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Diffstat (limited to 'src/pkg/runtime/mgc0.h')
| -rw-r--r-- | src/pkg/runtime/mgc0.h | 87 |
1 files changed, 0 insertions, 87 deletions
diff --git a/src/pkg/runtime/mgc0.h b/src/pkg/runtime/mgc0.h deleted file mode 100644 index 16000d1ae..000000000 --- a/src/pkg/runtime/mgc0.h +++ /dev/null @@ -1,87 +0,0 @@ -// Copyright 2012 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. - -// Garbage collector (GC) - -// GC instruction opcodes. -// -// The opcode of an instruction is followed by zero or more -// arguments to the instruction. -// -// Meaning of arguments: -// off Offset (in bytes) from the start of the current object -// objgc Pointer to GC info of an object -// objgcrel Offset to GC info of an object -// len Length of an array -// elemsize Size (in bytes) of an element -// size Size (in bytes) -// -// NOTE: There is a copy of these in ../reflect/type.go. -// They must be kept in sync. -enum { - GC_END, // End of object, loop or subroutine. Args: none - GC_PTR, // A typed pointer. Args: (off, objgc) - GC_APTR, // Pointer to an arbitrary object. Args: (off) - GC_ARRAY_START, // Start an array with a fixed length. Args: (off, len, elemsize) - GC_ARRAY_NEXT, // The next element of an array. Args: none - GC_CALL, // Call a subroutine. Args: (off, objgcrel) - GC_CHAN_PTR, // Go channel. Args: (off, ChanType*) - GC_STRING, // Go string. Args: (off) - GC_EFACE, // interface{}. Args: (off) - GC_IFACE, // interface{...}. Args: (off) - GC_SLICE, // Go slice. Args: (off, objgc) - GC_REGION, // A region/part of the current object. Args: (off, size, objgc) - - GC_NUM_INSTR, // Number of instruction opcodes -}; - -enum { - // Size of GC's fixed stack. - // - // The current GC implementation permits: - // - at most 1 stack allocation because of GC_CALL - // - at most GC_STACK_CAPACITY allocations because of GC_ARRAY_START - GC_STACK_CAPACITY = 8, -}; - -enum { - ScanStackByFrames = 1, - IgnorePreciseGC = 0, - - // Four bits per word (see #defines below). - wordsPerBitmapWord = sizeof(void*)*8/4, - bitShift = sizeof(void*)*8/4, -}; - -// Bits in per-word bitmap. -// #defines because enum might not be able to hold the values. -// -// Each word in the bitmap describes wordsPerBitmapWord words -// of heap memory. There are 4 bitmap bits dedicated to each heap word, -// so on a 64-bit system there is one bitmap word per 16 heap words. -// The bits in the word are packed together by type first, then by -// heap location, so each 64-bit bitmap word consists of, from top to bottom, -// the 16 bitMarked bits for the corresponding heap words, -// then the 16 bitScan/bitBlockBoundary bits, then the 16 bitAllocated bits. -// This layout makes it easier to iterate over the bits of a given type. -// -// The bitmap starts at mheap.arena_start and extends *backward* from -// there. On a 64-bit system the off'th word in the arena is tracked by -// the off/16+1'th word before mheap.arena_start. (On a 32-bit system, -// the only difference is that the divisor is 8.) -// -// To pull out the bits corresponding to a given pointer p, we use: -// -// off = p - (uintptr*)mheap.arena_start; // word offset -// b = (uintptr*)mheap.arena_start - off/wordsPerBitmapWord - 1; -// shift = off % wordsPerBitmapWord -// bits = *b >> shift; -// /* then test bits & bitAllocated, bits & bitMarked, etc. */ -// -#define bitAllocated ((uintptr)1<<(bitShift*0)) /* block start; eligible for garbage collection */ -#define bitScan ((uintptr)1<<(bitShift*1)) /* when bitAllocated is set */ -#define bitMarked ((uintptr)1<<(bitShift*2)) /* when bitAllocated is set */ -#define bitBlockBoundary ((uintptr)1<<(bitShift*1)) /* when bitAllocated is NOT set - mark for FlagNoGC objects */ - -#define bitMask (bitAllocated | bitScan | bitMarked) |