#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"
+#include "ppport.h"
+
+/* Not yet in ppport.h */
+#ifndef CvISXSUB
+# define CvISXSUB(cv) (CvXSUB(cv) ? TRUE : FALSE)
+#endif
#ifdef _MSC_VER
/* "structured exception" handling is a Microsoft extension to C and C++.
#define TAG //printf( "# %s(%d)\n", __FILE__, __LINE__ )
#define carp puts
+/* The idea is to have a tree structure to store 1 bit per possible pointer
+ address. The lowest 16 bits are stored in a block of 8092 bytes.
+ The blocks are in a 256-way tree, indexed by the reset of the pointer.
+ This can cope with 32 and 64 bit pointers, and any address space layout,
+ without excessive memory needs. The assumption is that your CPU cache
+ works :-) (And that we're not going to bust it) */
+
#define ALIGN_BITS ( sizeof(void*) >> 1 )
-#define BIT_BITS 3
-#define BYTE_BITS 14
-#define SLOT_BITS ( sizeof( void*) * 8 ) - ( ALIGN_BITS + BIT_BITS + BYTE_BITS )
-#define BYTES_PER_SLOT 1 << BYTE_BITS
-#define TRACKING_SLOTS 8192 // max. 8192 for 4GB/32-bit machine
+#define BYTE_BITS 3
+#define LEAF_BITS (16 - BYTE_BITS)
+#define LEAF_MASK 0x1FFF
-typedef char* TRACKING[ TRACKING_SLOTS ];
+typedef void * TRACKING[256];
/*
Checks to see if thing is in the bitstring.
Returns true or false, and
notes thing in the segmented bitstring.
*/
-IV check_new( TRACKING *tv, void *p ) {
- unsigned long slot = (unsigned long)p >> (SLOT_BITS + BIT_BITS + ALIGN_BITS);
- unsigned int byte = ((unsigned long)p >> (ALIGN_BITS + BIT_BITS)) & 0x00003fffU;
- unsigned int bit = ((unsigned long)p >> ALIGN_BITS) & 0x00000007U;
- unsigned int nop = (unsigned long)p & 0x3U;
-
- if (NULL == p || NULL == tv) return FALSE;
+static bool
+check_new(TRACKING *tv, const void *const p) {
+ unsigned int bits = 8 * sizeof(void*);
+ const size_t raw_p = PTR2nat(p);
+ /* This effectively rotates the value right by the number of low always-0
+ bits in an aligned pointer. The assmption is that most (if not all)
+ pointers are aligned, and these will be in the same chain of nodes
+ (and hence hot in the cache) but we can still deal with any unaligned
+ pointers. */
+ const size_t cooked_p
+ = (raw_p >> ALIGN_BITS) | (raw_p << (bits - BYTE_BITS));
+ const U8 this_bit = 1 << (cooked_p & 0x7);
+ U8 **leaf_p;
+ U8 *leaf;
+ unsigned int i;
+ void **tv_p = (void **) tv;
+
+ assert(tv);
+ if (NULL == p) return FALSE;
TRY_TO_CATCH_SEGV {
- char c = *(char *)p;
+ const char c = *(const char *)p;
}
CAUGHT_EXCEPTION {
if( dangle_whine )
warn( "Devel::Size: Encountered invalid pointer: %p\n", p );
return FALSE;
}
- dbg_printf((
- "address: %p slot: %p byte: %4x bit: %4x nop:%x\n",
- p, slot, byte, bit, nop
- ));
- TAG;
- if( slot >= TRACKING_SLOTS ) {
- die( "Devel::Size: Please rebuild D::S with TRACKING_SLOTS > %u\n", slot );
- }
- TAG;
- if( (*tv)[ slot ] == NULL ) {
- Newz( 0xfc0ff, (*tv)[ slot ], BYTES_PER_SLOT, char );
- }
TAG;
- if( (*tv)[ slot ][ byte ] & ( 1 << bit ) ) {
- return FALSE;
- }
- TAG;
- (*tv)[ slot ][ byte ] |= ( 1 << bit );
+
+ bits -= 8;
+ /* bits now 24 (32 bit pointers) or 56 (64 bit pointers) */
+
+ /* First level is always present. */
+ do {
+ i = (unsigned int)((cooked_p >> bits) & 0xFF);
+ if (!tv_p[i])
+ Newxz(tv_p[i], 256, void *);
+ tv_p = (void **)(tv_p[i]);
+ bits -= 8;
+ } while (bits > LEAF_BITS + BYTE_BITS);
+ /* bits now 16 always */
+ assert(bits == 16);
+ leaf_p = (U8 **)tv_p;
+ i = (unsigned int)((cooked_p >> bits) & 0xFF);
+ if (!leaf_p[i])
+ Newxz(leaf_p[i], 1 << LEAF_BITS, U8);
+ leaf = leaf_p[i];
+
TAG;
+
+ i = (unsigned int)((cooked_p >> BYTE_BITS) & LEAF_MASK);
+
+ if(leaf[i] & this_bit)
+ return FALSE;
+
+ leaf[i] |= this_bit;
return TRUE;
}
+static void
+free_tracking_at(void **tv, int level)
+{
+ int i = 255;
+
+ if (--level) {
+ /* Nodes */
+ do {
+ if (tv[i]) {
+ free_tracking_at(tv[i], level);
+ Safefree(tv[i]);
+ }
+ } while (i--);
+ } else {
+ /* Leaves */
+ do {
+ if (tv[i])
+ Safefree(tv[i]);
+ } while (i--);
+ }
+}
+
+static void
+free_tracking(TRACKING *tv)
+{
+ const int top_level = (sizeof(void *) * 8 - LEAF_BITS - BYTE_BITS) / 8;
+ free_tracking_at((void **)tv, top_level);
+ Safefree(tv);
+}
+
UV thing_size(const SV *const, TRACKING *);
typedef enum {
OPc_NULL, /* 0 */
if (check_new(tv, CvOUTSIDE(thing))) {
total_size += thing_size((SV *)CvOUTSIDE(thing), tv);
}
- if (check_new(tv, CvSTART(thing))) {
- total_size += op_size(CvSTART(thing), tv);
- }
- if (check_new(tv, CvROOT(thing))) {
- total_size += op_size(CvROOT(thing), tv);
+ if (CvISXSUB(thing)) {
+ SV *sv = cv_const_sv((CV *)thing);
+ if (sv) {
+ total_size += thing_size(sv, tv);
+ }
+ } else {
+ if (check_new(tv, CvSTART(thing))) {
+ total_size += op_size(CvSTART(thing), tv);
+ }
+ if (check_new(tv, CvROOT(thing))) {
+ total_size += op_size(CvROOT(thing), tv);
+ }
}
TAG;break;
case SVt_PVIO: TAG;
total_size += sizeof(XPVIO);
total_size += magic_size(thing, tv);
- if (check_new(tv, (SvPVX(thing)))) {
+ if (check_new(tv, (SvPVX_const(thing)))) {
total_size += ((XPVIO *) SvANY(thing))->xpv_cur;
}
/* Some embedded char pointers */
SV *orig_thing
CODE:
{
- int i;
SV *thing = orig_thing;
- /* Hash to track our seen pointers */
- //HV *tracking_hash = newHV();
SV *warn_flag;
TRACKING *tv;
Newz( 0xfc0ff, tv, 1, TRACKING );
#endif
RETVAL = thing_size(thing, tv);
- /* Clean up after ourselves */
- //SvREFCNT_dec(tracking_hash);
- for( i = 0; i < TRACKING_SLOTS; ++i ) {
- if( (*tv)[ i ] )
- Safefree( (*tv)[ i ] );
- }
- Safefree( tv );
+ free_tracking(tv);
}
OUTPUT:
RETVAL
SV *orig_thing
CODE:
{
- int i;
SV *thing = orig_thing;
- /* Hash to track our seen pointers */
- //HV *tracking_hash;
TRACKING *tv;
/* Array with things we still need to do */
AV *pending_array;
}
/* init these after the go_yell above */
- //tracking_hash = newHV();
Newz( 0xfc0ff, tv, 1, TRACKING );
pending_array = newAV();
#endif
}
} /* end while */
-
- /* Clean up after ourselves */
- //SvREFCNT_dec(tracking_hash);
- for( i = 0; i < TRACKING_SLOTS; ++i ) {
- if( (*tv)[ i ] )
- Safefree( (*tv)[ i ] );
- }
- Safefree( tv );
+
+ free_tracking(tv);
SvREFCNT_dec(pending_array);
}
OUTPUT:
projects / p5sagit/Devel-Size.git / blobdiff