Use finalizer to free GLPK problem.

lib/rglpk.rb

@@ -68,14 +68,15 @@ def initialize
       @rows = RowArray.new
       @cols = ColArray.new
       Glpk_wrapper.glp_create_index(@lp)
+
+      ObjectSpace.define_finalizer(self, self.class.finalizer(@lp))
     end
 
-    def destroy!
-      Glpk_wrapper.glp_delete_prob(@lp)
-
-      Glpk_wrapper.delete_intArray(@_ia)
-      Glpk_wrapper.delete_intArray(@_ja)
-      Glpk_wrapper.delete_doubleArray(@_ar)
+    def self.finalizer(lp)
+      proc do
+        Glpk_wrapper.glp_delete_index(lp)
+        Glpk_wrapper.glp_delete_prob(lp)
+      end
     end
 
     def name=(n)
@@ -125,6 +126,7 @@ def del_rows(a)
       r = Glpk_wrapper.new_intArray(a.size + 1)
       a.each_with_index{|n, i| Glpk_wrapper.intArray_setitem(r, i + 1, n)}
       Glpk_wrapper.glp_del_rows(@lp, a.size, r)
+      Glpk_wrapper.delete_intArray(r)
 
       a.each do |n|
         @rows.send(:delete_at, n)
@@ -143,6 +145,7 @@ def del_cols(a)
       r = Glpk_wrapper.new_intArray(a.size + 1)
       a.each_with_index{|n, i| Glpk_wrapper.intArray_setitem(r, i + 1, n)}
       Glpk_wrapper.glp_del_cols(@lp, a.size, r)
+      Glpk_wrapper.delete_intArray(r)
 
       a.each do |n|
         @cols.send(:delete_at, n)
@@ -170,11 +173,11 @@ def set_matrix(v)
         Glpk_wrapper.doubleArray_setitem(ar, y + 1, x)
       end
 
-      @_ia = ia
-      @_ja = ja
-      @_ar = ar
-
       Glpk_wrapper.glp_load_matrix(@lp, v.size, ia, ja, ar)
+
+      Glpk_wrapper.delete_intArray(ia)
+      Glpk_wrapper.delete_intArray(ja)
+      Glpk_wrapper.delete_doubleArray(ar)
     end
 
   private
@@ -273,6 +276,9 @@ def set(v)
         Glpk_wrapper.doubleArray_setitem(val, y + 1, x)}
 
       Glpk_wrapper.glp_set_mat_row(@p.lp, @i, v.size, ind, val)
+
+      Glpk_wrapper.delete_intArray(ind)
+      Glpk_wrapper.delete_doubleArray(val)
     end
 
     def get
@@ -285,6 +291,8 @@ def get
         j = Glpk_wrapper.intArray_getitem(ind, i + 1)
         row[j - 1] = v
       end
+      Glpk_wrapper.delete_intArray(ind)
+      Glpk_wrapper.delete_doubleArray(val)
       row
     end
 
@@ -353,6 +361,9 @@ def set(v)
         Glpk_wrapper.doubleArray_setitem(val, y + 1, x)}
 
       Glpk_wrapper.glp_set_mat_col(@p.lp, @j, v.size, ind, val)
+
+      Glpk_wrapper.delete_intArray(ind)
+      Glpk_wrapper.delete_doubleArray(val)
     end
 
     def get
@@ -365,6 +376,8 @@ def get
         j = Glpk_wrapper.intArray_getitem(ind, i + 1)
         col[j - 1] = v
       end
+      Glpk_wrapper.delete_intArray(ind)
+      Glpk_wrapper.delete_doubleArray(val)
       col
     end
 

test/helper.rb

@@ -2,4 +2,53 @@
 
 require 'test/unit'
 $LOAD_PATH << './ext'
-require here+'/../lib/rglpk'
+require here+'/../lib/rglpk'
+
+module Examples
+  def brief_example
+    # The same Brief Example as found in section 1.3 of 
+    # glpk-4.44/doc/glpk.pdf.
+    #
+    # maximize
+    #   z = 10 * x1 + 6 * x2 + 4 * x3
+    #
+    # subject to
+    #   p:      x1 +     x2 +     x3 <= 100
+    #   q: 10 * x1 + 4 * x2 + 5 * x3 <= 600
+    #   r:  2 * x1 + 2 * x2 + 6 * x3 <= 300
+    #
+    # where all variables are non-negative
+    #   x1 >= 0, x2 >= 0, x3 >= 0
+    #    
+    p = Rglpk::Problem.new
+    p.name = "sample"
+    p.obj.dir = Rglpk::GLP_MAX
+
+    rows = p.add_rows(3)
+    rows[0].name = "p"
+    rows[0].set_bounds(Rglpk::GLP_UP, 0, 100)
+    rows[1].name = "q"
+    rows[1].set_bounds(Rglpk::GLP_UP, 0, 600)
+    rows[2].name = "r"
+    rows[2].set_bounds(Rglpk::GLP_UP, 0, 300)
+
+    cols = p.add_cols(3)
+    cols[0].name = "x1"
+    cols[0].set_bounds(Rglpk::GLP_LO, 0.0, 0.0)
+    cols[1].name = "x2"
+    cols[1].set_bounds(Rglpk::GLP_LO, 0.0, 0.0)
+    cols[2].name = "x3"
+    cols[2].set_bounds(Rglpk::GLP_LO, 0.0, 0.0)
+
+    p.obj.coefs = [10, 6, 4]
+
+    p.set_matrix([
+       1, 1, 1,
+      10, 4, 5,
+       2, 2, 6
+    ])
+
+    p.simplex
+    p
+  end
+end

test/test_all.rb

@@ -3,4 +3,5 @@
 require here+'/helper'
 require here+'/test_basic'
 require here+'/test_problem_kind'
-require here+'/test_brief_example'
+require here+'/test_brief_example'
+require here+'/test_memory_prof'

test/test_brief_example.rb

@@ -1,50 +1,13 @@
 require File.expand_path('helper', File.dirname(__FILE__))
 
-class TestExample < Test::Unit::TestCase
-  def test_example
-    # The same Brief Example as found in section 1.3 of 
-    # glpk-4.44/doc/glpk.pdf.
-    #
-    # maximize
-    #   z = 10 * x1 + 6 * x2 + 4 * x3
-    #
-    # subject to
-    #   p:      x1 +     x2 +     x3 <= 100
-    #   q: 10 * x1 + 4 * x2 + 5 * x3 <= 600
-    #   r:  2 * x1 + 2 * x2 + 6 * x3 <= 300
-    #
-    # where all variables are non-negative
-    #   x1 >= 0, x2 >= 0, x3 >= 0
-    #    
-    p = Rglpk::Problem.new
-    p.name = "sample"
-    p.obj.dir = Rglpk::GLP_MAX
+class TestBriefExample < Test::Unit::TestCase
+  include Examples
+
+  def test_brief_example
+    p = brief_example
+    cols = p.cols
+    rows = p.rows
 
-    rows = p.add_rows(3)
-    rows[0].name = "p"
-    rows[0].set_bounds(Rglpk::GLP_UP, 0, 100)
-    rows[1].name = "q"
-    rows[1].set_bounds(Rglpk::GLP_UP, 0, 600)
-    rows[2].name = "r"
-    rows[2].set_bounds(Rglpk::GLP_UP, 0, 300)
-
-    cols = p.add_cols(3)
-    cols[0].name = "x1"
-    cols[0].set_bounds(Rglpk::GLP_LO, 0.0, 0.0)
-    cols[1].name = "x2"
-    cols[1].set_bounds(Rglpk::GLP_LO, 0.0, 0.0)
-    cols[2].name = "x3"
-    cols[2].set_bounds(Rglpk::GLP_LO, 0.0, 0.0)
-
-    p.obj.coefs = [10, 6, 4]
-
-    p.set_matrix([
-       1, 1, 1,
-      10, 4, 5,
-       2, 2, 6
-    ])
-
-    p.simplex
     z = p.obj.get
     x1 = cols[0].get_prim
     x2 = cols[1].get_prim

test/test_memory_prof.rb

@@ -1,75 +1,30 @@
 require File.expand_path('helper', File.dirname(__FILE__))
 
 class TestMemoryProf < Test::Unit::TestCase
+  include Examples
+
   def test_memory_prof
-    while true
+    5.times do
       1000.times do |i|
-        _test_example
+        brief_example
       end
 
-      out = `ps aux | grep "ruby test/test_memory_prof.rb"`
-      puts out.split("\n")[0]
+      change = change_to_real_memory_in_kb
+      assert (change < 10000), "memory leak #{change}kb"
     end
   end
 
-  def _test_example
-    # The same Brief Example as found in section 1.3 of 
-    # glpk-4.44/doc/glpk.pdf.
-    #
-    # maximize
-    #   z = 10 * x1 + 6 * x2 + 4 * x3
-    #
-    # subject to
-    #   p:      x1 +     x2 +     x3 <= 100
-    #   q: 10 * x1 + 4 * x2 + 5 * x3 <= 600
-    #   r:  2 * x1 + 2 * x2 + 6 * x3 <= 300
-    #
-    # where all variables are non-negative
-    #   x1 >= 0, x2 >= 0, x3 >= 0
-    #    
-    p = Rglpk::Problem.new
-    p.name = "sample"
-    p.obj.dir = Rglpk::GLP_MAX
-
-    rows = p.add_rows(3)
-    rows[0].name = "p"
-    rows[0].set_bounds(Rglpk::GLP_UP, 0, 100)
-    rows[1].name = "q"
-    rows[1].set_bounds(Rglpk::GLP_UP, 0, 600)
-    rows[2].name = "r"
-    rows[2].set_bounds(Rglpk::GLP_UP, 0, 300)
-
-    cols = p.add_cols(3)
-    cols[0].name = "x1"
-    cols[0].set_bounds(Rglpk::GLP_LO, 0.0, 0.0)
-    cols[1].name = "x2"
-    cols[1].set_bounds(Rglpk::GLP_LO, 0.0, 0.0)
-    cols[2].name = "x3"
-    cols[2].set_bounds(Rglpk::GLP_LO, 0.0, 0.0)
-
-    p.obj.coefs = [10, 6, 4]
-
-    p.set_matrix([
-       1, 1, 1,
-      10, 4, 5,
-       2, 2, 6
-    ])
-
-    p.simplex
-    z = p.obj.get
-    x1 = cols[0].get_prim
-    x2 = cols[1].get_prim
-    x3 = cols[2].get_prim
-
-    result = "z = %g; x1 = %g; x2 = %g; x3 = %g" % [z, x1, x2, x3]
-    assert_equal "z = 733.333; x1 = 33.3333; x2 = 66.6667; x3 = 0", result
-    assert_equal Rglpk::GLP_NU, rows[0].get_stat
-    assert_equal 100, rows[0].get_prim
-    assert_equal 3.333333333333333, rows[0].get_dual
-    # File.delete("test.lp") rescue Errno::ENOENT
-    # p.write_lp("test.lp")
-    # assert File.exists?("test.lp")    
-
-    p.destroy!
+  def real_memory_in_kb
+    # "=" after "rss" strips the header line.
+    `ps -p #{Process.pid} -o rss=`.to_i
+  end
+
+  def change_to_real_memory_in_kb
+    GC.start
+    r = real_memory_in_kb
+    @change_to_real_memory_in_kb__prev ||= r
+    r - @change_to_real_memory_in_kb__prev
+  ensure
+    @change_to_real_memory_in_kb__prev = r
   end
 end