Fixed improper locking procedure on global id

diff --git a/critters.py b/critters.py
index 3472b0cb24c5a8cd0e39bafa2a907693b3354237..91683542de9f25b2a84f9a06a87b32f1671dac74 100755 (executable)
--- a/critters.py
+++ b/critters.py
@@ -6,6 +6,7 @@ from werkzeug.security import generate_password_hash, check_password_hash
 from werkzeug.middleware.proxy_fix import ProxyFix
 from multiprocessing import Value
 from os import listdir
+import threading
 import sqlite3
 import random
 import json
@@ -20,9 +21,8 @@ db_keys = ["title", "album", "artist", "year", "link", "info", "category", "play
 allowed_audio = ["mp3", "wav", "ogg", "flac"]
 allowed_image = ["png", "jpg", "jpeg"]
 
-current_track_id = Value("I") # This is the global track ID
-with current_track_id.get_lock():
-       current_track_id.value = 1
+id_lock = threading.Lock()
+current_track_id = 1
 
 critters_path = os.environ["CRITTERS_PATH"]
 audio_path = critters_path + "/audio/"
@@ -190,6 +190,7 @@ def admin():
 @app.route("/api/next")
 @auth.login_required
 def set_current_id():
+       global current_track_id
        server_data = { # The value for each of the keys is the position in the database columns that peice of data can be found
                "id": 0, # (Note 1)
                "title": 1,
@@ -198,41 +199,42 @@ def set_current_id():
                "outtime": 11
                }
 
-       with current_track_id.get_lock(): # Lock for entire function
-               track_id = current_track_id.value
+       with id_lock:
+               track_id = current_track_id
 
-               current_album = ""
-               current_artist = ""
+       current_album = ""
+       current_artist = ""
 
-               con = sqlite3.connect(db_path)
-               cur = con.cursor()
-               track = cur.execute(f"SELECT album, artist FROM critters WHERE id={track_id}").fetchone()
+       con = sqlite3.connect(db_path)
+       cur = con.cursor()
+       track = cur.execute(f"SELECT album, artist FROM critters WHERE id={track_id}").fetchone()
 
-               if track is not None:
-                       current_album, current_artist = track
+       if track is not None:
+               current_album, current_artist = track
 
-               category_secifier = ""
-               if "c" in request.args:
-                       category = request.args.get("c")
-                       category_secifier = f" AND category = '{category}'"
+       category_secifier = ""
+       if "c" in request.args:
+               category = request.args.get("c")
+               category_secifier = f" AND category = '{category}'"
 
-               tracks = cur.execute(f"""
-                       SELECT * FROM critters WHERE
-                       playing = 'true' AND
-                       id != {track_id} AND
-                       album != '{current_album}' AND
-                       artist != '{current_artist}'{category_secifier}
-                       """).fetchall()
+       tracks = cur.execute(f"""
+               SELECT * FROM critters WHERE
+               playing = 'true' AND
+               id != {track_id} AND
+               album != '{current_album}' AND
+               artist != '{current_artist}'{category_secifier}
+               """).fetchall()
 
-               if tracks is not None:
-                       target_index = random.randint(0, len(tracks)-1)
+       if tracks is not None:
+               target_index = random.randint(0, len(tracks)-1)
 
-                       current_track_id.value = tracks[target_index][0]
+               with id_lock:
+                       current_track_id = tracks[target_index][0]
 
-                       for key, i in server_data.items():
-                               server_data[key] = tracks[target_index][i] # See note 1
+               for key, i in server_data.items():
+                       server_data[key] = tracks[target_index][i] # See note 1
 
-               return Response(json.dumps(server_data), mimetype="text/json")
+       return Response(json.dumps(server_data), mimetype="text/json")
 
 @app.route("/api/get", methods=['GET'])
 def get_tracks():
@@ -261,9 +263,11 @@ def get_tracks():
 # Call for getting single track details with all feilds in JSON
 @app.route("/api/<int:track_id>")
 def get_single_track(track_id):
+       global current_track_id
+
        if track_id == 0:
-               with current_track_id.get_lock():
-                       track_id = current_track_id.value
+               with id_lock:
+                       track_id = current_track_id
        con = sqlite3.connect(db_path)
        cur = con.cursor()
        track = cur.execute(f"SELECT * FROM critters WHERE id={track_id}").fetchone()
@@ -283,14 +287,17 @@ def get_single_track(track_id):
        if track is not None:
                for (i, key) in enumerate(track_data):
                        track_data[key] = track[i]
+
        return Response(json.dumps(track_data | cover_path), mimetype="text/json")
 
 # Call for getting single track details with a single feild
 @app.route("/api/<int:track_id>.<string:feild>")
 def get_single_field(track_id, feild):
+       global current_track_id
+
        if track_id == 0:
-               with current_track_id.get_lock():
-                       track_id = current_track_id.value
+               with id_lock:
+                       track_id = current_track_id
        result = "Unknown"
        if feild in db_keys:
                con = sqlite3.connect(db_path)