Re: ALLOC_IN_POOL, Re: lynx-dev lynx2.8.5dev.11

[Leonid Pauzner]

1-Dec-2002 23:30 Bela Lubkin wrote:

>   #define POOLallocHTLine(ptr, size)  { HTStyleChange* _tmp_;             \
>
> ALLOC_IN_POOL(HTMainText->pool,HTPool,\
>                                           _round_(LINE_SIZE(size)),       \
>                                           _tmp_,                          \
>                                           _align_);                       \
>                                         ptr = (HTLine*)_tmp_;             \
>                                       }

> The expansion is appalling, makes me think something here should be a
> function rather than a macro (word-wrapped by me):

>   { HTStyleChange * _tmp_ ; if (! HTMainText->pool) { _tmp_ = 0 ; } else {
>   if ((sizeof (void *) / sizeof (HTStyleChange))) HTMainText->pool->used
>   += (HTMainText->pool->used % (sizeof (void *) / sizeof (HTStyleChange)))
>   ; if ((8192 - 4 * sizeof (void *) - sizeof (struct _HTPool *) + sizeof
>   (int)) / sizeof (HTStyleChange) - HTMainText->pool->used >= ((sizeof
>   (HTLine) + (previous->size)) % sizeof (HTStyleChange) ? (sizeof
>   (HTLine) + (previous->size)) / sizeof (HTStyleChange) + 1 : (sizeof
>   (HTLine) + (previous->size)) / sizeof (HTStyleChange))) { _tmp_ =
>   HTMainText->pool->data + HTMainText->pool->used ; HTMainText->pool->used
>   += ((sizeof (HTLine) + (previous->size)) % sizeof (HTStyleChange) ?
>   (sizeof (HTLine) + (previous->size)) / sizeof (HTStyleChange) + 1
>   : (sizeof (HTLine) + (previous->size)) / sizeof (HTStyleChange)) ;
>   } else { HTPool * newpool = (HTPool *) LY_check_calloc (1 , sizeof
>   (HTPool)) ; if (! newpool) { _tmp_ = 0 ; } else { newpool->prev =
>   HTMainText->pool ; newpool->used = ((sizeof (HTLine) + (previous->size))
>   % sizeof (HTStyleChange) ? (sizeof (HTLine) + (previous->size)) / sizeof
>   (HTStyleChange) + 1 : (sizeof (HTLine) + (previous->size)) / sizeof
>   (HTStyleChange)) ; _tmp_ = newpool->data ; HTMainText->pool = newpool ;
>   } } } ; temp = (HTLine *) _tmp_ ; } ;

> The warning comes from this portion of it:

>   += (HTMainText->pool->used % (sizeof (void *) / sizeof (HTStyleChange)))

> sizeof(void *) on this machine is 4; sizeof(HTStyleChange) is 8.


The proposed patch, inspired by Bela Lubkin:

pack HTStyleChange bitfiels;
remove "alignment" issue completely;
use a constant to avoid multiple macro expansions (above).


--- gridtext.ori        Mon Dec  2 02:07:38 2002
+++ gridtext.c  Tue Dec  3 02:17:00 2002
@@ -149,16 +149,12 @@ PUBLIC int LYsb_begin = -1;
 PUBLIC int LYsb_end = -1;
 #endif

-#ifndef CHAR_BIT
-#define CHAR_BIT 8
-#endif

-    /*try to fit in 2 shorts*/
+    /*try to fit in 32bit */
 typedef struct {
-       unsigned int    direction:2;    /* on or off */
-       unsigned int    horizpos: (sizeof(short)*CHAR_BIT-2);
-           /* horizontal position of this change */
-       unsigned short  style;          /* which style to change to */
+       unsigned int    direction:2;   /* on or off */
+       unsigned int    horizpos:14;   /* horizontal position of this change */
+       unsigned int    style:16;      /* which style to change to */
 } HTStyleChange;

 #if defined(USE_COLOR_STYLE)
@@ -167,7 +163,7 @@ typedef struct {
 static HTStyleChange stylechanges_buffers[2][MAX_STYLES_ON_LINE];
 #endif

-#define POOL_SIZE (8192 - 4*sizeof(void*) - sizeof(struct _HTPool*) + 
sizeof(int)) / sizeof(HTStyleChange)
+enum { POOL_SIZE = (8192 - 4*sizeof(void*) - sizeof(struct _HTPool*) + 
sizeof(int)) / sizeof(HTStyleChange) };

 typedef struct _HTPool {
     HTStyleChange   data[POOL_SIZE];
@@ -205,7 +201,7 @@ pool provided their length will never ex
 to be very efficient.
  [Several types of memory-hungry objects are stored in the pool now:  styles,
 lines, anchors, and FormInfo. Arrays of HTStyleChange are stored as is,
-other objects are aligned to sizeof(void*) bytes and stored using a cast.]
+other objects are stored using a cast.]

  Pool are referenced by pointer to the chunk that contains free slots. Macros
 that allocate memory in pools update that pointer if needed.
@@ -214,7 +210,7 @@ ALLOC_IN_POOL.
  Here is a description of those macros as C++ functions (with names mentioned
 above and with use of C++ references)

-void ALLOC_IN_POOL( P*& pool, pool_type, int toalloc, T*& ptr, int align=1)
+void ALLOC_IN_POOL( P*& pool, pool_type, int toalloc, T*& ptr)
     - allocates 'toalloc' items in the pool of type 'pool_type' pointed by
     'pool', sets the pointer 'ptr' to the "allocated" memory and updates 'pool'
     if necessary. Sets 'ptr' to NULL if fails.
@@ -230,17 +226,15 @@ void POOL_FREE( pool_type , P*& ptr)

 *************************************************************************/
 /*
- * void ALLOC_IN_POOL( P*& pool, pool_type, int toalloc, T*& ptr, int align=1)
+ * void ALLOC_IN_POOL( P*& pool, pool_type, int toalloc, T*& ptr)
  *     - allocates 'toalloc' items in the pool of type 'pool_type' pointed by
  *     'pool', sets the pointer 'ptr' to the "allocated" memory and updates
  *     'pool' if necessary.  Sets 'ptr' to NULL if fails.
  */
-#define ALLOC_IN_POOL(pool,pool_type,toalloc,ptr,align) \
+#define ALLOC_IN_POOL(pool,pool_type,toalloc,ptr) \
     if (!pool) {                                       \
        ptr = NULL;                                     \
     } else {                                           \
-       if (align)                                      \
-           pool->used += (pool->used % align);         \
        if (POOL_SIZE - pool->used >= toalloc) {        \
            ptr = pool->data + pool->used;              \
            pool->used += toalloc;                      \
@@ -286,27 +280,25 @@ void POOL_FREE( pool_type , P*& ptr)
     }
 /**************************************************************************/

-#define _sz_        sizeof(HTStyleChange)      /* 4 */
-#define _align_     (sizeof(void*)/_sz_)       /*64bit OS!*/
-#define _round_(x)  (x%_sz_ ? x/_sz_ + 1: x/_sz_)
+#define _sz_           sizeof(HTStyleChange)      /* 4 */
+#define _round_up_(x)  (x%_sz_ ? x/_sz_ + 1: x/_sz_)

 #define POOLallocstyles(ptr, N)     ALLOC_IN_POOL(HTMainText->pool,HTPool,\
                                        N,                              \
-                                       ptr,                            \
-                                       1)
+                                       ptr)
 #define POOLallocHTLine(ptr, size)  { HTStyleChange* _tmp_;            \
+                                     int N = _round_up_(LINE_SIZE(size));  \
                                      ALLOC_IN_POOL(HTMainText->pool,HTPool,\
-                                       _round_(LINE_SIZE(size)),       \
-                                       _tmp_,                          \
-                                       _align_);                       \
-                                     ptr = (HTLine*)_tmp_;             \
+                                       N,      \
+                                       _tmp_); \
+                                     ptr = (HTLine*)_tmp_; \
                                    }
 #define POOLtypecalloc(T,ptr)      { HTStyleChange* _tmp_;             \
+                                     int N = _round_up_(sizeof(T));    \
                                      ALLOC_IN_POOL(HTMainText->pool,HTPool,\
-                                       _round_(sizeof(T)),             \
-                                       _tmp_,                          \
-                                       _align_);                       \
-                                     ptr = (T*)_tmp_;                  \
+                                       N,      \
+                                       _tmp_); \
+                                     ptr = (T*)_tmp_;  \
                                    }

 typedef struct _line {



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