Motivation:
When an error is hit during a read loop, a channel is able to tolerate
that error without closing. This is done for a number of reasons, but
the most important one is accepting sockets for already-closed
connections, which can trigger all kinds of errors on the read path.
Unfortunately, there was an edge-case in the code for handling this
case. If one or more reads in the loop had succeeded before the error
was caught, the inner code would be expecting a call to readIfNeeded,
but the outer code wouldn't make it. This would lead to autoRead
channels being wedged open.
Modifications:
This patch extends the Syscall Abstraction Layer to add support for
server sockets. It adds two tests: one for the basic accept flow, and
then one for the case discussed above.
This patch also refactors the code in BaseSocketChannel.readable0 to
more clearly show the path through the error case. There were a number
of early returns and partial conditionals that led to us checking the
same condition in a number of places. This refactor makes it clearer
that it is possible to exit this code in the happy path, with a
tolerated error, which should be considered the same as reading
_something_.
Result:
Harder to wedge a channel open.
Motivation:
Channels can read `ChannelOptions.maxMessagesPerRead` times from a
socket in each read cycle. They typically re-use the same buffer for
each read and rely on it CoWing if necessary. If we read more than once
in a cycle then we may CoW the buffer. Instead of reusing one buffer we
can reuse a pool of buffers limited by `maxMessagesPerRead` and cycle
through each, reducing the chance of CoWing the buffers.
Modifications:
- Extend `RecvByteBufferAllocator` to provide the size of the next
buffer with a default implementation returning `nil`.
- Add an recv buffer pool which lazily grows up to a fixed size and
attempts to reuse buffers where possible if doing so avoids CoWing.
Results:
Fewer allocations
* socket: Make destinationPtr param optional in sendmsg(...)
Signed-off-by: Si Beaumont <beaumont@apple.com>
* pdwm: Fixup documentation: scalar writes use sendmsg, not sendto
Signed-off-by: Si Beaumont <beaumont@apple.com>
* pdwm: Make sockaddr pointer param optional in scalarWriteOperation
Signed-off-by: Si Beaumont <beaumont@apple.com>
* pdwm: Add isConnected property to PendingDatagramWritesState
Signed-off-by: Si Beaumont <beaumont@apple.com>
* pdwm: If socket is connected use NULL msg_name in sendmsg(2)
Signed-off-by: Si Beaumont <beaumont@apple.com>
* BaseSocketChannel: Support connect after bind
Signed-off-by: Si Beaumont <beaumont@apple.com>
* DatagramChannel: Implement connectSocket(to:)
Signed-off-by: Si Beaumont <beaumont@apple.com>
* bootstrap: Rename bind0(makeChannel:registerAndBind:) to withNewChannel(makeChannel:bringup:)
Signed-off-by: Si Beaumont <beaumont@apple.com>
* bootstrap: Add set of DatagramBootstrap.connect(...) APIs
Signed-off-by: Si Beaumont <beaumont@apple.com>
* test: Remove DatagramChannelTests.testConnectionFails
Signed-off-by: Si Beaumont <beaumont@apple.com>
* test: Add ConnectedDatagramChannelTests, inheriting from DatagramChannelTests
Signed-off-by: Si Beaumont <beaumont@apple.com>
* NIOUDPEchoClient: Use connected-mode UDP
Signed-off-by: Si Beaumont <beaumont@apple.com>
* soundness: Update copyright notice
Signed-off-by: Si Beaumont <beaumont@apple.com>
* fixup: cleanup bootstrap APIs
Signed-off-by: Si Beaumont <beaumont@apple.com>
* pdwm: Check address of pending write if connected and add test
Signed-off-by: Si Beaumont <beaumont@apple.com>
* Revert "pdwm: Check address of pending write if connected and add test"
This reverts commit a4ee0756d5.
* channel: Fail buffered writes on connect and validate writes when connected
Signed-off-by: Si Beaumont <beaumont@apple.com>
* Run soundness.sh to get linux tests generated
Signed-off-by: Si Beaumont <beaumont@apple.com>
* NIOUDPEchoClient: Connect socket to remote only if --connect is used
Signed-off-by: Si Beaumont <beaumont@apple.com>
* socket: Support ByteBuffer (without AddressedEnvelope) for DatagramChannel
Signed-off-by: Si Beaumont <beaumont@apple.com>
* test: Simplify some test code
Signed-off-by: Si Beaumont <beaumont@apple.com>
* pdwm: Factor out common, private add(_ pendingWrite:)
Signed-off-by: Si Beaumont <beaumont@apple.com>
* channel: Support AddressedEnvelope on connected socket for control messages
Signed-off-by: Si Beaumont <beaumont@apple.com>
* channel: Defer to common unwrapData for error handling
Signed-off-by: Si Beaumont <beaumont@apple.com>
* channel: Throw more specific (new) errors, instead of IOError
Signed-off-by: Si Beaumont <beaumont@apple.com>
* SocketChannelLifecycleManager: Add supportsReconnect boolean property, used in DatagramChannel
Signed-off-by: Si Beaumont <beaumont@apple.com>
Motivation:
The remaining NIO code really conceptually belongs in a module called
NIOPosix, and NIOCore should really be called NIO. We can't really do
that last step, but we can prepare by pushing the bulk of the remaining
code into a module called NIOPosix.
Modifications:
- Move NIO to NIOPosix
- Make NIO an umbrella module.
Result:
NIOPosix exists.
Cory Benfield