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//===-- FifoFiles.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 "FifoFiles.h"
#include "JSONUtils.h"
#if !defined(_WIN32)
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#endif
#include <chrono>
#include <fstream>
#include <future>
#include <optional>
using namespace llvm;
namespace lldb_dap {
FifoFile::FifoFile(StringRef path) : m_path(path) {}
FifoFile::~FifoFile() {
#if !defined(_WIN32)
unlink(m_path.c_str());
#endif
}
Expected<std::shared_ptr<FifoFile>> CreateFifoFile(StringRef path) {
#if defined(_WIN32)
return createStringError(inconvertibleErrorCode(), "Unimplemented");
#else
if (int err = mkfifo(path.data(), 0600))
return createStringError(std::error_code(err, std::generic_category()),
"Couldn't create fifo file: %s", path.data());
return std::make_shared<FifoFile>(path);
#endif
}
FifoFileIO::FifoFileIO(StringRef fifo_file, StringRef other_endpoint_name)
: m_fifo_file(fifo_file), m_other_endpoint_name(other_endpoint_name) {}
Expected<json::Value> FifoFileIO::ReadJSON(std::chrono::milliseconds timeout) {
// We use a pointer for this future, because otherwise its normal destructor
// would wait for the getline to end, rendering the timeout useless.
std::optional<std::string> line;
std::future<void> *future =
new std::future<void>(std::async(std::launch::async, [&]() {
std::ifstream reader(m_fifo_file, std::ifstream::in);
std::string buffer;
std::getline(reader, buffer);
if (!buffer.empty())
line = buffer;
}));
if (future->wait_for(timeout) == std::future_status::timeout || !line)
// Indeed this is a leak, but it's intentional. "future" obj destructor
// will block on waiting for the worker thread to join. And the worker
// thread might be stuck in blocking I/O. Intentionally leaking the obj
// as a hack to avoid blocking main thread, and adding annotation to
// supress static code inspection warnings
// coverity[leaked_storage]
return createStringError(inconvertibleErrorCode(),
"Timed out trying to get messages from the " +
m_other_endpoint_name);
delete future;
return json::parse(*line);
}
Error FifoFileIO::SendJSON(const json::Value &json,
std::chrono::milliseconds timeout) {
bool done = false;
std::future<void> *future =
new std::future<void>(std::async(std::launch::async, [&]() {
std::ofstream writer(m_fifo_file, std::ofstream::out);
writer << JSONToString(json) << std::endl;
done = true;
}));
if (future->wait_for(timeout) == std::future_status::timeout || !done) {
// Indeed this is a leak, but it's intentional. "future" obj destructor will
// block on waiting for the worker thread to join. And the worker thread
// might be stuck in blocking I/O. Intentionally leaking the obj as a hack
// to avoid blocking main thread, and adding annotation to supress static
// code inspection warnings"
// coverity[leaked_storage]
return createStringError(inconvertibleErrorCode(),
"Timed out trying to send messages to the " +
m_other_endpoint_name);
}
delete future;
return Error::success();
}
} // namespace lldb_dap
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