2004-05-18 Paolo Carlini <pcarlini@suse.de>

	* include/ext/mt_allocator.h:(__mt_alloc::allocate): Minor
	tweaks.

2004-05-18  Dhruv Matani  <dhruvbird@gmx.net>

	* include/ext/mt_allocator.h:(__mt_alloc::allocate): Re-write
	allocation loop which removes blocks from the global free list
	from O(N) to O(1) when the required blocks are <= the number
	available.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@81992 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 61d4e52..7ec7e3c 100644 (file)
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,15 @@
+2004-05-18  Paolo Carlini  <pcarlini@suse.de>
+
+       * include/ext/mt_allocator.h:(__mt_alloc::allocate): Minor
+       tweaks.
+
+2004-05-18  Dhruv Matani  <dhruvbird@gmx.net>
+
+       * include/ext/mt_allocator.h:(__mt_alloc::allocate): Re-write
+       allocation loop which removes blocks from the global free list
+       from O(N) to O(1) when the required blocks are <= the number
+       available.
+
 2004-05-18  Jonathan Wakely  <redi@gcc.gnu.org>
 
        * include/ext/enc_filebuf.h: Move concept-check macro to class scope.

diff --git a/libstdc++-v3/include/ext/mt_allocator.h b/libstdc++-v3/include/ext/mt_allocator.h
index 1fc0ccb..9737700 100644 (file)
--- a/libstdc++-v3/include/ext/mt_allocator.h
+++ b/libstdc++-v3/include/ext/mt_allocator.h
@@ -342,23 +342,32 @@ namespace __gnu_cxx
                      __block->_M_next = reinterpret_cast<_Block_record*>(__c);
                      __block = __block->_M_next;
                    }
+                 __block->_M_next = NULL;
                }
              else
                {
-                 if (__block_count > __bin._M_free[0])
-                   __block_count = __bin._M_free[0];
-                 const size_t __added = __block_count;
-                 _Block_record* __first = __bin._M_first[0];
-                 __block = __first;
-                 --__block_count;
-                 while (__block_count-- > 0)
-                   __block = __block->_M_next;
-                 __bin._M_first[0] = __block->_M_next;
-                 __bin._M_free[0] -= __added;
+                 // Is the number of required blocks greater than or
+                 // equal to the number that can be provided by the
+                 // global free list?
+                 __bin._M_first[__thread_id] = __bin._M_first[0];
+                 if (__block_count >= __bin._M_free[0])
+                   {
+                     __bin._M_free[__thread_id] = __bin._M_free[0];
+                     __bin._M_free[0] = 0;
+                     __bin._M_first[0] = NULL;
+                   }
+                 else
+                   {
+                     __bin._M_free[__thread_id] = __block_count;
+                     __bin._M_free[0] -= __block_count;
+                     --__block_count;
+                     __block = __bin._M_first[0];
+                     while (__block_count-- > 0)
+                       __block = __block->_M_next;
+                     __bin._M_first[0] = __block->_M_next;
+                     __block->_M_next = NULL;
+                   }
                  __gthread_mutex_unlock(__bin._M_mutex);
-
-                 __bin._M_first[__thread_id] = __first;
-                 __bin._M_free[__thread_id] += __added;
                }
            }
          else
@@ -375,9 +384,8 @@ namespace __gnu_cxx
                  __block->_M_next = reinterpret_cast<_Block_record*>(__c);
                  __block = __block->_M_next;
                }
+             __block->_M_next = NULL;
            }
-
-         __block->_M_next = NULL;
        }
 
       __block = __bin._M_first[__thread_id];