1 // Copyright 2012 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 // Garbage collector (GC) 6 7 // GC instruction opcodes. 8 // 9 // The opcode of an instruction is followed by zero or more 10 // arguments to the instruction. 11 // 12 // Meaning of arguments: 13 // off Offset (in bytes) from the start of the current object 14 // objgc Pointer to GC info of an object 15 // objgcrel Offset to GC info of an object 16 // len Length of an array 17 // elemsize Size (in bytes) of an element 18 // size Size (in bytes) 19 // 20 // NOTE: There is a copy of these in ../reflect/type.go. 21 // They must be kept in sync. 22 enum { 23 GC_END, // End of object, loop or subroutine. Args: none 24 GC_PTR, // A typed pointer. Args: (off, objgc) 25 GC_APTR, // Pointer to an arbitrary object. Args: (off) 26 GC_ARRAY_START, // Start an array with a fixed length. Args: (off, len, elemsize) 27 GC_ARRAY_NEXT, // The next element of an array. Args: none 28 GC_CALL, // Call a subroutine. Args: (off, objgcrel) 29 GC_CHAN_PTR, // Go channel. Args: (off, ChanType*) 30 GC_STRING, // Go string. Args: (off) 31 GC_EFACE, // interface{}. Args: (off) 32 GC_IFACE, // interface{...}. Args: (off) 33 GC_SLICE, // Go slice. Args: (off, objgc) 34 GC_REGION, // A region/part of the current object. Args: (off, size, objgc) 35 36 GC_NUM_INSTR, // Number of instruction opcodes 37 }; 38 39 enum { 40 // Size of GC's fixed stack. 41 // 42 // The current GC implementation permits: 43 // - at most 1 stack allocation because of GC_CALL 44 // - at most GC_STACK_CAPACITY allocations because of GC_ARRAY_START 45 GC_STACK_CAPACITY = 8, 46 }; 47