* test/dl/test_dl2.rb (**) testing malloc and realloc

* ext/dl/dl.c (**) adding documentation

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@25605 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ext/dl/dl.c

@@ -16,6 +16,12 @@ rb_dl_dlopen(int argc, VALUE argv[], VALUE self)
     return rb_class_new_instance(argc, argv, rb_cDLHandle);
 }
 
+/*
+ * call-seq: DL.malloc
+ *
+ * Allocate +size+ bytes of memory and return the integer memory address
+ * for the allocated memory.
+ */
 VALUE
 rb_dl_malloc(VALUE self, VALUE size)
 {
@@ -26,6 +32,13 @@ rb_dl_malloc(VALUE self, VALUE size)
     return PTR2NUM(ptr);
 }
 
+/*
+ * call-seq: DL.realloc(addr, size)
+ *
+ * Change the size of the memory allocated at the memory location +addr+ to
+ * +size+ bytes.  Returns the memory address of the reallocated memory, which
+ * may be different than the address passed in.
+ */
 VALUE
 rb_dl_realloc(VALUE self, VALUE addr, VALUE size)
 {

test/dl/test_dl2.rb

@@ -3,6 +3,53 @@ require 'dl/callback'
 
 module DL
 class TestDL < TestBase
+  # TODO: refactor test repetition
+
+  def test_realloc
+    str = "abc"
+    ptr_id = DL.realloc(0, 4)
+    ptr    = CPtr.new(ptr_id, 4)
+
+    assert_equal ptr_id, ptr.to_i
+
+    cfunc  = CFunc.new(@libc['strcpy'], TYPE_VOIDP, 'strcpy')
+    x      = cfunc.call([ptr_id,str].pack("l!p").unpack("l!*"))
+    assert_equal("abc\0", ptr[0,4])
+    DL.free ptr_id
+  end
+
+  def test_realloc_secure
+    assert_raises(SecurityError) do
+      Thread.new do
+        $SAFE = 4
+        DL.realloc(0, 4)
+      end.join
+    end
+  end
+
+  def test_malloc
+    str = "abc"
+
+    ptr_id = DL.malloc(4)
+    ptr    = CPtr.new(ptr_id, 4)
+
+    assert_equal ptr_id, ptr.to_i
+
+    cfunc  = CFunc.new(@libc['strcpy'], TYPE_VOIDP, 'strcpy')
+    x      = cfunc.call([ptr_id,str].pack("l!p").unpack("l!*"))
+    assert_equal("abc\0", ptr[0,4])
+    DL.free ptr_id
+  end
+
+  def test_malloc_security
+    assert_raises(SecurityError) do
+      Thread.new do
+        $SAFE = 4
+        DL.malloc(4)
+      end.join
+    end
+  end
+
   def test_call_int()
     cfunc = CFunc.new(@libc['atoi'], TYPE_INT, 'atoi')
     x = cfunc.call(["100"].pack("p").unpack("l!*"))