Skip to main content

JVM & Android

On JVM and Android, socket uses Java NIO2's AsynchronousSocketChannel with a fallback to SocketChannel (NIO).

Implementation Details​

The JVM and Android targets share code via a custom commonJvmMain source set:

  • Primary: AsynchronousSocketChannel (NIO2) - fully async, callback-based
  • Fallback: SocketChannel (NIO) - for environments where NIO2 is unavailable
  • Buffer allocation: Uses BufferFactory.deterministic() by default for I/O buffers, providing direct ByteBuffer with explicit cleanup. This is required because the TLS handler (SSLEngine) and NIO channels need native memory access via nativeAddress.

TLS​

TLS is implemented using Java's SSLEngine, which wraps the underlying NIO socket channels. The SSLClientSocket class handles the TLS handshake and encrypt/decrypt pipeline.

Requirements​

  • JVM: Java 8+ (bytecode target)
  • Android: API 21+ (minSdk)
  • Build: JDK 21 (Gradle toolchain)

Source Sets​

commonJvmMain (shared JVM code)
├── jvmMain
└── androidMain