mirror of
https://github.com/python/cpython.git
synced 2024-11-25 01:20:47 +01:00
8f17d69b7b
This makes the following macros public as part of the non-limited C-API for locking a single object or two objects at once. * `Py_BEGIN_CRITICAL_SECTION(op)` / `Py_END_CRITICAL_SECTION()` * `Py_BEGIN_CRITICAL_SECTION2(a, b)` / `Py_END_CRITICAL_SECTION2()` The supporting functions and structs used by the macros are also exposed for cases where C macros are not available.
149 lines
3.3 KiB
C
149 lines
3.3 KiB
C
#include "Python.h"
|
|
|
|
#include "pycore_lock.h"
|
|
#include "pycore_critical_section.h"
|
|
|
|
#ifdef Py_GIL_DISABLED
|
|
static_assert(_Alignof(PyCriticalSection) >= 4,
|
|
"critical section must be aligned to at least 4 bytes");
|
|
#endif
|
|
|
|
void
|
|
_PyCriticalSection_BeginSlow(PyCriticalSection *c, PyMutex *m)
|
|
{
|
|
#ifdef Py_GIL_DISABLED
|
|
PyThreadState *tstate = _PyThreadState_GET();
|
|
c->_cs_mutex = NULL;
|
|
c->_cs_prev = (uintptr_t)tstate->critical_section;
|
|
tstate->critical_section = (uintptr_t)c;
|
|
|
|
PyMutex_Lock(m);
|
|
c->_cs_mutex = m;
|
|
#endif
|
|
}
|
|
|
|
void
|
|
_PyCriticalSection2_BeginSlow(PyCriticalSection2 *c, PyMutex *m1, PyMutex *m2,
|
|
int is_m1_locked)
|
|
{
|
|
#ifdef Py_GIL_DISABLED
|
|
PyThreadState *tstate = _PyThreadState_GET();
|
|
c->_cs_base._cs_mutex = NULL;
|
|
c->_cs_mutex2 = NULL;
|
|
c->_cs_base._cs_prev = tstate->critical_section;
|
|
tstate->critical_section = (uintptr_t)c | _Py_CRITICAL_SECTION_TWO_MUTEXES;
|
|
|
|
if (!is_m1_locked) {
|
|
PyMutex_Lock(m1);
|
|
}
|
|
PyMutex_Lock(m2);
|
|
c->_cs_base._cs_mutex = m1;
|
|
c->_cs_mutex2 = m2;
|
|
#endif
|
|
}
|
|
|
|
#ifdef Py_GIL_DISABLED
|
|
static PyCriticalSection *
|
|
untag_critical_section(uintptr_t tag)
|
|
{
|
|
return (PyCriticalSection *)(tag & ~_Py_CRITICAL_SECTION_MASK);
|
|
}
|
|
#endif
|
|
|
|
// Release all locks held by critical sections. This is called by
|
|
// _PyThreadState_Detach.
|
|
void
|
|
_PyCriticalSection_SuspendAll(PyThreadState *tstate)
|
|
{
|
|
#ifdef Py_GIL_DISABLED
|
|
uintptr_t *tagptr = &tstate->critical_section;
|
|
while (_PyCriticalSection_IsActive(*tagptr)) {
|
|
PyCriticalSection *c = untag_critical_section(*tagptr);
|
|
|
|
if (c->_cs_mutex) {
|
|
PyMutex_Unlock(c->_cs_mutex);
|
|
if ((*tagptr & _Py_CRITICAL_SECTION_TWO_MUTEXES)) {
|
|
PyCriticalSection2 *c2 = (PyCriticalSection2 *)c;
|
|
if (c2->_cs_mutex2) {
|
|
PyMutex_Unlock(c2->_cs_mutex2);
|
|
}
|
|
}
|
|
}
|
|
|
|
*tagptr |= _Py_CRITICAL_SECTION_INACTIVE;
|
|
tagptr = &c->_cs_prev;
|
|
}
|
|
#endif
|
|
}
|
|
|
|
void
|
|
_PyCriticalSection_Resume(PyThreadState *tstate)
|
|
{
|
|
#ifdef Py_GIL_DISABLED
|
|
uintptr_t p = tstate->critical_section;
|
|
PyCriticalSection *c = untag_critical_section(p);
|
|
assert(!_PyCriticalSection_IsActive(p));
|
|
|
|
PyMutex *m1 = c->_cs_mutex;
|
|
c->_cs_mutex = NULL;
|
|
|
|
PyMutex *m2 = NULL;
|
|
PyCriticalSection2 *c2 = NULL;
|
|
if ((p & _Py_CRITICAL_SECTION_TWO_MUTEXES)) {
|
|
c2 = (PyCriticalSection2 *)c;
|
|
m2 = c2->_cs_mutex2;
|
|
c2->_cs_mutex2 = NULL;
|
|
}
|
|
|
|
if (m1) {
|
|
PyMutex_Lock(m1);
|
|
}
|
|
if (m2) {
|
|
PyMutex_Lock(m2);
|
|
}
|
|
|
|
c->_cs_mutex = m1;
|
|
if (m2) {
|
|
c2->_cs_mutex2 = m2;
|
|
}
|
|
|
|
tstate->critical_section &= ~_Py_CRITICAL_SECTION_INACTIVE;
|
|
#endif
|
|
}
|
|
|
|
#undef PyCriticalSection_Begin
|
|
void
|
|
PyCriticalSection_Begin(PyCriticalSection *c, PyObject *op)
|
|
{
|
|
#ifdef Py_GIL_DISABLED
|
|
_PyCriticalSection_Begin(c, op);
|
|
#endif
|
|
}
|
|
|
|
#undef PyCriticalSection_End
|
|
void
|
|
PyCriticalSection_End(PyCriticalSection *c)
|
|
{
|
|
#ifdef Py_GIL_DISABLED
|
|
_PyCriticalSection_End(c);
|
|
#endif
|
|
}
|
|
|
|
#undef PyCriticalSection2_Begin
|
|
void
|
|
PyCriticalSection2_Begin(PyCriticalSection2 *c, PyObject *a, PyObject *b)
|
|
{
|
|
#ifdef Py_GIL_DISABLED
|
|
_PyCriticalSection2_Begin(c, a, b);
|
|
#endif
|
|
}
|
|
|
|
#undef PyCriticalSection2_End
|
|
void
|
|
PyCriticalSection2_End(PyCriticalSection2 *c)
|
|
{
|
|
#ifdef Py_GIL_DISABLED
|
|
_PyCriticalSection2_End(c);
|
|
#endif
|
|
}
|