| """Thread-safe network utilities.""" |
|
|
| import socket |
| import threading |
| from contextlib import contextmanager |
|
|
|
|
| class PortAllocator: |
| """Thread-safe port allocator that prevents port conflicts in concurrent environments. |
| |
| This class maintains a set of reserved ports and uses a lock to ensure that |
| port allocation is atomic. Once a port is allocated, it remains reserved until |
| explicitly released. |
| |
| Usage: |
| allocator = PortAllocator() |
| |
| # Option 1: Manual allocation and release |
| port = allocator.allocate(start_port=8080) |
| try: |
| # Use the port... |
| finally: |
| allocator.release(port) |
| |
| # Option 2: Context manager (recommended) |
| with allocator.allocate_context(start_port=8080) as port: |
| # Use the port... |
| # Port is automatically released when exiting the context |
| """ |
|
|
| def __init__(self): |
| self._lock = threading.Lock() |
| self._reserved_ports: set[int] = set() |
|
|
| def _is_port_available(self, port: int) -> bool: |
| """Check if a port is available for binding. |
| |
| Args: |
| port: The port number to check. |
| |
| Returns: |
| True if the port is available, False otherwise. |
| """ |
| if port in self._reserved_ports: |
| return False |
|
|
| with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s: |
| try: |
| s.bind(("localhost", port)) |
| return True |
| except OSError: |
| return False |
|
|
| def allocate(self, start_port: int = 8080, max_range: int = 100) -> int: |
| """Allocate an available port in a thread-safe manner. |
| |
| This method is thread-safe. It finds an available port, marks it as reserved, |
| and returns it. The port remains reserved until release() is called. |
| |
| Args: |
| start_port: The port number to start searching from. |
| max_range: Maximum number of ports to search. |
| |
| Returns: |
| An available port number. |
| |
| Raises: |
| RuntimeError: If no available port is found in the specified range. |
| """ |
| with self._lock: |
| for port in range(start_port, start_port + max_range): |
| if self._is_port_available(port): |
| self._reserved_ports.add(port) |
| return port |
|
|
| raise RuntimeError(f"No available port found in range {start_port}-{start_port + max_range}") |
|
|
| def release(self, port: int) -> None: |
| """Release a previously allocated port. |
| |
| Args: |
| port: The port number to release. |
| """ |
| with self._lock: |
| self._reserved_ports.discard(port) |
|
|
| @contextmanager |
| def allocate_context(self, start_port: int = 8080, max_range: int = 100): |
| """Context manager for port allocation with automatic release. |
| |
| Args: |
| start_port: The port number to start searching from. |
| max_range: Maximum number of ports to search. |
| |
| Yields: |
| An available port number. |
| """ |
| port = self.allocate(start_port, max_range) |
| try: |
| yield port |
| finally: |
| self.release(port) |
|
|
|
|
| |
| _global_port_allocator = PortAllocator() |
|
|
|
|
| def get_free_port(start_port: int = 8080, max_range: int = 100) -> int: |
| """Get a free port in a thread-safe manner. |
| |
| This function uses a global port allocator to ensure that concurrent calls |
| don't return the same port. The port is marked as reserved until release_port() |
| is called. |
| |
| Args: |
| start_port: The port number to start searching from. |
| max_range: Maximum number of ports to search. |
| |
| Returns: |
| An available port number. |
| |
| Raises: |
| RuntimeError: If no available port is found in the specified range. |
| """ |
| return _global_port_allocator.allocate(start_port, max_range) |
|
|
|
|
| def release_port(port: int) -> None: |
| """Release a previously allocated port. |
| |
| Args: |
| port: The port number to release. |
| """ |
| _global_port_allocator.release(port) |
|
|
