Reviewers: Michael Starzinger,
Description:
Do not allow external strings in old pointer space.
[email protected]
BUG=
Please review this at https://codereview.chromium.org/20723002/
SVN Base: https://v8.googlecode.com/svn/branches/bleeding_edge
Affected files:
M src/api.cc
M test/cctest/test-api.cc
Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index
5978ed270e34d51d8a5de093310ba023d0810a55..3f5a0793b21a5e53d68070494f18e28d79c57cf2
100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -5930,6 +5930,23 @@ i::Handle<i::String>
NewExternalAsciiStringHandle(i::Isolate* isolate,
}
+bool RedirectToExternalString(i::Isolate* isolate,
+ i::Handle<i::String> parent,
+ i::Handle<i::String> external) {
+ if (parent->IsConsString()) {
+ i::Handle<i::ConsString> cons = i::Handle<i::ConsString>::cast(parent);
+ cons->set_first(*external);
+ cons->set_second(isolate->heap()->empty_string());
+ } else {
+ ASSERT(parent->IsSlicedString());
+ i::Handle<i::SlicedString> slice =
i::Handle<i::SlicedString>::cast(parent);
+ slice->set_parent(*external);
+ slice->set_offset(0);
+ }
+ return true;
+}
+
+
Local<String> v8::String::NewExternal(
v8::String::ExternalStringResource* resource) {
i::Isolate* isolate = i::Isolate::Current();
@@ -5958,9 +5975,23 @@ bool
v8::String::MakeExternal(v8::String::ExternalStringResource* resource) {
return false;
}
CHECK(resource && resource->data());
- bool result = obj->MakeExternal(resource);
- if (result && !obj->IsInternalizedString()) {
- isolate->heap()->external_string_table()->AddString(*obj);
+
+ bool result;
+ i::Handle<i::String> external;
+ if (isolate->heap()->old_pointer_space()->Contains(*obj)) {
+ // We do not allow external strings in the old pointer space. Instead
of
+ // converting the string in-place, we keep the cons/sliced string and
+ // point it to a newly-allocated external string.
+ external = NewExternalStringHandle(isolate, resource);
+ result = RedirectToExternalString(isolate, obj, external);
+ } else {
+ result = obj->MakeExternal(resource);
+ external = obj;
+ }
+
+ ASSERT(external->IsExternalString());
+ if (result && !external->IsInternalizedString()) {
+ isolate->heap()->external_string_table()->AddString(*external);
}
return result;
}
@@ -5995,9 +6026,23 @@ bool v8::String::MakeExternal(
return false;
}
CHECK(resource && resource->data());
- bool result = obj->MakeExternal(resource);
- if (result && !obj->IsInternalizedString()) {
- isolate->heap()->external_string_table()->AddString(*obj);
+
+ bool result;
+ i::Handle<i::String> external;
+ if (isolate->heap()->old_pointer_space()->Contains(*obj)) {
+ // We do not allow external strings in the old pointer space. Instead
of
+ // converting the string in-place, we keep the cons/sliced string and
+ // point it to a newly-allocated external string.
+ external = NewExternalAsciiStringHandle(isolate, resource);
+ result = RedirectToExternalString(isolate, obj, external);
+ } else {
+ result = obj->MakeExternal(resource);
+ external = obj;
+ }
+
+ ASSERT(external->IsExternalString());
+ if (result && !external->IsInternalizedString()) {
+ isolate->heap()->external_string_table()->AddString(*external);
}
return result;
}
Index: test/cctest/test-api.cc
diff --git a/test/cctest/test-api.cc b/test/cctest/test-api.cc
index
724eb6a2fc2793f10fa8fbf341d0f67c6e42b316..7cb3c04087b69d5238b904861e20d4aaf75fc3fa
100644
--- a/test/cctest/test-api.cc
+++ b/test/cctest/test-api.cc
@@ -625,10 +625,14 @@ TEST(MakingExternalUnalignedAsciiString) {
LocalContext env;
v8::HandleScope scope(env->GetIsolate());
+ CompileRun("function cons(a, b) { return a + b; }"
+ "function slice(a) { return a.substring(1); }");
// Create a cons string that will land in old pointer space.
- Local<String> string = Local<String>::Cast(CompileRun(
- "function cons(a, b) { return a + b; }"
+ Local<String> cons = Local<String>::Cast(CompileRun(
"cons('abcdefghijklm', 'nopqrstuvwxyz');"));
+ // Create a sliced string that will land in old pointer space.
+ Local<String> slice = Local<String>::Cast(CompileRun(
+ "slice('abcdefghijklmnopqrstuvwxyz');"));
// Trigger GCs so that the newly allocated string moves to old gen.
SimulateFullSpace(HEAP->old_pointer_space());
@@ -637,9 +641,13 @@ TEST(MakingExternalUnalignedAsciiString) {
// Turn into external string with unaligned resource data.
int dispose_count = 0;
- const char* c_source = "_abcdefghijklmnopqrstuvwxyz";
- bool success = string->MakeExternal(
- new TestAsciiResource(i::StrDup(c_source) + 1, &dispose_count));
+ const char* c_cons = "_abcdefghijklmnopqrstuvwxyz";
+ bool success = cons->MakeExternal(
+ new TestAsciiResource(i::StrDup(c_cons) + 1, &dispose_count));
+ CHECK(success);
+ const char* c_slice = "_bcdefghijklmnopqrstuvwxyz";
+ success = slice->MakeExternal(
+ new TestAsciiResource(i::StrDup(c_slice) + 1, &dispose_count));
CHECK(success);
// Trigger GCs and force evacuation.
--
--
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