diff options
Diffstat (limited to 'Python/pystate.c')
| -rw-r--r-- | Python/pystate.c | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/Python/pystate.c b/Python/pystate.c index cfd61d0098..2a6f16c87f 100644 --- a/Python/pystate.c +++ b/Python/pystate.c @@ -414,6 +414,53 @@ PyThreadState_DeleteCurrent() #endif /* WITH_THREAD */ +/* + * Delete all thread states except the one passed as argument. + * Note that, if there is a current thread state, it *must* be the one + * passed as argument. Also, this won't touch any other interpreters + * than the current one, since we don't know which thread state should + * be kept in those other interpreteres. + */ +void +_PyThreadState_DeleteExcept(PyThreadState *tstate) +{ + PyInterpreterState *interp = tstate->interp; + PyThreadState *p, *next, *garbage; + HEAD_LOCK(); + /* Remove all thread states, except tstate, from the linked list of + thread states. This will allow calling PyThreadState_Clear() + without holding the lock. + XXX This would be simpler with a doubly-linked list. */ + garbage = interp->tstate_head; + interp->tstate_head = tstate; + if (garbage == tstate) { + garbage = garbage->next; + tstate->next = NULL; + } + else { + for (p = garbage; p; p = p->next) { + if (p->next == tstate) { + p->next = tstate->next; + tstate->next = NULL; + break; + } + } + } + if (tstate->next != NULL) + Py_FatalError("_PyThreadState_DeleteExcept: tstate not found " + "in interpreter thread states"); + HEAD_UNLOCK(); + /* Clear and deallocate all stale thread states. Even if this + executes Python code, we should be safe since it executes + in the current thread, not one of the stale threads. */ + for (p = garbage; p; p = next) { + next = p->next; + PyThreadState_Clear(p); + free(p); + } +} + + PyThreadState * PyThreadState_Get(void) { @@ -697,6 +744,15 @@ PyGILState_GetThisThreadState(void) return (PyThreadState *)PyThread_get_key_value(autoTLSkey); } +int +PyGILState_Check(void) +{ + /* can't use PyThreadState_Get() since it will assert that it has the GIL */ + PyThreadState *tstate = (PyThreadState*)_Py_atomic_load_relaxed( + &_PyThreadState_Current); + return tstate && (tstate == PyGILState_GetThisThreadState()); +} + PyGILState_STATE PyGILState_Ensure(void) { |