src/java.base/linux/classes/jdk/internal/platform/CgroupSubsystemFactory.java

@  rev 57734 : Review feedback
|
o  rev 57733 : 8231111: Cgroups v2: Rework Metrics in java.base so as to recognize unified hierarchy
|  Reviewed-by: bobv, mchung
~
o  rev 56862 : 8231111: Cgroups v2: Rework Metrics in java.base so as to recognize unified hierarchy
|  Reviewed-by: bobv
~

@@ -24,10 +24,12 @@
  */
 
 package jdk.internal.platform;
 
 import java.io.IOException;
+import java.lang.System.Logger;
+import java.lang.System.Logger.Level;
 import java.nio.file.Paths;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.stream.Collectors;

@@ -43,11 +45,11 @@
     private static final String CPUACCT_CTRL = "cpuacct";
     private static final String CPUSET_CTRL = "cpuset";
     private static final String BLKIO_CTRL = "blkio";
     private static final String MEMORY_CTRL = "memory";
 
-    static CgroupSubsystem create() {
+    static CgroupMetrics create() {
         Map<String, CgroupInfo> infos = new HashMap<>();
         try {
             List<String> lines = CgroupUtil.readAllLinesPrivileged(Paths.get("/proc/cgroups"));
             for (String line : lines) {
                 if (line.startsWith("#")) {

@@ -84,11 +86,12 @@
         }
         // Warn about mixed cgroups v1 and cgroups v2 controllers. The code is
         // not ready to deal with that on a per-controller basis. Return no metrics
         // in that case
         if (anyCgroupsV1Controller && anyCgroupsV2Controller) {
-            System.err.println("Warning: Mixed cgroupv1 and cgroupv2 not supported. Metrics disabled.");
+            Logger logger = System.getLogger("jdk.internal.platform");
+            logger.log(Level.WARNING, "Mixed cgroupv1 and cgroupv2 not supported. Metrics disabled.");
             return null;
         }
 
         if (isCgroupsV2) {
             // read mountinfo so as to determine root mount path

@@ -109,11 +112,11 @@
                 for (String line: lines) {
                     String[] tokens = line.split(":");
                     if (tokens.length != 3) {
                         return null; // something is not right.
                     }
-                    if (!Integer.valueOf(0).toString().equals(tokens[0])) {
+                    if (!"0".equals(tokens[0])) {
                         // hierarchy must be zero for cgroups v2
                         return null;
                     }
                     cgroupPath = tokens[2];
                     break;

@@ -122,11 +125,11 @@
                 return null;
             }
             CgroupSubsystemController unified = new CgroupV2SubsystemController(
                     mountPath,
                     cgroupPath);
-            return new CgroupV2Subsystem(unified);
+            return new CgroupMetrics(new CgroupV2Subsystem(unified));
         } else {
-            return CgroupV1Subsystem.getInstance();
+            return new CgroupV1Metrics(CgroupV1Subsystem.getInstance());
         }
     }
 }