1 //===-- FifoFiles.cpp -------------------------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "FifoFiles.h"
10 
11 #if !defined(_WIN32)
12 #include <sys/stat.h>
13 #include <sys/types.h>
14 #include <unistd.h>
15 #endif
16 
17 #include <chrono>
18 #include <fstream>
19 #include <future>
20 #include <thread>
21 
22 #include "llvm/Support/FileSystem.h"
23 
24 #include "lldb/lldb-defines.h"
25 
26 using namespace llvm;
27 
28 namespace lldb_vscode {
29 
30 FifoFile::FifoFile(StringRef path) : m_path(path) {}
31 
32 FifoFile::~FifoFile() {
33 #if !defined(_WIN32)
34   unlink(m_path.c_str());
35 #endif
36 }
37 
38 Expected<std::shared_ptr<FifoFile>> CreateFifoFile(StringRef path) {
39 #if defined(_WIN32)
40   return createStringError(inconvertibleErrorCode(), "Unimplemented");
41 #else
42   if (int err = mkfifo(path.data(), 0600))
43     return createStringError(std::error_code(err, std::generic_category()),
44                              "Couldn't create fifo file: %s", path.data());
45   return std::make_shared<FifoFile>(path);
46 #endif
47 }
48 
49 FifoFileIO::FifoFileIO(StringRef fifo_file, StringRef other_endpoint_name)
50     : m_fifo_file(fifo_file), m_other_endpoint_name(other_endpoint_name) {}
51 
52 Expected<json::Value> FifoFileIO::ReadJSON(std::chrono::milliseconds timeout) {
53   // We use a pointer for this future, because otherwise its normal destructor
54   // would wait for the getline to end, rendering the timeout useless.
55   Optional<std::string> line;
56   std::future<void> *future =
57       new std::future<void>(std::async(std::launch::async, [&]() {
58         std::ifstream reader(m_fifo_file, std::ifstream::in);
59         std::string buffer;
60         std::getline(reader, buffer);
61         if (!buffer.empty())
62           line = buffer;
63       }));
64   if (future->wait_for(timeout) == std::future_status::timeout || !line)
65     return createStringError(inconvertibleErrorCode(),
66                              "Timed out trying to get messages from the " +
67                                  m_other_endpoint_name);
68   delete future;
69   return json::parse(*line);
70 }
71 
72 Error FifoFileIO::SendJSON(const json::Value &json,
73                            std::chrono::milliseconds timeout) {
74   bool done = false;
75   std::future<void> *future =
76       new std::future<void>(std::async(std::launch::async, [&]() {
77         std::ofstream writer(m_fifo_file, std::ofstream::out);
78         writer << JSONToString(json) << std::endl;
79         done = true;
80       }));
81   if (future->wait_for(timeout) == std::future_status::timeout || !done) {
82     return createStringError(inconvertibleErrorCode(),
83                              "Timed out trying to send messages to the " +
84                                  m_other_endpoint_name);
85   }
86   delete future;
87   return Error::success();
88 }
89 
90 } // namespace lldb_vscode
91