1 2 /* Thread and interpreter state structures and their interfaces */ 3 4 5 #ifndef Py_PYSTATE_H 6 #define Py_PYSTATE_H 7 #ifdef __cplusplus 8 extern "C" { 9 #endif 10 11 /* This limitation is for performance and simplicity. If needed it can be 12 removed (with effort). */ 13 #define MAX_CO_EXTRA_USERS 255 14 15 /* State shared between threads */ 16 17 struct _ts; /* Forward */ 18 struct _is; /* Forward */ 19 struct _frame; /* Forward declaration for PyFrameObject. */ 20 21 #ifdef Py_LIMITED_API 22 typedef struct _is PyInterpreterState; 23 #else 24 typedef PyObject* (*_PyFrameEvalFunction)(struct _frame *, int); 25 26 typedef struct _is { 27 28 struct _is *next; 29 struct _ts *tstate_head; 30 31 PyObject *modules; 32 PyObject *modules_by_index; 33 PyObject *sysdict; 34 PyObject *builtins; 35 PyObject *importlib; 36 37 PyObject *codec_search_path; 38 PyObject *codec_search_cache; 39 PyObject *codec_error_registry; 40 int codecs_initialized; 41 int fscodec_initialized; 42 43 #ifdef HAVE_DLOPEN 44 int dlopenflags; 45 #endif 46 47 PyObject *builtins_copy; 48 PyObject *import_func; 49 /* Initialized to PyEval_EvalFrameDefault(). */ 50 _PyFrameEvalFunction eval_frame; 51 } PyInterpreterState; 52 #endif 53 54 55 /* State unique per thread */ 56 57 #ifndef Py_LIMITED_API 58 /* Py_tracefunc return -1 when raising an exception, or 0 for success. */ 59 typedef int (*Py_tracefunc)(PyObject *, struct _frame *, int, PyObject *); 60 61 /* The following values are used for 'what' for tracefunc functions: */ 62 #define PyTrace_CALL 0 63 #define PyTrace_EXCEPTION 1 64 #define PyTrace_LINE 2 65 #define PyTrace_RETURN 3 66 #define PyTrace_C_CALL 4 67 #define PyTrace_C_EXCEPTION 5 68 #define PyTrace_C_RETURN 6 69 #endif 70 71 #ifdef Py_LIMITED_API 72 typedef struct _ts PyThreadState; 73 #else 74 typedef struct _ts { 75 /* See Python/ceval.c for comments explaining most fields */ 76 77 struct _ts *prev; 78 struct _ts *next; 79 PyInterpreterState *interp; 80 81 struct _frame *frame; 82 int recursion_depth; 83 char overflowed; /* The stack has overflowed. Allow 50 more calls 84 to handle the runtime error. */ 85 char recursion_critical; /* The current calls must not cause 86 a stack overflow. */ 87 /* 'tracing' keeps track of the execution depth when tracing/profiling. 88 This is to prevent the actual trace/profile code from being recorded in 89 the trace/profile. */ 90 int tracing; 91 int use_tracing; 92 93 Py_tracefunc c_profilefunc; 94 Py_tracefunc c_tracefunc; 95 PyObject *c_profileobj; 96 PyObject *c_traceobj; 97 98 PyObject *curexc_type; 99 PyObject *curexc_value; 100 PyObject *curexc_traceback; 101 102 PyObject *exc_type; 103 PyObject *exc_value; 104 PyObject *exc_traceback; 105 106 PyObject *dict; /* Stores per-thread state */ 107 108 int gilstate_counter; 109 110 PyObject *async_exc; /* Asynchronous exception to raise */ 111 long thread_id; /* Thread id where this tstate was created */ 112 113 int trash_delete_nesting; 114 PyObject *trash_delete_later; 115 116 /* Called when a thread state is deleted normally, but not when it 117 * is destroyed after fork(). 118 * Pain: to prevent rare but fatal shutdown errors (issue 18808), 119 * Thread.join() must wait for the join'ed thread's tstate to be unlinked 120 * from the tstate chain. That happens at the end of a thread's life, 121 * in pystate.c. 122 * The obvious way doesn't quite work: create a lock which the tstate 123 * unlinking code releases, and have Thread.join() wait to acquire that 124 * lock. The problem is that we _are_ at the end of the thread's life: 125 * if the thread holds the last reference to the lock, decref'ing the 126 * lock will delete the lock, and that may trigger arbitrary Python code 127 * if there's a weakref, with a callback, to the lock. But by this time 128 * _PyThreadState_Current is already NULL, so only the simplest of C code 129 * can be allowed to run (in particular it must not be possible to 130 * release the GIL). 131 * So instead of holding the lock directly, the tstate holds a weakref to 132 * the lock: that's the value of on_delete_data below. Decref'ing a 133 * weakref is harmless. 134 * on_delete points to _threadmodule.c's static release_sentinel() function. 135 * After the tstate is unlinked, release_sentinel is called with the 136 * weakref-to-lock (on_delete_data) argument, and release_sentinel releases 137 * the indirectly held lock. 138 */ 139 void (*on_delete)(void *); 140 void *on_delete_data; 141 142 PyObject *coroutine_wrapper; 143 int in_coroutine_wrapper; 144 145 Py_ssize_t co_extra_user_count; 146 freefunc co_extra_freefuncs[MAX_CO_EXTRA_USERS]; 147 148 PyObject *async_gen_firstiter; 149 PyObject *async_gen_finalizer; 150 151 /* XXX signal handlers should also be here */ 152 153 } PyThreadState; 154 #endif 155 156 157 PyAPI_FUNC(PyInterpreterState *) PyInterpreterState_New(void); 158 PyAPI_FUNC(void) PyInterpreterState_Clear(PyInterpreterState *); 159 PyAPI_FUNC(void) PyInterpreterState_Delete(PyInterpreterState *); 160 #ifndef Py_LIMITED_API 161 PyAPI_FUNC(int) _PyState_AddModule(PyObject*, struct PyModuleDef*); 162 #endif /* !Py_LIMITED_API */ 163 #if !defined(Py_LIMITED_API) || Py_LIMITED_API+0 >= 0x03030000 164 /* New in 3.3 */ 165 PyAPI_FUNC(int) PyState_AddModule(PyObject*, struct PyModuleDef*); 166 PyAPI_FUNC(int) PyState_RemoveModule(struct PyModuleDef*); 167 #endif 168 PyAPI_FUNC(PyObject*) PyState_FindModule(struct PyModuleDef*); 169 #ifndef Py_LIMITED_API 170 PyAPI_FUNC(void) _PyState_ClearModules(void); 171 #endif 172 173 PyAPI_FUNC(PyThreadState *) PyThreadState_New(PyInterpreterState *); 174 #ifndef Py_LIMITED_API 175 PyAPI_FUNC(PyThreadState *) _PyThreadState_Prealloc(PyInterpreterState *); 176 PyAPI_FUNC(void) _PyThreadState_Init(PyThreadState *); 177 #endif /* !Py_LIMITED_API */ 178 PyAPI_FUNC(void) PyThreadState_Clear(PyThreadState *); 179 PyAPI_FUNC(void) PyThreadState_Delete(PyThreadState *); 180 #ifndef Py_LIMITED_API 181 PyAPI_FUNC(void) _PyThreadState_DeleteExcept(PyThreadState *tstate); 182 #endif /* !Py_LIMITED_API */ 183 #ifdef WITH_THREAD 184 PyAPI_FUNC(void) PyThreadState_DeleteCurrent(void); 185 #ifndef Py_LIMITED_API 186 PyAPI_FUNC(void) _PyGILState_Reinit(void); 187 #endif /* !Py_LIMITED_API */ 188 #endif 189 190 /* Return the current thread state. The global interpreter lock must be held. 191 * When the current thread state is NULL, this issues a fatal error (so that 192 * the caller needn't check for NULL). */ 193 PyAPI_FUNC(PyThreadState *) PyThreadState_Get(void); 194 195 #ifndef Py_LIMITED_API 196 /* Similar to PyThreadState_Get(), but don't issue a fatal error 197 * if it is NULL. */ 198 PyAPI_FUNC(PyThreadState *) _PyThreadState_UncheckedGet(void); 199 #endif /* !Py_LIMITED_API */ 200 201 PyAPI_FUNC(PyThreadState *) PyThreadState_Swap(PyThreadState *); 202 PyAPI_FUNC(PyObject *) PyThreadState_GetDict(void); 203 PyAPI_FUNC(int) PyThreadState_SetAsyncExc(long, PyObject *); 204 205 206 /* Variable and macro for in-line access to current thread state */ 207 208 /* Assuming the current thread holds the GIL, this is the 209 PyThreadState for the current thread. */ 210 #ifdef Py_BUILD_CORE 211 PyAPI_DATA(_Py_atomic_address) _PyThreadState_Current; 212 # define PyThreadState_GET() \ 213 ((PyThreadState*)_Py_atomic_load_relaxed(&_PyThreadState_Current)) 214 #else 215 # define PyThreadState_GET() PyThreadState_Get() 216 #endif 217 218 typedef 219 enum {PyGILState_LOCKED, PyGILState_UNLOCKED} 220 PyGILState_STATE; 221 222 #ifdef WITH_THREAD 223 224 /* Ensure that the current thread is ready to call the Python 225 C API, regardless of the current state of Python, or of its 226 thread lock. This may be called as many times as desired 227 by a thread so long as each call is matched with a call to 228 PyGILState_Release(). In general, other thread-state APIs may 229 be used between _Ensure() and _Release() calls, so long as the 230 thread-state is restored to its previous state before the Release(). 231 For example, normal use of the Py_BEGIN_ALLOW_THREADS/ 232 Py_END_ALLOW_THREADS macros are acceptable. 233 234 The return value is an opaque "handle" to the thread state when 235 PyGILState_Ensure() was called, and must be passed to 236 PyGILState_Release() to ensure Python is left in the same state. Even 237 though recursive calls are allowed, these handles can *not* be shared - 238 each unique call to PyGILState_Ensure must save the handle for its 239 call to PyGILState_Release. 240 241 When the function returns, the current thread will hold the GIL. 242 243 Failure is a fatal error. 244 */ 245 PyAPI_FUNC(PyGILState_STATE) PyGILState_Ensure(void); 246 247 /* Release any resources previously acquired. After this call, Python's 248 state will be the same as it was prior to the corresponding 249 PyGILState_Ensure() call (but generally this state will be unknown to 250 the caller, hence the use of the GILState API.) 251 252 Every call to PyGILState_Ensure must be matched by a call to 253 PyGILState_Release on the same thread. 254 */ 255 PyAPI_FUNC(void) PyGILState_Release(PyGILState_STATE); 256 257 /* Helper/diagnostic function - get the current thread state for 258 this thread. May return NULL if no GILState API has been used 259 on the current thread. Note that the main thread always has such a 260 thread-state, even if no auto-thread-state call has been made 261 on the main thread. 262 */ 263 PyAPI_FUNC(PyThreadState *) PyGILState_GetThisThreadState(void); 264 265 #ifndef Py_LIMITED_API 266 /* Issue #26558: Flag to disable PyGILState_Check(). 267 If set to non-zero, PyGILState_Check() always return 1. */ 268 PyAPI_DATA(int) _PyGILState_check_enabled; 269 270 /* Helper/diagnostic function - return 1 if the current thread 271 currently holds the GIL, 0 otherwise. 272 273 The function returns 1 if _PyGILState_check_enabled is non-zero. */ 274 PyAPI_FUNC(int) PyGILState_Check(void); 275 276 /* Unsafe function to get the single PyInterpreterState used by this process' 277 GILState implementation. 278 279 Return NULL before _PyGILState_Init() is called and after _PyGILState_Fini() 280 is called. */ 281 PyAPI_FUNC(PyInterpreterState *) _PyGILState_GetInterpreterStateUnsafe(void); 282 #endif 283 284 #endif /* #ifdef WITH_THREAD */ 285 286 /* The implementation of sys._current_frames() Returns a dict mapping 287 thread id to that thread's current frame. 288 */ 289 #ifndef Py_LIMITED_API 290 PyAPI_FUNC(PyObject *) _PyThread_CurrentFrames(void); 291 #endif 292 293 /* Routines for advanced debuggers, requested by David Beazley. 294 Don't use unless you know what you are doing! */ 295 #ifndef Py_LIMITED_API 296 PyAPI_FUNC(PyInterpreterState *) PyInterpreterState_Head(void); 297 PyAPI_FUNC(PyInterpreterState *) PyInterpreterState_Next(PyInterpreterState *); 298 PyAPI_FUNC(PyThreadState *) PyInterpreterState_ThreadHead(PyInterpreterState *); 299 PyAPI_FUNC(PyThreadState *) PyThreadState_Next(PyThreadState *); 300 301 typedef struct _frame *(*PyThreadFrameGetter)(PyThreadState *self_); 302 #endif 303 304 /* hook for PyEval_GetFrame(), requested for Psyco */ 305 #ifndef Py_LIMITED_API 306 PyAPI_DATA(PyThreadFrameGetter) _PyThreadState_GetFrame; 307 #endif 308 309 #ifdef __cplusplus 310 } 311 #endif 312 #endif /* !Py_PYSTATE_H */ 313
