// Return span from an MCache.
void
runtime·MCentral_UncacheSpan(MCentral *c, MSpan *s)
{
MLink *v;
int32 cap, n;
runtime·lock(c);
s->incache = false;
// Move any explicitly freed items from the freebuf to the freelist.
while((v = s->freebuf) != nil) {
s->freebuf = v->next;
runtime·markfreed(v);
v->next = s->freelist;
s->freelist = v;
s->ref--;
}
if(s->ref == 0) {
// Free back to heap. Unlikely, but possible.
MCentral_ReturnToHeap(c, s); // unlocks c
return;
}
cap = (s->npages << PageShift) / s->elemsize;
n = cap - s->ref;
if(n > 0) {
c->nfree += n;
runtime·MSpanList_Remove(s);
runtime·MSpanList_Insert(&c->nonempty, s);
}
runtime·unlock(c);
}
void
runtime·free ( void *v )
{
int32 sizeclass;
MSpan *s;
MCache *c;
uint32 prof;
uintptr size;
#line 2161 "C:\Go\src\pkg\runtime\malloc.goc"
if ( v == nil )
return;
#line 2167 "C:\Go\src\pkg\runtime\malloc.goc"
if ( m->mallocing )
runtime·throw ( "malloc/free - deadlock" ) ;
m->mallocing = 1;
#line 2171 "C:\Go\src\pkg\runtime\malloc.goc"
if ( !runtime·mlookup ( v , nil , nil , &s ) ) {
runtime·printf ( "free %p: not an allocated block\n" , v ) ;
runtime·throw ( "free runtime·mlookup" ) ;
}
prof = runtime·blockspecial ( v ) ;
#line 2178 "C:\Go\src\pkg\runtime\malloc.goc"
sizeclass = s->sizeclass;
c = m->mcache;
if ( sizeclass == 0 ) {
#line 2182 "C:\Go\src\pkg\runtime\malloc.goc"
size = s->npages<<PageShift;
* ( uintptr* ) ( s->start<<PageShift ) = 1;
#line 2186 "C:\Go\src\pkg\runtime\malloc.goc"
runtime·markfreed ( v , size ) ;
runtime·unmarkspan ( v , 1<<PageShift ) ;
runtime·MHeap_Free ( &runtime·mheap , s , 1 ) ;
} else {
#line 2191 "C:\Go\src\pkg\runtime\malloc.goc"
size = runtime·class_to_size[sizeclass];
if ( size > sizeof ( uintptr ) )
( ( uintptr* ) v ) [1] = 1;
#line 2197 "C:\Go\src\pkg\runtime\malloc.goc"
runtime·markfreed ( v , size ) ;
c->local_by_size[sizeclass].nfree++;
runtime·MCache_Free ( c , v , sizeclass , size ) ;
}
c->local_alloc -= size;
if ( prof )
runtime·MProf_Free ( v , size ) ;
m->mallocing = 0;
}
// Helper: free one object back into the central free list.
// Caller must hold lock on c on entry. Holds lock on exit.
static void
MCentral_Free(MCentral *c, MLink *v)
{
MSpan *s;
// Find span for v.
s = runtime·MHeap_Lookup(&runtime·mheap, v);
if(s == nil || s->ref == 0)
runtime·throw("invalid free");
if(s->sweepgen != runtime·mheap.sweepgen)
runtime·throw("free into unswept span");
// If the span is currently being used unsynchronized by an MCache,
// we can't modify the freelist. Add to the freebuf instead. The
// items will get moved to the freelist when the span is returned
// by the MCache.
if(s->incache) {
v->next = s->freebuf;
s->freebuf = v;
return;
}
// Move span to nonempty if necessary.
if(s->freelist == nil) {
runtime·MSpanList_Remove(s);
runtime·MSpanList_Insert(&c->nonempty, s);
}
// Add the object to span's free list.
runtime·markfreed(v);
v->next = s->freelist;
s->freelist = v;
s->ref--;
c->nfree++;
// If s is completely freed, return it to the heap.
if(s->ref == 0) {
MCentral_ReturnToHeap(c, s); // unlocks c
runtime·lock(c);
}
}
