[Truffle] Add Process.ppid

Author: bjfish

truffle/src/main/java/org/jruby/truffle/nodes/rubinius/PosixNodes.java

@@ -615,6 +615,20 @@ public int isATTY(int fd) {
 
     }
 
+    @CoreMethod(names = "getppid", isModuleFunction = true)
+    public abstract static class GetppidNode extends CoreMethodArrayArgumentsNode {
+
+        public GetppidNode(RubyContext context, SourceSection sourceSection) {
+            super(context, sourceSection);
+        }
+
+        @Specialization
+        public int getppid() {
+            return posix().getppid();
+        }
+
+    }
+
     @CoreMethod(names = "symlink", isModuleFunction = true, required = 2)
     public abstract static class SymlinkNode extends CoreMethodArrayArgumentsNode {
 

truffle/src/main/ruby/core/rubinius/common/process.rb

@@ -90,6 +90,12 @@ def self.getpgrp
     ret
   end
 
+  def self.ppid
+    ret = FFI::Platform::POSIX.getppid
+    Errno.handle if ret == -1
+    ret
+  end
+
   def self.uid=(uid)
     # the 4 rescue clauses below are needed
     # until respond_to? can be used to query the implementation of methods attached via FFI