This requires some trickery to properly save the exception state if the
generator creates its own exception state.

This prevents generator exception state from leaking into the caller.

Closes #12475.

qsize() raises NotImplementedError on OS X, don't use it.

Original patch by Nicolas Estibals.  My tweaks to the patch were mostly
style/cosmetic, and adding more tests.

freed by the garbage collector while the Heap lock is held.

freed by the garbage collector while the Heap lock is held.

the garbage collector while the Heap lock is held.

Move also the "ready" trigger after the installation of the signal handler and
the call to siginterrupt().

Use a timeout of 5 seconds instead of 3. Two seconds are supposed to be enough,
but some of our buildbots are really slow (especially the FreeBSD 6 VM).

Move also the "ready" trigger after the installation of the signal handler and
the call to siginterrupt().

Use a timeout of 5 seconds instead of 3. Two seconds are supposed to be enough,
but some of our buildbots are really slow (especially the FreeBSD 6 VM).