Merge 44786b477e into d352540a02

s2a/build.gradle

@@ -47,21 +47,11 @@ dependencies {
             classifier = "linux-aarch_64"
         }
     }
-    testRuntimeOnly (libraries.netty.tcnative) {
-        artifact {
-            classifier = "osx-x86_64"
-        }
-    }
     testRuntimeOnly (libraries.netty.tcnative) {
         artifact {
             classifier = "osx-aarch_64"
         }
     }
-    testRuntimeOnly (libraries.netty.tcnative) {
-        artifact {
-            classifier = "windows-x86_64"
-        }
-    }
 
     signature (libraries.signature.java) {
         artifact {

s2a/src/main/java/io/grpc/s2a/S2AChannelCredentials.java

@@ -18,6 +18,7 @@ package io.grpc.s2a;
 
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkNotNull;
+import static com.google.common.base.Preconditions.checkState;
 import static com.google.common.base.Strings.isNullOrEmpty;
 
 import com.google.common.annotations.VisibleForTesting;
@@ -52,6 +53,7 @@ public final class S2AChannelCredentials {
   public static Builder newBuilder(String s2aAddress, ChannelCredentials s2aChannelCredentials) {
     checkArgument(!isNullOrEmpty(s2aAddress), "S2A address must not be null or empty.");
     checkNotNull(s2aChannelCredentials, "S2A channel credentials must not be null");
+    checkState(isPlatformSupported(), "S2A is not suported on Windows or MacOS Intel");
     return new Builder(s2aAddress, s2aChannelCredentials);
   }
 
@@ -131,5 +133,20 @@ public final class S2AChannelCredentials {
     }
   }
 
+  /**
+   * S2A has a runtime dependency on netty-tcnative. This function returns true
+   * if netty-tcnative is supported on the current platform.
+   * 
+   * @return whether S2A is supported on current platform
+   */
+  private static boolean isPlatformSupported() {
+    if (System.getProperty("os.name").contains("Windows")
+          || (System.getProperty("os.name").contains("OS X")
+              && System.getProperty("os.arch").contains("x86_64"))) {
+      return false;
+    }
+    return true;
+  }
+
   private S2AChannelCredentials() {}
 }