mirror of
https://github.com/golang/go
synced 2024-11-11 20:20:23 -07:00
runtime: remove legacy eager write barrier
Now that the buffered write barrier is implemented for all architectures, we can remove the old eager write barrier implementation. This CL removes the implementation from the runtime, support in the compiler for calling it, and updates some compiler tests that relied on the old eager barrier support. It also makes sure that all of the useful comments from the old write barrier implementation still have a place to live. Fixes #22460. Updates #21640 since this fixes the layering concerns of the write barrier (but not the other things in that issue). Change-Id: I580f93c152e89607e0a72fe43370237ba97bae74 Reviewed-on: https://go-review.googlesource.com/92705 Run-TryBot: Austin Clements <austin@google.com> Reviewed-by: Rick Hudson <rlh@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
This commit is contained in:
Austin Clements
parent
245310883d
commit
2010189407
@ -468,7 +468,7 @@ var linuxAMD64Tests = []*asmTest{
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*t = T2{}
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}
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`,
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pos: []string{"\tXORPS\tX., X", "\tMOVUPS\tX., \\(.*\\)", "\tMOVQ\t\\$0, 16\\(.*\\)", "\tCALL\truntime\\.(writebarrierptr|gcWriteBarrier)\\(SB\\)"},
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pos: []string{"\tXORPS\tX., X", "\tMOVUPS\tX., \\(.*\\)", "\tMOVQ\t\\$0, 16\\(.*\\)", "\tCALL\truntime\\.gcWriteBarrier\\(SB\\)"},
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},
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// Rotate tests
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{
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@ -105,56 +105,55 @@ var runtimeDecls = [...]struct {
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{"chansend1", funcTag, 81},
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{"closechan", funcTag, 23},
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{"writeBarrier", varTag, 83},
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{"writebarrierptr", funcTag, 84},
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{"typedmemmove", funcTag, 85},
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{"typedmemclr", funcTag, 86},
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{"typedslicecopy", funcTag, 87},
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{"selectnbsend", funcTag, 88},
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{"selectnbrecv", funcTag, 89},
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{"selectnbrecv2", funcTag, 91},
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{"newselect", funcTag, 92},
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{"selectsend", funcTag, 93},
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{"selectrecv", funcTag, 94},
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{"typedmemmove", funcTag, 84},
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{"typedmemclr", funcTag, 85},
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{"typedslicecopy", funcTag, 86},
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{"selectnbsend", funcTag, 87},
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{"selectnbrecv", funcTag, 88},
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{"selectnbrecv2", funcTag, 90},
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{"newselect", funcTag, 91},
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{"selectsend", funcTag, 92},
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{"selectrecv", funcTag, 93},
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{"selectdefault", funcTag, 55},
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{"selectgo", funcTag, 95},
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{"selectgo", funcTag, 94},
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{"block", funcTag, 5},
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{"makeslice", funcTag, 97},
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{"makeslice64", funcTag, 98},
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{"growslice", funcTag, 99},
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{"memmove", funcTag, 100},
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{"memclrNoHeapPointers", funcTag, 101},
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{"memclrHasPointers", funcTag, 101},
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{"memequal", funcTag, 102},
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{"memequal8", funcTag, 103},
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{"memequal16", funcTag, 103},
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{"memequal32", funcTag, 103},
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{"memequal64", funcTag, 103},
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{"memequal128", funcTag, 103},
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{"int64div", funcTag, 104},
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{"uint64div", funcTag, 105},
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{"int64mod", funcTag, 104},
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{"uint64mod", funcTag, 105},
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{"float64toint64", funcTag, 106},
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{"float64touint64", funcTag, 107},
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{"float64touint32", funcTag, 108},
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{"int64tofloat64", funcTag, 109},
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{"uint64tofloat64", funcTag, 110},
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{"uint32tofloat64", funcTag, 111},
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{"complex128div", funcTag, 112},
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{"racefuncenter", funcTag, 113},
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{"makeslice", funcTag, 96},
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{"makeslice64", funcTag, 97},
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{"growslice", funcTag, 98},
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{"memmove", funcTag, 99},
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{"memclrNoHeapPointers", funcTag, 100},
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{"memclrHasPointers", funcTag, 100},
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{"memequal", funcTag, 101},
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{"memequal8", funcTag, 102},
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{"memequal16", funcTag, 102},
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{"memequal32", funcTag, 102},
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{"memequal64", funcTag, 102},
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{"memequal128", funcTag, 102},
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{"int64div", funcTag, 103},
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{"uint64div", funcTag, 104},
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{"int64mod", funcTag, 103},
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{"uint64mod", funcTag, 104},
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{"float64toint64", funcTag, 105},
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{"float64touint64", funcTag, 106},
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{"float64touint32", funcTag, 107},
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{"int64tofloat64", funcTag, 108},
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{"uint64tofloat64", funcTag, 109},
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{"uint32tofloat64", funcTag, 110},
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{"complex128div", funcTag, 111},
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{"racefuncenter", funcTag, 112},
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{"racefuncexit", funcTag, 5},
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{"raceread", funcTag, 113},
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{"racewrite", funcTag, 113},
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{"racereadrange", funcTag, 114},
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{"racewriterange", funcTag, 114},
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{"msanread", funcTag, 114},
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{"msanwrite", funcTag, 114},
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{"raceread", funcTag, 112},
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{"racewrite", funcTag, 112},
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{"racereadrange", funcTag, 113},
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{"racewriterange", funcTag, 113},
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{"msanread", funcTag, 113},
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{"msanwrite", funcTag, 113},
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{"support_popcnt", varTag, 11},
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{"support_sse41", varTag, 11},
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}
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func runtimeTypes() []*types.Type {
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var typs [115]*types.Type
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var typs [114]*types.Type
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typs[0] = types.Bytetype
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typs[1] = types.NewPtr(typs[0])
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typs[2] = types.Types[TANY]
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@ -239,36 +238,35 @@ func runtimeTypes() []*types.Type {
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typs[81] = functype(nil, []*Node{anonfield(typs[80]), anonfield(typs[3])}, nil)
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typs[82] = types.NewArray(typs[0], 3)
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typs[83] = tostruct([]*Node{namedfield("enabled", typs[11]), namedfield("pad", typs[82]), namedfield("needed", typs[11]), namedfield("cgo", typs[11]), namedfield("alignme", typs[17])})
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typs[84] = functype(nil, []*Node{anonfield(typs[3]), anonfield(typs[2])}, nil)
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typs[85] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[3]), anonfield(typs[3])}, nil)
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typs[86] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[3])}, nil)
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typs[87] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[2]), anonfield(typs[2])}, []*Node{anonfield(typs[32])})
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typs[88] = functype(nil, []*Node{anonfield(typs[80]), anonfield(typs[3])}, []*Node{anonfield(typs[11])})
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typs[89] = functype(nil, []*Node{anonfield(typs[3]), anonfield(typs[77])}, []*Node{anonfield(typs[11])})
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typs[90] = types.NewPtr(typs[11])
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typs[91] = functype(nil, []*Node{anonfield(typs[3]), anonfield(typs[90]), anonfield(typs[77])}, []*Node{anonfield(typs[11])})
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typs[92] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[15]), anonfield(typs[8])}, nil)
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typs[93] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[80]), anonfield(typs[3])}, nil)
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typs[94] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[77]), anonfield(typs[3]), anonfield(typs[90])}, nil)
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typs[95] = functype(nil, []*Node{anonfield(typs[1])}, []*Node{anonfield(typs[32])})
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typs[96] = types.NewSlice(typs[2])
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typs[97] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[32]), anonfield(typs[32])}, []*Node{anonfield(typs[96])})
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typs[98] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[15]), anonfield(typs[15])}, []*Node{anonfield(typs[96])})
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typs[99] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[96]), anonfield(typs[32])}, []*Node{anonfield(typs[96])})
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typs[100] = functype(nil, []*Node{anonfield(typs[3]), anonfield(typs[3]), anonfield(typs[48])}, nil)
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typs[101] = functype(nil, []*Node{anonfield(typs[57]), anonfield(typs[48])}, nil)
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typs[102] = functype(nil, []*Node{anonfield(typs[3]), anonfield(typs[3]), anonfield(typs[48])}, []*Node{anonfield(typs[11])})
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typs[103] = functype(nil, []*Node{anonfield(typs[3]), anonfield(typs[3])}, []*Node{anonfield(typs[11])})
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typs[104] = functype(nil, []*Node{anonfield(typs[15]), anonfield(typs[15])}, []*Node{anonfield(typs[15])})
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typs[105] = functype(nil, []*Node{anonfield(typs[17]), anonfield(typs[17])}, []*Node{anonfield(typs[17])})
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typs[106] = functype(nil, []*Node{anonfield(typs[13])}, []*Node{anonfield(typs[15])})
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typs[107] = functype(nil, []*Node{anonfield(typs[13])}, []*Node{anonfield(typs[17])})
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typs[108] = functype(nil, []*Node{anonfield(typs[13])}, []*Node{anonfield(typs[59])})
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typs[109] = functype(nil, []*Node{anonfield(typs[15])}, []*Node{anonfield(typs[13])})
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typs[110] = functype(nil, []*Node{anonfield(typs[17])}, []*Node{anonfield(typs[13])})
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typs[111] = functype(nil, []*Node{anonfield(typs[59])}, []*Node{anonfield(typs[13])})
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typs[112] = functype(nil, []*Node{anonfield(typs[19]), anonfield(typs[19])}, []*Node{anonfield(typs[19])})
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typs[113] = functype(nil, []*Node{anonfield(typs[48])}, nil)
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typs[114] = functype(nil, []*Node{anonfield(typs[48]), anonfield(typs[48])}, nil)
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typs[84] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[3]), anonfield(typs[3])}, nil)
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typs[85] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[3])}, nil)
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typs[86] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[2]), anonfield(typs[2])}, []*Node{anonfield(typs[32])})
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typs[87] = functype(nil, []*Node{anonfield(typs[80]), anonfield(typs[3])}, []*Node{anonfield(typs[11])})
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typs[88] = functype(nil, []*Node{anonfield(typs[3]), anonfield(typs[77])}, []*Node{anonfield(typs[11])})
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typs[89] = types.NewPtr(typs[11])
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typs[90] = functype(nil, []*Node{anonfield(typs[3]), anonfield(typs[89]), anonfield(typs[77])}, []*Node{anonfield(typs[11])})
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typs[91] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[15]), anonfield(typs[8])}, nil)
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typs[92] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[80]), anonfield(typs[3])}, nil)
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typs[93] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[77]), anonfield(typs[3]), anonfield(typs[89])}, nil)
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typs[94] = functype(nil, []*Node{anonfield(typs[1])}, []*Node{anonfield(typs[32])})
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typs[95] = types.NewSlice(typs[2])
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typs[96] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[32]), anonfield(typs[32])}, []*Node{anonfield(typs[95])})
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typs[97] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[15]), anonfield(typs[15])}, []*Node{anonfield(typs[95])})
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typs[98] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[95]), anonfield(typs[32])}, []*Node{anonfield(typs[95])})
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typs[99] = functype(nil, []*Node{anonfield(typs[3]), anonfield(typs[3]), anonfield(typs[48])}, nil)
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typs[100] = functype(nil, []*Node{anonfield(typs[57]), anonfield(typs[48])}, nil)
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typs[101] = functype(nil, []*Node{anonfield(typs[3]), anonfield(typs[3]), anonfield(typs[48])}, []*Node{anonfield(typs[11])})
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typs[102] = functype(nil, []*Node{anonfield(typs[3]), anonfield(typs[3])}, []*Node{anonfield(typs[11])})
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typs[103] = functype(nil, []*Node{anonfield(typs[15]), anonfield(typs[15])}, []*Node{anonfield(typs[15])})
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typs[104] = functype(nil, []*Node{anonfield(typs[17]), anonfield(typs[17])}, []*Node{anonfield(typs[17])})
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typs[105] = functype(nil, []*Node{anonfield(typs[13])}, []*Node{anonfield(typs[15])})
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typs[106] = functype(nil, []*Node{anonfield(typs[13])}, []*Node{anonfield(typs[17])})
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typs[107] = functype(nil, []*Node{anonfield(typs[13])}, []*Node{anonfield(typs[59])})
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typs[108] = functype(nil, []*Node{anonfield(typs[15])}, []*Node{anonfield(typs[13])})
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typs[109] = functype(nil, []*Node{anonfield(typs[17])}, []*Node{anonfield(typs[13])})
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typs[110] = functype(nil, []*Node{anonfield(typs[59])}, []*Node{anonfield(typs[13])})
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typs[111] = functype(nil, []*Node{anonfield(typs[19]), anonfield(typs[19])}, []*Node{anonfield(typs[19])})
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typs[112] = functype(nil, []*Node{anonfield(typs[48])}, nil)
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typs[113] = functype(nil, []*Node{anonfield(typs[48]), anonfield(typs[48])}, nil)
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return typs[:]
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}
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@ -136,8 +136,6 @@ var writeBarrier struct {
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alignme uint64
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}
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func writebarrierptr(dst *any, src any)
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// *byte is really *runtime.Type
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func typedmemmove(typ *byte, dst *any, src *any)
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func typedmemclr(typ *byte, dst *any)
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@ -292,7 +292,6 @@ var (
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assertI2I2,
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goschedguarded,
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writeBarrier,
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writebarrierptr,
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gcWriteBarrier,
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typedmemmove,
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typedmemclr,
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@ -44,7 +44,6 @@ var (
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Debug_slice int
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Debug_vlog bool
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Debug_wb int
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Debug_eagerwb int
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Debug_pctab string
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Debug_locationlist int
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Debug_typecheckinl int
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@ -73,7 +72,6 @@ var debugtab = []struct {
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{"slice", "print information about slice compilation", &Debug_slice},
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{"typeassert", "print information about type assertion inlining", &Debug_typeassert},
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{"wb", "print information about write barriers", &Debug_wb},
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{"eagerwb", "use unbuffered write barrier", &Debug_eagerwb},
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{"export", "print export data", &Debug_export},
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{"pctab", "print named pc-value table", &Debug_pctab},
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{"locationlists", "print information about DWARF location list creation", &Debug_locationlist},
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@ -407,14 +405,6 @@ func Main(archInit func(*Arch)) {
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Debug['l'] = 1 - Debug['l']
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}
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switch objabi.GOARCH {
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case "amd64", "amd64p32", "386", "arm", "arm64", "ppc64", "ppc64le", "mips64", "mips64le", "mips", "mipsle", "s390x":
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default:
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// Other architectures don't support the buffered
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// write barrier yet.
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Debug_eagerwb = 1
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}
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trackScopes = flagDWARF && ((Debug['l'] == 0 && Debug['N'] != 0) || Ctxt.Flag_locationlists)
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Widthptr = thearch.LinkArch.PtrSize
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@ -95,7 +95,6 @@ func initssaconfig() {
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assertI2I2 = sysfunc("assertI2I2")
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goschedguarded = sysfunc("goschedguarded")
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writeBarrier = sysfunc("writeBarrier")
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writebarrierptr = sysfunc("writebarrierptr")
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gcWriteBarrier = sysfunc("gcWriteBarrier")
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typedmemmove = sysfunc("typedmemmove")
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typedmemclr = sysfunc("typedmemclr")
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@ -5380,10 +5379,6 @@ func (e *ssafn) Debug_checknil() bool {
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return Debug_checknil != 0
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}
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func (e *ssafn) Debug_eagerwb() bool {
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return Debug_eagerwb != 0
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}
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func (e *ssafn) UseWriteBarrier() bool {
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return use_writebarrier
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}
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@ -5394,8 +5389,6 @@ func (e *ssafn) Syslook(name string) *obj.LSym {
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return goschedguarded
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case "writeBarrier":
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return writeBarrier
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case "writebarrierptr":
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return writebarrierptr
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case "gcWriteBarrier":
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return gcWriteBarrier
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case "typedmemmove":
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@ -89,7 +89,6 @@ type Logger interface {
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// Forwards the Debug flags from gc
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Debug_checknil() bool
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Debug_eagerwb() bool
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}
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type Frontend interface {
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@ -134,7 +134,6 @@ func (d DummyFrontend) Log() bool { return true }
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func (d DummyFrontend) Fatalf(_ src.XPos, msg string, args ...interface{}) { d.t.Fatalf(msg, args...) }
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func (d DummyFrontend) Warnl(_ src.XPos, msg string, args ...interface{}) { d.t.Logf(msg, args...) }
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func (d DummyFrontend) Debug_checknil() bool { return false }
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func (d DummyFrontend) Debug_eagerwb() bool { return false }
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var dummyTypes Types
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@ -31,7 +31,7 @@ func needwb(v *Value) bool {
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// and runtime calls, like
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//
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// if writeBarrier.enabled {
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// writebarrierptr(ptr, val)
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// gcWriteBarrier(ptr, val) // Not a regular Go call
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// } else {
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// *ptr = val
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// }
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@ -44,7 +44,7 @@ func writebarrier(f *Func) {
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}
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var sb, sp, wbaddr, const0 *Value
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var writebarrierptr, typedmemmove, typedmemclr, gcWriteBarrier *obj.LSym
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var typedmemmove, typedmemclr, gcWriteBarrier *obj.LSym
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var stores, after []*Value
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var sset *sparseSet
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var storeNumber []int32
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@ -96,10 +96,7 @@ func writebarrier(f *Func) {
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}
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wbsym := f.fe.Syslook("writeBarrier")
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wbaddr = f.Entry.NewValue1A(initpos, OpAddr, f.Config.Types.UInt32Ptr, wbsym, sb)
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writebarrierptr = f.fe.Syslook("writebarrierptr")
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if !f.fe.Debug_eagerwb() {
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gcWriteBarrier = f.fe.Syslook("gcWriteBarrier")
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}
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gcWriteBarrier = f.fe.Syslook("gcWriteBarrier")
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typedmemmove = f.fe.Syslook("typedmemmove")
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typedmemclr = f.fe.Syslook("typedmemclr")
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const0 = f.ConstInt32(initpos, f.Config.Types.UInt32, 0)
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@ -198,7 +195,6 @@ func writebarrier(f *Func) {
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var val *Value
|
||||
switch w.Op {
|
||||
case OpStoreWB:
|
||||
fn = writebarrierptr
|
||||
val = w.Args[1]
|
||||
nWBops--
|
||||
case OpMoveWB:
|
||||
@ -217,11 +213,13 @@ func writebarrier(f *Func) {
|
||||
switch w.Op {
|
||||
case OpStoreWB, OpMoveWB, OpZeroWB:
|
||||
volatile := w.Op == OpMoveWB && isVolatile(val)
|
||||
if w.Op == OpStoreWB && !f.fe.Debug_eagerwb() {
|
||||
if w.Op == OpStoreWB {
|
||||
memThen = bThen.NewValue3A(pos, OpWB, types.TypeMem, gcWriteBarrier, ptr, val, memThen)
|
||||
} else {
|
||||
memThen = wbcall(pos, bThen, fn, typ, ptr, val, memThen, sp, sb, volatile)
|
||||
}
|
||||
// Note that we set up a writebarrier function call.
|
||||
f.fe.SetWBPos(pos)
|
||||
case OpVarDef, OpVarLive, OpVarKill:
|
||||
memThen = bThen.NewValue1A(pos, w.Op, types.TypeMem, w.Aux, memThen)
|
||||
}
|
||||
@ -239,11 +237,6 @@ func writebarrier(f *Func) {
|
||||
case OpVarDef, OpVarLive, OpVarKill:
|
||||
memElse = bElse.NewValue1A(pos, w.Op, types.TypeMem, w.Aux, memElse)
|
||||
}
|
||||
|
||||
if fn != nil {
|
||||
// Note that we set up a writebarrier function call.
|
||||
f.fe.SetWBPos(pos)
|
||||
}
|
||||
}
|
||||
|
||||
// merge memory
|
||||
|
||||
@ -25,5 +25,3 @@ runtime/asm_386.s: [386] uint32tofloat64: function uint32tofloat64 missing Go de
|
||||
runtime/asm_386.s: [386] float64touint32: function float64touint32 missing Go declaration
|
||||
|
||||
runtime/asm_386.s: [386] stackcheck: function stackcheck missing Go declaration
|
||||
|
||||
runtime/asm_ARCHSUFF.s: [GOARCH] gcWriteBarrier: function gcWriteBarrier missing Go declaration
|
||||
|
||||
@ -15,6 +15,9 @@ runtime/asm_ARCHSUFF.s: [GOARCH] cannot check cross-package assembly function: E
|
||||
runtime/asm_ARCHSUFF.s: [GOARCH] cannot check cross-package assembly function: IndexByte is in package bytes
|
||||
runtime/asm_ARCHSUFF.s: [GOARCH] cannot check cross-package assembly function: IndexByte is in package strings
|
||||
|
||||
// The write barrier is called directly by the compiler, so no Go def
|
||||
runtime/asm_ARCHSUFF.s: [GOARCH] gcWriteBarrier: function gcWriteBarrier missing Go declaration
|
||||
|
||||
// Legitimate vet complaints in which we are testing for correct runtime behavior
|
||||
// in bad situations that vet can also detect statically.
|
||||
encoding/json/decode_test.go: struct field m has json tag but is not exported
|
||||
|
||||
@ -31,4 +31,3 @@ runtime/duff_amd64.s: [amd64] duffcopy: function duffcopy missing Go declaration
|
||||
runtime/asm_amd64.s: [amd64] stackcheck: function stackcheck missing Go declaration
|
||||
runtime/asm_amd64.s: [amd64] indexShortStr: function indexShortStr missing Go declaration
|
||||
runtime/asm_amd64.s: [amd64] countByte: function countByte missing Go declaration
|
||||
runtime/asm_amd64.s: [amd64] gcWriteBarrier: function gcWriteBarrier missing Go declaration
|
||||
|
||||
@ -16,5 +16,3 @@ runtime/tls_arm.s: [arm] load_g: function load_g missing Go declaration
|
||||
runtime/tls_arm.s: [arm] _initcgo: function _initcgo missing Go declaration
|
||||
|
||||
runtime/internal/atomic/asm_arm.s: [arm] cas: function cas missing Go declaration
|
||||
|
||||
runtime/asm_ARCHSUFF.s: [GOARCH] gcWriteBarrier: function gcWriteBarrier missing Go declaration
|
||||
|
||||
@ -9,5 +9,3 @@ runtime/duff_arm64.s: [arm64] duffzero: function duffzero missing Go declaration
|
||||
runtime/duff_arm64.s: [arm64] duffcopy: function duffcopy missing Go declaration
|
||||
runtime/tls_arm64.s: [arm64] load_g: function load_g missing Go declaration
|
||||
runtime/tls_arm64.s: [arm64] save_g: function save_g missing Go declaration
|
||||
|
||||
runtime/asm_ARCHSUFF.s: [GOARCH] gcWriteBarrier: function gcWriteBarrier missing Go declaration
|
||||
|
||||
@ -4,5 +4,3 @@ runtime/asm_mips64x.s: [GOARCH] abort: function abort missing Go declaration
|
||||
runtime/duff_mips64x.s: [GOARCH] duffzero: function duffzero missing Go declaration
|
||||
runtime/tls_mips64x.s: [GOARCH] save_g: function save_g missing Go declaration
|
||||
runtime/tls_mips64x.s: [GOARCH] load_g: function load_g missing Go declaration
|
||||
|
||||
runtime/asm_ARCHSUFF.s: [GOARCH] gcWriteBarrier: function gcWriteBarrier missing Go declaration
|
||||
|
||||
@ -7,5 +7,3 @@ runtime/asm_mipsx.s: [GOARCH] cannot check cross-package assembly function: Comp
|
||||
runtime/sys_linux_mipsx.s: [GOARCH] clone: 12(R29) should be mp+8(FP)
|
||||
runtime/sys_linux_mipsx.s: [GOARCH] clone: 4(R29) should be flags+0(FP)
|
||||
runtime/sys_linux_mipsx.s: [GOARCH] clone: 8(R29) should be stk+4(FP)
|
||||
|
||||
runtime/asm_ARCHSUFF.s: [GOARCH] gcWriteBarrier: function gcWriteBarrier missing Go declaration
|
||||
|
||||
@ -27,5 +27,3 @@ runtime/asm_amd64p32.s: [amd64p32] indexbytebody: function indexbytebody missing
|
||||
runtime/asm_amd64p32.s: [amd64p32] asmcgocall: RET without writing to 4-byte ret+8(FP)
|
||||
|
||||
runtime/asm_amd64p32.s: [amd64p32] stackcheck: function stackcheck missing Go declaration
|
||||
|
||||
runtime/asm_ARCHSUFF.s: [GOARCH] gcWriteBarrier: function gcWriteBarrier missing Go declaration
|
||||
|
||||
@ -10,5 +10,3 @@ runtime/asm_ppc64x.s: [GOARCH] addmoduledata: function addmoduledata missing Go
|
||||
runtime/duff_ppc64x.s: [GOARCH] duffzero: function duffzero missing Go declaration
|
||||
runtime/tls_ppc64x.s: [GOARCH] save_g: function save_g missing Go declaration
|
||||
runtime/tls_ppc64x.s: [GOARCH] load_g: function load_g missing Go declaration
|
||||
|
||||
runtime/asm_ARCHSUFF.s: [GOARCH] gcWriteBarrier: function gcWriteBarrier missing Go declaration
|
||||
|
||||
@ -15,5 +15,3 @@ runtime/memclr_s390x.s: [s390x] memclr_s390x_exrl_xc: function memclr_s390x_exrl
|
||||
runtime/memmove_s390x.s: [s390x] memmove_s390x_exrl_mvc: function memmove_s390x_exrl_mvc missing Go declaration
|
||||
runtime/tls_s390x.s: [s390x] save_g: function save_g missing Go declaration
|
||||
runtime/tls_s390x.s: [s390x] load_g: function load_g missing Go declaration
|
||||
|
||||
runtime/asm_ARCHSUFF.s: [GOARCH] gcWriteBarrier: function gcWriteBarrier missing Go declaration
|
||||
|
||||
@ -2397,7 +2397,13 @@ TEXT runtime·gcWriteBarrier(SB),NOSPLIT,$120
|
||||
CMPQ R14, (p_wbBuf+wbBuf_end)(R13)
|
||||
// Record the write.
|
||||
MOVQ AX, -16(R14) // Record value
|
||||
MOVQ (DI), R13 // TODO: This turns bad writes into bad reads.
|
||||
// Note: This turns bad pointer writes into bad
|
||||
// pointer reads, which could be confusing. We could avoid
|
||||
// reading from obviously bad pointers, which would
|
||||
// take care of the vast majority of these. We could
|
||||
// patch this up in the signal handler, or use XCHG to
|
||||
// combine the read and the write.
|
||||
MOVQ (DI), R13
|
||||
MOVQ R13, -8(R14) // Record *slot
|
||||
// Is the buffer full? (flags set in CMPQ above)
|
||||
JEQ flush
|
||||
|
||||
@ -6,10 +6,10 @@
|
||||
//
|
||||
// For the concurrent garbage collector, the Go compiler implements
|
||||
// updates to pointer-valued fields that may be in heap objects by
|
||||
// emitting calls to write barriers. This file contains the actual write barrier
|
||||
// implementation, gcmarkwb_m, and the various wrappers called by the
|
||||
// compiler to implement pointer assignment, slice assignment,
|
||||
// typed memmove, and so on.
|
||||
// emitting calls to write barriers. The main write barrier for
|
||||
// individual pointer writes is gcWriteBarrier and is implemented in
|
||||
// assembly. This file contains write barrier entry points for bulk
|
||||
// operations. See also mwbbuf.go.
|
||||
|
||||
package runtime
|
||||
|
||||
@ -18,10 +18,7 @@ import (
|
||||
"unsafe"
|
||||
)
|
||||
|
||||
// gcmarkwb_m is the mark-phase write barrier, the only barrier we have.
|
||||
// The rest of this file exists only to make calls to this function.
|
||||
//
|
||||
// This is a hybrid barrier that combines a Yuasa-style deletion
|
||||
// Go uses a hybrid barrier that combines a Yuasa-style deletion
|
||||
// barrier—which shades the object whose reference is being
|
||||
// overwritten—with Dijkstra insertion barrier—which shades the object
|
||||
// whose reference is being written. The insertion part of the barrier
|
||||
@ -137,105 +134,17 @@ import (
|
||||
// reachable by some goroutine that currently cannot reach it.
|
||||
//
|
||||
//
|
||||
//go:nowritebarrierrec
|
||||
//go:systemstack
|
||||
func gcmarkwb_m(slot *uintptr, ptr uintptr) {
|
||||
if writeBarrier.needed {
|
||||
// Note: This turns bad pointer writes into bad
|
||||
// pointer reads, which could be confusing. We avoid
|
||||
// reading from obviously bad pointers, which should
|
||||
// take care of the vast majority of these. We could
|
||||
// patch this up in the signal handler, or use XCHG to
|
||||
// combine the read and the write. Checking inheap is
|
||||
// insufficient since we need to track changes to
|
||||
// roots outside the heap.
|
||||
//
|
||||
// Note: profbuf.go omits a barrier during signal handler
|
||||
// profile logging; that's safe only because this deletion barrier exists.
|
||||
// If we remove the deletion barrier, we'll have to work out
|
||||
// a new way to handle the profile logging.
|
||||
if slot1 := uintptr(unsafe.Pointer(slot)); slot1 >= minPhysPageSize {
|
||||
if optr := *slot; optr != 0 {
|
||||
shade(optr)
|
||||
}
|
||||
}
|
||||
// TODO: Make this conditional on the caller's stack color.
|
||||
if ptr != 0 && inheap(ptr) {
|
||||
shade(ptr)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// writebarrierptr_prewrite1 invokes a write barrier for *dst = src
|
||||
// prior to the write happening.
|
||||
// Signal handler pointer writes:
|
||||
//
|
||||
// Write barrier calls must not happen during critical GC and scheduler
|
||||
// related operations. In particular there are times when the GC assumes
|
||||
// that the world is stopped but scheduler related code is still being
|
||||
// executed, dealing with syscalls, dealing with putting gs on runnable
|
||||
// queues and so forth. This code cannot execute write barriers because
|
||||
// the GC might drop them on the floor. Stopping the world involves removing
|
||||
// the p associated with an m. We use the fact that m.p == nil to indicate
|
||||
// that we are in one these critical section and throw if the write is of
|
||||
// a pointer to a heap object.
|
||||
//go:nosplit
|
||||
func writebarrierptr_prewrite1(dst *uintptr, src uintptr) {
|
||||
mp := acquirem()
|
||||
if mp.inwb || mp.dying > 0 {
|
||||
// We explicitly allow write barriers in startpanic_m,
|
||||
// since we're going down anyway. Ignore them here.
|
||||
releasem(mp)
|
||||
return
|
||||
}
|
||||
systemstack(func() {
|
||||
if mp.p == 0 && memstats.enablegc && !mp.inwb && inheap(src) {
|
||||
throw("writebarrierptr_prewrite1 called with mp.p == nil")
|
||||
}
|
||||
mp.inwb = true
|
||||
gcmarkwb_m(dst, src)
|
||||
})
|
||||
mp.inwb = false
|
||||
releasem(mp)
|
||||
}
|
||||
|
||||
// NOTE: Really dst *unsafe.Pointer, src unsafe.Pointer,
|
||||
// but if we do that, Go inserts a write barrier on *dst = src.
|
||||
//go:nosplit
|
||||
func writebarrierptr(dst *uintptr, src uintptr) {
|
||||
if writeBarrier.cgo {
|
||||
cgoCheckWriteBarrier(dst, src)
|
||||
}
|
||||
if !writeBarrier.needed {
|
||||
*dst = src
|
||||
return
|
||||
}
|
||||
if src != 0 && src < minPhysPageSize {
|
||||
systemstack(func() {
|
||||
print("runtime: writebarrierptr *", dst, " = ", hex(src), "\n")
|
||||
throw("bad pointer in write barrier")
|
||||
})
|
||||
}
|
||||
writebarrierptr_prewrite1(dst, src)
|
||||
*dst = src
|
||||
}
|
||||
|
||||
// writebarrierptr_prewrite is like writebarrierptr, but the store
|
||||
// will be performed by the caller after this call. The caller must
|
||||
// not allow preemption between this call and the write.
|
||||
// In general, the signal handler cannot safely invoke the write
|
||||
// barrier because it may run without a P or even during the write
|
||||
// barrier.
|
||||
//
|
||||
//go:nosplit
|
||||
func writebarrierptr_prewrite(dst *uintptr, src uintptr) {
|
||||
if writeBarrier.cgo {
|
||||
cgoCheckWriteBarrier(dst, src)
|
||||
}
|
||||
if !writeBarrier.needed {
|
||||
return
|
||||
}
|
||||
if src != 0 && src < minPhysPageSize {
|
||||
systemstack(func() { throw("bad pointer in write barrier") })
|
||||
}
|
||||
writebarrierptr_prewrite1(dst, src)
|
||||
}
|
||||
// There is exactly one exception: profbuf.go omits a barrier during
|
||||
// signal handler profile logging. That's safe only because of the
|
||||
// deletion barrier. See profbuf.go for a detailed argument. If we
|
||||
// remove the deletion barrier, we'll have to work out a new way to
|
||||
// handle the profile logging.
|
||||
|
||||
// typedmemmove copies a value of type t to dst from src.
|
||||
// Must be nosplit, see #16026.
|
||||
|
||||
@ -5,6 +5,9 @@
|
||||
// This implements the write barrier buffer. The write barrier itself
|
||||
// is gcWriteBarrier and is implemented in assembly.
|
||||
//
|
||||
// See mbarrier.go for algorithmic details on the write barrier. This
|
||||
// file deals only with the buffer.
|
||||
//
|
||||
// The write barrier has a fast path and a slow path. The fast path
|
||||
// simply enqueues to a per-P write barrier buffer. It's written in
|
||||
// assembly and doesn't clobber any general purpose registers, so it
|
||||
@ -111,16 +114,21 @@ func (b *wbBuf) discard() {
|
||||
// if !buf.putFast(old, new) {
|
||||
// wbBufFlush(...)
|
||||
// }
|
||||
// ... actual memory write ...
|
||||
//
|
||||
// The arguments to wbBufFlush depend on whether the caller is doing
|
||||
// its own cgo pointer checks. If it is, then this can be
|
||||
// wbBufFlush(nil, 0). Otherwise, it must pass the slot address and
|
||||
// new.
|
||||
//
|
||||
// Since buf is a per-P resource, the caller must ensure there are no
|
||||
// preemption points while buf is in use.
|
||||
// The caller must ensure there are no preemption points during the
|
||||
// above sequence. There must be no preemption points while buf is in
|
||||
// use because it is a per-P resource. There must be no preemption
|
||||
// points between the buffer put and the write to memory because this
|
||||
// could allow a GC phase change, which could result in missed write
|
||||
// barriers.
|
||||
//
|
||||
// It must be nowritebarrierrec to because write barriers here would
|
||||
// putFast must be nowritebarrierrec to because write barriers here would
|
||||
// corrupt the write barrier buffer. It (and everything it calls, if
|
||||
// it called anything) has to be nosplit to avoid scheduling on to a
|
||||
// different P and a different buffer.
|
||||
@ -214,6 +222,14 @@ func wbBufFlush1(_p_ *p) {
|
||||
//
|
||||
// TODO: Should scanobject/scanblock just stuff pointers into
|
||||
// the wbBuf? Then this would become the sole greying path.
|
||||
//
|
||||
// TODO: We could avoid shading any of the "new" pointers in
|
||||
// the buffer if the stack has been shaded, or even avoid
|
||||
// putting them in the buffer at all (which would double its
|
||||
// capacity). This is slightly complicated with the buffer; we
|
||||
// could track whether any un-shaded goroutine has used the
|
||||
// buffer, or just track globally whether there are any
|
||||
// un-shaded stacks and flush after each stack scan.
|
||||
gcw := &_p_.gcw
|
||||
pos := 0
|
||||
arenaStart := mheap_.arena_start
|
||||
|
||||
@ -1,4 +1,4 @@
|
||||
// errorcheck -0 -live -d=eagerwb
|
||||
// errorcheck -0 -live
|
||||
|
||||
// Copyright 2016 The Go Authors. All rights reserved.
|
||||
// Use of this source code is governed by a BSD-style
|
||||
@ -7,10 +7,6 @@
|
||||
// Issue 15747: liveness analysis was marking heap-escaped params live too much,
|
||||
// and worse was using the wrong bitmap bits to do so.
|
||||
|
||||
// TODO(austin): This expects function calls to the write barrier, so
|
||||
// we enable the legacy eager write barrier. Fix this once the
|
||||
// buffered write barrier works on all arches.
|
||||
|
||||
package p
|
||||
|
||||
var global *[]byte
|
||||
@ -21,14 +17,14 @@ type T struct{ M string }
|
||||
|
||||
var b bool
|
||||
|
||||
func f1(q *Q, xx []byte) interface{} { // ERROR "live at call to newobject: xx$" "live at call to writebarrierptr: &xx$" "live at entry to f1: xx$"
|
||||
func f1(q *Q, xx []byte) interface{} { // ERROR "live at call to newobject: xx$" "live at entry to f1: xx$"
|
||||
// xx was copied from the stack to the heap on the previous line:
|
||||
// xx was live for the first two prints but then it switched to &xx
|
||||
// being live. We should not see plain xx again.
|
||||
if b {
|
||||
global = &xx // ERROR "live at call to writebarrierptr: &xx$"
|
||||
global = &xx
|
||||
}
|
||||
xx, _, err := f2(xx, 5) // ERROR "live at call to f2: &xx$" "live at call to writebarrierptr: err.data err.type$"
|
||||
xx, _, err := f2(xx, 5) // ERROR "live at call to f2: &xx$"
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
@ -38,7 +34,7 @@ func f1(q *Q, xx []byte) interface{} { // ERROR "live at call to newobject: xx$"
|
||||
//go:noinline
|
||||
func f2(d []byte, n int) (odata, res []byte, e interface{}) { // ERROR "live at entry to f2: d$"
|
||||
if n > len(d) {
|
||||
return d, nil, &T{M: "hello"} // ERROR "live at call to newobject: d" "live at call to writebarrierptr: d"
|
||||
return d, nil, &T{M: "hello"} // ERROR "live at call to newobject: d"
|
||||
}
|
||||
res = d[:n]
|
||||
odata = d[n:]
|
||||
|
||||
@ -1,4 +1,4 @@
|
||||
// errorcheck -0 -live -l -d=compilelater,eagerwb
|
||||
// errorcheck -0 -live -l -d=compilelater
|
||||
|
||||
// Copyright 2017 The Go Authors. All rights reserved.
|
||||
// Use of this source code is governed by a BSD-style
|
||||
@ -8,10 +8,6 @@
|
||||
// due to propagation of addrtaken to outer variables for
|
||||
// closure variables.
|
||||
|
||||
// TODO(austin): This expects function calls to the write barrier, so
|
||||
// we enable the legacy eager write barrier. Fix this once the
|
||||
// buffered write barrier works on all arches.
|
||||
|
||||
package p
|
||||
|
||||
type T struct {
|
||||
@ -21,7 +17,7 @@ type T struct {
|
||||
func f(a T) { // ERROR "live at entry to f: a"
|
||||
var e interface{}
|
||||
func() { // ERROR "live at entry to f.func1: a &e"
|
||||
e = a.s // ERROR "live at call to convT2Estring: a &e" "live at call to writebarrierptr: a"
|
||||
e = a.s // ERROR "live at call to convT2Estring: a &e"
|
||||
}() // ERROR "live at call to f.func1: e$"
|
||||
// Before the fix, both a and e were live at the previous line.
|
||||
_ = e
|
||||
|
||||
Loading…
Reference in New Issue
Block a user