From 71a0f6ef85f2124d5fb25b55d6ec577a56265fe4 Mon Sep 17 00:00:00 2001
From: AnyISalIn <anyisalin@gmail.com>
Date: Mon, 21 Aug 2023 17:48:56 +0800
Subject: [PATCH] feat: replace threading.Lock() to FIFOLock

Signed-off-by: AnyISalIn <anyisalin@gmail.com>
---
 modules/call_queue.py |  5 ++---
 modules/fifo_lock.py  | 37 +++++++++++++++++++++++++++++++++++++
 modules/progress.py   |  7 ++++++-
 3 files changed, 45 insertions(+), 4 deletions(-)
 create mode 100644 modules/fifo_lock.py

diff --git a/modules/call_queue.py b/modules/call_queue.py
index f2eb17d6166..ddf0d57383c 100644
--- a/modules/call_queue.py
+++ b/modules/call_queue.py
@@ -1,11 +1,10 @@
 from functools import wraps
 import html
-import threading
 import time
 
-from modules import shared, progress, errors, devices
+from modules import shared, progress, errors, devices, fifo_lock
 
-queue_lock = threading.Lock()
+queue_lock = fifo_lock.FIFOLock()
 
 
 def wrap_queued_call(func):
diff --git a/modules/fifo_lock.py b/modules/fifo_lock.py
new file mode 100644
index 00000000000..c35b3ae25a3
--- /dev/null
+++ b/modules/fifo_lock.py
@@ -0,0 +1,37 @@
+import threading
+import collections
+
+
+# reference: https://gist.github.com/vitaliyp/6d54dd76ca2c3cdfc1149d33007dc34a
+class FIFOLock(object):
+    def __init__(self):
+        self._lock = threading.Lock()
+        self._inner_lock = threading.Lock()
+        self._pending_threads = collections.deque()
+
+    def acquire(self, blocking=True):
+        with self._inner_lock:
+            lock_acquired = self._lock.acquire(False)
+            if lock_acquired:
+                return True
+            elif not blocking:
+                return False
+
+            release_event = threading.Event()
+            self._pending_threads.append(release_event)
+
+        release_event.wait()
+        return self._lock.acquire()
+
+    def release(self):
+        with self._inner_lock:
+            if self._pending_threads:
+                release_event = self._pending_threads.popleft()
+                release_event.set()
+
+            self._lock.release()
+
+    __enter__ = acquire
+
+    def __exit__(self, t, v, tb):
+        self.release()
diff --git a/modules/progress.py b/modules/progress.py
index e32b59dd5d2..a25a0113274 100644
--- a/modules/progress.py
+++ b/modules/progress.py
@@ -72,7 +72,12 @@ def progressapi(req: ProgressRequest):
     completed = req.id_task in finished_tasks
 
     if not active:
-        return ProgressResponse(active=active, queued=queued, completed=completed, id_live_preview=-1, textinfo="In queue..." if queued else "Waiting...")
+        textinfo = "Waiting..."
+        if queued:
+            sorted_queued = sorted(pending_tasks.keys(), key=lambda x: pending_tasks[x])
+            queue_index = sorted_queued.index(req.id_task)
+            textinfo = "In queue: {}/{}".format(queue_index + 1, len(sorted_queued))
+        return ProgressResponse(active=active, queued=queued, completed=completed, id_live_preview=-1, textinfo=textinfo)
 
     progress = 0