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-rw-r--r--src/pkg/runtime/iface.goc620
1 files changed, 620 insertions, 0 deletions
diff --git a/src/pkg/runtime/iface.goc b/src/pkg/runtime/iface.goc
new file mode 100644
index 000000000..c0a17e303
--- /dev/null
+++ b/src/pkg/runtime/iface.goc
@@ -0,0 +1,620 @@
+// Copyright 2009 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
+#include "runtime.h"
+#include "arch_GOARCH.h"
+#include "type.h"
+#include "typekind.h"
+#include "malloc.h"
+#include "../../cmd/ld/textflag.h"
+
+func printiface(i Iface) {
+ runtime·printf("(%p,%p)", i.tab, i.data);
+}
+
+func printeface(e Eface) {
+ runtime·printf("(%p,%p)", e.type, e.data);
+}
+
+static Itab* hash[1009];
+static Lock ifacelock;
+
+static Itab*
+itab(InterfaceType *inter, Type *type, int32 canfail)
+{
+ int32 locked;
+ int32 ni;
+ Method *t, *et;
+ IMethod *i, *ei;
+ uint32 h;
+ String *iname, *ipkgPath;
+ Itab *m;
+ UncommonType *x;
+ Type *itype;
+ Eface err;
+
+ if(inter->mhdr.len == 0)
+ runtime·throw("internal error - misuse of itab");
+
+ locked = 0;
+
+ // easy case
+ x = type->x;
+ if(x == nil) {
+ if(canfail)
+ return nil;
+ iname = inter->m[0].name;
+ goto throw;
+ }
+
+ // compiler has provided some good hash codes for us.
+ h = inter->hash;
+ h += 17 * type->hash;
+ // TODO(rsc): h += 23 * x->mhash ?
+ h %= nelem(hash);
+
+ // look twice - once without lock, once with.
+ // common case will be no lock contention.
+ for(locked=0; locked<2; locked++) {
+ if(locked)
+ runtime·lock(&ifacelock);
+ for(m=runtime·atomicloadp(&hash[h]); m!=nil; m=m->link) {
+ if(m->inter == inter && m->type == type) {
+ if(m->bad) {
+ m = nil;
+ if(!canfail) {
+ // 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 jump
+ // down to the interface check, which will
+ // do more work but give a better error.
+ goto search;
+ }
+ }
+ if(locked)
+ runtime·unlock(&ifacelock);
+ return m;
+ }
+ }
+ }
+
+ ni = inter->mhdr.len;
+ m = runtime·persistentalloc(sizeof(*m) + ni*sizeof m->fun[0], 0, &mstats.other_sys);
+ m->inter = inter;
+ m->type = type;
+
+search:
+ // both inter and type 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).
+ i = inter->m;
+ ei = i + inter->mhdr.len;
+ t = x->m;
+ et = t + x->mhdr.len;
+ for(; i < ei; i++) {
+ itype = i->type;
+ iname = i->name;
+ ipkgPath = i->pkgPath;
+ for(;; t++) {
+ if(t >= et) {
+ if(!canfail) {
+ throw:
+ // didn't find method
+ runtime·newTypeAssertionError(
+ nil, type->string, inter->string,
+ iname, &err);
+ if(locked)
+ runtime·unlock(&ifacelock);
+ runtime·panic(err);
+ return nil; // not reached
+ }
+ m->bad = 1;
+ goto out;
+ }
+ if(t->mtyp == itype && t->name == iname && t->pkgPath == ipkgPath)
+ break;
+ }
+ if(m)
+ m->fun[i - inter->m] = t->ifn;
+ }
+
+out:
+ if(!locked)
+ runtime·panicstring("invalid itab locking");
+ m->link = hash[h];
+ runtime·atomicstorep(&hash[h], m);
+ runtime·unlock(&ifacelock);
+ if(m->bad)
+ return nil;
+ return m;
+}
+
+// call the callback for every itab that is currently allocated.
+void
+runtime·iterate_itabs(void (*callback)(Itab*))
+{
+ int32 i;
+ Itab *tab;
+
+ for(i = 0; i < nelem(hash); i++) {
+ for(tab = hash[i]; tab != nil; tab = tab->link) {
+ callback(tab);
+ }
+ }
+}
+
+static void
+copyin(Type *t, void *src, void **dst)
+{
+ uintptr size;
+ void *p;
+ Alg *alg;
+
+ size = t->size;
+ alg = t->alg;
+
+ if(size <= sizeof(*dst))
+ alg->copy(size, dst, src);
+ else {
+ p = runtime·cnew(t);
+ alg->copy(size, p, src);
+ *dst = p;
+ }
+}
+
+static void
+copyout(Type *t, void **src, void *dst)
+{
+ uintptr size;
+ Alg *alg;
+
+ size = t->size;
+ alg = t->alg;
+
+ if(size <= sizeof(*src))
+ alg->copy(size, dst, src);
+ else
+ alg->copy(size, dst, *src);
+}
+
+#pragma textflag NOSPLIT
+func typ2Itab(t *Type, inter *InterfaceType, cache **Itab) (tab *Itab) {
+ tab = itab(inter, t, 0);
+ runtime·atomicstorep(cache, tab);
+}
+
+#pragma textflag NOSPLIT
+func convT2I(t *Type, inter *InterfaceType, cache **Itab, elem *byte) (ret Iface) {
+ Itab *tab;
+
+ tab = runtime·atomicloadp(cache);
+ if(!tab) {
+ tab = itab(inter, t, 0);
+ runtime·atomicstorep(cache, tab);
+ }
+ ret.tab = tab;
+ copyin(t, elem, &ret.data);
+}
+
+#pragma textflag NOSPLIT
+func convT2E(t *Type, elem *byte) (ret Eface) {
+ ret.type = t;
+ copyin(t, elem, &ret.data);
+}
+
+static void assertI2Tret(Type *t, Iface i, byte *ret);
+
+/*
+ * NOTE: Cannot use 'func' here, because we have to declare
+ * a return value, the only types we have are at least 1 byte large,
+ * goc2c will zero the return value, and the actual return value
+ * might have size 0 bytes, in which case the zeroing of the
+ * 1 or more bytes would be wrong.
+ * Using C lets us control (avoid) the initial zeroing.
+ */
+#pragma textflag NOSPLIT
+void
+runtime·assertI2T(Type *t, Iface i, GoOutput retbase)
+{
+ assertI2Tret(t, i, (byte*)&retbase);
+}
+
+static void
+assertI2Tret(Type *t, Iface i, byte *ret)
+{
+ Itab *tab;
+ Eface err;
+
+ tab = i.tab;
+ if(tab == nil) {
+ runtime·newTypeAssertionError(
+ nil, nil, t->string,
+ nil, &err);
+ runtime·panic(err);
+ }
+ if(tab->type != t) {
+ runtime·newTypeAssertionError(
+ tab->inter->string, tab->type->string, t->string,
+ nil, &err);
+ runtime·panic(err);
+ }
+ copyout(t, &i.data, ret);
+}
+
+#pragma textflag NOSPLIT
+func assertI2T2(t *Type, i Iface) (ret byte, ...) {
+ bool *ok;
+ int32 wid;
+
+ wid = t->size;
+ ok = (bool*)(&ret + wid);
+
+ if(i.tab == nil || i.tab->type != t) {
+ *ok = false;
+ runtime·memclr(&ret, wid);
+ return;
+ }
+
+ *ok = true;
+ copyout(t, &i.data, &ret);
+}
+
+func assertI2TOK(t *Type, i Iface) (ok bool) {
+ ok = i.tab!=nil && i.tab->type==t;
+}
+
+static void assertE2Tret(Type *t, Eface e, byte *ret);
+
+/*
+ * NOTE: Cannot use 'func' here. See assertI2T above.
+ */
+#pragma textflag NOSPLIT
+void
+runtime·assertE2T(Type *t, Eface e, GoOutput retbase)
+{
+ assertE2Tret(t, e, (byte*)&retbase);
+}
+
+static void
+assertE2Tret(Type *t, Eface e, byte *ret)
+{
+ Eface err;
+
+ if(e.type == nil) {
+ runtime·newTypeAssertionError(
+ nil, nil, t->string,
+ nil, &err);
+ runtime·panic(err);
+ }
+ if(e.type != t) {
+ runtime·newTypeAssertionError(
+ nil, e.type->string, t->string,
+ nil, &err);
+ runtime·panic(err);
+ }
+ copyout(t, &e.data, ret);
+}
+
+#pragma textflag NOSPLIT
+func assertE2T2(t *Type, e Eface) (ret byte, ...) {
+ bool *ok;
+ int32 wid;
+
+ wid = t->size;
+ ok = (bool*)(&ret + wid);
+
+ if(t != e.type) {
+ *ok = false;
+ runtime·memclr(&ret, wid);
+ return;
+ }
+
+ *ok = true;
+ copyout(t, &e.data, &ret);
+}
+
+func assertE2TOK(t *Type, e Eface) (ok bool) {
+ ok = t==e.type;
+}
+
+func convI2E(i Iface) (ret Eface) {
+ Itab *tab;
+
+ ret.data = i.data;
+ if((tab = i.tab) == nil)
+ ret.type = nil;
+ else
+ ret.type = tab->type;
+}
+
+func assertI2E(inter *InterfaceType, i Iface) (ret Eface) {
+ Itab *tab;
+ Eface err;
+
+ tab = i.tab;
+ if(tab == nil) {
+ // explicit conversions require non-nil interface value.
+ runtime·newTypeAssertionError(
+ nil, nil, inter->string,
+ nil, &err);
+ runtime·panic(err);
+ }
+ ret.data = i.data;
+ ret.type = tab->type;
+}
+
+func assertI2E2(inter *InterfaceType, i Iface) (ret Eface, ok bool) {
+ Itab *tab;
+
+ USED(inter);
+ tab = i.tab;
+ if(tab == nil) {
+ ret.type = nil;
+ ok = 0;
+ } else {
+ ret.type = tab->type;
+ ok = 1;
+ }
+ ret.data = i.data;
+}
+
+func convI2I(inter *InterfaceType, i Iface) (ret Iface) {
+ Itab *tab;
+
+ ret.data = i.data;
+ if((tab = i.tab) == nil)
+ ret.tab = nil;
+ else if(tab->inter == inter)
+ ret.tab = tab;
+ else
+ ret.tab = itab(inter, tab->type, 0);
+}
+
+void
+runtime·ifaceI2I(InterfaceType *inter, Iface i, Iface *ret)
+{
+ Itab *tab;
+ Eface err;
+
+ tab = i.tab;
+ if(tab == nil) {
+ // explicit conversions require non-nil interface value.
+ runtime·newTypeAssertionError(
+ nil, nil, inter->string,
+ nil, &err);
+ runtime·panic(err);
+ }
+ ret->data = i.data;
+ ret->tab = itab(inter, tab->type, 0);
+}
+
+func assertI2I(inter *InterfaceType, i Iface) (ret Iface) {
+ runtime·ifaceI2I(inter, i, &ret);
+}
+
+func assertI2I2(inter *InterfaceType, i Iface) (ret Iface, ok bool) {
+ Itab *tab;
+
+ tab = i.tab;
+ if(tab != nil && (tab->inter == inter || (tab = itab(inter, tab->type, 1)) != nil)) {
+ ret.data = i.data;
+ ret.tab = tab;
+ ok = 1;
+ } else {
+ ret.data = 0;
+ ret.tab = 0;
+ ok = 0;
+ }
+}
+
+void
+runtime·ifaceE2I(InterfaceType *inter, Eface e, Iface *ret)
+{
+ Type *t;
+ Eface err;
+
+ t = e.type;
+ if(t == nil) {
+ // explicit conversions require non-nil interface value.
+ runtime·newTypeAssertionError(
+ nil, nil, inter->string,
+ nil, &err);
+ runtime·panic(err);
+ }
+ ret->data = e.data;
+ ret->tab = itab(inter, t, 0);
+}
+
+bool
+runtime·ifaceE2I2(InterfaceType *inter, Eface e, Iface *ret)
+{
+ ret->tab = itab(inter, e.type, 1);
+ if(ret->tab == nil)
+ return false;
+ ret->data = e.data;
+ return true;
+}
+
+func reflect·ifaceE2I(inter *InterfaceType, e Eface, dst *Iface) {
+ runtime·ifaceE2I(inter, e, dst);
+}
+
+func assertE2I(inter *InterfaceType, e Eface) (ret Iface) {
+ runtime·ifaceE2I(inter, e, &ret);
+}
+
+func assertE2I2(inter *InterfaceType, e Eface) (ret Iface, ok bool) {
+ if(e.type == nil) {
+ ok = 0;
+ ret.data = nil;
+ ret.tab = nil;
+ } else if((ret.tab = itab(inter, e.type, 1)) == nil) {
+ ok = 0;
+ ret.data = nil;
+ } else {
+ ok = 1;
+ ret.data = e.data;
+ }
+}
+
+func assertE2E(inter *InterfaceType, e Eface) (ret Eface) {
+ Type *t;
+ Eface err;
+
+ t = e.type;
+ if(t == nil) {
+ // explicit conversions require non-nil interface value.
+ runtime·newTypeAssertionError(
+ nil, nil, inter->string,
+ nil, &err);
+ runtime·panic(err);
+ }
+ ret = e;
+}
+
+func assertE2E2(inter *InterfaceType, e Eface) (ret Eface, ok bool) {
+ USED(inter);
+ ret = e;
+ ok = e.type != nil;
+}
+
+static uintptr
+ifacehash1(void *data, Type *t, uintptr h)
+{
+ Alg *alg;
+ uintptr size;
+ Eface err;
+
+ if(t == nil)
+ return 0;
+
+ alg = t->alg;
+ size = t->size;
+ if(alg->hash == runtime·nohash) {
+ // calling nohash will panic too,
+ // but we can print a better error.
+ runtime·newErrorString(runtime·catstring(runtime·gostringnocopy((byte*)"hash of unhashable type "), *t->string), &err);
+ runtime·panic(err);
+ }
+ if(size <= sizeof(data))
+ alg->hash(&h, size, &data);
+ else
+ alg->hash(&h, size, data);
+ return h;
+}
+
+uintptr
+runtime·ifacehash(Iface a, uintptr h)
+{
+ if(a.tab == nil)
+ return h;
+ return ifacehash1(a.data, a.tab->type, h);
+}
+
+uintptr
+runtime·efacehash(Eface a, uintptr h)
+{
+ return ifacehash1(a.data, a.type, h);
+}
+
+static bool
+ifaceeq1(void *data1, void *data2, Type *t)
+{
+ uintptr size;
+ Alg *alg;
+ Eface err;
+ bool eq;
+
+ alg = t->alg;
+ size = t->size;
+
+ if(alg->equal == runtime·noequal) {
+ // calling noequal will panic too,
+ // but we can print a better error.
+ runtime·newErrorString(runtime·catstring(runtime·gostringnocopy((byte*)"comparing uncomparable type "), *t->string), &err);
+ runtime·panic(err);
+ }
+
+ eq = 0;
+ if(size <= sizeof(data1))
+ alg->equal(&eq, size, &data1, &data2);
+ else
+ alg->equal(&eq, size, data1, data2);
+ return eq;
+}
+
+bool
+runtime·ifaceeq_c(Iface i1, Iface i2)
+{
+ if(i1.tab != i2.tab)
+ return false;
+ if(i1.tab == nil)
+ return true;
+ return ifaceeq1(i1.data, i2.data, i1.tab->type);
+}
+
+bool
+runtime·efaceeq_c(Eface e1, Eface e2)
+{
+ if(e1.type != e2.type)
+ return false;
+ if(e1.type == nil)
+ return true;
+ return ifaceeq1(e1.data, e2.data, e1.type);
+}
+
+func ifaceeq(i1 Iface, i2 Iface) (ret bool) {
+ ret = runtime·ifaceeq_c(i1, i2);
+}
+
+func efaceeq(e1 Eface, e2 Eface) (ret bool) {
+ ret = runtime·efaceeq_c(e1, e2);
+}
+
+func ifacethash(i1 Iface) (ret uint32) {
+ Itab *tab;
+
+ ret = 0;
+ tab = i1.tab;
+ if(tab != nil)
+ ret = tab->type->hash;
+}
+
+func efacethash(e1 Eface) (ret uint32) {
+ Type *t;
+
+ ret = 0;
+ t = e1.type;
+ if(t != nil)
+ ret = t->hash;
+}
+
+func reflect·unsafe_Typeof(e Eface) (ret Eface) {
+ if(e.type == nil) {
+ ret.type = nil;
+ ret.data = nil;
+ } else {
+ ret = *(Eface*)(e.type);
+ }
+}
+
+func reflect·unsafe_New(t *Type) (ret *byte) {
+ ret = runtime·cnew(t);
+}
+
+func reflect·unsafe_NewArray(t *Type, n int) (ret *byte) {
+ ret = runtime·cnewarray(t, n);
+}
+
+func reflect·typelinks() (ret Slice) {
+ extern Type *typelink[], *etypelink[];
+ static int32 first = 1;
+ ret.array = (byte*)typelink;
+ ret.len = etypelink - typelink;
+ ret.cap = ret.len;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2025-04-29 05:20:50 +0000