gcc/libgo/runtime/malloc.goc

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// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// See malloc.h for overview.
//
// TODO(rsc): double-check stats.
package runtime
#include <stddef.h>
#include <errno.h>
#include <stdlib.h>
#include "go-alloc.h"
#include "runtime.h"
#include "arch.h"
#include "malloc.h"
#include "interface.h"
#include "go-type.h"
#include "race.h"
// Map gccgo field names to gc field names.
// Eface aka __go_empty_interface.
#define type __type_descriptor
// Type aka __go_type_descriptor
#define kind __code
#define string __reflection
#define KindPtr GO_PTR
#define KindNoPointers GO_NO_POINTERS
// Mark mheap as 'no pointers', it does not contain interesting pointers but occupies ~45K.
MHeap runtime_mheap;
int32 runtime_checking;
extern MStats mstats; // defined in zruntime_def_$GOOS_$GOARCH.go
extern volatile intgo runtime_MemProfileRate
__asm__ (GOSYM_PREFIX "runtime.MemProfileRate");
// Allocate an object of at least size bytes.
// Small objects are allocated from the per-thread cache's free lists.
// Large objects (> 32 kB) are allocated straight from the heap.
// If the block will be freed with runtime_free(), typ must be 0.
void*
runtime_mallocgc(uintptr size, uintptr typ, uint32 flag)
{
M *m;
G *g;
int32 sizeclass;
intgo rate;
MCache *c;
MCacheList *l;
uintptr npages;
MSpan *s;
MLink *v;
bool incallback;
if(size == 0) {
// All 0-length allocations use this pointer.
// The language does not require the allocations to
// have distinct values.
return &runtime_zerobase;
}
m = runtime_m();
g = runtime_g();
incallback = false;
if(m->mcache == nil && g->ncgo > 0) {
// For gccgo this case can occur when a cgo or SWIG function
// has an interface return type and the function
// returns a non-pointer, so memory allocation occurs
// after syscall.Cgocall but before syscall.CgocallDone.
// We treat it as a callback.
runtime_exitsyscall();
m = runtime_m();
incallback = true;
flag |= FlagNoInvokeGC;
}
if(runtime_gcwaiting() && g != m->g0 && m->locks == 0 && !(flag & FlagNoInvokeGC)) {
runtime_gosched();
m = runtime_m();
}
if(m->mallocing)
runtime_throw("malloc/free - deadlock");
// Disable preemption during settype_flush.
// We can not use m->mallocing for this, because settype_flush calls mallocgc.
m->locks++;
m->mallocing = 1;
if(DebugTypeAtBlockEnd)
size += sizeof(uintptr);
c = m->mcache;
if(size <= MaxSmallSize) {
// Allocate from mcache free lists.
// Inlined version of SizeToClass().
if(size <= 1024-8)
sizeclass = runtime_size_to_class8[(size+7)>>3];
else
sizeclass = runtime_size_to_class128[(size-1024+127) >> 7];
size = runtime_class_to_size[sizeclass];
l = &c->list[sizeclass];
if(l->list == nil)
runtime_MCache_Refill(c, sizeclass);
v = l->list;
l->list = v->next;
l->nlist--;
if(!(flag & FlagNoZero)) {
v->next = nil;
// block is zeroed iff second word is zero ...
if(size > sizeof(uintptr) && ((uintptr*)v)[1] != 0)
runtime_memclr((byte*)v, size);
}
c->local_cachealloc += size;
} else {
// TODO(rsc): Report tracebacks for very large allocations.
// Allocate directly from heap.
npages = size >> PageShift;
if((size & PageMask) != 0)
npages++;
s = runtime_MHeap_Alloc(&runtime_mheap, npages, 0, 1, !(flag & FlagNoZero));
if(s == nil)
runtime_throw("out of memory");
s->limit = (byte*)(s->start<<PageShift) + size;
size = npages<<PageShift;
v = (void*)(s->start << PageShift);
// setup for mark sweep
runtime_markspan(v, 0, 0, true);
}
if(!(flag & FlagNoGC))
runtime_markallocated(v, size, (flag&FlagNoScan) != 0);
if(DebugTypeAtBlockEnd)
*(uintptr*)((uintptr)v+size-sizeof(uintptr)) = typ;
// TODO: save type even if FlagNoScan? Potentially expensive but might help
// heap profiling/tracing.
if(UseSpanType && !(flag & FlagNoScan) && typ != 0) {
uintptr *buf, i;
buf = m->settype_buf;
i = m->settype_bufsize;
buf[i++] = (uintptr)v;
buf[i++] = typ;
m->settype_bufsize = i;
}
m->mallocing = 0;
if(UseSpanType && !(flag & FlagNoScan) && typ != 0 && m->settype_bufsize == nelem(m->settype_buf))
runtime_settype_flush(m);
m->locks--;
if(!(flag & FlagNoProfiling) && (rate = runtime_MemProfileRate) > 0) {
if(size >= (uint32) rate)
goto profile;
if((uint32) m->mcache->next_sample > size)
m->mcache->next_sample -= size;
else {
// pick next profile time
// If you change this, also change allocmcache.
if(rate > 0x3fffffff) // make 2*rate not overflow
rate = 0x3fffffff;
m->mcache->next_sample = runtime_fastrand1() % (2*rate);
profile:
runtime_setblockspecial(v, true);
runtime_MProf_Malloc(v, size);
}
}
if(!(flag & FlagNoInvokeGC) && mstats.heap_alloc >= mstats.next_gc)
runtime_gc(0);
if(raceenabled)
runtime_racemalloc(v, size);
if(incallback)
runtime_entersyscall();
return v;
}
void*
__go_alloc(uintptr size)
{
return runtime_mallocgc(size, 0, FlagNoInvokeGC);
}
// Free the object whose base pointer is v.
void
__go_free(void *v)
{
M *m;
int32 sizeclass;
MSpan *s;
MCache *c;
uint32 prof;
uintptr size;
if(v == nil)
return;
// If you change this also change mgc0.c:/^sweep,
// which has a copy of the guts of free.
m = runtime_m();
if(m->mallocing)
runtime_throw("malloc/free - deadlock");
m->mallocing = 1;
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);
if(raceenabled)
runtime_racefree(v);
// Find size class for v.
sizeclass = s->sizeclass;
c = m->mcache;
if(sizeclass == 0) {
// Large object.
size = s->npages<<PageShift;
*(uintptr*)(s->start<<PageShift) = (uintptr)0xfeedfeedfeedfeedll; // mark as "needs to be zeroed"
// Must mark v freed before calling unmarkspan and MHeap_Free:
// they might coalesce v into other spans and change the bitmap further.
runtime_markfreed(v, size);
runtime_unmarkspan(v, 1<<PageShift);
runtime_MHeap_Free(&runtime_mheap, s, 1);
c->local_nlargefree++;
c->local_largefree += size;
} else {
// Small object.
size = runtime_class_to_size[sizeclass];
if(size > sizeof(uintptr))
((uintptr*)v)[1] = (uintptr)0xfeedfeedfeedfeedll; // mark as "needs to be zeroed"
// Must mark v freed before calling MCache_Free:
// it might coalesce v and other blocks into a bigger span
// and change the bitmap further.
runtime_markfreed(v, size);
c->local_nsmallfree[sizeclass]++;
runtime_MCache_Free(c, v, sizeclass, size);
}
if(prof)
runtime_MProf_Free(v, size);
m->mallocing = 0;
}
int32
runtime_mlookup(void *v, byte **base, uintptr *size, MSpan **sp)
{
M *m;
uintptr n, i;
byte *p;
MSpan *s;
m = runtime_m();
m->mcache->local_nlookup++;
if (sizeof(void*) == 4 && m->mcache->local_nlookup >= (1<<30)) {
// purge cache stats to prevent overflow
runtime_lock(&runtime_mheap);
runtime_purgecachedstats(m->mcache);
runtime_unlock(&runtime_mheap);
}
s = runtime_MHeap_LookupMaybe(&runtime_mheap, v);
if(sp)
*sp = s;
if(s == nil) {
runtime_checkfreed(v, 1);
if(base)
*base = nil;
if(size)
*size = 0;
return 0;
}
p = (byte*)((uintptr)s->start<<PageShift);
if(s->sizeclass == 0) {
// Large object.
if(base)
*base = p;
if(size)
*size = s->npages<<PageShift;
return 1;
}
n = s->elemsize;
if(base) {
i = ((byte*)v - p)/n;
*base = p + i*n;
}
if(size)
*size = n;
return 1;
}
MCache*
runtime_allocmcache(void)
{
intgo rate;
MCache *c;
runtime_lock(&runtime_mheap);
c = runtime_FixAlloc_Alloc(&runtime_mheap.cachealloc);
runtime_unlock(&runtime_mheap);
runtime_memclr((byte*)c, sizeof(*c));
// Set first allocation sample size.
rate = runtime_MemProfileRate;
if(rate > 0x3fffffff) // make 2*rate not overflow
rate = 0x3fffffff;
if(rate != 0)
c->next_sample = runtime_fastrand1() % (2*rate);
return c;
}
void
runtime_freemcache(MCache *c)
{
runtime_MCache_ReleaseAll(c);
runtime_lock(&runtime_mheap);
runtime_purgecachedstats(c);
runtime_FixAlloc_Free(&runtime_mheap.cachealloc, c);
runtime_unlock(&runtime_mheap);
}
void
runtime_purgecachedstats(MCache *c)
{
MHeap *h;
int32 i;
// Protected by either heap or GC lock.
h = &runtime_mheap;
mstats.heap_alloc += c->local_cachealloc;
c->local_cachealloc = 0;
mstats.nlookup += c->local_nlookup;
c->local_nlookup = 0;
h->largefree += c->local_largefree;
c->local_largefree = 0;
h->nlargefree += c->local_nlargefree;
c->local_nlargefree = 0;
for(i=0; i<(int32)nelem(c->local_nsmallfree); i++) {
h->nsmallfree[i] += c->local_nsmallfree[i];
c->local_nsmallfree[i] = 0;
}
}
extern uintptr runtime_sizeof_C_MStats
__asm__ (GOSYM_PREFIX "runtime.Sizeof_C_MStats");
#define MaxArena32 (2U<<30)
void
runtime_mallocinit(void)
{
byte *p;
uintptr arena_size, bitmap_size, spans_size;
extern byte _end[];
byte *want;
uintptr limit;
uint64 i;
runtime_sizeof_C_MStats = sizeof(MStats);
p = nil;
arena_size = 0;
bitmap_size = 0;
spans_size = 0;
// for 64-bit build
USED(p);
USED(arena_size);
USED(bitmap_size);
USED(spans_size);
runtime_InitSizes();
// limit = runtime_memlimit();
// See https://code.google.com/p/go/issues/detail?id=5049
// TODO(rsc): Fix after 1.1.
limit = 0;
// Set up the allocation arena, a contiguous area of memory where
// allocated data will be found. The arena begins with a bitmap large
// enough to hold 4 bits per allocated word.
if(sizeof(void*) == 8 && (limit == 0 || limit > (1<<30))) {
// On a 64-bit machine, allocate from a single contiguous reservation.
// 128 GB (MaxMem) should be big enough for now.
//
// The code will work with the reservation at any address, but ask
// SysReserve to use 0x0000XXc000000000 if possible (XX=00...7f).
// Allocating a 128 GB region takes away 37 bits, and the amd64
// doesn't let us choose the top 17 bits, so that leaves the 11 bits
// in the middle of 0x00c0 for us to choose. Choosing 0x00c0 means
// that the valid memory addresses will begin 0x00c0, 0x00c1, ..., 0x00df.
// In little-endian, that's c0 00, c1 00, ..., df 00. None of those are valid
// UTF-8 sequences, and they are otherwise as far away from
// ff (likely a common byte) as possible. If that fails, we try other 0xXXc0
// addresses. An earlier attempt to use 0x11f8 caused out of memory errors
// on OS X during thread allocations. 0x00c0 causes conflicts with
// AddressSanitizer which reserves all memory up to 0x0100.
// These choices are both for debuggability and to reduce the
// odds of the conservative garbage collector not collecting memory
// because some non-pointer block of memory had a bit pattern
// that matched a memory address.
//
// Actually we reserve 136 GB (because the bitmap ends up being 8 GB)
// but it hardly matters: e0 00 is not valid UTF-8 either.
//
// If this fails we fall back to the 32 bit memory mechanism
arena_size = MaxMem;
bitmap_size = arena_size / (sizeof(void*)*8/4);
spans_size = arena_size / PageSize * sizeof(runtime_mheap.spans[0]);
spans_size = ROUND(spans_size, PageSize);
for(i = 0; i <= 0x7f; i++) {
p = (void*)(uintptr)(i<<40 | 0x00c0ULL<<32);
p = runtime_SysReserve(p, bitmap_size + spans_size + arena_size);
if(p != nil)
break;
}
}
if (p == nil) {
// On a 32-bit machine, we can't typically get away
// with a giant virtual address space reservation.
// Instead we map the memory information bitmap
// immediately after the data segment, large enough
// to handle another 2GB of mappings (256 MB),
// along with a reservation for another 512 MB of memory.
// When that gets used up, we'll start asking the kernel
// for any memory anywhere and hope it's in the 2GB
// following the bitmap (presumably the executable begins
// near the bottom of memory, so we'll have to use up
// most of memory before the kernel resorts to giving out
// memory before the beginning of the text segment).
//
// Alternatively we could reserve 512 MB bitmap, enough
// for 4GB of mappings, and then accept any memory the
// kernel threw at us, but normally that's a waste of 512 MB
// of address space, which is probably too much in a 32-bit world.
bitmap_size = MaxArena32 / (sizeof(void*)*8/4);
arena_size = 512<<20;
spans_size = MaxArena32 / PageSize * sizeof(runtime_mheap.spans[0]);
if(limit > 0 && arena_size+bitmap_size+spans_size > limit) {
bitmap_size = (limit / 9) & ~((1<<PageShift) - 1);
arena_size = bitmap_size * 8;
spans_size = arena_size / PageSize * sizeof(runtime_mheap.spans[0]);
}
spans_size = ROUND(spans_size, PageSize);
// SysReserve treats the address we ask for, end, as a hint,
// not as an absolute requirement. If we ask for the end
// of the data segment but the operating system requires
// a little more space before we can start allocating, it will
// give out a slightly higher pointer. Except QEMU, which
// is buggy, as usual: it won't adjust the pointer upward.
// So adjust it upward a little bit ourselves: 1/4 MB to get
// away from the running binary image and then round up
// to a MB boundary.
want = (byte*)ROUND((uintptr)_end + (1<<18), 1<<20);
if(0xffffffff - (uintptr)want <= bitmap_size + spans_size + arena_size)
want = 0;
p = runtime_SysReserve(want, bitmap_size + spans_size + arena_size);
if(p == nil)
runtime_throw("runtime: cannot reserve arena virtual address space");
if((uintptr)p & (((uintptr)1<<PageShift)-1))
runtime_printf("runtime: SysReserve returned unaligned address %p; asked for %p", p,
bitmap_size+spans_size+arena_size);
}
if((uintptr)p & (((uintptr)1<<PageShift)-1))
runtime_throw("runtime: SysReserve returned unaligned address");
runtime_mheap.spans = (MSpan**)p;
runtime_mheap.bitmap = p + spans_size;
runtime_mheap.arena_start = p + spans_size + bitmap_size;
runtime_mheap.arena_used = runtime_mheap.arena_start;
runtime_mheap.arena_end = runtime_mheap.arena_start + arena_size;
// Initialize the rest of the allocator.
runtime_MHeap_Init(&runtime_mheap);
runtime_m()->mcache = runtime_allocmcache();
// See if it works.
runtime_free(runtime_malloc(1));
}
void*
runtime_MHeap_SysAlloc(MHeap *h, uintptr n)
{
byte *p;
if(n > (uintptr)(h->arena_end - h->arena_used)) {
// We are in 32-bit mode, maybe we didn't use all possible address space yet.
// Reserve some more space.
byte *new_end;
uintptr needed;
needed = (uintptr)h->arena_used + n - (uintptr)h->arena_end;
needed = ROUND(needed, 256<<20);
new_end = h->arena_end + needed;
if(new_end <= h->arena_start + MaxArena32) {
p = runtime_SysReserve(h->arena_end, new_end - h->arena_end);
if(p == h->arena_end)
h->arena_end = new_end;
}
}
if(n <= (uintptr)(h->arena_end - h->arena_used)) {
// Keep taking from our reservation.
p = h->arena_used;
runtime_SysMap(p, n, &mstats.heap_sys);
h->arena_used += n;
runtime_MHeap_MapBits(h);
runtime_MHeap_MapSpans(h);
if(raceenabled)
runtime_racemapshadow(p, n);
return p;
}
// If using 64-bit, our reservation is all we have.
if(sizeof(void*) == 8 && (uintptr)h->bitmap >= 0xffffffffU)
return nil;
// On 32-bit, once the reservation is gone we can
// try to get memory at a location chosen by the OS
// and hope that it is in the range we allocated bitmap for.
p = runtime_SysAlloc(n, &mstats.heap_sys);
if(p == nil)
return nil;
if(p < h->arena_start || (uintptr)(p+n - h->arena_start) >= MaxArena32) {
runtime_printf("runtime: memory allocated by OS (%p) not in usable range [%p,%p)\n",
p, h->arena_start, h->arena_start+MaxArena32);
runtime_SysFree(p, n, &mstats.heap_sys);
return nil;
}
if(p+n > h->arena_used) {
h->arena_used = p+n;
if(h->arena_used > h->arena_end)
h->arena_end = h->arena_used;
runtime_MHeap_MapBits(h);
runtime_MHeap_MapSpans(h);
if(raceenabled)
runtime_racemapshadow(p, n);
}
return p;
}
static struct
{
Lock;
byte* pos;
byte* end;
} persistent;
enum
{
PersistentAllocChunk = 256<<10,
PersistentAllocMaxBlock = 64<<10, // VM reservation granularity is 64K on windows
};
// Wrapper around SysAlloc that can allocate small chunks.
// There is no associated free operation.
// Intended for things like function/type/debug-related persistent data.
// If align is 0, uses default align (currently 8).
void*
runtime_persistentalloc(uintptr size, uintptr align, uint64 *stat)
{
byte *p;
if(align != 0) {
if(align&(align-1))
runtime_throw("persistentalloc: align is now a power of 2");
if(align > PageSize)
runtime_throw("persistentalloc: align is too large");
} else
align = 8;
if(size >= PersistentAllocMaxBlock)
return runtime_SysAlloc(size, stat);
runtime_lock(&persistent);
persistent.pos = (byte*)ROUND((uintptr)persistent.pos, align);
if(persistent.pos + size > persistent.end) {
persistent.pos = runtime_SysAlloc(PersistentAllocChunk, &mstats.other_sys);
if(persistent.pos == nil) {
runtime_unlock(&persistent);
runtime_throw("runtime: cannot allocate memory");
}
persistent.end = persistent.pos + PersistentAllocChunk;
}
p = persistent.pos;
persistent.pos += size;
runtime_unlock(&persistent);
if(stat != &mstats.other_sys) {
// reaccount the allocation against provided stat
runtime_xadd64(stat, size);
runtime_xadd64(&mstats.other_sys, -(uint64)size);
}
return p;
}
static Lock settype_lock;
void
runtime_settype_flush(M *mp)
{
uintptr *buf, *endbuf;
uintptr size, ofs, j, t;
uintptr ntypes, nbytes2, nbytes3;
uintptr *data2;
byte *data3;
void *v;
uintptr typ, p;
MSpan *s;
buf = mp->settype_buf;
endbuf = buf + mp->settype_bufsize;
runtime_lock(&settype_lock);
while(buf < endbuf) {
v = (void*)*buf;
*buf = 0;
buf++;
typ = *buf;
buf++;
// (Manually inlined copy of runtime_MHeap_Lookup)
p = (uintptr)v>>PageShift;
p -= (uintptr)runtime_mheap.arena_start >> PageShift;
s = runtime_mheap.spans[p];
if(s->sizeclass == 0) {
s->types.compression = MTypes_Single;
s->types.data = typ;
continue;
}
size = s->elemsize;
ofs = ((uintptr)v - (s->start<<PageShift)) / size;
switch(s->types.compression) {
case MTypes_Empty:
ntypes = (s->npages << PageShift) / size;
nbytes3 = 8*sizeof(uintptr) + 1*ntypes;
data3 = runtime_mallocgc(nbytes3, 0, FlagNoProfiling|FlagNoScan|FlagNoInvokeGC);
s->types.compression = MTypes_Bytes;
s->types.data = (uintptr)data3;
((uintptr*)data3)[1] = typ;
data3[8*sizeof(uintptr) + ofs] = 1;
break;
case MTypes_Words:
((uintptr*)s->types.data)[ofs] = typ;
break;
case MTypes_Bytes:
data3 = (byte*)s->types.data;
for(j=1; j<8; j++) {
if(((uintptr*)data3)[j] == typ) {
break;
}
if(((uintptr*)data3)[j] == 0) {
((uintptr*)data3)[j] = typ;
break;
}
}
if(j < 8) {
data3[8*sizeof(uintptr) + ofs] = j;
} else {
ntypes = (s->npages << PageShift) / size;
nbytes2 = ntypes * sizeof(uintptr);
data2 = runtime_mallocgc(nbytes2, 0, FlagNoProfiling|FlagNoScan|FlagNoInvokeGC);
s->types.compression = MTypes_Words;
s->types.data = (uintptr)data2;
// Move the contents of data3 to data2. Then deallocate data3.
for(j=0; j<ntypes; j++) {
t = data3[8*sizeof(uintptr) + j];
t = ((uintptr*)data3)[t];
data2[j] = t;
}
data2[ofs] = typ;
}
break;
}
}
runtime_unlock(&settype_lock);
mp->settype_bufsize = 0;
}
uintptr
runtime_gettype(void *v)
{
MSpan *s;
uintptr t, ofs;
byte *data;
s = runtime_MHeap_LookupMaybe(&runtime_mheap, v);
if(s != nil) {
t = 0;
switch(s->types.compression) {
case MTypes_Empty:
break;
case MTypes_Single:
t = s->types.data;
break;
case MTypes_Words:
ofs = (uintptr)v - (s->start<<PageShift);
t = ((uintptr*)s->types.data)[ofs/s->elemsize];
break;
case MTypes_Bytes:
ofs = (uintptr)v - (s->start<<PageShift);
data = (byte*)s->types.data;
t = data[8*sizeof(uintptr) + ofs/s->elemsize];
t = ((uintptr*)data)[t];
break;
default:
runtime_throw("runtime_gettype: invalid compression kind");
}
if(0) {
runtime_lock(&settype_lock);
runtime_printf("%p -> %d,%X\n", v, (int32)s->types.compression, (int64)t);
runtime_unlock(&settype_lock);
}
return t;
}
return 0;
}
// Runtime stubs.
void*
runtime_mal(uintptr n)
{
return runtime_mallocgc(n, 0, 0);
}
void *
runtime_new(const Type *typ)
{
return runtime_mallocgc(typ->__size, (uintptr)typ | TypeInfo_SingleObject, typ->kind&KindNoPointers ? FlagNoScan : 0);
}
static void*
cnew(const Type *typ, intgo n, int32 objtyp)
{
if((objtyp&(PtrSize-1)) != objtyp)
runtime_throw("runtime: invalid objtyp");
if(n < 0 || (typ->__size > 0 && (uintptr)n > (MaxMem/typ->__size)))
runtime_panicstring("runtime: allocation size out of range");
return runtime_mallocgc(typ->__size*n, (uintptr)typ | objtyp, typ->kind&KindNoPointers ? FlagNoScan : 0);
}
// same as runtime_new, but callable from C
void*
runtime_cnew(const Type *typ)
{
return cnew(typ, 1, TypeInfo_SingleObject);
}
void*
runtime_cnewarray(const Type *typ, intgo n)
{
return cnew(typ, n, TypeInfo_Array);
}
func GC() {
runtime_gc(1);
}
func SetFinalizer(obj Eface, finalizer Eface) {
byte *base;
uintptr size;
const FuncType *ft;
const Type *fint;
const PtrType *ot;
if(obj.__type_descriptor == nil) {
runtime_printf("runtime.SetFinalizer: first argument is nil interface\n");
goto throw;
}
if(obj.__type_descriptor->__code != GO_PTR) {
runtime_printf("runtime.SetFinalizer: first argument is %S, not pointer\n", *obj.__type_descriptor->__reflection);
goto throw;
}
if(!runtime_mlookup(obj.__object, &base, &size, nil) || obj.__object != base) {
runtime_printf("runtime.SetFinalizer: pointer not at beginning of allocated block\n");
goto throw;
}
ft = nil;
ot = (const PtrType*)obj.__type_descriptor;
fint = nil;
if(finalizer.__type_descriptor != nil) {
if(finalizer.__type_descriptor->__code != GO_FUNC)
goto badfunc;
ft = (const FuncType*)finalizer.__type_descriptor;
if(ft->__dotdotdot || ft->__in.__count != 1)
goto badfunc;
fint = *(Type**)ft->__in.__values;
if(__go_type_descriptors_equal(fint, obj.__type_descriptor)) {
// ok - same type
} else if(fint->__code == GO_PTR && (fint->__uncommon == nil || fint->__uncommon->__name == nil || obj.type->__uncommon == nil || obj.type->__uncommon->__name == nil) && __go_type_descriptors_equal(((const PtrType*)fint)->__element_type, ((const PtrType*)obj.type)->__element_type)) {
// ok - not same type, but both pointers,
// one or the other is unnamed, and same element type, so assignable.
} else if(fint->kind == GO_INTERFACE && ((const InterfaceType*)fint)->__methods.__count == 0) {
// ok - satisfies empty interface
} else if(fint->kind == GO_INTERFACE && __go_convert_interface_2(fint, obj.__type_descriptor, 1) != nil) {
// ok - satisfies non-empty interface
} else
goto badfunc;
}
if(!runtime_addfinalizer(obj.__object, finalizer.__type_descriptor != nil ? *(void**)finalizer.__object : nil, ft, ot)) {
runtime_printf("runtime.SetFinalizer: finalizer already set\n");
goto throw;
}
return;
badfunc:
runtime_printf("runtime.SetFinalizer: cannot pass %S to finalizer %S\n", *obj.__type_descriptor->__reflection, *finalizer.__type_descriptor->__reflection);
throw:
runtime_throw("runtime.SetFinalizer");
}