ProcessBuilder

java-api/src/java9/java/xyz/wagyourtail/jvmdg/j9/stub/java_base/J_L_ProcessBuilder.java

@@ -0,0 +1,65 @@
+package xyz.wagyourtail.jvmdg.j9.stub.java_base;
+
+import xyz.wagyourtail.jvmdg.version.Ref;
+import xyz.wagyourtail.jvmdg.version.Stub;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.CompletableFuture;
+
+public class J_L_ProcessBuilder {
+
+    @Stub(ref = @Ref("java/lang/ProcessBuilder"))
+    public static List<Process> startPipeline(List<ProcessBuilder> builders) throws IOException {
+        List<Process> processes = new ArrayList<>();
+        try {
+            InputStream prevOutput = null;
+            for (int i = 0; i < builders.size(); i++) {
+                ProcessBuilder processBuilder = builders.get(i);
+                if (i > 0) {
+                    ProcessBuilder.Redirect redirect = processBuilder.redirectInput();
+                    if (redirect != ProcessBuilder.Redirect.PIPE) {
+                        throw new IllegalArgumentException("builder redirectInput() must be PIPE except for the first builder: " + processBuilder.redirectInput());
+                    }
+                }
+                if (i < builders.size() - 1) {
+                    ProcessBuilder.Redirect redirect = processBuilder.redirectOutput();
+                    if (redirect != ProcessBuilder.Redirect.PIPE) {
+                        throw new IllegalArgumentException("builder redirectOutput() must be PIPE except for the last builder: " + processBuilder.redirectOutput());
+                    }
+                }
+                Process p = processBuilder.start();
+                OutputStream nextInput = p.getOutputStream();
+                if (i > 0) {
+                    InputStream finalPrevOutput = prevOutput;
+                    CompletableFuture.runAsync(() -> {
+                        try {
+                            J_I_InputStream.transferTo(finalPrevOutput, nextInput);
+                        } catch (IOException e) {
+                            throw new RuntimeException(e);
+                        }
+                    });
+                }
+                processes.add(p);
+                prevOutput = p.getInputStream();
+            }
+        } catch (Exception e) {
+            for (Process process : processes) {
+                process.destroyForcibly();
+            }
+            for (Process process : processes) {
+                try {
+                    process.waitFor();
+                } catch (InterruptedException ie) {
+                    Thread.currentThread().interrupt();
+                }
+            }
+            throw e;
+        }
+        return processes;
+    }
+
+}

java-api/src/main/java/xyz/wagyourtail/jvmdg/providers/Java9Downgrader.java

@@ -37,9 +37,8 @@ public void init() {
         stub(J_L_Module.class);
         stub(J_L_ModuleLayer.class);
         stub(J_L_Process.class);
-        // ProcessBuilder
+        stub(J_L_ProcessBuilder.class);
         stub(J_L_ProcessHandle.class);
-        // ProcessHandleImpl
         stub(J_L_Runtime.class);
         stub(J_L_Runtime.Version.class);
         stub(J_L_Short.class);