void Agc_trace(
SEGCTLPTR *heap_segments
)
{
AREA heap;
AREA area; /* The current area being traced */
TRACINGSTACK tstack; /* Stack of areas to be traced */
SEGCTLPTR segctlp;
SEGCTLPTR *segctlpp;
SIZE temp;
#ifndef A_FUNNY_STEPAREAPTR /* cop-out for weird architectures */
{
/* Check that STEPAREAPTR works correctly on this machine for this nastily aligned structure */
/* If C compiler does tight packing, this could be a problem for the garbage collector */
ASSERT_DECL( struct { PTR p1; char c; PTR p2; } *ass_struct = NIL )
ASSERT_INIT( ( area.addr = (PTR)&ass_struct->c , area.size = sizeof(*ass_struct) ) );
ASSERT_INIT( STEPAREA( area ) );
ASSERT(area.addr == (PTR)&ass_struct->p2,Agc_collect,STEPAREA misbehaving);
}
#endif
heap.addr = SEGSTART( *heap_segments ); heap.size = 0 ;/* inital values to be improved in loop*/
REPORT1(3, "%s\n", "Started trace... setting up bitmaps...");
for ( segctlp = *heap_segments; segctlp != NIL; segctlp = segctlp->next )
{
REPORT6(6,"Agc_collect{mark}: segctlp=0x%p, elsize=%d, start=0x%p, end=0x%p, size=%d,els=%d\n",
(void *)segctlp,SEGELSIZE(segctlp),(void *)SEGSTART(segctlp),(void *)SEGEND(segctlp),SEGSIZE(segctlp),SEGELS(segctlp));
if ( ! ( SEGELSIZE( segctlp ) > 0 && (char *)SEGEND( segctlp ) > (char *)SEGSTART( segctlp ) ) )
{
/* Segment control information has been corrupted. */
/* Most likely this is because of a user scope/bound error, or CTRANS bug; though possibly a collector bug. */
GC_ERROR(HEAP segments corrupt);
}
if ( (char *)SEGSTART( segctlp ) < (char *)(heap.addr) )
{
heap.size += (SIZE)((char *)(heap.addr) - (char *)SEGSTART( segctlp ));
heap.addr = SEGSTART( segctlp );
}
if ( SEGEND( segctlp ) > (PTR)((char *)(heap.addr)+heap.size) )
heap.size = (SIZE)((char *)SEGEND( segctlp ) - (char*)(heap.addr));
GRAB_BITMAP( segctlp->bitmap, SEGELS( segctlp ) + 3 );
SETMARK( segctlp->bitmap, SEGELS( segctlp ) + 0 );
ASSERT(!TSTMARK(segctlp->bitmap,SEGELS(segctlp)+1),Agc_collect,bitmap trailer set at grab);
SETMARK( segctlp->bitmap, SEGELS( segctlp ) + 2 );
/* create an artificial endpoint which can be scanned to */
REPORT2(6,"Agc_collect:\t\tbitmap, ptr=0x%p, size=%d\n", (void *)(segctlp->bitmap), SEGELS( segctlp ));
}
REPORT2(5,"Agc_collect: heap address=0x%p, heap size=%d\n",(void *)heap.addr,heap.size);
INIT_STACK(tstack);
ASSERT_INIT(PUSH(tstack,(PTR)Agc_collect,-42)); /* Assertion mark */
PUSH(tstack, NIL, 0); /* identifies exhausted stack */
REPORT1(3, "%s\n", "Initialising stack scan...");
INIT_AREA(area); /* set area to first area to search - could also PUSH
any additional areas (or use NEXT_AREA) */
do
{
for ( ; !NILAREA(area); /* POP() at end of loop as it may contain statements */ )
{
REPORT3(6,"Agc_collect: AREA scan, ptr=0x%p -> 0x%p, size=%d\n",
(void *)area.addr,(void *)((char *)area.addr+area.size),area.size);
ASSERT(area.size >= 0 && area.size < 100*1024*1024 /* 100Mb */,Agc_collect,area size not sensible);
for ( ; area.size >= sizeof(PTR); STEPAREA(area) )
{
SIZE els, el_in_seg;
PTR p = * (PTR *) area.addr; /* View word as a pointer */
REPORT3(9,"Agc_collect: AREA scan step, ptr=0x%p, size=%d, p=0x%p\n",
(void *)area.addr,area.size,(void *)p);
/* Continue loop if 'p' is unlikely to be a heap pointer. */
/* Keeping the loop small may help some machines with small instruction caches. */
if ( !VALIDPTR( p ) || !PTRINAREA(p,heap) ) continue;
/* p is very likely to be a heap pointer */
for ( segctlpp = heap_segments; (segctlp = *segctlpp) != NIL; segctlpp = &((segctlp)->next ))
{
if ( (char *)p >= (char *)SEGSTART(segctlp) && (char *)p < (char *)SEGEND(segctlp) )
{
/* Segment for heap pointer */
goto found_segment;
}
}
/* Not a valid heap pointer */
continue; /* back to STEPAREA loop */
found_segment:
REPORT3(6,"Agc_collect, found_segment: ptr=0x%p, segctlp=0x%p, elsize=%d\n",
(void *)p,(void *)segctlp,SEGELSIZE(segctlp));
/*
** Move segment to front of segment list, to effect a 'cacheing' as in allocation.
** We believe that there is locality in types of heap pointers,
** (consider lists and trees) so it is likely that next
** lookup will immediately succeed.
** However a fast search startegy might be better ???
**
** Note that typical programs only have a small number of segs,
** many of which are infrequently used.
** Multics Algol68 compiler uses 12 segs;
** ELLA uses ??? segs.
*/
*segctlpp = segctlp->next;
segctlp->next = *heap_segments;
*heap_segments = segctlp;
#ifdef MUST_POINT_TO_WORD
/*
* Ignore pointers that are not word aligned,
* unless in a segment of objects of size that is not a multiple of word.
*/
if ( (SEGELSIZE(segctlp) & (WORDSIZE-1)) == 0 && (((CODEDPTR)(p) & (WORDSIZE-1)) != 0) )
continue; /* p not to word aligned object, forget it */
#endif
#ifdef MUST_POINT_TO_LWORD
/*
* Ignore pointers that are not long word aligned,
* unless in a segment of objects of size that is not a multiple of long word.
*/
if ( (SEGELSIZE(segctlp) & (sizeof(long)-1)) == 0 && (((CODEDPTR)(p) & (sizeof(long)-1)) != 0) )
continue; /* p not to long aligned object, forget it */
#endif
IDENTIFY_ALIGN_EL( p, el_in_seg, segctlp );
#ifdef MUST_POINT_TO_START
/* Ignore pointers that point within objects */
/* This could be implemented more efficiently */
if ( p != * (PTR *) area.addr )
continue; /* p not to start of element, forget it */
#endif
#ifdef NO_GCMARK
els = 1;
#else
ANAL_DESC( els, p, area );
#endif
REPORT3(6,"Agc_collect, aligned and analysed ptr: ptr=0x%p, element in seg=%d, elements=%d\n",
(void *)p,el_in_seg,els);
#ifdef A_GC_HALFWORD_ALIGNED
/* Interpret this as half word aligned (2byte) DJS 8/12/94 */
/* +++ !!! ???
** Crappy quick fix to keep elements word aligned for the Apollo
** (also done for Sun/68000, though it has not been proved that this is necessary).
** Apollo does not permit word objects to be aligned at any byte boundry,
** even though 68020/68030 does. This must be because C compiler generates
** strange code, or page faults for words that straddle page boundries are
** handled badly.
*/
if ( SEGELSIZE(segctlp) == 1 )
{
if ( (long)p & 1 )
{
p--;
el_in_seg--;
els++;
}
if ( els & 1 )
{
els++;
}
if ( els <= 1 || els > SEGELS(segctlp) || p+(els*SEGELSIZE(segctlp)) > SEGEND(segctlp) )
{
els = 2;
}
REPORT3(6,"Agc_collect, adjusted to: ptr=0x%x, element in seg=%d, elements=%d\n",
p,el_in_seg,els);
goto els_sensible;
}
#endif
#ifdef A_GC_WORD_ALIGNED
/* +++ !!! ???
** Crappy quick fix to keep elements word aligned.
*/
if ( SEGELSIZE(segctlp) == 1 )
{
if ( !WORDALIGNED(p) )
{
int offset = (int)((CODEDPTR)p & (WORDSIZE-1));
p = (char *)p - offset;
el_in_seg -= offset;
els += offset;
}
if ( !WORDALIGNED(els) )
{
els = (SIZE)ALIGN_NEXT(els,WORDSIZE);
}
if ( (els < WORDSIZE) || (els > SEGELS(segctlp)) || ((char *)p+(els*SEGELSIZE(segctlp)) > (char *)SEGEND(segctlp) ))
{
els = WORDSIZE;
}
REPORT3(6,"Agc_collect, adjusted to: ptr=0x%p, element in seg=%d, elements=%d\n",
(void *)p,el_in_seg,els);
goto els_sensible;
}
#endif
/* 'els' may be a very silly number, check it is reasonable */
/* before doing arithmetic that may overflow. */
if ( els <= 1 || els > SEGELS(segctlp) || (char *)p+(els*SEGELSIZE(segctlp)) > (char *)SEGEND(segctlp) )
{
/* els = 1; assumed in case array descriptor mis analysed, the ptr is still valid */
if ( !TSTMARK( segctlp->bitmap, el_in_seg ) )
{
SETMARK( segctlp->bitmap, el_in_seg );
if ( SEGELSIZE(segctlp) >= PTRSIZE )
{
/* need only scan elements that are large enough to hold pointer */
PUSH( tstack, p, SEGELSIZE(segctlp) );
REPORT2(6,"Agc_collect: PUSH( ptr=0x%p, size=%d )\n",
(void *)p,SEGELSIZE(segctlp));
}
}
}
else
{
els_sensible:
CALCTSTMARKS( segctlp->bitmap, el_in_seg, els, temp );
if ( !RESTSTMARKS( segctlp->bitmap, el_in_seg, els, temp ) )
{
/*
** At least one element in area has not been marked before.
**
** We could just mark and push unmarked areas,
** but this complicates logic for a fairly rare eventuality,
** mainly caused by the trimming of heap rows.
*/
SETMARKS( segctlp->bitmap, el_in_seg, els );
if ( SEGELSIZE(segctlp) >= PTRSIZE )
{
/* need only scan elements that are large enough to hold pointer */
PUSH( tstack, p, els*SEGELSIZE(segctlp) );
REPORT2(6,"Agc_collect: PUSH( ptr=0x%p, size=%d )\n",
(void *)p,els*SEGELSIZE(segctlp));
}
}
}
}
area = POP(tstack);
}
/* Stack is exhausted, replace end marker */
PUSH(tstack, NIL, 0); /* identifies exhausted stack */
NEXT_AREA(area);
REPORT2(6,"Agc_collect: NEXT_AREA, ptr=0x%p, size=%d\n",(void *)area.addr,area.size);
}
while( area.addr != NIL );
area = POP(tstack); /* pop of (NIL, 0) to leave stack empty and tidy before calling FREE_STACK() */
ASSERT_INIT( area=POP(tstack) );
ASSERT(area.addr == (PTR)Agc_collect && area.size == -42,Agc_collect,tracing stack misuse);
FREE_STACK(tstack);
REPORT1(3, "%s\n", "End of trace");
}
void*
pcsl_mem_malloc_impl0(unsigned int size, char* filename, int lineno) {
#else
void*
pcsl_mem_malloc_impl0(unsigned int size) {
#endif
unsigned int numBytesToAllocate = size;
void* loc = NULL;
_PcslMemHdrPtr tempHdr = NULL;
char* temp = NULL;
char* pcslMemoryPtr;
_PcslMemHdrPtr pcslMemoryHdr;
#ifdef PCSL_DEBUG
int guardSize = 0;
void* guardPos = NULL;
int i = 0;
numBytesToAllocate += GUARD_SIZE;
#endif
while ( (numBytesToAllocate & ALIGNMENT) != 0 ) {
numBytesToAllocate++;
}
/* find a free slot */
for (pcslMemoryPtr = PcslMemoryStart;
pcslMemoryPtr < PcslMemoryEnd;
pcslMemoryPtr += pcslMemoryHdr->size + sizeof(_PcslMemHdr)) {
pcslMemoryHdr = (_PcslMemHdrPtr)pcslMemoryPtr;
if (pcslMemoryHdr->magic != MAGIC) {
REPORT1("ERROR: Memory corruption at 0x%p\n", pcslMemoryPtr);
return((void *) 0);
} else {
while ( 1 ) {
/* coalescing */
if (pcslMemoryHdr->free == 1) {
/* if current block is free */
temp = (char*)pcslMemoryHdr;
temp += pcslMemoryHdr->size + sizeof(_PcslMemHdr);
tempHdr = (_PcslMemHdrPtr)temp;
if ((temp < PcslMemoryEnd) &&
(tempHdr->free == 1) && (tempHdr->magic == MAGIC)) {
/* and the next block is free too */
/* then coalesce */
pcslMemoryHdr->size += tempHdr->size
+ sizeof(_PcslMemHdr);
#ifdef PCSL_DEBUG
pcslMemoryHdr->guardSize = 0;
#endif
REPORT2("DEBUG: Coalescing blocks 0x%p and 0x%p\n",
pcslMemoryHdr, tempHdr);
} else {
break;
}
} else {
break;
}
} /* while */
/* allocating */
if ((pcslMemoryHdr->free == 1) &&
(pcslMemoryHdr->size >= numBytesToAllocate)) {
if (pcslMemoryHdr->size > (numBytesToAllocate
+ sizeof(_PcslMemHdr) + 4)) {
/* split block */
_PcslMemHdrPtr nextHdr;
nextHdr = (_PcslMemHdrPtr)((char *)pcslMemoryPtr
+ numBytesToAllocate
+ sizeof(_PcslMemHdr));
nextHdr->magic = MAGIC;
nextHdr->free = 1;
nextHdr->size = pcslMemoryHdr->size
- numBytesToAllocate
- sizeof(_PcslMemHdr);
#ifdef PCSL_DEBUG
nextHdr->guard = GUARD_WORD;
nextHdr->guardSize = 0;
#endif
pcslMemoryHdr->size = numBytesToAllocate;
}
pcslMemoryHdr->free = 0;
loc = (void*)((char*)pcslMemoryHdr + sizeof(_PcslMemHdr));
#ifdef PCSL_DEBUG
pcslMemoryHdr->guard = GUARD_WORD; /* Add head guard */
pcslMemoryHdr->filename = filename;
pcslMemoryHdr->lineno = lineno;
/* Add tail guard */
guardSize = pcslMemoryHdr->size - size;
pcslMemoryHdr->guardSize = guardSize;
guardPos = (void*)((char*)loc + pcslMemoryHdr->size
- guardSize);
for(i=0; i<guardSize; i++) {
((unsigned char*)guardPos)[i] = GUARD_BYTE;
}
PcslMemoryAllocated += numBytesToAllocate;
if (PcslMemoryAllocated > PcslMemoryHighWaterMark) {
PcslMemoryHighWaterMark = PcslMemoryAllocated;
}
report("DEBUG: Requested %d provided %d at 0x%p\n",
numBytesToAllocate, pcslMemoryHdr->size, loc);
print_alloc("allocated", filename, lineno);
#endif
return(loc);
} /* end of allocating */
} /* end of else */
} /* end of for */
REPORT1("DEBUG: Unable to allocate %d bytes\n", numBytesToAllocate);
return((void *)0);
}