Merge pull request #4681 from Vlatombe/JENKINS-62006

core/src/main/java/hudson/slaves/SlaveComputer.java

@@ -54,6 +54,7 @@ import hudson.util.StreamTaskListener;
 import hudson.util.VersionNumber;
 import hudson.util.io.RewindableFileOutputStream;
 import hudson.util.io.RewindableRotatingFileOutputStream;
+import jenkins.agents.AgentComputerUtil;
 import jenkins.model.Jenkins;
 import jenkins.security.ChannelConfigurator;
 import jenkins.security.MasterToSlaveCallable;
@@ -1067,17 +1068,11 @@ public class SlaveComputer extends Computer {
      *
      * @return null if the calling thread doesn't have any trace of where its master is.
      * @since 1.362
+     * @deprecated Use {@link AgentComputerUtil#getChannelToMaster()} instead.
      */
+    @Deprecated
     public static VirtualChannel getChannelToMaster() {
-        if (Jenkins.getInstanceOrNull()!=null) // check if calling thread is on master or on slave
-            return FilePath.localChannel;
-
-        // if this method is called from within the agent computation thread, this should work
-        Channel c = Channel.current();
-        if (c!=null && Boolean.TRUE.equals(c.getProperty("slave")))
-            return c;
-
-        return null;
+        return AgentComputerUtil.getChannelToMaster();
     }
 
     /**

core/src/main/java/hudson/util/ProcessTree.java

@@ -33,7 +33,7 @@ import hudson.FilePath;
 import hudson.Util;
 import hudson.remoting.Channel;
 import hudson.remoting.VirtualChannel;
-import hudson.slaves.SlaveComputer;
+import jenkins.agents.AgentComputerUtil;
 import hudson.util.ProcessKillingVeto.VetoCause;
 import hudson.util.ProcessTree.OSProcess;
 import hudson.util.ProcessTreeRemoting.IOSProcess;
@@ -193,7 +193,7 @@ public abstract class ProcessTree implements Iterable<OSProcess>, IProcessTree,
     /*package*/ final List<ProcessKiller> getKillers() throws InterruptedException {
         if (killers==null)
             try {
-                VirtualChannel channelToMaster = SlaveComputer.getChannelToMaster();
+                VirtualChannel channelToMaster = AgentComputerUtil.getChannelToMaster();
                 if (channelToMaster!=null) {
                     killers = channelToMaster.call(new ListAll());
                 } else {
@@ -288,7 +288,7 @@ public abstract class ProcessTree implements Iterable<OSProcess>, IProcessTree,
             // Quick check, does anything exist to check against
             if (!skipVetoes) {
                 try {
-                    VirtualChannel channelToMaster = SlaveComputer.getChannelToMaster();
+                    VirtualChannel channelToMaster = AgentComputerUtil.getChannelToMaster();
                     if (channelToMaster!=null) {
                         CheckVetoes vetoCheck = new CheckVetoes(this);
                         causeMessage = channelToMaster.call(vetoCheck);
@@ -429,7 +429,7 @@ public abstract class ProcessTree implements Iterable<OSProcess>, IProcessTree,
         // Check for the existance of vetoers if I don't know already
         if (vetoersExist == null) {
             try {
-                VirtualChannel channelToMaster = SlaveComputer.getChannelToMaster();
+                VirtualChannel channelToMaster = AgentComputerUtil.getChannelToMaster();
                 if (channelToMaster != null) {
                     vetoersExist = channelToMaster.call(new DoVetoersExist());
                 }

core/src/main/java/jenkins/agents/AgentComputerUtil.java

@@ -0,0 +1,60 @@
+/*
+ * The MIT License
+ *
+ * Copyright 2020 CloudBees, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package jenkins.agents;
+
+import edu.umd.cs.findbugs.annotations.CheckForNull;
+import hudson.FilePath;
+import hudson.remoting.Channel;
+import hudson.remoting.VirtualChannel;
+import jenkins.model.Jenkins;
+
+public final class AgentComputerUtil {
+    private AgentComputerUtil() {
+    }
+
+    /**
+     * Obtains a {@link VirtualChannel} that allows some computation to be performed on the master.
+     * This method can be called from any thread on the master, or from agent (more precisely,
+     * it only works from the remoting request-handling thread in agents, which means if you've started
+     * separate thread on agents, that'll fail.)
+     *
+     * @return null if the calling thread doesn't have any trace of where its master is.
+     * @since TODO
+     */
+    @CheckForNull
+    public static VirtualChannel getChannelToMaster() {
+        if (Jenkins.getInstanceOrNull() != null) {// check if calling thread is on master or on agent
+            return FilePath.localChannel;
+        }
+
+        // if this method is called from within the agent computation thread, this should work
+        Channel c = Channel.current();
+        if (c != null && Boolean.TRUE.equals(c.getProperty("slave"))) {
+            return c;
+        }
+
+        return null;
+    }
+}