(grafted from c80083ad142db2939507800c755082293a87f2de)

between tracemalloc_remove_trace() and tracemalloc_add_trace() to reduce the
risk of race condition.

tracemalloc_add_trace() cannot fail anymore in tracemalloc_realloc() when
tracemalloc_realloc() resizes a memory block.

PyGILState_Ensure()/PyGILState_Release() calls to the raw wrappers to simplify
the code.

Rename also tracemalloc_log_alloc/log_free() to
tracemalloc_add_trace/remove_trace().

can now avoid a second syscall if the ioctl() function can be used, or if the
non-blocking flag of the socket is unchanged.

Improve also wait() documentation: mention that the first parameter is a
sequence

Issue #19877: fix regression in test_pathlib when Windows has symlink support available (i.e. in administrator mode).
Patch by Vajrasky Kok.

already done by PyMODINIT_FUNC.

Example based on tcp_echo.py example from Tulip source code.

Remove also a duplicated Protocols section!

* complete create_connection() prototype
* link to Server
* document get_extra_info() keys

Patch by Vajrasky Kok.

indication for TLS/SSL connections.

indication for TLS/SSL connections.