Beginning of multi-user support (#2262)

Adds a lock to generate_reply

modules/text_generation.py

@@ -1,6 +1,7 @@
 import ast
 import random
 import re
+import threading
 import time
 import traceback
 
@@ -17,6 +18,15 @@ from modules.logging_colors import logger
 from modules.models import clear_torch_cache, local_rank
 
 
+def generate_reply(*args, **kwargs):
+    shared.generation_lock.acquire()
+    try:
+        for result in _generate_reply(*args, **kwargs):
+            yield result
+    finally:
+        shared.generation_lock.release()
+
+
 def get_max_prompt_length(state):
     max_length = state['truncation_length'] - state['max_new_tokens']
     if shared.soft_prompt:
@@ -154,7 +164,7 @@ def generate_reply_wrapper(question, state, eos_token=None, stopping_strings=Non
         yield formatted_outputs(reply, shared.model_name)
 
 
-def generate_reply(question, state, eos_token=None, stopping_strings=None, is_chat=False):
+def _generate_reply(question, state, eos_token=None, stopping_strings=None, is_chat=False):
     state = apply_extensions('state', state)
     generate_func = apply_extensions('custom_generate_reply')
     if generate_func is None: