#ifndef Py_INTERNAL_GIL_H
#define Py_INTERNAL_GIL_H
#ifdef __cplusplus
extern "C" {
#endif
#include "pyatomic.h"
#include "internal/condvar.h"
#ifndef Py_HAVE_CONDVAR
#error You need either a POSIX-compatible or a Windows system!
#endif
/* Enable if you want to force the switching of threads at least
every `interval`. */
#undef FORCE_SWITCHING
#define FORCE_SWITCHING
struct _gil_runtime_state {
/* microseconds (the Python API uses seconds, though) */
unsigned long interval;
/* Last PyThreadState holding / having held the GIL. This helps us
know whether anyone else was scheduled after we dropped the GIL. */
_Py_atomic_address last_holder;
/* Whether the GIL is already taken (-1 if uninitialized). This is
atomic because it can be read without any lock taken in ceval.c. */
_Py_atomic_int locked;
/* Number of GIL switches since the beginning. */
unsigned long switch_number;
/* This condition variable allows one or several threads to wait
until the GIL is released. In addition, the mutex also protects
the above variables. */
PyCOND_T cond;
PyMUTEX_T mutex;
#ifdef FORCE_SWITCHING
/* This condition variable helps the GIL-releasing thread wait for
a GIL-awaiting thread to be scheduled and take the GIL. */
PyCOND_T switch_cond;
PyMUTEX_T switch_mutex;
#endif
};
#ifdef __cplusplus
}
#endif
#endif /* !Py_INTERNAL_GIL_H */
