Ryan Macnak
ec77e28f26
Instead of switching over each of the different callback types and duplicating the call-dart-spill-call-runtime-restore in the stub, have the initial runtime call return a function pointer for the runtime call to end that kind of callback. A separate case for tail calls is still needed. TEST=ci Change-Id: I691487ca12337ddef1adaeec4c163c56e2feb09e Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/488261 Commit-Queue: Ryan Macnak <rmacnak@google.com> Reviewed-by: Alexander Aprelev <aam@google.com>
37 lines
1.5 KiB
C++
37 lines
1.5 KiB
C++
// Copyright (c) 2019, the Dart project authors. Please see the AUTHORS file
|
|
// for details. All rights reserved. Use of this source code is governed by a
|
|
// BSD-style license that can be found in the LICENSE file.
|
|
|
|
#include "vm/bss_relocs.h"
|
|
#include "vm/native_symbol.h"
|
|
#include "vm/runtime_entry.h"
|
|
#include "vm/thread.h"
|
|
|
|
namespace dart {
|
|
|
|
void BSS::InitializeBSSEntry(BSS::Relocation relocation,
|
|
uword new_value,
|
|
uword* bss_start) {
|
|
auto slot = std::atomic_ref(bss_start[BSS::RelocationIndex(relocation)]);
|
|
uword old_value = slot.load(std::memory_order_relaxed);
|
|
// FullSnapshotReader::ReadProgramSnapshot, and thus BSS::Initialize, can
|
|
// get called multiple times for the same isolate in different threads, though
|
|
// the initialized value will be consistent and thus change only once. Avoid
|
|
// calling compare_exchange_strong unless we actually need to change the
|
|
// value, to avoid spurious read/write races by TSAN.
|
|
if (old_value == new_value) return;
|
|
if (!slot.compare_exchange_strong(old_value, new_value,
|
|
std::memory_order_relaxed)) {
|
|
RELEASE_ASSERT(old_value == new_value);
|
|
}
|
|
}
|
|
|
|
void BSS::Initialize(Thread* current, uword* bss_start, bool vm) {
|
|
// TODO(https://dartbug.com/52579): Remove.
|
|
InitializeBSSEntry(Relocation::DLRT_GetFfiCallbackMetadata,
|
|
reinterpret_cast<uword>(DLRT_GetFfiCallbackMetadata),
|
|
bss_start);
|
|
}
|
|
|
|
} // namespace dart
|