On Mon, 16 Jun 2025 06:54:56 GMT, Jaikiran Pai <j...@openjdk.org> wrote:
> Can I please get a review of this change which proposes to enhance the > implementation of `ServerSocket` and `ServerSocketChannel` to allow for > `backlog` values to be greater than 200 on Windows? This addresses > https://bugs.openjdk.org/browse/JDK-8330940. > > As noted in that enhancement request, right now on Windows, if the backlog is > specified to be more than 200, then Windows caps it to a platform internal > `SOMAXCONN`. As noted in the documentation here > https://learn.microsoft.com/en-us/windows/win32/api/winsock2/nf-winsock2-listen > applications can increase that limit by using the `SOMAXCONN_HINT` macro. > That macro then adjusts the value to be between 200 and 65535, thus allowing > for a higher backlog of connections. > > The commit in this PR uses this macro when the specified backlog is 200 or > more. A new jtreg test has been introduced to verify this change. This test > and other existing tests in tier1, tier2 and tier3 continue to pass. > > A similar restriction on the backlog value applies in Linux too > https://github.com/torvalds/linux/blob/master/Documentation/networking/ip-sysctl.rst#tcp-variables. > But from what I can see, unlike Windows, it cannot be adjusted when calling > `listen()`. test/jdk/java/net/ServerSocket/LargeBacklogTest.java line 43: > 41: * @run junit LargeBacklogTest > 42: */ > 43: class LargeBacklogTest { How reliable is this test? If it is reliable then we can add tests for SocketChannelChannel::socket and AsynchronousServerSocket too. test/jdk/java/net/ServerSocket/LargeBacklogTest.java line 72: > 70: private static void testBackloggedConnects(final int backlog, final > int serverPort) { > 71: int numSuccessfulConnects = 0; > 72: System.out.println("attempting " + backlog + " connections to > port " + serverPort); I don't know if this is a left over trace message or not. If intended then you might have to change it to use System.err so that it inlines with the test (at least I think JUnit uses System.err, TestNG uses System.out). ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/25819#discussion_r2149266221 PR Review Comment: https://git.openjdk.org/jdk/pull/25819#discussion_r2149267956
