Small tidy up.

Author: aardvark179

src/main/java/org/truffleruby/core/thread/ThreadLocalBuffer.java

@@ -17,12 +17,12 @@
 public final class ThreadLocalBuffer {
 
     public static final ThreadLocalBuffer NULL_BUFFER = new ThreadLocalBuffer(new Pointer(0, 0), null);
+    private static final long ALIGNMENT = 8L;
+    private static final long ALIGNMENT_MASK = ALIGNMENT - 1;
 
     public final Pointer start;
     long remaining;
     private final ThreadLocalBuffer parent;
-    private final long ALIGNMENT = 8L;
-    private final long ALIGNMENT_MASK = ALIGNMENT - 1;
 
     private ThreadLocalBuffer(Pointer start, ThreadLocalBuffer parent) {
         this.start = start;
@@ -90,7 +90,7 @@ public Pointer allocate(RubyThread thread, long size, ConditionProfile allocatio
         }
     }
 
-    private long alignUp(long size) {
+    private static long alignUp(long size) {
         return (size + ALIGNMENT_MASK) & ~ALIGNMENT_MASK;
     }
 

src/main/ruby/truffleruby/core/io.rb

@@ -142,13 +142,13 @@ def fill(io, max = DEFAULT_READ_SIZE)
       count = Primitive.min(unused, max)
 
       total_read = 0
-      Truffle::POSIX.read_to_buffer_at_least_one_byte(io, count) do |buffer, bytes_read|
+      Truffle::POSIX.read_to_buffer_at_least_one_byte(io, count) do |pointer, bytes_read|
         # Detect if another thread has updated the buffer
         # and now there isn't enough room for this data.
         if bytes_read > unused
           raise RuntimeError, 'internal implementation error - IO buffer overrun'
         end
-        Primitive.pointer_read_bytes_to_byte_array(@storage, @used, buffer.address, bytes_read)
+        Primitive.pointer_read_bytes_to_byte_array(@storage, @used, pointer.address, bytes_read)
         @used += bytes_read
         total_read += bytes_read
       end
@@ -1266,9 +1266,8 @@ def read_to_separator_with_limit
     def read_all
       str = +''
       unless @buffer.exhausted?
-        if !(tmp_str = @buffer.shift).empty?
-          str << tmp_str
-        end
+        tmp_str = @buffer.shift
+        str << tmp_str unless tmp_str.empty?
       end
 
       while (tmp_str = Truffle::POSIX.read_string_at_least_one_byte(@io, InternalBuffer::DEFAULT_READ_SIZE))

src/main/ruby/truffleruby/core/posix.rb

@@ -362,6 +362,8 @@ def self.read_string_at_least_one_byte(io, count)
     end
   end
 
+  # Read up to count bytes of io to the thread-local IO buffer, and
+  # yields the buffer (a FFI::Pointer) and bytes_read
   def self.read_to_buffer_at_least_one_byte(io, count, &block)
     while true
       # must call #read_to_buffer in order to properly support polyglot STDIO