From c7f0276005b033f299ca2c56f42c247697025ad6 Mon Sep 17 00:00:00 2001
From: Viktor Lofgren <vlofgren@marginalia.nu>
Date: Tue, 22 Aug 2023 11:48:54 +0200
Subject: [PATCH] (control) Don't spin on process output printing

This is the "correct" way of copying stdout and stderr to the curren't process' output.
---
 .../control/process/ProcessService.java       | 63 +++++++++++++++----
 1 file changed, 51 insertions(+), 12 deletions(-)

diff --git a/code/services-core/control-service/src/main/java/nu/marginalia/control/process/ProcessService.java b/code/services-core/control-service/src/main/java/nu/marginalia/control/process/ProcessService.java
index 25583f43..14403dfb 100644
--- a/code/services-core/control-service/src/main/java/nu/marginalia/control/process/ProcessService.java
+++ b/code/services-core/control-service/src/main/java/nu/marginalia/control/process/ProcessService.java
@@ -11,6 +11,7 @@ import org.slf4j.MarkerFactory;
 import javax.inject.Inject;
 import javax.inject.Singleton;
 import java.io.BufferedReader;
+import java.io.IOException;
 import java.io.InputStreamReader;
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -72,24 +73,16 @@ public class ProcessService {
             processes.put(processId, process);
         }
 
-        try (var es = new BufferedReader(new InputStreamReader(process.getErrorStream()));
-             var os = new BufferedReader(new InputStreamReader(process.getInputStream()))
-        ) {
-            eventLog.logEvent("PROCESS-STARTED", processId.toString());
-
-            while (process.isAlive()) {
-                if (es.ready())
-                    logger.warn(processMarker, es.readLine());
-                if (os.ready())
-                    logger.info(processMarker, os.readLine());
-            }
+        try {
+            new Thread(new ProcessLogStderr(process)).start();
+            new Thread(new ProcessLogStdout(process)).start();
 
             final int returnCode = process.waitFor();
             logger.info("Process {} terminated with code {}", processId, returnCode);
             return 0 == returnCode;
         }
         catch (Exception ex) {
-            logger.info("Process {} terminated with code exception", processId);
+            logger.info("Process {} terminated with exception", processId);
             throw ex;
         }
         finally {
@@ -98,6 +91,7 @@ public class ProcessService {
         }
     }
 
+
     private String[] createCommandArguments(String processPath, String[] parameters) {
         final String[] args = new String[parameters.length + 1];
         args[0] = processPath;
@@ -153,4 +147,49 @@ public class ProcessService {
         return key + "=" + val;
     }
 
+
+
+
+    class ProcessLogStderr implements Runnable {
+        private final Process process;
+
+        public ProcessLogStderr(Process process) {
+            this.process = process;
+        }
+
+        @Override
+        public void run() {
+            try (var es = new BufferedReader(new InputStreamReader(process.getErrorStream()))) {
+                String line;
+                while (((line = es.readLine()) != null)) {
+                    logger.warn(processMarker, line);
+                }
+            }
+            catch (IOException ex) {
+                logger.error("Error reading process error stream", ex);
+            }
+        }
+    }
+
+    class ProcessLogStdout implements Runnable {
+        private final Process process;
+
+        public ProcessLogStdout(Process process) {
+            this.process = process;
+        }
+
+        @Override
+        public void run() {
+            try (var is = new BufferedReader(new InputStreamReader(process.getInputStream()))) {
+                String line;
+                while (((line = is.readLine()) != null)) {
+                    logger.info(processMarker, line);
+                }
+            }
+            catch (IOException ex) {
+                logger.error("Error reading process output stream", ex);
+            }
+        }
+    }
+
 }