1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
|
//===--- Cancellation.cpp -----------------------------------------*-C++-*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "support/Cancellation.h"
#include <atomic>
namespace clang {
namespace clangd {
char CancelledError::ID = 0;
// We don't want a cancelable scope to "shadow" an enclosing one.
struct CancelState {
std::shared_ptr<std::atomic<int>> Cancelled;
const CancelState *Parent;
};
static Key<CancelState> StateKey;
std::pair<Context, Canceler> cancelableTask(int Reason) {
assert(Reason != 0 && "Can't detect cancellation if Reason is zero");
CancelState State;
State.Cancelled = std::make_shared<std::atomic<int>>();
State.Parent = Context::current().get(StateKey);
return {
Context::current().derive(StateKey, State),
[Reason, Flag(State.Cancelled)] { *Flag = Reason; },
};
}
int isCancelled(const Context &Ctx) {
for (const CancelState *State = Ctx.get(StateKey); State != nullptr;
State = State->Parent)
if (int Reason = State->Cancelled->load())
return Reason;
return 0;
}
} // namespace clangd
} // namespace clang
|
