Run processes without forced GC or a login shell

SpecsUtils/src/pt/up/fe/specs/util/SpecsGraphviz.java

@@ -29,8 +29,13 @@ public class SpecsGraphviz {
     private static final Lazy<Boolean> IS_DOT_AVAILABLE = Lazy.newInstance(SpecsGraphviz::checkDot);
 
     private static boolean checkDot() {
-        var result = SpecsSystem.runProcess(Arrays.asList("dot", "-?"), false, false);
-        return result.getReturnValue() == 0;
+        try {
+            var result = SpecsSystem.runProcess(Arrays.asList("dot", "-?"), false, false);
+            return result.getReturnValue() == 0;
+        } catch (RuntimeException e) {
+            // The launch itself failed, e.g. Graphviz is not installed
+            return false;
+        }
     }
 
     public static boolean isDotAvailable() {
@@ -47,9 +52,19 @@ public static void renderDot(File dotFile, DotRenderFormat format, File outputFi
         var command = Arrays.asList("dot", format.getFlag(), dotFile.getAbsolutePath(), "-o",
                 outputFile.getAbsolutePath());
 
-        var result = SpecsSystem.runProcess(command, false, false);
-        if (result.getReturnValue() == 0) {
-            SpecsLogs.debug(() -> "Rendered dot file '" + dotFile.getAbsolutePath() + "' as " + format);
+        try {
+            var result = SpecsSystem.runProcess(command, false, false);
+            if (result.getReturnValue() == 0) {
+                SpecsLogs.debug(() -> "Rendered dot file '" + dotFile.getAbsolutePath() + "' as " + format);
+            }
+        } catch (RuntimeException e) {
+            // Only a missing Graphviz installation is skipped; any other
+            // failure is rethrown
+            if (!SpecsSystem.isLaunchFailure(e)) {
+                throw e;
+            }
+
+            SpecsLogs.msgInfo("Graphviz not available, could not render dot file '" + dotFile.getAbsolutePath() + "'");
         }
     }
 

SpecsUtils/src/pt/up/fe/specs/util/SpecsSystem.java

@@ -190,15 +190,7 @@ public static <O, E> ProcessOutput<O, E> runProcess(ProcessBuilder builder,
 
         Process process;
         try {
-            // Experiment: Calling Garbage Collector before starting process in order to
-            // reduce memory required to fork VM
-            // http://www.bryanmarty.com/2012/01/14/forking-jvm/
-            long totalMemBefore = Runtime.getRuntime().totalMemory();
-            System.gc();
-            long totalMemAfter = Runtime.getRuntime().totalMemory();
-            SpecsLogs.msgLib("Preparing to run process, memory before -> after GC: "
-                    + SpecsStrings.parseSize(totalMemBefore) + " -> " + SpecsStrings.parseSize(totalMemAfter));
-            process = builder.start();
+        process = builder.start();
 
         } catch (IOException e) {
             throw new RuntimeException("Could not start process", e);
@@ -254,19 +246,6 @@ private static void processCommand(ProcessBuilder builder) {
             newCommand.add("/c");
             newCommand.addAll(builder.command());
 
-            builder.command(newCommand);
-        } else if (isLinux()) {
-            // Update command
-            List<String> newCommand = new ArrayList<>(4);
-            newCommand.add("bash");
-            // Same user
-            newCommand.add("-l");
-            // Command
-            newCommand.add("-c");
-            newCommand.add(builder.command().stream()
-                    .map(arg -> arg.replace(" ", "\\ "))
-                    .collect(Collectors.joining(" ")));
-
             builder.command(newCommand);
         }
 
@@ -599,6 +578,26 @@ public static boolean isCommandAvailable(List<String> command, File workingdir)
 
     }
 
+    /**
+     * Checks if the throwable was caused by a failure to launch the process
+     * itself (e.g., command not found or not executable), as opposed to a
+     * failure after a successful launch.
+     *
+     * @param throwable
+     * @return
+     */
+    public static boolean isLaunchFailure(Throwable throwable) {
+        for (Throwable currentThrowable = throwable; currentThrowable != null; currentThrowable = currentThrowable
+                .getCause()) {
+            if (currentThrowable instanceof IOException) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+
     /**
      * Adds a path to the java.library.path property, and flushes the path cache so
      * that subsequent System.load calls

SpecsUtils/src/pt/up/fe/specs/util/jobs/execution/ProcessExecution.java

@@ -16,6 +16,7 @@
 import java.io.File;
 import java.util.List;
 
+import pt.up.fe.specs.util.SpecsLogs;
 import pt.up.fe.specs.util.SpecsSystem;
 
 /**
@@ -45,7 +46,20 @@ public ProcessExecution(List<String> commandArgs, String workingFoldername) {
      */
     @Override
     public int run() {
-        return SpecsSystem.run(this.commandArgs, new File(this.workingFoldername));
+        try {
+            return SpecsSystem.run(this.commandArgs, new File(this.workingFoldername));
+        } catch (RuntimeException e) {
+            // Only a launch failure due to a missing command maps to a return
+            // code (the shell convention of 127, 'command not found'). Any
+            // other failure is not representable as an exit code and is
+            // rethrown, as the process may even have been running.
+            if (!SpecsSystem.isLaunchFailure(e)) {
+                throw e;
+            }
+
+            SpecsLogs.msgInfo("Could not run command '" + getCommandString() + "': " + e.getMessage());
+            return 127;
+        }
     }
 
     @Override