8231111: Cgroups v2: Rework Metrics in java.base so as to recognize unified hierarchy

jdk/make/lib/CoreLibraries.gmk

@@ -165,7 +165,7 @@ endif
 
 # Make it possible to override this variable
 ifeq ($(OPENJDK_TARGET_OS), linux)
-  # Linux-only symbol Java_jdk_internal_platform_cgroupv1_Metrics_isUseContainerSupport
+  # Linux-only symbol Java_jdk_internal_platform_CgroupMetrics_isUseContainerSupport
   LIBJAVA_MAPFILE ?= $(JDK_TOPDIR)/make/mapfiles/libjava/mapfile-linux
 else
   LIBJAVA_MAPFILE ?= $(JDK_TOPDIR)/make/mapfiles/libjava/mapfile-vers

jdk/make/mapfiles/libjava/mapfile-linux

@@ -278,7 +278,7 @@ SUNWprivate_1.1 {
                 Java_sun_misc_VM_initialize;
 		Java_sun_misc_VMSupport_initAgentProperties;
 		Java_sun_misc_VMSupport_getVMTemporaryDirectory;
-		Java_jdk_internal_platform_cgroupv1_Metrics_isUseContainerSupport;
+		Java_jdk_internal_platform_CgroupMetrics_isUseContainerSupport;
 
                 # ZipFile.c needs this one
 		throwFileNotFoundException;

jdk/src/linux/classes/jdk/internal/platform/CgroupInfo.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2020, Red Hat Inc.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.internal.platform;
+
+/**
+ * Data structure to hold info from /proc/self/cgroup
+ *
+ * man 7 cgroups
+ *
+ * @see CgroupSubsystemFactory
+ */
+class CgroupInfo {
+
+    private final String name;
+    private final int hierarchyId;
+    private final boolean enabled;
+
+    private CgroupInfo(String name, int hierarchyId, boolean enabled) {
+        this.name = name;
+        this.hierarchyId = hierarchyId;
+        this.enabled = enabled;
+    }
+
+    String getName() {
+        return name;
+    }
+
+    int getHierarchyId() {
+        return hierarchyId;
+    }
+
+    boolean isEnabled() {
+        return enabled;
+    }
+
+    static CgroupInfo fromCgroupsLine(String line) {
+        String[] tokens = line.split("\\s+");
+        if (tokens.length != 4) {
+            return null;
+        }
+        // discard 3'rd field, num_cgroups
+        return new CgroupInfo(tokens[0] /* name */,
+                              Integer.parseInt(tokens[1]) /* hierarchyId */,
+                              (Integer.parseInt(tokens[3]) == 1) /* enabled */);
+    }
+
+}

jdk/src/linux/classes/jdk/internal/platform/CgroupMetrics.java

@@ -0,0 +1,172 @@
+/*
+ * Copyright (c) 2020, Red Hat Inc.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.internal.platform;
+
+import java.util.Objects;
+
+public class CgroupMetrics implements Metrics {
+
+    private final CgroupSubsystem subsystem;
+
+    CgroupMetrics(CgroupSubsystem subsystem) {
+        this.subsystem = Objects.requireNonNull(subsystem);
+    }
+
+    @Override
+    public String getProvider() {
+        return subsystem.getProvider();
+    }
+
+    @Override
+    public long getCpuUsage() {
+        return subsystem.getCpuUsage();
+    }
+
+    @Override
+    public long[] getPerCpuUsage() {
+        return subsystem.getPerCpuUsage();
+    }
+
+    @Override
+    public long getCpuUserUsage() {
+        return subsystem.getCpuUserUsage();
+    }
+
+    @Override
+    public long getCpuSystemUsage() {
+        return subsystem.getCpuSystemUsage();
+    }
+
+    @Override
+    public long getCpuPeriod() {
+        return subsystem.getCpuPeriod();
+    }
+
+    @Override
+    public long getCpuQuota() {
+        return subsystem.getCpuQuota();
+    }
+
+    @Override
+    public long getCpuShares() {
+        return subsystem.getCpuShares();
+    }
+
+    @Override
+    public long getCpuNumPeriods() {
+        return subsystem.getCpuNumPeriods();
+    }
+
+    @Override
+    public long getCpuNumThrottled() {
+        return subsystem.getCpuNumThrottled();
+    }
+
+    @Override
+    public long getCpuThrottledTime() {
+        return subsystem.getCpuThrottledTime();
+    }
+
+    @Override
+    public long getEffectiveCpuCount() {
+        return subsystem.getEffectiveCpuCount();
+    }
+
+    @Override
+    public int[] getCpuSetCpus() {
+        return subsystem.getCpuSetCpus();
+    }
+
+    @Override
+    public int[] getEffectiveCpuSetCpus() {
+        return subsystem.getEffectiveCpuSetCpus();
+    }
+
+    @Override
+    public int[] getCpuSetMems() {
+        return subsystem.getCpuSetMems();
+    }
+
+    @Override
+    public int[] getEffectiveCpuSetMems() {
+        return subsystem.getEffectiveCpuSetMems();
+    }
+
+    public long getMemoryFailCount() {
+        return subsystem.getMemoryFailCount();
+    }
+
+    @Override
+    public long getMemoryLimit() {
+        return subsystem.getMemoryLimit();
+    }
+
+    @Override
+    public long getMemoryUsage() {
+        return subsystem.getMemoryUsage();
+    }
+
+    @Override
+    public long getTcpMemoryUsage() {
+        return subsystem.getTcpMemoryUsage();
+    }
+
+    @Override
+    public long getMemoryAndSwapLimit() {
+        return subsystem.getMemoryAndSwapLimit();
+    }
+
+    @Override
+    public long getMemoryAndSwapUsage() {
+        return subsystem.getMemoryAndSwapUsage();
+    }
+
+    @Override
+    public long getMemorySoftLimit() {
+        return subsystem.getMemorySoftLimit();
+    }
+
+    @Override
+    public long getBlkIOServiceCount() {
+        return subsystem.getBlkIOServiceCount();
+    }
+
+    @Override
+    public long getBlkIOServiced() {
+        return subsystem.getBlkIOServiced();
+    }
+
+    public static Metrics getInstance() {
+        if (!isUseContainerSupport()) {
+            // Return null on -XX:-UseContainerSupport
+            return null;
+        }
+        return CgroupSubsystemFactory.create();
+    }
+
+    private static native boolean isUseContainerSupport();
+
+}

jdk/src/linux/classes/jdk/internal/platform/CgroupSubsystem.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2020, Red Hat Inc.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.internal.platform;
+
+/**
+ * Marker interface for cgroup-based metrics
+ *
+ */
+public interface CgroupSubsystem extends Metrics {
+
+    /**
+     * Returned for metrics of type long if the underlying implementation
+     * has determined that no limit is being imposed.
+     */
+    public static final long LONG_RETVAL_UNLIMITED = -1;
+
+}