| extern "C" { | |
| /* Enable if you want to force the switching of threads at least | |
| every `interval`. */ | |
| struct _gil_runtime_state { | |
| /* 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; | |
| /* 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; | |
| /* 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; | |
| }; | |
| } | |