| // Copyright 2014 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. |
| |
| package runtime |
| |
| import ( |
| "internal/abi" |
| "internal/goarch" |
| "internal/runtime/atomic" |
| "internal/runtime/sys" |
| "unsafe" |
| ) |
| |
| const itabInitSize = 512 |
| |
| var ( |
| itabLock mutex // lock for accessing itab table |
| itabTable = &itabTableInit // pointer to current table |
| itabTableInit = itabTableType{size: itabInitSize} // starter table |
| ) |
| |
| // Note: change the formula in the mallocgc call in itabAdd if you change these fields. |
| type itabTableType struct { |
| size uintptr // length of entries array. Always a power of 2. |
| count uintptr // current number of filled entries. |
| entries [itabInitSize]*itab // really [size] large |
| } |
| |
| func itabHashFunc(inter *interfacetype, typ *_type) uintptr { |
| // compiler has provided some good hash codes for us. |
| return uintptr(inter.Type.Hash ^ typ.Hash) |
| } |
| |
| // getitab should be an internal detail, |
| // but widely used packages access it using linkname. |
| // Notable members of the hall of shame include: |
| // - github.com/bytedance/sonic |
| // |
| // Do not remove or change the type signature. |
| // See go.dev/issue/67401. |
| // |
| //go:linkname getitab |
| func getitab(inter *interfacetype, typ *_type, canfail bool) *itab { |
| if len(inter.Methods) == 0 { |
| throw("internal error - misuse of itab") |
| } |
| |
| // easy case |
| if typ.TFlag&abi.TFlagUncommon == 0 { |
| if canfail { |
| return nil |
| } |
| name := toRType(&inter.Type).nameOff(inter.Methods[0].Name) |
| panic(&TypeAssertionError{nil, typ, &inter.Type, name.Name()}) |
| } |
| |
| var m *itab |
| |
| // First, look in the existing table to see if we can find the itab we need. |
| // This is by far the most common case, so do it without locks. |
| // Use atomic to ensure we see any previous writes done by the thread |
| // that updates the itabTable field (with atomic.Storep in itabAdd). |
| t := (*itabTableType)(atomic.Loadp(unsafe.Pointer(&itabTable))) |
| if m = t.find(inter, typ); m != nil { |
| goto finish |
| } |
| |
| // Not found. Grab the lock and try again. |
| lock(&itabLock) |
| if m = itabTable.find(inter, typ); m != nil { |
| unlock(&itabLock) |
| goto finish |
| } |
| |
| // Entry doesn't exist yet. Make a new entry & add it. |
| m = (*itab)(persistentalloc(unsafe.Sizeof(itab{})+uintptr(len(inter.Methods)-1)*goarch.PtrSize, 0, &memstats.other_sys)) |
| m.Inter = inter |
| m.Type = typ |
| // The hash is used in type switches. However, compiler statically generates itab's |
| // for all interface/type pairs used in switches (which are added to itabTable |
| // in itabsinit). The dynamically-generated itab's never participate in type switches, |
| // and thus the hash is irrelevant. |
| // Note: m.Hash is _not_ the hash used for the runtime itabTable hash table. |
| m.Hash = 0 |
| itabInit(m, true) |
| itabAdd(m) |
| unlock(&itabLock) |
| finish: |
| if m.Fun[0] != 0 { |
| return m |
| } |
| if canfail { |
| return nil |
| } |
| // this can only happen if the conversion |
| // was already done once using the , ok form |
| // and we have a cached negative result. |
| // The cached result doesn't record which |
| // interface function was missing, so initialize |
| // the itab again to get the missing function name. |
| panic(&TypeAssertionError{concrete: typ, asserted: &inter.Type, missingMethod: itabInit(m, false)}) |
| } |
| |
| // find finds the given interface/type pair in t. |
| // Returns nil if the given interface/type pair isn't present. |
| func (t *itabTableType) find(inter *interfacetype, typ *_type) *itab { |
| // Implemented using quadratic probing. |
| // Probe sequence is h(i) = h0 + i*(i+1)/2 mod 2^k. |
| // We're guaranteed to hit all table entries using this probe sequence. |
| mask := t.size - 1 |
| h := itabHashFunc(inter, typ) & mask |
| for i := uintptr(1); ; i++ { |
| p := (**itab)(add(unsafe.Pointer(&t.entries), h*goarch.PtrSize)) |
| // Use atomic read here so if we see m != nil, we also see |
| // the initializations of the fields of m. |
| // m := *p |
| m := (*itab)(atomic.Loadp(unsafe.Pointer(p))) |
| if m == nil { |
| return nil |
| } |
| if m.Inter == inter && m.Type == typ { |
| return m |
| } |
| h += i |
| h &= mask |
| } |
| } |
| |
| // itabAdd adds the given itab to the itab hash table. |
| // itabLock must be held. |
| func itabAdd(m *itab) { |
| // Bugs can lead to calling this while mallocing is set, |
| // typically because this is called while panicking. |
| // Crash reliably, rather than only when we need to grow |
| // the hash table. |
| if getg().m.mallocing != 0 { |
| throw("malloc deadlock") |
| } |
| |
| t := itabTable |
| if t.count >= 3*(t.size/4) { // 75% load factor |
| // Grow hash table. |
| // t2 = new(itabTableType) + some additional entries |
| // We lie and tell malloc we want pointer-free memory because |
| // all the pointed-to values are not in the heap. |
| t2 := (*itabTableType)(mallocgc((2+2*t.size)*goarch.PtrSize, nil, true)) |
| t2.size = t.size * 2 |
| |
| // Copy over entries. |
| // Note: while copying, other threads may look for an itab and |
| // fail to find it. That's ok, they will then try to get the itab lock |
| // and as a consequence wait until this copying is complete. |
| iterate_itabs(t2.add) |
| if t2.count != t.count { |
| throw("mismatched count during itab table copy") |
| } |
| // Publish new hash table. Use an atomic write: see comment in getitab. |
| atomicstorep(unsafe.Pointer(&itabTable), unsafe.Pointer(t2)) |
| // Adopt the new table as our own. |
| t = itabTable |
| // Note: the old table can be GC'ed here. |
| } |
| t.add(m) |
| } |
| |
| // add adds the given itab to itab table t. |
| // itabLock must be held. |
| func (t *itabTableType) add(m *itab) { |
| // See comment in find about the probe sequence. |
| // Insert new itab in the first empty spot in the probe sequence. |
| mask := t.size - 1 |
| h := itabHashFunc(m.Inter, m.Type) & mask |
| for i := uintptr(1); ; i++ { |
| p := (**itab)(add(unsafe.Pointer(&t.entries), h*goarch.PtrSize)) |
| m2 := *p |
| if m2 == m { |
| // A given itab may be used in more than one module |
| // and thanks to the way global symbol resolution works, the |
| // pointed-to itab may already have been inserted into the |
| // global 'hash'. |
| return |
| } |
| if m2 == nil { |
| // Use atomic write here so if a reader sees m, it also |
| // sees the correctly initialized fields of m. |
| // NoWB is ok because m is not in heap memory. |
| // *p = m |
| atomic.StorepNoWB(unsafe.Pointer(p), unsafe.Pointer(m)) |
| t.count++ |
| return |
| } |
| h += i |
| h &= mask |
| } |
| } |
| |
| // itabInit fills in the m.Fun array with all the code pointers for |
| // the m.Inter/m.Type pair. If the type does not implement the interface, |
| // it sets m.Fun[0] to 0 and returns the name of an interface function that is missing. |
| // If !firstTime, itabInit will not write anything to m.Fun (see issue 65962). |
| // It is ok to call this multiple times on the same m, even concurrently |
| // (although it will only be called once with firstTime==true). |
| func itabInit(m *itab, firstTime bool) string { |
| inter := m.Inter |
| typ := m.Type |
| x := typ.Uncommon() |
| |
| // both inter and typ have method sorted by name, |
| // and interface names are unique, |
| // so can iterate over both in lock step; |
| // the loop is O(ni+nt) not O(ni*nt). |
| ni := len(inter.Methods) |
| nt := int(x.Mcount) |
| xmhdr := (*[1 << 16]abi.Method)(add(unsafe.Pointer(x), uintptr(x.Moff)))[:nt:nt] |
| j := 0 |
| methods := (*[1 << 16]unsafe.Pointer)(unsafe.Pointer(&m.Fun[0]))[:ni:ni] |
| var fun0 unsafe.Pointer |
| imethods: |
| for k := 0; k < ni; k++ { |
| i := &inter.Methods[k] |
| itype := toRType(&inter.Type).typeOff(i.Typ) |
| name := toRType(&inter.Type).nameOff(i.Name) |
| iname := name.Name() |
| ipkg := pkgPath(name) |
| if ipkg == "" { |
| ipkg = inter.PkgPath.Name() |
| } |
| for ; j < nt; j++ { |
| t := &xmhdr[j] |
| rtyp := toRType(typ) |
| tname := rtyp.nameOff(t.Name) |
| if rtyp.typeOff(t.Mtyp) == itype && tname.Name() == iname { |
| pkgPath := pkgPath(tname) |
| if pkgPath == "" { |
| pkgPath = rtyp.nameOff(x.PkgPath).Name() |
| } |
| if tname.IsExported() || pkgPath == ipkg { |
| ifn := rtyp.textOff(t.Ifn) |
| if k == 0 { |
| fun0 = ifn // we'll set m.Fun[0] at the end |
| } else if firstTime { |
| methods[k] = ifn |
| } |
| continue imethods |
| } |
| } |
| } |
| // didn't find method |
| // Leaves m.Fun[0] set to 0. |
| return iname |
| } |
| if firstTime { |
| m.Fun[0] = uintptr(fun0) |
| } |
| return "" |
| } |
| |
| func itabsinit() { |
| lockInit(&itabLock, lockRankItab) |
| lock(&itabLock) |
| for _, md := range activeModules() { |
| for _, i := range md.itablinks { |
| itabAdd(i) |
| } |
| } |
| unlock(&itabLock) |
| } |
| |
| // panicdottypeE is called when doing an e.(T) conversion and the conversion fails. |
| // have = the dynamic type we have. |
| // want = the static type we're trying to convert to. |
| // iface = the static type we're converting from. |
| func panicdottypeE(have, want, iface *_type) { |
| panic(&TypeAssertionError{iface, have, want, ""}) |
| } |
| |
| // panicdottypeI is called when doing an i.(T) conversion and the conversion fails. |
| // Same args as panicdottypeE, but "have" is the dynamic itab we have. |
| func panicdottypeI(have *itab, want, iface *_type) { |
| var t *_type |
| if have != nil { |
| t = have.Type |
| } |
| panicdottypeE(t, want, iface) |
| } |
| |
| // panicnildottype is called when doing an i.(T) conversion and the interface i is nil. |
| // want = the static type we're trying to convert to. |
| func panicnildottype(want *_type) { |
| panic(&TypeAssertionError{nil, nil, want, ""}) |
| // TODO: Add the static type we're converting from as well. |
| // It might generate a better error message. |
| // Just to match other nil conversion errors, we don't for now. |
| } |
| |
| // The specialized convTx routines need a type descriptor to use when calling mallocgc. |
| // We don't need the type to be exact, just to have the correct size, alignment, and pointer-ness. |
| // However, when debugging, it'd be nice to have some indication in mallocgc where the types came from, |
| // so we use named types here. |
| // We then construct interface values of these types, |
| // and then extract the type word to use as needed. |
| type ( |
| uint16InterfacePtr uint16 |
| uint32InterfacePtr uint32 |
| uint64InterfacePtr uint64 |
| stringInterfacePtr string |
| sliceInterfacePtr []byte |
| ) |
| |
| var ( |
| uint16Eface any = uint16InterfacePtr(0) |
| uint32Eface any = uint32InterfacePtr(0) |
| uint64Eface any = uint64InterfacePtr(0) |
| stringEface any = stringInterfacePtr("") |
| sliceEface any = sliceInterfacePtr(nil) |
| |
| uint16Type *_type = efaceOf(&uint16Eface)._type |
| uint32Type *_type = efaceOf(&uint32Eface)._type |
| uint64Type *_type = efaceOf(&uint64Eface)._type |
| stringType *_type = efaceOf(&stringEface)._type |
| sliceType *_type = efaceOf(&sliceEface)._type |
| ) |
| |
| // The conv and assert functions below do very similar things. |
| // The convXXX functions are guaranteed by the compiler to succeed. |
| // The assertXXX functions may fail (either panicking or returning false, |
| // depending on whether they are 1-result or 2-result). |
| // The convXXX functions succeed on a nil input, whereas the assertXXX |
| // functions fail on a nil input. |
| |
| // convT converts a value of type t, which is pointed to by v, to a pointer that can |
| // be used as the second word of an interface value. |
| func convT(t *_type, v unsafe.Pointer) unsafe.Pointer { |
| if raceenabled { |
| raceReadObjectPC(t, v, getcallerpc(), abi.FuncPCABIInternal(convT)) |
| } |
| if msanenabled { |
| msanread(v, t.Size_) |
| } |
| if asanenabled { |
| asanread(v, t.Size_) |
| } |
| x := mallocgc(t.Size_, t, true) |
| typedmemmove(t, x, v) |
| return x |
| } |
| func convTnoptr(t *_type, v unsafe.Pointer) unsafe.Pointer { |
| // TODO: maybe take size instead of type? |
| if raceenabled { |
| raceReadObjectPC(t, v, getcallerpc(), abi.FuncPCABIInternal(convTnoptr)) |
| } |
| if msanenabled { |
| msanread(v, t.Size_) |
| } |
| if asanenabled { |
| asanread(v, t.Size_) |
| } |
| |
| x := mallocgc(t.Size_, t, false) |
| memmove(x, v, t.Size_) |
| return x |
| } |
| |
| func convT16(val uint16) (x unsafe.Pointer) { |
| if val < uint16(len(staticuint64s)) { |
| x = unsafe.Pointer(&staticuint64s[val]) |
| if goarch.BigEndian { |
| x = add(x, 6) |
| } |
| } else { |
| x = mallocgc(2, uint16Type, false) |
| *(*uint16)(x) = val |
| } |
| return |
| } |
| |
| func convT32(val uint32) (x unsafe.Pointer) { |
| if val < uint32(len(staticuint64s)) { |
| x = unsafe.Pointer(&staticuint64s[val]) |
| if goarch.BigEndian { |
| x = add(x, 4) |
| } |
| } else { |
| x = mallocgc(4, uint32Type, false) |
| *(*uint32)(x) = val |
| } |
| return |
| } |
| |
| // convT64 should be an internal detail, |
| // but widely used packages access it using linkname. |
| // Notable members of the hall of shame include: |
| // - github.com/bytedance/sonic |
| // |
| // Do not remove or change the type signature. |
| // See go.dev/issue/67401. |
| // |
| //go:linkname convT64 |
| func convT64(val uint64) (x unsafe.Pointer) { |
| if val < uint64(len(staticuint64s)) { |
| x = unsafe.Pointer(&staticuint64s[val]) |
| } else { |
| x = mallocgc(8, uint64Type, false) |
| *(*uint64)(x) = val |
| } |
| return |
| } |
| |
| // convTstring should be an internal detail, |
| // but widely used packages access it using linkname. |
| // Notable members of the hall of shame include: |
| // - github.com/bytedance/sonic |
| // |
| // Do not remove or change the type signature. |
| // See go.dev/issue/67401. |
| // |
| //go:linkname convTstring |
| func convTstring(val string) (x unsafe.Pointer) { |
| if val == "" { |
| x = unsafe.Pointer(&zeroVal[0]) |
| } else { |
| x = mallocgc(unsafe.Sizeof(val), stringType, true) |
| *(*string)(x) = val |
| } |
| return |
| } |
| |
| // convTslice should be an internal detail, |
| // but widely used packages access it using linkname. |
| // Notable members of the hall of shame include: |
| // - github.com/bytedance/sonic |
| // |
| // Do not remove or change the type signature. |
| // See go.dev/issue/67401. |
| // |
| //go:linkname convTslice |
| func convTslice(val []byte) (x unsafe.Pointer) { |
| // Note: this must work for any element type, not just byte. |
| if (*slice)(unsafe.Pointer(&val)).array == nil { |
| x = unsafe.Pointer(&zeroVal[0]) |
| } else { |
| x = mallocgc(unsafe.Sizeof(val), sliceType, true) |
| *(*[]byte)(x) = val |
| } |
| return |
| } |
| |
| func assertE2I(inter *interfacetype, t *_type) *itab { |
| if t == nil { |
| // explicit conversions require non-nil interface value. |
| panic(&TypeAssertionError{nil, nil, &inter.Type, ""}) |
| } |
| return getitab(inter, t, false) |
| } |
| |
| func assertE2I2(inter *interfacetype, t *_type) *itab { |
| if t == nil { |
| return nil |
| } |
| return getitab(inter, t, true) |
| } |
| |
| // typeAssert builds an itab for the concrete type t and the |
| // interface type s.Inter. If the conversion is not possible it |
| // panics if s.CanFail is false and returns nil if s.CanFail is true. |
| func typeAssert(s *abi.TypeAssert, t *_type) *itab { |
| var tab *itab |
| if t == nil { |
| if !s.CanFail { |
| panic(&TypeAssertionError{nil, nil, &s.Inter.Type, ""}) |
| } |
| } else { |
| tab = getitab(s.Inter, t, s.CanFail) |
| } |
| |
| if !abi.UseInterfaceSwitchCache(GOARCH) { |
| return tab |
| } |
| |
| // Maybe update the cache, so the next time the generated code |
| // doesn't need to call into the runtime. |
| if cheaprand()&1023 != 0 { |
| // Only bother updating the cache ~1 in 1000 times. |
| return tab |
| } |
| // Load the current cache. |
| oldC := (*abi.TypeAssertCache)(atomic.Loadp(unsafe.Pointer(&s.Cache))) |
| |
| if cheaprand()&uint32(oldC.Mask) != 0 { |
| // As cache gets larger, choose to update it less often |
| // so we can amortize the cost of building a new cache. |
| return tab |
| } |
| |
| // Make a new cache. |
| newC := buildTypeAssertCache(oldC, t, tab) |
| |
| // Update cache. Use compare-and-swap so if multiple threads |
| // are fighting to update the cache, at least one of their |
| // updates will stick. |
| atomic_casPointer((*unsafe.Pointer)(unsafe.Pointer(&s.Cache)), unsafe.Pointer(oldC), unsafe.Pointer(newC)) |
| |
| return tab |
| } |
| |
| func buildTypeAssertCache(oldC *abi.TypeAssertCache, typ *_type, tab *itab) *abi.TypeAssertCache { |
| oldEntries := unsafe.Slice(&oldC.Entries[0], oldC.Mask+1) |
| |
| // Count the number of entries we need. |
| n := 1 |
| for _, e := range oldEntries { |
| if e.Typ != 0 { |
| n++ |
| } |
| } |
| |
| // Figure out how big a table we need. |
| // We need at least one more slot than the number of entries |
| // so that we are guaranteed an empty slot (for termination). |
| newN := n * 2 // make it at most 50% full |
| newN = 1 << sys.Len64(uint64(newN-1)) // round up to a power of 2 |
| |
| // Allocate the new table. |
| newSize := unsafe.Sizeof(abi.TypeAssertCache{}) + uintptr(newN-1)*unsafe.Sizeof(abi.TypeAssertCacheEntry{}) |
| newC := (*abi.TypeAssertCache)(mallocgc(newSize, nil, true)) |
| newC.Mask = uintptr(newN - 1) |
| newEntries := unsafe.Slice(&newC.Entries[0], newN) |
| |
| // Fill the new table. |
| addEntry := func(typ *_type, tab *itab) { |
| h := int(typ.Hash) & (newN - 1) |
| for { |
| if newEntries[h].Typ == 0 { |
| newEntries[h].Typ = uintptr(unsafe.Pointer(typ)) |
| newEntries[h].Itab = uintptr(unsafe.Pointer(tab)) |
| return |
| } |
| h = (h + 1) & (newN - 1) |
| } |
| } |
| for _, e := range oldEntries { |
| if e.Typ != 0 { |
| addEntry((*_type)(unsafe.Pointer(e.Typ)), (*itab)(unsafe.Pointer(e.Itab))) |
| } |
| } |
| addEntry(typ, tab) |
| |
| return newC |
| } |
| |
| // Empty type assert cache. Contains one entry with a nil Typ (which |
| // causes a cache lookup to fail immediately.) |
| var emptyTypeAssertCache = abi.TypeAssertCache{Mask: 0} |
| |
| // interfaceSwitch compares t against the list of cases in s. |
| // If t matches case i, interfaceSwitch returns the case index i and |
| // an itab for the pair <t, s.Cases[i]>. |
| // If there is no match, return N,nil, where N is the number |
| // of cases. |
| func interfaceSwitch(s *abi.InterfaceSwitch, t *_type) (int, *itab) { |
| cases := unsafe.Slice(&s.Cases[0], s.NCases) |
| |
| // Results if we don't find a match. |
| case_ := len(cases) |
| var tab *itab |
| |
| // Look through each case in order. |
| for i, c := range cases { |
| tab = getitab(c, t, true) |
| if tab != nil { |
| case_ = i |
| break |
| } |
| } |
| |
| if !abi.UseInterfaceSwitchCache(GOARCH) { |
| return case_, tab |
| } |
| |
| // Maybe update the cache, so the next time the generated code |
| // doesn't need to call into the runtime. |
| if cheaprand()&1023 != 0 { |
| // Only bother updating the cache ~1 in 1000 times. |
| // This ensures we don't waste memory on switches, or |
| // switch arguments, that only happen a few times. |
| return case_, tab |
| } |
| // Load the current cache. |
| oldC := (*abi.InterfaceSwitchCache)(atomic.Loadp(unsafe.Pointer(&s.Cache))) |
| |
| if cheaprand()&uint32(oldC.Mask) != 0 { |
| // As cache gets larger, choose to update it less often |
| // so we can amortize the cost of building a new cache |
| // (that cost is linear in oldc.Mask). |
| return case_, tab |
| } |
| |
| // Make a new cache. |
| newC := buildInterfaceSwitchCache(oldC, t, case_, tab) |
| |
| // Update cache. Use compare-and-swap so if multiple threads |
| // are fighting to update the cache, at least one of their |
| // updates will stick. |
| atomic_casPointer((*unsafe.Pointer)(unsafe.Pointer(&s.Cache)), unsafe.Pointer(oldC), unsafe.Pointer(newC)) |
| |
| return case_, tab |
| } |
| |
| // buildInterfaceSwitchCache constructs an interface switch cache |
| // containing all the entries from oldC plus the new entry |
| // (typ,case_,tab). |
| func buildInterfaceSwitchCache(oldC *abi.InterfaceSwitchCache, typ *_type, case_ int, tab *itab) *abi.InterfaceSwitchCache { |
| oldEntries := unsafe.Slice(&oldC.Entries[0], oldC.Mask+1) |
| |
| // Count the number of entries we need. |
| n := 1 |
| for _, e := range oldEntries { |
| if e.Typ != 0 { |
| n++ |
| } |
| } |
| |
| // Figure out how big a table we need. |
| // We need at least one more slot than the number of entries |
| // so that we are guaranteed an empty slot (for termination). |
| newN := n * 2 // make it at most 50% full |
| newN = 1 << sys.Len64(uint64(newN-1)) // round up to a power of 2 |
| |
| // Allocate the new table. |
| newSize := unsafe.Sizeof(abi.InterfaceSwitchCache{}) + uintptr(newN-1)*unsafe.Sizeof(abi.InterfaceSwitchCacheEntry{}) |
| newC := (*abi.InterfaceSwitchCache)(mallocgc(newSize, nil, true)) |
| newC.Mask = uintptr(newN - 1) |
| newEntries := unsafe.Slice(&newC.Entries[0], newN) |
| |
| // Fill the new table. |
| addEntry := func(typ *_type, case_ int, tab *itab) { |
| h := int(typ.Hash) & (newN - 1) |
| for { |
| if newEntries[h].Typ == 0 { |
| newEntries[h].Typ = uintptr(unsafe.Pointer(typ)) |
| newEntries[h].Case = case_ |
| newEntries[h].Itab = uintptr(unsafe.Pointer(tab)) |
| return |
| } |
| h = (h + 1) & (newN - 1) |
| } |
| } |
| for _, e := range oldEntries { |
| if e.Typ != 0 { |
| addEntry((*_type)(unsafe.Pointer(e.Typ)), e.Case, (*itab)(unsafe.Pointer(e.Itab))) |
| } |
| } |
| addEntry(typ, case_, tab) |
| |
| return newC |
| } |
| |
| // Empty interface switch cache. Contains one entry with a nil Typ (which |
| // causes a cache lookup to fail immediately.) |
| var emptyInterfaceSwitchCache = abi.InterfaceSwitchCache{Mask: 0} |
| |
| // reflect_ifaceE2I is for package reflect, |
| // but widely used packages access it using linkname. |
| // Notable members of the hall of shame include: |
| // - gitee.com/quant1x/gox |
| // - github.com/modern-go/reflect2 |
| // - github.com/v2pro/plz |
| // |
| // Do not remove or change the type signature. |
| // |
| //go:linkname reflect_ifaceE2I reflect.ifaceE2I |
| func reflect_ifaceE2I(inter *interfacetype, e eface, dst *iface) { |
| *dst = iface{assertE2I(inter, e._type), e.data} |
| } |
| |
| //go:linkname reflectlite_ifaceE2I internal/reflectlite.ifaceE2I |
| func reflectlite_ifaceE2I(inter *interfacetype, e eface, dst *iface) { |
| *dst = iface{assertE2I(inter, e._type), e.data} |
| } |
| |
| func iterate_itabs(fn func(*itab)) { |
| // Note: only runs during stop the world or with itabLock held, |
| // so no other locks/atomics needed. |
| t := itabTable |
| for i := uintptr(0); i < t.size; i++ { |
| m := *(**itab)(add(unsafe.Pointer(&t.entries), i*goarch.PtrSize)) |
| if m != nil { |
| fn(m) |
| } |
| } |
| } |
| |
| // staticuint64s is used to avoid allocating in convTx for small integer values. |
| var staticuint64s = [...]uint64{ |
| 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, |
| 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, |
| 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, |
| 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, |
| 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, |
| 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, |
| 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, |
| 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, |
| 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, |
| 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, |
| 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, |
| 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, |
| 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, |
| 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, |
| 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, |
| 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, |
| 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, |
| 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, |
| 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, |
| 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, |
| 0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, |
| 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, |
| 0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, |
| 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, |
| 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, |
| 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf, |
| 0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, |
| 0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf, |
| 0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, |
| 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, |
| 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, |
| 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff, |
| } |
| |
| // The linker redirects a reference of a method that it determined |
| // unreachable to a reference to this function, so it will throw if |
| // ever called. |
| func unreachableMethod() { |
| throw("unreachable method called. linker bug?") |
| } |