lyngio: added processes and docs for it, JVM and linux

lyngio/src/linuxMain/kotlin/net/sergeych/lyngio/process/PlatformLinux.kt

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package net.sergeych.lyngio.process
+
+import kotlinx.cinterop.*
+import platform.posix.*
+
+@OptIn(ExperimentalForeignApi::class)
+internal actual fun getNativeKernelVersion(): String? {
+    return memScoped {
+        val u = alloc<utsname>()
+        if (uname(u.ptr) == 0) {
+            u.release.toKString()
+        } else null
+    }
+}
+
+internal actual fun isNativeProcessSupported(): Boolean = true
+
+internal actual fun getNativeProcessRunner(): LyngProcessRunner = PosixProcessRunner

lyngio/src/linuxMain/kotlin/net/sergeych/lyngio/process/PosixProcessRunner.kt

@@ -0,0 +1,152 @@
+/*
+ * Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package net.sergeych.lyngio.process
+
+import kotlinx.cinterop.*
+import kotlinx.coroutines.*
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.flow.flowOn
+import platform.posix.*
+
+@OptIn(ExperimentalForeignApi::class)
+internal class NativeLyngProcess(
+    private val pid: pid_t,
+    private val stdoutFd: Int,
+    private val stderrFd: Int
+) : LyngProcess {
+    override val stdout: Flow<String> = createPipeFlow(stdoutFd)
+    override val stderr: Flow<String> = createPipeFlow(stderrFd)
+
+    override suspend fun sendSignal(signal: ProcessSignal) {
+        val sig = when (signal) {
+            ProcessSignal.SIGINT -> SIGINT
+            ProcessSignal.SIGTERM -> SIGTERM
+            ProcessSignal.SIGKILL -> SIGKILL
+        }
+        if (kill(pid, sig) != 0) {
+            throw RuntimeException("Failed to send signal $signal to process $pid: ${strerror(errno)?.toKString()}")
+        }
+    }
+
+    override suspend fun waitFor(): Int = withContext(Dispatchers.Default) {
+        memScoped {
+            val status = alloc<IntVar>()
+            if (waitpid(pid, status.ptr, 0) == -1) {
+                throw RuntimeException("Failed to wait for process $pid: ${strerror(errno)?.toKString()}")
+            }
+            val s = status.value
+            if ((s and 0x7f) == 0) (s shr 8) and 0xff else -1
+        }
+    }
+
+    override fun destroy() {
+        kill(pid, SIGKILL)
+    }
+}
+
+@OptIn(ExperimentalForeignApi::class)
+private fun createPipeFlow(fd: Int): Flow<String> = flow {
+    val buffer = ByteArray(4096)
+    val lineBuffer = StringBuilder()
+    
+    try {
+        while (true) {
+            val bytesRead = buffer.usePinned { pinned ->
+                read(fd, pinned.addressOf(0), buffer.size.toULong())
+            }
+            
+            if (bytesRead <= 0L) break
+            
+            val text = buffer.decodeToString(endIndex = bytesRead.toInt())
+            lineBuffer.append(text)
+            
+            var newlineIdx = lineBuffer.indexOf('\n')
+            while (newlineIdx != -1) {
+                val line = lineBuffer.substring(0, newlineIdx)
+                emit(line)
+                lineBuffer.deleteRange(0, newlineIdx + 1)
+                newlineIdx = lineBuffer.indexOf('\n')
+            }
+        }
+        if (lineBuffer.isNotEmpty()) {
+            emit(lineBuffer.toString())
+        }
+    } finally {
+        close(fd)
+    }
+}.flowOn(Dispatchers.Default)
+
+@OptIn(ExperimentalForeignApi::class)
+object PosixProcessRunner : LyngProcessRunner {
+    override suspend fun execute(executable: String, args: List<String>): LyngProcess = withContext(Dispatchers.Default) {
+        memScoped {
+            val pipeStdout = allocArray<IntVar>(2)
+            val pipeStderr = allocArray<IntVar>(2)
+            
+            if (pipe(pipeStdout) != 0) throw RuntimeException("Failed to create stdout pipe")
+            if (pipe(pipeStderr) != 0) {
+                close(pipeStdout[0])
+                close(pipeStdout[1])
+                throw RuntimeException("Failed to create stderr pipe")
+            }
+            
+            val pid = fork()
+            if (pid == -1) {
+                close(pipeStdout[0])
+                close(pipeStdout[1])
+                close(pipeStderr[0])
+                close(pipeStderr[1])
+                throw RuntimeException("Failed to fork: ${strerror(errno)?.toKString()}")
+            }
+            
+            if (pid == 0) {
+                // Child process
+                dup2(pipeStdout[1], 1)
+                dup2(pipeStderr[1], 2)
+                
+                close(pipeStdout[0])
+                close(pipeStdout[1])
+                close(pipeStderr[0])
+                close(pipeStderr[1])
+                
+                val argv = allocArray<CPointerVar<ByteVar>>(args.size + 2)
+                argv[0] = executable.cstr.ptr
+                for (i in args.indices) {
+                    argv[i + 1] = args[i].cstr.ptr
+                }
+                argv[args.size + 1] = null
+                
+                execvp(executable, argv)
+                
+                // If we are here, exec failed
+                _exit(1)
+            }
+            
+            // Parent process
+            close(pipeStdout[1])
+            close(pipeStderr[1])
+            
+            NativeLyngProcess(pid, pipeStdout[0], pipeStderr[0])
+        }
+    }
+
+    override suspend fun shell(command: String): LyngProcess {
+        return execute("/bin/sh", listOf("-c", command))
+    }
+}