From e397ce25a61777bc9d27732ccddd8e85e92b8f5b Mon Sep 17 00:00:00 2001 From: kaneki003 Date: Sat, 31 May 2025 19:02:18 +0530 Subject: [PATCH 1/6] Updated Yamux impl.,added tests for yamux and mplex --- libp2p/stream_muxer/mplex/mplex_stream.py | 101 +++++---- libp2p/stream_muxer/yamux/yamux.py | 92 ++++++-- newsfragments/639.feature.rst | 1 + .../test_mplex_read_write_lock.py | 124 +++++++++++ .../test_yamux_read_write_lock.py | 207 ++++++++++++++++++ 5 files changed, 458 insertions(+), 67 deletions(-) create mode 100644 newsfragments/639.feature.rst create mode 100644 tests/core/stream_muxer/test_mplex_read_write_lock.py create mode 100644 tests/core/stream_muxer/test_yamux_read_write_lock.py diff --git a/libp2p/stream_muxer/mplex/mplex_stream.py b/libp2p/stream_muxer/mplex/mplex_stream.py index 3b640df1..dc65ac5f 100644 --- a/libp2p/stream_muxer/mplex/mplex_stream.py +++ b/libp2p/stream_muxer/mplex/mplex_stream.py @@ -46,8 +46,9 @@ class MplexStream(IMuxedStream): read_deadline: int | None write_deadline: int | None - # TODO: Add lock for read/write to avoid interleaving receiving messages? close_lock: trio.Lock + read_lock: trio.Lock + write_lock: trio.Lock # NOTE: `dataIn` is size of 8 in Go implementation. incoming_data_channel: "trio.MemoryReceiveChannel[bytes]" @@ -80,6 +81,8 @@ class MplexStream(IMuxedStream): self.event_remote_closed = trio.Event() self.event_reset = trio.Event() self.close_lock = trio.Lock() + self.read_lock = trio.Lock() + self.write_lock = trio.Lock() self.incoming_data_channel = incoming_data_channel self._buf = bytearray() @@ -113,48 +116,49 @@ class MplexStream(IMuxedStream): :param n: number of bytes to read :return: bytes actually read """ - if n is not None and n < 0: - raise ValueError( - "the number of bytes to read `n` must be non-negative or " - f"`None` to indicate read until EOF, got n={n}" - ) - if self.event_reset.is_set(): - raise MplexStreamReset - if n is None: - return await self._read_until_eof() - if len(self._buf) == 0: - data: bytes - # Peek whether there is data available. If yes, we just read until there is - # no data, then return. - try: - data = self.incoming_data_channel.receive_nowait() - self._buf.extend(data) - except trio.EndOfChannel: - raise MplexStreamEOF - except trio.WouldBlock: - # We know `receive` will be blocked here. Wait for data here with - # `receive` and catch all kinds of errors here. + async with self.read_lock: + if n is not None and n < 0: + raise ValueError( + "the number of bytes to read `n` must be non-negative or " + f"`None` to indicate read until EOF, got n={n}" + ) + if self.event_reset.is_set(): + raise MplexStreamReset + if n is None: + return await self._read_until_eof() + if len(self._buf) == 0: + data: bytes + # Peek whether there is data available. If yes, we just read until + # there is no data, then return. try: - data = await self.incoming_data_channel.receive() + data = self.incoming_data_channel.receive_nowait() self._buf.extend(data) except trio.EndOfChannel: - if self.event_reset.is_set(): - raise MplexStreamReset - if self.event_remote_closed.is_set(): - raise MplexStreamEOF - except trio.ClosedResourceError as error: - # Probably `incoming_data_channel` is closed in `reset` when we are - # waiting for `receive`. - if self.event_reset.is_set(): - raise MplexStreamReset - raise Exception( - "`incoming_data_channel` is closed but stream is not reset. " - "This should never happen." - ) from error - self._buf.extend(self._read_return_when_blocked()) - payload = self._buf[:n] - self._buf = self._buf[len(payload) :] - return bytes(payload) + raise MplexStreamEOF + except trio.WouldBlock: + # We know `receive` will be blocked here. Wait for data here with + # `receive` and catch all kinds of errors here. + try: + data = await self.incoming_data_channel.receive() + self._buf.extend(data) + except trio.EndOfChannel: + if self.event_reset.is_set(): + raise MplexStreamReset + if self.event_remote_closed.is_set(): + raise MplexStreamEOF + except trio.ClosedResourceError as error: + # Probably `incoming_data_channel` is closed in `reset` when + # we are waiting for `receive`. + if self.event_reset.is_set(): + raise MplexStreamReset + raise Exception( + "`incoming_data_channel` is closed but stream is not reset." + "This should never happen." + ) from error + self._buf.extend(self._read_return_when_blocked()) + payload = self._buf[:n] + self._buf = self._buf[len(payload) :] + return bytes(payload) async def write(self, data: bytes) -> None: """ @@ -162,14 +166,15 @@ class MplexStream(IMuxedStream): :return: number of bytes written """ - if self.event_local_closed.is_set(): - raise MplexStreamClosed(f"cannot write to closed stream: data={data!r}") - flag = ( - HeaderTags.MessageInitiator - if self.is_initiator - else HeaderTags.MessageReceiver - ) - await self.muxed_conn.send_message(flag, data, self.stream_id) + async with self.write_lock: + if self.event_local_closed.is_set(): + raise MplexStreamClosed(f"cannot write to closed stream: data={data!r}") + flag = ( + HeaderTags.MessageInitiator + if self.is_initiator + else HeaderTags.MessageReceiver + ) + await self.muxed_conn.send_message(flag, data, self.stream_id) async def close(self) -> None: """ diff --git a/libp2p/stream_muxer/yamux/yamux.py b/libp2p/stream_muxer/yamux/yamux.py index 92123465..faf24b29 100644 --- a/libp2p/stream_muxer/yamux/yamux.py +++ b/libp2p/stream_muxer/yamux/yamux.py @@ -77,6 +77,8 @@ class YamuxStream(IMuxedStream): self.send_window = DEFAULT_WINDOW_SIZE self.recv_window = DEFAULT_WINDOW_SIZE self.window_lock = trio.Lock() + self.read_lock = trio.Lock() + self.write_lock = trio.Lock() async def __aenter__(self) -> "YamuxStream": """Enter the async context manager.""" @@ -98,16 +100,32 @@ class YamuxStream(IMuxedStream): # Flow control: Check if we have enough send window total_len = len(data) sent = 0 - + logging.debug(f"Stream {self.stream_id}: Starts writing {total_len} bytes ") while sent < total_len: + # Wait for available window with timeout + timeout = False async with self.window_lock: - # Wait for available window - while self.send_window == 0 and not self.closed: - # Release lock while waiting + if self.send_window == 0: + logging.debug( + f"Stream {self.stream_id}: Window is zero, waiting for update" + ) + # Release lock and wait with timeout self.window_lock.release() - await trio.sleep(0.01) + # To avoid re-acquiring the lock immediately, + with trio.move_on_after(5.0) as cancel_scope: + while self.send_window == 0 and not self.closed: + await trio.sleep(0.01) + # If we timed out, cancel the scope + timeout = cancel_scope.cancelled_caught + # Re-acquire lock await self.window_lock.acquire() + # If we timed out waiting for window update, raise an error + if timeout: + raise MuxedStreamError( + "Timed out waiting for window update after 5 seconds." + ) + if self.closed: raise MuxedStreamError("Stream is closed") @@ -123,25 +141,53 @@ class YamuxStream(IMuxedStream): await self.conn.secured_conn.write(header + chunk) sent += to_send - # If window is getting low, consider updating - if self.send_window < DEFAULT_WINDOW_SIZE // 2: - await self.send_window_update() + async def send_window_update( + self, increment: int | None, skip_lock: bool = False + ) -> None: + """ + Send a window update to peer. - async def send_window_update(self, increment: int | None = None) -> None: - """Send a window update to peer.""" + param:increment: The amount to increment the window size by. + If None, uses the difference between DEFAULT_WINDOW_SIZE + and current receive window. + param:skip_lock (bool): If True, skips acquiring window_lock. + This should only be used when calling from a context + that already holds the lock. + """ + increment_value = 0 if increment is None: - increment = DEFAULT_WINDOW_SIZE - self.recv_window - - if increment <= 0: + increment_value = DEFAULT_WINDOW_SIZE - self.recv_window + else: + increment_value = increment + if increment_value <= 0: + # If increment is zero or negative, skip sending update + logging.debug( + f"Stream {self.stream_id}: Skipping window update" + f"(increment={increment})" + ) return + logging.debug( + f"Stream {self.stream_id}: Sending window update with increment={increment}" + ) - async with self.window_lock: - self.recv_window += increment + async def _do_window_update() -> None: + self.recv_window += increment_value header = struct.pack( - YAMUX_HEADER_FORMAT, 0, TYPE_WINDOW_UPDATE, 0, self.stream_id, increment + YAMUX_HEADER_FORMAT, + 0, + TYPE_WINDOW_UPDATE, + 0, + self.stream_id, + increment_value, ) await self.conn.secured_conn.write(header) + if skip_lock: + await _do_window_update() + else: + async with self.window_lock: + await _do_window_update() + async def read(self, n: int | None = -1) -> bytes: # Handle None value for n by converting it to -1 if n is None: @@ -198,11 +244,19 @@ class YamuxStream(IMuxedStream): # Return all buffered data data = bytes(buffer) buffer.clear() - logging.debug(f"Stream {self.stream_id}: Returning {len(data)} bytes") return data - # For specific size read (n > 0), return available data immediately - return await self.conn.read_stream(self.stream_id, n) + data = await self.conn.read_stream(self.stream_id, n) + async with self.window_lock: + self.recv_window -= len(data) + # Automatically send a window update if recv_window is low + if self.recv_window <= DEFAULT_WINDOW_SIZE // 2: + logging.debug( + f"Stream {self.stream_id}: " + f"Low recv_window ({self.recv_window}), sending update" + ) + await self.send_window_update(None, skip_lock=True) + return data async def close(self) -> None: if not self.send_closed: diff --git a/newsfragments/639.feature.rst b/newsfragments/639.feature.rst new file mode 100644 index 00000000..3f3d7510 --- /dev/null +++ b/newsfragments/639.feature.rst @@ -0,0 +1 @@ +Added separate read and write locks to the `MplexStream` & `YamuxStream` class.This ensures thread-safe access and data integrity when multiple coroutines interact with the same MplexStream instance. diff --git a/tests/core/stream_muxer/test_mplex_read_write_lock.py b/tests/core/stream_muxer/test_mplex_read_write_lock.py new file mode 100644 index 00000000..afc197ac --- /dev/null +++ b/tests/core/stream_muxer/test_mplex_read_write_lock.py @@ -0,0 +1,124 @@ +import pytest +import trio + +from libp2p.abc import ISecureConn +from libp2p.crypto.keys import PrivateKey, PublicKey +from libp2p.peer.id import ID +from libp2p.stream_muxer.mplex.constants import ( + HeaderTags, +) +from libp2p.stream_muxer.mplex.datastructures import ( + StreamID, +) +from libp2p.stream_muxer.mplex.mplex import ( + Mplex, +) +from libp2p.stream_muxer.mplex.mplex_stream import ( + MplexStream, +) + + +class DummySecureConn(ISecureConn): + """A minimal implementation of ISecureConn for testing.""" + + async def write(self, data: bytes) -> None: + pass + + async def read(self, n: int | None = -1) -> bytes: + return b"" + + async def close(self) -> None: + pass + + def get_remote_address(self) -> tuple[str, int] | None: + return None + + def get_local_peer(self) -> ID: + return ID(b"local") + + def get_local_private_key(self) -> PrivateKey: + return PrivateKey() # Dummy key for testing + + def get_remote_peer(self) -> ID: + return ID(b"remote") + + def get_remote_public_key(self) -> PublicKey: + return PublicKey() # Dummy key for testing + + +class DummyMuxedConn(Mplex): + """A minimal mock of Mplex for testing read/write locks.""" + + def __init__(self) -> None: + self.secured_conn = DummySecureConn() + self.peer_id = ID(b"dummy") + self.streams = {} + self.streams_lock = trio.Lock() + self.event_shutting_down = trio.Event() + self.event_closed = trio.Event() + self.event_started = trio.Event() + self.stream_backlog_limit = 256 + self.stream_backlog_semaphore = trio.Semaphore(256) + channels = trio.open_memory_channel[MplexStream](0) + self.new_stream_send_channel, self.new_stream_receive_channel = channels + + async def send_message( + self, flag: HeaderTags, data: bytes, stream_id: StreamID + ) -> None: + await trio.sleep(0.01) + + +@pytest.mark.trio +async def test_concurrent_writes_are_serialized(): + stream_id = StreamID(1, True) + send_log = [] + + class LoggingMuxedConn(DummyMuxedConn): + async def send_message( + self, flag: HeaderTags, data: bytes, stream_id: StreamID + ) -> None: + send_log.append(data) + await trio.sleep(0.01) + + memory_send, memory_recv = trio.open_memory_channel(8) + stream = MplexStream( + name="test", + stream_id=stream_id, + muxed_conn=LoggingMuxedConn(), + incoming_data_channel=memory_recv, + ) + + async def writer(data): + await stream.write(data) + + async with trio.open_nursery() as nursery: + for i in range(5): + nursery.start_soon(writer, f"msg-{i}".encode()) + # Order doesn't matter due to concurrent execution + assert sorted(send_log) == sorted([f"msg-{i}".encode() for i in range(5)]) + + +@pytest.mark.trio +async def test_concurrent_reads_are_serialized(): + stream_id = StreamID(2, True) + muxed_conn = DummyMuxedConn() + memory_send, memory_recv = trio.open_memory_channel(8) + results = [] + stream = MplexStream( + name="test", + stream_id=stream_id, + muxed_conn=muxed_conn, + incoming_data_channel=memory_recv, + ) + for i in range(5): + await memory_send.send(f"data-{i}".encode()) + await memory_send.aclose() + + async def reader(): + data = await stream.read(6) + results.append(data) + + async with trio.open_nursery() as nursery: + for _ in range(5): + nursery.start_soon(reader) + assert sorted(results) == [f"data-{i}".encode() for i in range(5)] diff --git a/tests/core/stream_muxer/test_yamux_read_write_lock.py b/tests/core/stream_muxer/test_yamux_read_write_lock.py new file mode 100644 index 00000000..74a4c2f1 --- /dev/null +++ b/tests/core/stream_muxer/test_yamux_read_write_lock.py @@ -0,0 +1,207 @@ +import logging + +import pytest +import trio +from trio.testing import ( + memory_stream_pair, +) + +from libp2p.abc import IRawConnection +from libp2p.crypto.ed25519 import ( + create_new_key_pair, +) +from libp2p.peer.id import ( + ID, +) +from libp2p.security.insecure.transport import ( + InsecureTransport, +) +from libp2p.stream_muxer.yamux.yamux import ( + Yamux, + YamuxStream, +) + + +class TrioStreamAdapter(IRawConnection): + """Adapter to make trio memory streams work with libp2p.""" + + def __init__(self, send_stream, receive_stream, is_initiator=False): + self.send_stream = send_stream + self.receive_stream = receive_stream + self.is_initiator = is_initiator + + async def write(self, data: bytes) -> None: + logging.debug(f"Attempting to write {len(data)} bytes") + with trio.move_on_after(2): + await self.send_stream.send_all(data) + + async def read(self, n: int | None = None) -> bytes: + if n is None or n <= 0: + raise ValueError("Reading unbounded or zero bytes not supported") + logging.debug(f"Attempting to read {n} bytes") + with trio.move_on_after(2): + data = await self.receive_stream.receive_some(n) + logging.debug(f"Read {len(data)} bytes") + return data + + async def close(self) -> None: + logging.debug("Closing stream") + await self.send_stream.aclose() + await self.receive_stream.aclose() + + def get_remote_address(self) -> tuple[str, int] | None: + """Return None since this is a test adapter without real network info.""" + return None + + +@pytest.fixture +def key_pair(): + return create_new_key_pair() + + +@pytest.fixture +def peer_id(key_pair): + return ID.from_pubkey(key_pair.public_key) + + +@pytest.fixture +async def secure_conn_pair(key_pair, peer_id): + """Create a pair of secure connections for testing.""" + logging.debug("Setting up secure_conn_pair") + client_send, server_receive = memory_stream_pair() + server_send, client_receive = memory_stream_pair() + + client_rw = TrioStreamAdapter(client_send, client_receive) + server_rw = TrioStreamAdapter(server_send, server_receive) + + insecure_transport = InsecureTransport(key_pair) + + async def run_outbound(nursery_results): + with trio.move_on_after(5): + client_conn = await insecure_transport.secure_outbound(client_rw, peer_id) + logging.debug("Outbound handshake complete") + nursery_results["client"] = client_conn + + async def run_inbound(nursery_results): + with trio.move_on_after(5): + server_conn = await insecure_transport.secure_inbound(server_rw) + logging.debug("Inbound handshake complete") + nursery_results["server"] = server_conn + + nursery_results = {} + async with trio.open_nursery() as nursery: + nursery.start_soon(run_outbound, nursery_results) + nursery.start_soon(run_inbound, nursery_results) + await trio.sleep(0.1) # Give tasks a chance to finish + + client_conn = nursery_results.get("client") + server_conn = nursery_results.get("server") + + if client_conn is None or server_conn is None: + raise RuntimeError("Handshake failed: client_conn or server_conn is None") + + logging.debug("secure_conn_pair setup complete") + return client_conn, server_conn + + +@pytest.fixture +async def yamux_pair(secure_conn_pair, peer_id): + """Create a pair of Yamux multiplexers for testing.""" + logging.debug("Setting up yamux_pair") + client_conn, server_conn = secure_conn_pair + client_yamux = Yamux(client_conn, peer_id, is_initiator=True) + server_yamux = Yamux(server_conn, peer_id, is_initiator=False) + async with trio.open_nursery() as nursery: + with trio.move_on_after(5): + nursery.start_soon(client_yamux.start) + nursery.start_soon(server_yamux.start) + await trio.sleep(0.1) + logging.debug("yamux_pair started") + yield client_yamux, server_yamux + logging.debug("yamux_pair cleanup") + + +@pytest.mark.trio +async def test_yamux_race_condition_without_locks(yamux_pair): + """ + Test for race-around/interleaving in Yamux streams when read/write + locks are disabled. + This launches concurrent writers/readers on both sides of a stream. + If there is no proper locking, the received data may be interleaved + or corrupted. + + The test creates structured messages and verifies they are received + intact and in order. + Without proper locking, concurrent read/write operations could cause + data corruption + or message interleaving, which this test will catch. + """ + client_yamux, server_yamux = yamux_pair + client_stream: YamuxStream = await client_yamux.open_stream() + server_stream: YamuxStream = await server_yamux.accept_stream() + MSG_COUNT = 10 + MSG_SIZE = 256 * 1024 + client_msgs = [ + f"CLIENT-MSG-{i:03d}-".encode().ljust(MSG_SIZE, b"C") for i in range(MSG_COUNT) + ] + server_msgs = [ + f"SERVER-MSG-{i:03d}-".encode().ljust(MSG_SIZE, b"S") for i in range(MSG_COUNT) + ] + client_received = [] + server_received = [] + + async def writer(stream, msgs, name): + """Write messages with minimal delays to encourage race conditions.""" + for i, msg in enumerate(msgs): + await stream.write(msg) + # Yield control frequently to encourage interleaving + if i % 5 == 0: + await trio.sleep(0.005) + + async def reader(stream, received, name): + """Read messages and store them for verification.""" + for i in range(MSG_COUNT): + data = await stream.read(MSG_SIZE) + received.append(data) + if i % 3 == 0: + await trio.sleep(0.001) + + # Running all operations concurrently + async with trio.open_nursery() as nursery: + nursery.start_soon(writer, client_stream, client_msgs, "client") + nursery.start_soon(writer, server_stream, server_msgs, "server") + nursery.start_soon(reader, client_stream, client_received, "client") + nursery.start_soon(reader, server_stream, server_received, "server") + + assert len(client_received) == MSG_COUNT, ( + f"Client received {len(client_received)} messages, expected {MSG_COUNT}" + ) + assert len(server_received) == MSG_COUNT, ( + f"Server received {len(server_received)} messages, expected {MSG_COUNT}" + ) + assert client_received == server_msgs, ( + "Client did not receive server messages in order or intact!" + ) + assert server_received == client_msgs, ( + "Server did not receive client messages in order or intact!" + ) + for i, msg in enumerate(client_received): + # logging.debug(f"datatype of msg: {type(msg)}, length: {len(msg)}") + # logging.debug(f"datatype of msg: {type(b"SERVER-MSG-")}") + assert len(msg) == MSG_SIZE, ( + f"Client message {i} has wrong size: {len(msg)} != {MSG_SIZE}" + ) + assert msg.startswith(b"SERVER-MSG-"), ( + f"Client message {i} doesn't start with expected prefix" + ) + + for i, msg in enumerate(server_received): + assert len(msg) == MSG_SIZE, ( + f"Server message {i} has wrong size: {len(msg)} != {MSG_SIZE}" + ) + assert msg.startswith(b"CLIENT-MSG-"), ( + f"Server message {i} doesn't start with expected prefix" + ) + + await client_stream.close() + await server_stream.close() From 209deffc8aaf438caea7f18fd0f4615d90044cbf Mon Sep 17 00:00:00 2001 From: kaneki003 Date: Sat, 21 Jun 2025 13:39:03 +0530 Subject: [PATCH 2/6] resolved recv_window updates,added support for read_EOF --- libp2p/stream_muxer/yamux/yamux.py | 105 +++++++----------- .../test_mplex_read_write_lock.py | 15 ++- 2 files changed, 52 insertions(+), 68 deletions(-) diff --git a/libp2p/stream_muxer/yamux/yamux.py b/libp2p/stream_muxer/yamux/yamux.py index faf24b29..f58e98c4 100644 --- a/libp2p/stream_muxer/yamux/yamux.py +++ b/libp2p/stream_muxer/yamux/yamux.py @@ -141,9 +141,7 @@ class YamuxStream(IMuxedStream): await self.conn.secured_conn.write(header + chunk) sent += to_send - async def send_window_update( - self, increment: int | None, skip_lock: bool = False - ) -> None: + async def send_window_update(self, increment: int, skip_lock: bool = False) -> None: """ Send a window update to peer. @@ -154,12 +152,7 @@ class YamuxStream(IMuxedStream): This should only be used when calling from a context that already holds the lock. """ - increment_value = 0 - if increment is None: - increment_value = DEFAULT_WINDOW_SIZE - self.recv_window - else: - increment_value = increment - if increment_value <= 0: + if increment <= 0: # If increment is zero or negative, skip sending update logging.debug( f"Stream {self.stream_id}: Skipping window update" @@ -171,14 +164,13 @@ class YamuxStream(IMuxedStream): ) async def _do_window_update() -> None: - self.recv_window += increment_value header = struct.pack( YAMUX_HEADER_FORMAT, 0, TYPE_WINDOW_UPDATE, 0, self.stream_id, - increment_value, + increment, ) await self.conn.secured_conn.write(header) @@ -188,6 +180,22 @@ class YamuxStream(IMuxedStream): async with self.window_lock: await _do_window_update() + async def read_EOF(self) -> bytes: + """ + To read data from stream until it is closed. + """ + data = b"" + try: + while True: + recv = await self.read() + if recv: + data += recv + except MuxedStreamEOF: + logging.debug( + f"Stream {self.stream_id}:EOF reached,total data read:{len(data)} bytes" + ) + return data + async def read(self, n: int | None = -1) -> bytes: # Handle None value for n by converting it to -1 if n is None: @@ -202,61 +210,34 @@ class YamuxStream(IMuxedStream): # If reading until EOF (n == -1), block until stream is closed if n == -1: - while not self.recv_closed and not self.conn.event_shutting_down.is_set(): - # Check if there's data in the buffer - buffer = self.conn.stream_buffers.get(self.stream_id) - if buffer and len(buffer) > 0: - # Wait for closure even if data is available - logging.debug( - f"Stream {self.stream_id}:Waiting for FIN before returning data" - ) - await self.conn.stream_events[self.stream_id].wait() - self.conn.stream_events[self.stream_id] = trio.Event() - else: - # No data, wait for data or closure - logging.debug(f"Stream {self.stream_id}: Waiting for data or FIN") - await self.conn.stream_events[self.stream_id].wait() - self.conn.stream_events[self.stream_id] = trio.Event() - - # After loop, check if stream is closed or shutting down - async with self.conn.streams_lock: - if self.conn.event_shutting_down.is_set(): - logging.debug(f"Stream {self.stream_id}: Connection shutting down") - raise MuxedStreamEOF("Connection shut down") - if self.closed: - if self.reset_received: - logging.debug(f"Stream {self.stream_id}: Stream was reset") - raise MuxedStreamReset("Stream was reset") - else: - logging.debug( - f"Stream {self.stream_id}: Stream closed cleanly (EOF)" - ) - raise MuxedStreamEOF("Stream closed cleanly (EOF)") - buffer = self.conn.stream_buffers.get(self.stream_id) - if buffer is None: - logging.debug( - f"Stream {self.stream_id}: Buffer gone, assuming closed" - ) - raise MuxedStreamEOF("Stream buffer closed") - if self.recv_closed and len(buffer) == 0: - logging.debug(f"Stream {self.stream_id}: EOF reached") - raise MuxedStreamEOF("Stream is closed for receiving") - # Return all buffered data + # Check if there's data in the buffer + buffer = self.conn.stream_buffers.get(self.stream_id) + size = len(buffer) if buffer else 0 + if size > 0: + # If any data is available,return it immediately + assert buffer is not None data = bytes(buffer) buffer.clear() - return data - - data = await self.conn.read_stream(self.stream_id, n) - async with self.window_lock: - self.recv_window -= len(data) - # Automatically send a window update if recv_window is low - if self.recv_window <= DEFAULT_WINDOW_SIZE // 2: + async with self.window_lock: + self.recv_window += len(data) + await self.send_window_update(len(data), skip_lock=True) + return data + # Otherwise,wait for data or FIN + if self.recv_closed: + raise MuxedStreamEOF("Stream is closed for receiving") + await self.conn.stream_events[self.stream_id].wait() + self.conn.stream_events[self.stream_id] = trio.Event() + return b"" + else: + data = await self.conn.read_stream(self.stream_id, n) + async with self.window_lock: + self.recv_window += len(data) logging.debug( - f"Stream {self.stream_id}: " - f"Low recv_window ({self.recv_window}), sending update" + f"Stream {self.stream_id}: Sending window update after read, " + f"increment={len(data)}" ) - await self.send_window_update(None, skip_lock=True) - return data + await self.send_window_update(len(data), skip_lock=True) + return data async def close(self) -> None: if not self.send_closed: diff --git a/tests/core/stream_muxer/test_mplex_read_write_lock.py b/tests/core/stream_muxer/test_mplex_read_write_lock.py index afc197ac..d00d5b8e 100644 --- a/tests/core/stream_muxer/test_mplex_read_write_lock.py +++ b/tests/core/stream_muxer/test_mplex_read_write_lock.py @@ -1,7 +1,7 @@ import pytest import trio -from libp2p.abc import ISecureConn +from libp2p.abc import IMuxedStream, ISecureConn from libp2p.crypto.keys import PrivateKey, PublicKey from libp2p.peer.id import ID from libp2p.stream_muxer.mplex.constants import ( @@ -59,13 +59,15 @@ class DummyMuxedConn(Mplex): self.event_started = trio.Event() self.stream_backlog_limit = 256 self.stream_backlog_semaphore = trio.Semaphore(256) - channels = trio.open_memory_channel[MplexStream](0) + # Use IMuxedStream for type consistency with Mplex + channels = trio.open_memory_channel[IMuxedStream](0) self.new_stream_send_channel, self.new_stream_receive_channel = channels async def send_message( - self, flag: HeaderTags, data: bytes, stream_id: StreamID - ) -> None: + self, flag: HeaderTags, data: bytes | None, stream_id: StreamID + ) -> int: await trio.sleep(0.01) + return 0 @pytest.mark.trio @@ -75,10 +77,11 @@ async def test_concurrent_writes_are_serialized(): class LoggingMuxedConn(DummyMuxedConn): async def send_message( - self, flag: HeaderTags, data: bytes, stream_id: StreamID - ) -> None: + self, flag: HeaderTags, data: bytes | None, stream_id: StreamID + ) -> int: send_log.append(data) await trio.sleep(0.01) + return 0 memory_send, memory_recv = trio.open_memory_channel(8) stream = MplexStream( From df17788ec3d9ed8b4f4fc32920ba0fabc1020510 Mon Sep 17 00:00:00 2001 From: kaneki003 Date: Sat, 21 Jun 2025 14:10:09 +0530 Subject: [PATCH 3/6] resolving build-fails --- tests/core/stream_muxer/test_yamux.py | 6 ++++-- tests/core/stream_muxer/test_yamux_read_write_lock.py | 6 ------ 2 files changed, 4 insertions(+), 8 deletions(-) diff --git a/tests/core/stream_muxer/test_yamux.py b/tests/core/stream_muxer/test_yamux.py index 81d05676..bfd8eb5a 100644 --- a/tests/core/stream_muxer/test_yamux.py +++ b/tests/core/stream_muxer/test_yamux.py @@ -224,14 +224,16 @@ async def test_yamux_stream_reset(yamux_pair): await client_stream.reset() # After reset, reading should raise MuxedStreamReset or MuxedStreamEOF try: - await server_stream.read() + while True: + await server_stream.read() except (MuxedStreamEOF, MuxedStreamError): pass else: pytest.fail("Expected MuxedStreamEOF or MuxedStreamError") # Verify subsequent operations fail with StreamReset or EOF with pytest.raises(MuxedStreamError): - await server_stream.read() + while True: + await server_stream.read() with pytest.raises(MuxedStreamError): await server_stream.write(b"test") logging.debug("test_yamux_stream_reset complete") diff --git a/tests/core/stream_muxer/test_yamux_read_write_lock.py b/tests/core/stream_muxer/test_yamux_read_write_lock.py index 74a4c2f1..b73284e8 100644 --- a/tests/core/stream_muxer/test_yamux_read_write_lock.py +++ b/tests/core/stream_muxer/test_yamux_read_write_lock.py @@ -191,17 +191,11 @@ async def test_yamux_race_condition_without_locks(yamux_pair): assert len(msg) == MSG_SIZE, ( f"Client message {i} has wrong size: {len(msg)} != {MSG_SIZE}" ) - assert msg.startswith(b"SERVER-MSG-"), ( - f"Client message {i} doesn't start with expected prefix" - ) for i, msg in enumerate(server_received): assert len(msg) == MSG_SIZE, ( f"Server message {i} has wrong size: {len(msg)} != {MSG_SIZE}" ) - assert msg.startswith(b"CLIENT-MSG-"), ( - f"Server message {i} doesn't start with expected prefix" - ) await client_stream.close() await server_stream.close() From d7cdae8a0fc1a58e874af1847e40c466069435f1 Mon Sep 17 00:00:00 2001 From: kaneki003 Date: Sat, 21 Jun 2025 17:51:27 +0530 Subject: [PATCH 4/6] intgrated n==-1 case in read() --- libp2p/stream_muxer/yamux/yamux.py | 84 +++++++++++-------- .../test_yamux_read_write_lock.py | 33 +++++--- 2 files changed, 70 insertions(+), 47 deletions(-) diff --git a/libp2p/stream_muxer/yamux/yamux.py b/libp2p/stream_muxer/yamux/yamux.py index f58e98c4..023251ed 100644 --- a/libp2p/stream_muxer/yamux/yamux.py +++ b/libp2p/stream_muxer/yamux/yamux.py @@ -180,22 +180,6 @@ class YamuxStream(IMuxedStream): async with self.window_lock: await _do_window_update() - async def read_EOF(self) -> bytes: - """ - To read data from stream until it is closed. - """ - data = b"" - try: - while True: - recv = await self.read() - if recv: - data += recv - except MuxedStreamEOF: - logging.debug( - f"Stream {self.stream_id}:EOF reached,total data read:{len(data)} bytes" - ) - return data - async def read(self, n: int | None = -1) -> bytes: # Handle None value for n by converting it to -1 if n is None: @@ -208,25 +192,57 @@ class YamuxStream(IMuxedStream): ) raise MuxedStreamEOF("Stream is closed for receiving") - # If reading until EOF (n == -1), block until stream is closed if n == -1: - # Check if there's data in the buffer - buffer = self.conn.stream_buffers.get(self.stream_id) - size = len(buffer) if buffer else 0 - if size > 0: - # If any data is available,return it immediately - assert buffer is not None - data = bytes(buffer) - buffer.clear() - async with self.window_lock: - self.recv_window += len(data) - await self.send_window_update(len(data), skip_lock=True) - return data - # Otherwise,wait for data or FIN - if self.recv_closed: - raise MuxedStreamEOF("Stream is closed for receiving") - await self.conn.stream_events[self.stream_id].wait() - self.conn.stream_events[self.stream_id] = trio.Event() + data = b"" + while not self.conn.event_shutting_down.is_set(): + # Check if there's data in the buffer + buffer = self.conn.stream_buffers.get(self.stream_id) + + # If buffer is not available, check if stream is closed + if buffer is None: + logging.debug(f"Stream {self.stream_id}: No buffer available") + raise MuxedStreamEOF("Stream buffer closed") + + # If we have data in buffer, process it + if len(buffer) > 0: + chunk = bytes(buffer) + buffer.clear() + data += chunk + + # Send window update for the chunk we just read + async with self.window_lock: + self.recv_window += len(chunk) + logging.debug(f"Stream {self.stream_id}: Update {len(chunk)}") + await self.send_window_update(len(chunk), skip_lock=True) + + # If stream is closed (FIN received) and buffer is empty, break + if self.recv_closed and len(buffer) == 0: + logging.debug(f"Stream {self.stream_id}: Closed with empty buffer") + break + + # If stream was reset, raise reset error + if self.reset_received: + logging.debug(f"Stream {self.stream_id}: Stream was reset") + raise MuxedStreamReset("Stream was reset") + + # Wait for more data or stream closure + logging.debug(f"Stream {self.stream_id}: Waiting for data or FIN") + await self.conn.stream_events[self.stream_id].wait() + self.conn.stream_events[self.stream_id] = trio.Event() + + # After loop exit, first check if we have data to return + if data: + logging.debug( + f"Stream {self.stream_id}: Returning {len(data)} bytes after loop" + ) + return data + + # No data accumulated, now check why we exited the loop + if self.conn.event_shutting_down.is_set(): + logging.debug(f"Stream {self.stream_id}: Connection shutting down") + raise MuxedStreamEOF("Connection shut down") + + # Return empty data return b"" else: data = await self.conn.read_stream(self.stream_id, n) diff --git a/tests/core/stream_muxer/test_yamux_read_write_lock.py b/tests/core/stream_muxer/test_yamux_read_write_lock.py index b73284e8..6981f9d3 100644 --- a/tests/core/stream_muxer/test_yamux_read_write_lock.py +++ b/tests/core/stream_muxer/test_yamux_read_write_lock.py @@ -16,6 +16,7 @@ from libp2p.peer.id import ( from libp2p.security.insecure.transport import ( InsecureTransport, ) +from libp2p.stream_muxer.exceptions import MuxedStreamEOF from libp2p.stream_muxer.yamux.yamux import ( Yamux, YamuxStream, @@ -139,8 +140,8 @@ async def test_yamux_race_condition_without_locks(yamux_pair): client_yamux, server_yamux = yamux_pair client_stream: YamuxStream = await client_yamux.open_stream() server_stream: YamuxStream = await server_yamux.accept_stream() - MSG_COUNT = 10 - MSG_SIZE = 256 * 1024 + MSG_COUNT = 1 + MSG_SIZE = 512 * 1024 client_msgs = [ f"CLIENT-MSG-{i:03d}-".encode().ljust(MSG_SIZE, b"C") for i in range(MSG_COUNT) ] @@ -160,11 +161,17 @@ async def test_yamux_race_condition_without_locks(yamux_pair): async def reader(stream, received, name): """Read messages and store them for verification.""" - for i in range(MSG_COUNT): - data = await stream.read(MSG_SIZE) - received.append(data) - if i % 3 == 0: - await trio.sleep(0.001) + try: + data = await stream.read() + if data: + received.append(data) + except MuxedStreamEOF: + pass + # for i in range(MSG_COUNT): + # data = await stream.read() + # received.append(data) + # if i % 3 == 0: + # await trio.sleep(0.001) # Running all operations concurrently async with trio.open_nursery() as nursery: @@ -173,12 +180,12 @@ async def test_yamux_race_condition_without_locks(yamux_pair): nursery.start_soon(reader, client_stream, client_received, "client") nursery.start_soon(reader, server_stream, server_received, "server") - assert len(client_received) == MSG_COUNT, ( - f"Client received {len(client_received)} messages, expected {MSG_COUNT}" - ) - assert len(server_received) == MSG_COUNT, ( - f"Server received {len(server_received)} messages, expected {MSG_COUNT}" - ) + # assert len(client_received) == MSG_COUNT, ( + # f"Client received {len(client_received)} messages, expected {MSG_COUNT}" + # ) + # assert len(server_received) == MSG_COUNT, ( + # f"Server received {len(server_received)} messages, expected {MSG_COUNT}" + # ) assert client_received == server_msgs, ( "Client did not receive server messages in order or intact!" ) From 724375e1fabac07751242af9beafe20c304ec65c Mon Sep 17 00:00:00 2001 From: kaneki003 Date: Tue, 24 Jun 2025 18:05:15 +0530 Subject: [PATCH 5/6] updated doc-string and reverted mplex-changes --- libp2p/stream_muxer/mplex/mplex_stream.py | 101 +++++++------- libp2p/stream_muxer/yamux/yamux.py | 2 - newsfragments/639.feature.rst | 7 +- .../test_mplex_read_write_lock.py | 127 ------------------ tests/core/stream_muxer/test_yamux.py | 6 +- ...write_lock.py => test_yamux_read_write.py} | 0 6 files changed, 56 insertions(+), 187 deletions(-) delete mode 100644 tests/core/stream_muxer/test_mplex_read_write_lock.py rename tests/core/stream_muxer/{test_yamux_read_write_lock.py => test_yamux_read_write.py} (100%) diff --git a/libp2p/stream_muxer/mplex/mplex_stream.py b/libp2p/stream_muxer/mplex/mplex_stream.py index dc65ac5f..3b640df1 100644 --- a/libp2p/stream_muxer/mplex/mplex_stream.py +++ b/libp2p/stream_muxer/mplex/mplex_stream.py @@ -46,9 +46,8 @@ class MplexStream(IMuxedStream): read_deadline: int | None write_deadline: int | None + # TODO: Add lock for read/write to avoid interleaving receiving messages? close_lock: trio.Lock - read_lock: trio.Lock - write_lock: trio.Lock # NOTE: `dataIn` is size of 8 in Go implementation. incoming_data_channel: "trio.MemoryReceiveChannel[bytes]" @@ -81,8 +80,6 @@ class MplexStream(IMuxedStream): self.event_remote_closed = trio.Event() self.event_reset = trio.Event() self.close_lock = trio.Lock() - self.read_lock = trio.Lock() - self.write_lock = trio.Lock() self.incoming_data_channel = incoming_data_channel self._buf = bytearray() @@ -116,49 +113,48 @@ class MplexStream(IMuxedStream): :param n: number of bytes to read :return: bytes actually read """ - async with self.read_lock: - if n is not None and n < 0: - raise ValueError( - "the number of bytes to read `n` must be non-negative or " - f"`None` to indicate read until EOF, got n={n}" - ) - if self.event_reset.is_set(): - raise MplexStreamReset - if n is None: - return await self._read_until_eof() - if len(self._buf) == 0: - data: bytes - # Peek whether there is data available. If yes, we just read until - # there is no data, then return. + if n is not None and n < 0: + raise ValueError( + "the number of bytes to read `n` must be non-negative or " + f"`None` to indicate read until EOF, got n={n}" + ) + if self.event_reset.is_set(): + raise MplexStreamReset + if n is None: + return await self._read_until_eof() + if len(self._buf) == 0: + data: bytes + # Peek whether there is data available. If yes, we just read until there is + # no data, then return. + try: + data = self.incoming_data_channel.receive_nowait() + self._buf.extend(data) + except trio.EndOfChannel: + raise MplexStreamEOF + except trio.WouldBlock: + # We know `receive` will be blocked here. Wait for data here with + # `receive` and catch all kinds of errors here. try: - data = self.incoming_data_channel.receive_nowait() + data = await self.incoming_data_channel.receive() self._buf.extend(data) except trio.EndOfChannel: - raise MplexStreamEOF - except trio.WouldBlock: - # We know `receive` will be blocked here. Wait for data here with - # `receive` and catch all kinds of errors here. - try: - data = await self.incoming_data_channel.receive() - self._buf.extend(data) - except trio.EndOfChannel: - if self.event_reset.is_set(): - raise MplexStreamReset - if self.event_remote_closed.is_set(): - raise MplexStreamEOF - except trio.ClosedResourceError as error: - # Probably `incoming_data_channel` is closed in `reset` when - # we are waiting for `receive`. - if self.event_reset.is_set(): - raise MplexStreamReset - raise Exception( - "`incoming_data_channel` is closed but stream is not reset." - "This should never happen." - ) from error - self._buf.extend(self._read_return_when_blocked()) - payload = self._buf[:n] - self._buf = self._buf[len(payload) :] - return bytes(payload) + if self.event_reset.is_set(): + raise MplexStreamReset + if self.event_remote_closed.is_set(): + raise MplexStreamEOF + except trio.ClosedResourceError as error: + # Probably `incoming_data_channel` is closed in `reset` when we are + # waiting for `receive`. + if self.event_reset.is_set(): + raise MplexStreamReset + raise Exception( + "`incoming_data_channel` is closed but stream is not reset. " + "This should never happen." + ) from error + self._buf.extend(self._read_return_when_blocked()) + payload = self._buf[:n] + self._buf = self._buf[len(payload) :] + return bytes(payload) async def write(self, data: bytes) -> None: """ @@ -166,15 +162,14 @@ class MplexStream(IMuxedStream): :return: number of bytes written """ - async with self.write_lock: - if self.event_local_closed.is_set(): - raise MplexStreamClosed(f"cannot write to closed stream: data={data!r}") - flag = ( - HeaderTags.MessageInitiator - if self.is_initiator - else HeaderTags.MessageReceiver - ) - await self.muxed_conn.send_message(flag, data, self.stream_id) + if self.event_local_closed.is_set(): + raise MplexStreamClosed(f"cannot write to closed stream: data={data!r}") + flag = ( + HeaderTags.MessageInitiator + if self.is_initiator + else HeaderTags.MessageReceiver + ) + await self.muxed_conn.send_message(flag, data, self.stream_id) async def close(self) -> None: """ diff --git a/libp2p/stream_muxer/yamux/yamux.py b/libp2p/stream_muxer/yamux/yamux.py index 023251ed..f90ba9a1 100644 --- a/libp2p/stream_muxer/yamux/yamux.py +++ b/libp2p/stream_muxer/yamux/yamux.py @@ -77,8 +77,6 @@ class YamuxStream(IMuxedStream): self.send_window = DEFAULT_WINDOW_SIZE self.recv_window = DEFAULT_WINDOW_SIZE self.window_lock = trio.Lock() - self.read_lock = trio.Lock() - self.write_lock = trio.Lock() async def __aenter__(self) -> "YamuxStream": """Enter the async context manager.""" diff --git a/newsfragments/639.feature.rst b/newsfragments/639.feature.rst index 3f3d7510..93476b68 100644 --- a/newsfragments/639.feature.rst +++ b/newsfragments/639.feature.rst @@ -1 +1,6 @@ -Added separate read and write locks to the `MplexStream` & `YamuxStream` class.This ensures thread-safe access and data integrity when multiple coroutines interact with the same MplexStream instance. +Fixed several flow-control and concurrency issues in the `YamuxStream` class. Previously, stress-testing revealed that transferring data over `DEFAULT_WINDOW_SIZE` would break the stream due to inconsistent window update handling and lock management. The fixes include: + +- Removed sending of window updates during writes to maintain correct flow-control. +- Added proper timeout handling when releasing and acquiring locks to prevent concurrency errors. +- Corrected the `read` function to properly handle window updates for both `read_until_EOF` and `read_n_bytes`. +- Added event logging at `send_window_updates` and `waiting_for_window_updates` for better observability. diff --git a/tests/core/stream_muxer/test_mplex_read_write_lock.py b/tests/core/stream_muxer/test_mplex_read_write_lock.py deleted file mode 100644 index d00d5b8e..00000000 --- a/tests/core/stream_muxer/test_mplex_read_write_lock.py +++ /dev/null @@ -1,127 +0,0 @@ -import pytest -import trio - -from libp2p.abc import IMuxedStream, ISecureConn -from libp2p.crypto.keys import PrivateKey, PublicKey -from libp2p.peer.id import ID -from libp2p.stream_muxer.mplex.constants import ( - HeaderTags, -) -from libp2p.stream_muxer.mplex.datastructures import ( - StreamID, -) -from libp2p.stream_muxer.mplex.mplex import ( - Mplex, -) -from libp2p.stream_muxer.mplex.mplex_stream import ( - MplexStream, -) - - -class DummySecureConn(ISecureConn): - """A minimal implementation of ISecureConn for testing.""" - - async def write(self, data: bytes) -> None: - pass - - async def read(self, n: int | None = -1) -> bytes: - return b"" - - async def close(self) -> None: - pass - - def get_remote_address(self) -> tuple[str, int] | None: - return None - - def get_local_peer(self) -> ID: - return ID(b"local") - - def get_local_private_key(self) -> PrivateKey: - return PrivateKey() # Dummy key for testing - - def get_remote_peer(self) -> ID: - return ID(b"remote") - - def get_remote_public_key(self) -> PublicKey: - return PublicKey() # Dummy key for testing - - -class DummyMuxedConn(Mplex): - """A minimal mock of Mplex for testing read/write locks.""" - - def __init__(self) -> None: - self.secured_conn = DummySecureConn() - self.peer_id = ID(b"dummy") - self.streams = {} - self.streams_lock = trio.Lock() - self.event_shutting_down = trio.Event() - self.event_closed = trio.Event() - self.event_started = trio.Event() - self.stream_backlog_limit = 256 - self.stream_backlog_semaphore = trio.Semaphore(256) - # Use IMuxedStream for type consistency with Mplex - channels = trio.open_memory_channel[IMuxedStream](0) - self.new_stream_send_channel, self.new_stream_receive_channel = channels - - async def send_message( - self, flag: HeaderTags, data: bytes | None, stream_id: StreamID - ) -> int: - await trio.sleep(0.01) - return 0 - - -@pytest.mark.trio -async def test_concurrent_writes_are_serialized(): - stream_id = StreamID(1, True) - send_log = [] - - class LoggingMuxedConn(DummyMuxedConn): - async def send_message( - self, flag: HeaderTags, data: bytes | None, stream_id: StreamID - ) -> int: - send_log.append(data) - await trio.sleep(0.01) - return 0 - - memory_send, memory_recv = trio.open_memory_channel(8) - stream = MplexStream( - name="test", - stream_id=stream_id, - muxed_conn=LoggingMuxedConn(), - incoming_data_channel=memory_recv, - ) - - async def writer(data): - await stream.write(data) - - async with trio.open_nursery() as nursery: - for i in range(5): - nursery.start_soon(writer, f"msg-{i}".encode()) - # Order doesn't matter due to concurrent execution - assert sorted(send_log) == sorted([f"msg-{i}".encode() for i in range(5)]) - - -@pytest.mark.trio -async def test_concurrent_reads_are_serialized(): - stream_id = StreamID(2, True) - muxed_conn = DummyMuxedConn() - memory_send, memory_recv = trio.open_memory_channel(8) - results = [] - stream = MplexStream( - name="test", - stream_id=stream_id, - muxed_conn=muxed_conn, - incoming_data_channel=memory_recv, - ) - for i in range(5): - await memory_send.send(f"data-{i}".encode()) - await memory_send.aclose() - - async def reader(): - data = await stream.read(6) - results.append(data) - - async with trio.open_nursery() as nursery: - for _ in range(5): - nursery.start_soon(reader) - assert sorted(results) == [f"data-{i}".encode() for i in range(5)] diff --git a/tests/core/stream_muxer/test_yamux.py b/tests/core/stream_muxer/test_yamux.py index bfd8eb5a..81d05676 100644 --- a/tests/core/stream_muxer/test_yamux.py +++ b/tests/core/stream_muxer/test_yamux.py @@ -224,16 +224,14 @@ async def test_yamux_stream_reset(yamux_pair): await client_stream.reset() # After reset, reading should raise MuxedStreamReset or MuxedStreamEOF try: - while True: - await server_stream.read() + await server_stream.read() except (MuxedStreamEOF, MuxedStreamError): pass else: pytest.fail("Expected MuxedStreamEOF or MuxedStreamError") # Verify subsequent operations fail with StreamReset or EOF with pytest.raises(MuxedStreamError): - while True: - await server_stream.read() + await server_stream.read() with pytest.raises(MuxedStreamError): await server_stream.write(b"test") logging.debug("test_yamux_stream_reset complete") diff --git a/tests/core/stream_muxer/test_yamux_read_write_lock.py b/tests/core/stream_muxer/test_yamux_read_write.py similarity index 100% rename from tests/core/stream_muxer/test_yamux_read_write_lock.py rename to tests/core/stream_muxer/test_yamux_read_write.py From 5ac4fc1abaa0fc5d6d55350cb711550916b9e95e Mon Sep 17 00:00:00 2001 From: kaneki003 Date: Thu, 3 Jul 2025 22:20:35 +0530 Subject: [PATCH 6/6] seperated tests for better understanding --- .../stream_muxer/test_yamux_interleaving.py | 199 ++++++++++++++++++ ...rite.py => test_yamux_interleaving_EOF.py} | 17 +- 2 files changed, 201 insertions(+), 15 deletions(-) create mode 100644 tests/core/stream_muxer/test_yamux_interleaving.py rename tests/core/stream_muxer/{test_yamux_read_write.py => test_yamux_interleaving_EOF.py} (90%) diff --git a/tests/core/stream_muxer/test_yamux_interleaving.py b/tests/core/stream_muxer/test_yamux_interleaving.py new file mode 100644 index 00000000..1ce62952 --- /dev/null +++ b/tests/core/stream_muxer/test_yamux_interleaving.py @@ -0,0 +1,199 @@ +import logging + +import pytest +import trio +from trio.testing import ( + memory_stream_pair, +) + +from libp2p.abc import IRawConnection +from libp2p.crypto.ed25519 import ( + create_new_key_pair, +) +from libp2p.peer.id import ( + ID, +) +from libp2p.security.insecure.transport import ( + InsecureTransport, +) +from libp2p.stream_muxer.yamux.yamux import ( + Yamux, + YamuxStream, +) + + +class TrioStreamAdapter(IRawConnection): + """Adapter to make trio memory streams work with libp2p.""" + + def __init__(self, send_stream, receive_stream, is_initiator=False): + self.send_stream = send_stream + self.receive_stream = receive_stream + self.is_initiator = is_initiator + + async def write(self, data: bytes) -> None: + logging.debug(f"Attempting to write {len(data)} bytes") + with trio.move_on_after(2): + await self.send_stream.send_all(data) + + async def read(self, n: int | None = None) -> bytes: + if n is None or n <= 0: + raise ValueError("Reading unbounded or zero bytes not supported") + logging.debug(f"Attempting to read {n} bytes") + with trio.move_on_after(2): + data = await self.receive_stream.receive_some(n) + logging.debug(f"Read {len(data)} bytes") + return data + + async def close(self) -> None: + logging.debug("Closing stream") + await self.send_stream.aclose() + await self.receive_stream.aclose() + + def get_remote_address(self) -> tuple[str, int] | None: + """Return None since this is a test adapter without real network info.""" + return None + + +@pytest.fixture +def key_pair(): + return create_new_key_pair() + + +@pytest.fixture +def peer_id(key_pair): + return ID.from_pubkey(key_pair.public_key) + + +@pytest.fixture +async def secure_conn_pair(key_pair, peer_id): + """Create a pair of secure connections for testing.""" + logging.debug("Setting up secure_conn_pair") + client_send, server_receive = memory_stream_pair() + server_send, client_receive = memory_stream_pair() + + client_rw = TrioStreamAdapter(client_send, client_receive) + server_rw = TrioStreamAdapter(server_send, server_receive) + + insecure_transport = InsecureTransport(key_pair) + + async def run_outbound(nursery_results): + with trio.move_on_after(5): + client_conn = await insecure_transport.secure_outbound(client_rw, peer_id) + logging.debug("Outbound handshake complete") + nursery_results["client"] = client_conn + + async def run_inbound(nursery_results): + with trio.move_on_after(5): + server_conn = await insecure_transport.secure_inbound(server_rw) + logging.debug("Inbound handshake complete") + nursery_results["server"] = server_conn + + nursery_results = {} + async with trio.open_nursery() as nursery: + nursery.start_soon(run_outbound, nursery_results) + nursery.start_soon(run_inbound, nursery_results) + await trio.sleep(0.1) # Give tasks a chance to finish + + client_conn = nursery_results.get("client") + server_conn = nursery_results.get("server") + + if client_conn is None or server_conn is None: + raise RuntimeError("Handshake failed: client_conn or server_conn is None") + + logging.debug("secure_conn_pair setup complete") + return client_conn, server_conn + + +@pytest.fixture +async def yamux_pair(secure_conn_pair, peer_id): + """Create a pair of Yamux multiplexers for testing.""" + logging.debug("Setting up yamux_pair") + client_conn, server_conn = secure_conn_pair + client_yamux = Yamux(client_conn, peer_id, is_initiator=True) + server_yamux = Yamux(server_conn, peer_id, is_initiator=False) + async with trio.open_nursery() as nursery: + with trio.move_on_after(5): + nursery.start_soon(client_yamux.start) + nursery.start_soon(server_yamux.start) + await trio.sleep(0.1) + logging.debug("yamux_pair started") + yield client_yamux, server_yamux + logging.debug("yamux_pair cleanup") + + +@pytest.mark.trio +async def test_yamux_race_condition_without_locks(yamux_pair): + """ + Test for race-around/interleaving in Yamux streams,when reading in + segments of data. + This launches concurrent writers/readers on both sides of a stream. + If there is no proper locking, the received data may be interleaved + or corrupted. + + The test creates structured messages and verifies they are received + intact and in order. + Without proper locking, concurrent read/write operations could cause + data corruption + or message interleaving, which this test will catch. + """ + client_yamux, server_yamux = yamux_pair + client_stream: YamuxStream = await client_yamux.open_stream() + server_stream: YamuxStream = await server_yamux.accept_stream() + MSG_COUNT = 10 + MSG_SIZE = 256 * 1024 # At max,only DEFAULT_WINDOW_SIZE bytes can be read + client_msgs = [ + f"CLIENT-MSG-{i:03d}-".encode().ljust(MSG_SIZE, b"C") for i in range(MSG_COUNT) + ] + server_msgs = [ + f"SERVER-MSG-{i:03d}-".encode().ljust(MSG_SIZE, b"S") for i in range(MSG_COUNT) + ] + client_received = [] + server_received = [] + + async def writer(stream, msgs, name): + """Write messages with minimal delays to encourage race conditions.""" + for i, msg in enumerate(msgs): + await stream.write(msg) + # Yield control frequently to encourage interleaving + if i % 5 == 0: + await trio.sleep(0.005) + + async def reader(stream, received, name): + """Read messages and store them for verification.""" + for i in range(MSG_COUNT): + data = await stream.read(MSG_SIZE) + received.append(data) + if i % 3 == 0: + await trio.sleep(0.001) + + # Running all operations concurrently + async with trio.open_nursery() as nursery: + nursery.start_soon(writer, client_stream, client_msgs, "client") + nursery.start_soon(writer, server_stream, server_msgs, "server") + nursery.start_soon(reader, client_stream, client_received, "client") + nursery.start_soon(reader, server_stream, server_received, "server") + + assert len(client_received) == MSG_COUNT, ( + f"Client received {len(client_received)} messages, expected {MSG_COUNT}" + ) + assert len(server_received) == MSG_COUNT, ( + f"Server received {len(server_received)} messages, expected {MSG_COUNT}" + ) + assert client_received == server_msgs, ( + "Client did not receive server messages in order or intact!" + ) + assert server_received == client_msgs, ( + "Server did not receive client messages in order or intact!" + ) + for i, msg in enumerate(client_received): + assert len(msg) == MSG_SIZE, ( + f"Client message {i} has wrong size: {len(msg)} != {MSG_SIZE}" + ) + + for i, msg in enumerate(server_received): + assert len(msg) == MSG_SIZE, ( + f"Server message {i} has wrong size: {len(msg)} != {MSG_SIZE}" + ) + + await client_stream.close() + await server_stream.close() diff --git a/tests/core/stream_muxer/test_yamux_read_write.py b/tests/core/stream_muxer/test_yamux_interleaving_EOF.py similarity index 90% rename from tests/core/stream_muxer/test_yamux_read_write.py rename to tests/core/stream_muxer/test_yamux_interleaving_EOF.py index 6981f9d3..23d2c2b4 100644 --- a/tests/core/stream_muxer/test_yamux_read_write.py +++ b/tests/core/stream_muxer/test_yamux_interleaving_EOF.py @@ -125,8 +125,8 @@ async def yamux_pair(secure_conn_pair, peer_id): @pytest.mark.trio async def test_yamux_race_condition_without_locks(yamux_pair): """ - Test for race-around/interleaving in Yamux streams when read/write - locks are disabled. + Test for race-around/interleaving in Yamux streams,when reading till + EOF is being used. This launches concurrent writers/readers on both sides of a stream. If there is no proper locking, the received data may be interleaved or corrupted. @@ -167,11 +167,6 @@ async def test_yamux_race_condition_without_locks(yamux_pair): received.append(data) except MuxedStreamEOF: pass - # for i in range(MSG_COUNT): - # data = await stream.read() - # received.append(data) - # if i % 3 == 0: - # await trio.sleep(0.001) # Running all operations concurrently async with trio.open_nursery() as nursery: @@ -180,12 +175,6 @@ async def test_yamux_race_condition_without_locks(yamux_pair): nursery.start_soon(reader, client_stream, client_received, "client") nursery.start_soon(reader, server_stream, server_received, "server") - # assert len(client_received) == MSG_COUNT, ( - # f"Client received {len(client_received)} messages, expected {MSG_COUNT}" - # ) - # assert len(server_received) == MSG_COUNT, ( - # f"Server received {len(server_received)} messages, expected {MSG_COUNT}" - # ) assert client_received == server_msgs, ( "Client did not receive server messages in order or intact!" ) @@ -193,8 +182,6 @@ async def test_yamux_race_condition_without_locks(yamux_pair): "Server did not receive client messages in order or intact!" ) for i, msg in enumerate(client_received): - # logging.debug(f"datatype of msg: {type(msg)}, length: {len(msg)}") - # logging.debug(f"datatype of msg: {type(b"SERVER-MSG-")}") assert len(msg) == MSG_SIZE, ( f"Client message {i} has wrong size: {len(msg)} != {MSG_SIZE}" )