Getting the CI to pass consistently on Windows (hopefully)

.github/workflows/backend.yml

@@ -39,81 +39,12 @@ jobs:
             - '.github/**'
           scripts:
             - 'scripts/**'
-  client-test:
-    needs: [changes]
-    if: needs.changes.outputs.python-client == 'true' || needs.changes.outputs.workflows == 'true'
-    strategy:
-      matrix:
-        os: ["ubuntu-latest", "windows-latest"]
-        test-type: ["not flaky", "flaky"]
-        python-version: ["3.8"]
-    runs-on: ${{ matrix.os }}
-    continue-on-error: ${{ matrix.test-type == 'flaky' }}
-    defaults:
-      run:
-        working-directory: client/python
-    steps:
-    - uses: actions/checkout@v3
-    - name: Install Python
-      uses: actions/setup-python@v4
-      with:
-        python-version: ${{ matrix.python-version }}
-        cache: pip
-        cache-dependency-path: |
-          client/python/requirements.txt
-          requirements.txt
-          test/requirements.txt
-    - name: Create env
-      run: |
-        python -m pip install --upgrade virtualenv
-        python -m virtualenv venv
-    - uses: actions/cache@master
-      id: cache
-      with:
-        path: |
-          client/python/venv/*
-        key: python-client-${{ runner.os }}-pip-${{ hashFiles('client/python/requirements.txt') }}-${{ hashFiles('client/python/test/requirements.txt') }}
-    - name: Install Test Requirements (Linux)
-      if: steps.cache.outputs.cache-hit != 'true' && runner.os == 'Linux'
-      run: |
-        . venv/bin/activate
-        python -m pip install -r test/requirements.txt
-    - name: Install Client Library (Linux)
-      if: runner.os == 'Linux'
-      run: |
-        . venv/bin/activate
-        python -m pip install -e .
-    - name: Lint (Linux)
-      if: runner.os == 'Linux'
-      run: |
-        . venv/bin/activate
-        bash scripts/lint.sh
-    - name: Tests (Linux)
-      if: runner.os == 'Linux'
-      run: |
-        . venv/bin/activate
-        python -m pytest -m "${{ matrix.test-type }}"
-    - name: Install Test Requirements (Windows)
-      if: steps.cache.outputs.cache-hit != 'true' && runner.os == 'Windows'
-      run: |
-        venv\Scripts\activate
-        pip install -r test/requirements.txt
-    - name: Install Client Library (Windows)
-      if: runner.os == 'Windows'
-      run: |
-        venv\Scripts\activate
-        pip install -e .
-    - name: Tests (Windows)
-      if: runner.os == 'Windows'
-      run: |
-        venv\Scripts\activate
-        python -m pytest -m "${{ matrix.test-type }}"
   test:
     needs: [changes]
     if: needs.changes.outputs.gradio == 'true' || needs.changes.outputs.workflows == 'true' || needs.changes.outputs.scripts == 'true' || needs.changes.outputs.test == 'true'
     strategy:
       matrix:
-        os: ["ubuntu-latest", "windows-latest"]
+        os: ["windows-latest"]
         test-type: ["not flaky", "flaky"]
         python-version: ["3.8"]
     runs-on: ${{ matrix.os }}

gradio/blocks.py

@@ -665,9 +665,7 @@ def __init__(
             title: The tab title to display when this is opened in a browser window.
             css: custom css or path to custom css file to apply to entire Blocks
         """
-        # Cleanup shared parameters with Interface #TODO: is this part still necessary after Interface with Blocks?
         self.limiter = None
-        self.save_to = None
         if theme is None:
             theme = DefaultTheme()
         elif isinstance(theme, str):

gradio/exceptions.py

@@ -19,6 +19,10 @@ class InvalidApiNameError(ValueError):
     pass
 
 
+class ServerFailedToStartError(Exception):
+    pass
+
+
 InvalidApiName = InvalidApiNameError  # backwards compatibility
 
 

gradio/interface.py

@@ -363,7 +363,6 @@ def __init__(
         self.max_batch_size = max_batch_size
         self.allow_duplication = allow_duplication
 
-        self.save_to = None  # Used for selenium tests
         self.share = None
         self.share_url = None
         self.local_url = None

gradio/networking.py

@@ -14,6 +14,7 @@
 import requests
 import uvicorn
 
+from gradio.exceptions import ServerFailedToStartError
 from gradio.routes import App
 from gradio.tunneling import Tunnel
 
@@ -35,8 +36,13 @@ def install_signal_handlers(self):
     def run_in_thread(self):
         self.thread = threading.Thread(target=self.run, daemon=True)
         self.thread.start()
+        start = time.time()
         while not self.started:
             time.sleep(1e-3)
+            if time.time() - start > 5:
+                raise ServerFailedToStartError(
+                    "Server failed to start. Please check that the port is available."
+                )
 
     def close(self):
         self.should_exit = True
@@ -108,36 +114,12 @@ def start_server(
         app: the FastAPI app object
         server: the server object that is a subclass of uvicorn.Server (used to close the server)
     """
-    server_name = server_name or LOCALHOST_NAME
-    # if port is not specified, search for first available port
-    if server_port is None:
-        port = get_first_available_port(
-            INITIAL_PORT_VALUE, INITIAL_PORT_VALUE + TRY_NUM_PORTS
-        )
-    else:
-        try:
-            s = socket.socket()
-            s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
-            s.bind((LOCALHOST_NAME, server_port))
-            s.close()
-        except OSError as err:
-            raise OSError(
-                f"Port {server_port} is in use. If a gradio.Blocks is running on the port, "
-                f"you can close() it or gradio.close_all()."
-            ) from err
-        port = server_port
+    if ssl_keyfile is not None and ssl_certfile is None:
+        raise ValueError("ssl_certfile must be provided if ssl_keyfile is provided.")
 
+    server_name = server_name or LOCALHOST_NAME
     url_host_name = "localhost" if server_name == "0.0.0.0" else server_name
 
-    if ssl_keyfile is not None:
-        if ssl_certfile is None:
-            raise ValueError(
-                "ssl_certfile must be provided if ssl_keyfile is provided."
-            )
-        path_to_local_server = f"https://{url_host_name}:{port}/"
-    else:
-        path_to_local_server = f"http://{url_host_name}:{port}/"
-
     # Strip IPv6 brackets from the address if they exist.
     # This is needed as http://[::1]:port/ is a valid browser address,
     # but not a valid IPv6 address, so asyncio will throw an exception.
@@ -148,20 +130,52 @@ def start_server(
 
     app = App.create_app(blocks, app_kwargs=app_kwargs)
 
-    if blocks.save_to is not None:  # Used for selenium tests
-        blocks.save_to["port"] = port
-    config = uvicorn.Config(
-        app=app,
-        port=port,
-        host=host,
-        log_level="warning",
-        ssl_keyfile=ssl_keyfile,
-        ssl_certfile=ssl_certfile,
-        ssl_keyfile_password=ssl_keyfile_password,
-        ws_max_size=1024 * 1024 * 1024,  # Setting max websocket size to be 1 GB
+    # if port is not specified, search for an open port in the range of 7860 to 7959
+    server_ports = (
+        [server_port]
+        if server_port is not None
+        else range(INITIAL_PORT_VALUE, INITIAL_PORT_VALUE + TRY_NUM_PORTS)
     )
-    server = Server(config=config)
-    server.run_in_thread()
+
+    for port in server_ports:
+        try:
+            # The fastest way to check if a port is available is to try to bind to it with socket.
+            # If the port is not available, socket will throw an OSError.
+            s = socket.socket()
+            s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+            # Really, we should be checking if (server_name, server_port) is available, but
+            # socket.bind() doesn't seem to throw an OSError with ipv6 addresses, based on my testing.
+            # Instead, we just check if the port is available on localhost.
+            s.bind((LOCALHOST_NAME, port))
+            s.close()
+
+            # To avoid race conditions, so we also check if the port by trying to start the uvicorn server.
+            # If the port is not available, this will throw a ServerFailedToStartError.
+            config = uvicorn.Config(
+                app=app,
+                port=port,
+                host=host,
+                log_level="warning",
+                ssl_keyfile=ssl_keyfile,
+                ssl_certfile=ssl_certfile,
+                ssl_keyfile_password=ssl_keyfile_password,
+                ws_max_size=1024 * 1024 * 1024,  # Setting max websocket size to be 1 GB
+            )
+            server = Server(config=config)
+            server.run_in_thread()
+            break
+        except (OSError, ServerFailedToStartError):
+            pass
+    else:
+        raise OSError(
+            f"Cannot find empty port in range: {min(server_ports)}-{max(server_ports)}. You can specify a different port by setting the GRADIO_SERVER_PORT environment variable or passing the `server_port` parameter to `launch()`."
+        )
+
+    if ssl_keyfile is not None:
+        path_to_local_server = f"https://{url_host_name}:{port}/"
+    else:
+        path_to_local_server = f"http://{url_host_name}:{port}/"
+
     return server_name, port, path_to_local_server, app, server