add memory limit

runner/runner.go

@@ -225,6 +225,9 @@ func (r *Runner) runGroup(g *dsl.Group) *GroupResult {
 		if t.Timeout == 0 {
 			t.Timeout = g.Timeout
 		}
+		if t.MemoryLimit == 0 {
+			t.MemoryLimit = g.MemoryLimit
+		}
 		if t.Wrapper == "" {
 			t.Wrapper = g.Wrapper
 		}
@@ -313,10 +316,34 @@ func (r *Runner) runTest(t *dsl.Test) *TestResult {
 	cmd.Stdout = stdout
 	cmd.Stderr = stderr
 
+	tr.MemoryLimit = t.MemoryLimit
+	lim := newLimiter(t.MemoryLimit)
+	if err := lim.prepare(cmd); err != nil {
+		tr.Status = StatusRuntimeError
+		tr.addFailure("memory limiter setup: %v", err)
+		return tr
+	}
+	defer lim.cleanup()
+
 	start := time.Now()
-	runErr := cmd.Run()
+	if err := cmd.Start(); err != nil {
+		tr.Status = StatusRuntimeError
+		tr.addFailure("start: %v", err)
+		return tr
+	}
+	if err := lim.afterStart(cmd); err != nil {
+		killProcessGroup(cmd)
+		_ = cmd.Wait()
+		tr.Status = StatusRuntimeError
+		tr.addFailure("memory limiter attach: %v", err)
+		return tr
+	}
+	runErr := cmd.Wait()
 	tr.Elapsed = time.Since(start)
 
+	stats := lim.collect()
+	tr.PeakMemory = stats.PeakMemory
+
 	if ctx.Err() == context.DeadlineExceeded {
 		killProcessGroup(cmd)
 	}
@@ -334,6 +361,12 @@ func (r *Runner) runTest(t *dsl.Test) *TestResult {
 		return tr
 	}
 
+	if stats.MemoryExceeded {
+		tr.Status = StatusMLE
+		tr.addFailure("memory limit exceeded (limit %d bytes, peak %d bytes)", t.MemoryLimit, stats.PeakMemory)
+		return tr
+	}
+
 	actualCode := 0
 	if runErr != nil {
 		if exitErr, ok := runErr.(*exec.ExitError); ok {