mirror of
https://github.com/python/cpython
synced 2024-09-30 10:29:32 +00:00
853163d3b5
Add the ability to enable/disable the GIL at runtime, and use that in the C module loading code. We can't know before running a module init function if it supports free-threading, so the GIL is temporarily enabled before doing so. If the module declares support for running without the GIL, the GIL is later disabled. Otherwise, the GIL is permanently enabled, and will never be disabled again for the life of the current interpreter.
67 lines
2.1 KiB
C
67 lines
2.1 KiB
C
#ifndef Py_INTERNAL_GIL_H
|
|
#define Py_INTERNAL_GIL_H
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
#ifndef Py_BUILD_CORE
|
|
# error "this header requires Py_BUILD_CORE define"
|
|
#endif
|
|
|
|
#include "pycore_condvar.h" // PyCOND_T
|
|
|
|
#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 {
|
|
#ifdef Py_GIL_DISABLED
|
|
/* If this GIL is disabled, enabled == 0.
|
|
|
|
If this GIL is enabled transiently (most likely to initialize a module
|
|
of unknown safety), enabled indicates the number of active transient
|
|
requests.
|
|
|
|
If this GIL is enabled permanently, enabled == INT_MAX.
|
|
|
|
It must not be modified directly; use _PyEval_EnableGILTransiently(),
|
|
_PyEval_EnableGILPermanently(), and _PyEval_DisableGIL()
|
|
|
|
It is always read and written atomically, but a thread can assume its
|
|
value will be stable as long as that thread is attached or knows that no
|
|
other threads are attached (e.g., during a stop-the-world.). */
|
|
int enabled;
|
|
#endif
|
|
/* 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. */
|
|
PyThreadState* 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. */
|
|
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 */
|