	EDIT
📄 pycore_object_state.h	H	942 B	2026-10-25 18:31	EDIT
📄 pycore_obmalloc.h	H	26.8 KB	2026-10-25 18:31	EDIT
📄 pycore_obmalloc_init.h	H	1.9 KB	2026-10-25 18:31	EDIT
📄 pycore_opcode_metadata.h	H	82.9 KB	2026-10-25 18:31	EDIT
📄 pycore_opcode_utils.h	H	2.1 KB	2026-10-25 18:31	EDIT
📄 pycore_optimizer.h	H	8.1 KB	2026-10-25 18:31	EDIT
📄 pycore_parking_lot.h	H	3.3 KB	2026-10-25 18:31	EDIT
📄 pycore_parser.h	H	2 KB	2026-10-25 18:31	EDIT
📄 pycore_pathconfig.h	H	658 B	2026-10-25 18:31	EDIT
📄 pycore_pyarena.h	H	2.8 KB	2026-10-25 18:31	EDIT
📄 pycore_pyatomic_ft_wrappers.h	H	7.9 KB	2026-10-25 18:31	EDIT
📄 pycore_pybuffer.h	H	510 B	2026-10-25 18:31	EDIT
📄 pycore_pyerrors.h	H	4.8 KB	2026-10-25 18:31	EDIT
📄 pycore_pyhash.h	H	2.8 KB	2026-10-25 18:31	EDIT
📄 pycore_pylifecycle.h	H	4.2 KB	2026-10-25 18:31	EDIT
📄 pycore_pymath.h	H	8.4 KB	2026-10-25 18:31	EDIT
📄 pycore_pymem.h	H	5.2 KB	2026-10-25 18:31	EDIT
📄 pycore_pymem_init.h	H	3.4 KB	2026-10-25 18:31	EDIT
📄 pycore_pystate.h	H	9.7 KB	2026-10-25 18:31	EDIT
📄 pycore_pystats.h	H	420 B	2026-10-25 18:31	EDIT
📄 pycore_pythonrun.h	H	832 B	2026-10-25 18:31	EDIT
📄 pycore_pythread.h	H	5.9 KB	2026-10-25 18:31	EDIT
📄 pycore_qsbr.h	H	5.4 KB	2026-10-25 18:31	EDIT
📄 pycore_range.h	H	346 B	2026-10-25 18:31	EDIT
📄 pycore_runtime.h	H	12.9 KB	2026-10-25 18:31	EDIT
📄 pycore_runtime_init.h	H	12.7 KB	2026-10-25 18:31	EDIT
📄 pycore_runtime_init_generated.h	H	45.7 KB	2026-10-25 18:31	EDIT
📄 pycore_semaphore.h	H	1.7 KB	2026-10-25 18:31	EDIT
📄 pycore_setobject.h	H	951 B	2026-10-25 18:31	EDIT
📄 pycore_signal.h	H	2.9 KB	2026-10-25 18:31	EDIT
📄 pycore_sliceobject.h	H	369 B	2026-10-25 18:31	EDIT
📄 pycore_stackref.h	H	5.1 KB	2026-10-25 18:31	EDIT
📄 pycore_strhex.h	H	1013 B	2026-10-25 18:31	EDIT
📄 pycore_structseq.h	H	963 B	2026-10-25 18:31	EDIT
📄 pycore_symtable.h	H	8.5 KB	2026-10-25 18:31	EDIT
📄 pycore_sysmodule.h	H	1.1 KB	2026-10-25 18:31	EDIT
📄 pycore_time.h	H	11.5 KB	2026-10-25 18:31	EDIT
📄 pycore_token.h	H	2.9 KB	2026-10-25 18:31	EDIT
📄 pycore_traceback.h	H	3.5 KB	2026-10-25 18:31	EDIT
📄 pycore_tracemalloc.h	H	4.4 KB	2026-10-25 18:31	EDIT
📄 pycore_tstate.h	H	1.3 KB	2026-10-25 18:31	EDIT
📄 pycore_tuple.h	H	820 B	2026-10-25 18:31	EDIT
📄 pycore_typeobject.h	H	8.7 KB	2026-10-25 18:31	EDIT
📄 pycore_typevarobject.h	H	924 B	2026-10-25 18:31	EDIT
📄 pycore_ucnhash.h	H	958 B	2026-10-25 18:31	EDIT
📄 pycore_unicodeobject.h	H	13 KB	2026-10-25 18:31	EDIT
📄 pycore_unicodeobject_generated.h	H	129 KB	2026-10-25 18:31	EDIT
📄 pycore_unionobject.h	H	742 B	2026-10-25 18:31	EDIT
📄 pycore_uop_ids.h	H	10.1 KB	2026-10-25 18:31	EDIT
📄 pycore_uop_metadata.h	H	38.7 KB	2026-10-25 18:31	EDIT
📄 pycore_warnings.h	H	840 B	2026-10-25 18:31	EDIT
📄 pycore_weakref.h	H	3.8 KB	2026-10-25 18:31	EDIT