Add "stopping" state.

[solowalker27]

Fixes #981

[mattiekat]

Looks good to me. Tested working on my setup.

[mangatmodi]

I saw the code and it should work, but I am trying to think why this is introduced.

here -

locust/locust/runners.py

Line 436 in 68ac9d3

self.client.send(Message("client_ready", None, self.client_id))

Client on being stop sends client_ready message. Master now hatch the client here -

locust/locust/runners.py

Line 346 in 68ac9d3

self.start_hatching(self.num_clients, self.hatch_rate)

Which was added in recent commit - 1549929

Client is now in HATCHING state -

locust/locust/runners.py

Line 426 in 68ac9d3

self.slave_state = STATE_HATCHING

With a bit of bad luck(or enough number of runs), server might receive one of the client as hatching and hence the condition will become false -

locust/locust/runners.py

Line 374 in 68ac9d3

if not self.state == STATE_INIT and all(map(lambda x: x.state != STATE_RUNNING and x.state != STATE_HATCHING, self.clients.all)):

Adding STOPPING works as it will avoid hatching the clients, no matter the status. It seems good enough, but I see the problem when a client is stopped, it shouldn't be ready.

[mangatmodi]

I think it is ready because master can send another test request, after stopping one.

[cgoldberg]

LGTM.. I'll merge this and we'll test more against master.
thanks! 👍

[wincus]

validated that this fixed the issue on our setup as well. Thanks!

[tsykora-verimatrix]

glad to see this fixed, good job, is it going to be part of 0.12.0 or how it will be released?