mirror of
https://github.com/golang/go
synced 2024-11-26 22:31:23 -07:00
3f8aa662e9
mark and sweep, stop the world garbage collector (intermediate step in the way to ref counting). can run pretty with an explicit gc after each file. R=r DELTA=502 (346 added, 143 deleted, 13 changed) OCL=20630 CL=20635
81 lines
1.8 KiB
C
81 lines
1.8 KiB
C
// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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#include "../../../src/runtime/runtime.h"
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typedef struct PageMap PageMap;
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enum
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{
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PageShift = 12,
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PageMask = (1<<PageShift) - 1,
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};
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#define RefFree 0xffffffffU
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#define RefManual 0xfffffffeU
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#define RefStack 0xfffffffdU
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enum {
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PMBits = 64 - PageShift,
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PMLevels = 4,
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PMLevelBits = 13,
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PMLevelSize = 1<<PMLevelBits,
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PMLevelMask = PMLevelSize - 1,
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};
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struct PageMap
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{
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void *level0[PMLevelSize];
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};
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typedef struct Span Span;
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typedef struct Central Central;
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// A Span contains metadata about a range of pages.
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enum {
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SpanInUse = 0, // span has been handed out by allocator
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SpanFree = 1, // span is in central free list
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};
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struct Span
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{
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Span *aprev; // in list of all spans
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Span *anext;
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Span *next; // in free lists
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byte *base; // first byte in span
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uintptr length; // number of pages in span
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int32 cl;
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int32 state; // state (enum above)
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union {
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int32 ref; // reference count if state == SpanInUse (for GC)
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int32 *refbase; // ptr to packed ref counts
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};
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// void *type; // object type if state == SpanInUse (for GC)
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};
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// The Central cache contains a list of free spans,
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// as well as free lists of small blocks.
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struct Central
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{
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Lock;
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Span *free[256];
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Span *large; // free spans >= MaxPage pages
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};
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extern int64 allocator·allocated;
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extern int64 allocator·footprint;
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extern bool allocator·frozen;
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void* trivalloc(int32);
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void* pmlookup(PageMap*, uintptr);
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void* pminsert(PageMap*, uintptr, void*);
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void* alloc(int32);
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void free(void*);
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bool findobj(void*, void**, int64*, int32**);
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extern Central central;
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extern PageMap spanmap;
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extern int32 classtosize[SmallFreeClasses];
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extern Span *spanfirst, *spanlast;
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