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 | #include "JSONUtils.h" |
11 | |
12 | #if !defined(_WIN32) |
13 | #include <sys/stat.h> |
14 | #include <sys/types.h> |
15 | #include <unistd.h> |
16 | #endif |
17 | |
18 | #include <chrono> |
19 | #include <fstream> |
20 | #include <future> |
21 | #include <optional> |
22 | |
23 | using namespace llvm; |
24 | |
25 | namespace lldb_dap { |
26 | |
27 | FifoFile::FifoFile(StringRef path) : m_path(path) {} |
28 | |
29 | FifoFile::~FifoFile() { |
30 | #if !defined(_WIN32) |
31 | unlink(name: m_path.c_str()); |
32 | #endif |
33 | } |
34 | |
35 | Expected<std::shared_ptr<FifoFile>> CreateFifoFile(StringRef path) { |
36 | #if defined(_WIN32) |
37 | return createStringError(inconvertibleErrorCode(), "Unimplemented" ); |
38 | #else |
39 | if (int err = mkfifo(path: path.data(), mode: 0600)) |
40 | return createStringError(EC: std::error_code(err, std::generic_category()), |
41 | Fmt: "Couldn't create fifo file: %s" , Vals: path.data()); |
42 | return std::make_shared<FifoFile>(args&: path); |
43 | #endif |
44 | } |
45 | |
46 | FifoFileIO::FifoFileIO(StringRef fifo_file, StringRef other_endpoint_name) |
47 | : m_fifo_file(fifo_file), m_other_endpoint_name(other_endpoint_name) {} |
48 | |
49 | Expected<json::Value> FifoFileIO::ReadJSON(std::chrono::milliseconds timeout) { |
50 | // We use a pointer for this future, because otherwise its normal destructor |
51 | // would wait for the getline to end, rendering the timeout useless. |
52 | std::optional<std::string> line; |
53 | std::future<void> *future = |
54 | new std::future<void>(std::async(policy: std::launch::async, fn: [&]() { |
55 | std::ifstream reader(m_fifo_file, std::ifstream::in); |
56 | std::string buffer; |
57 | std::getline(is&: reader, str&: buffer); |
58 | if (!buffer.empty()) |
59 | line = buffer; |
60 | })); |
61 | if (future->wait_for(rel: timeout) == std::future_status::timeout || !line) |
62 | // Indeed this is a leak, but it's intentional. "future" obj destructor |
63 | // will block on waiting for the worker thread to join. And the worker |
64 | // thread might be stuck in blocking I/O. Intentionally leaking the obj |
65 | // as a hack to avoid blocking main thread, and adding annotation to |
66 | // supress static code inspection warnings |
67 | |
68 | // coverity[leaked_storage] |
69 | return createStringError(EC: inconvertibleErrorCode(), |
70 | S: "Timed out trying to get messages from the " + |
71 | m_other_endpoint_name); |
72 | delete future; |
73 | return json::parse(JSON: *line); |
74 | } |
75 | |
76 | Error FifoFileIO::SendJSON(const json::Value &json, |
77 | std::chrono::milliseconds timeout) { |
78 | bool done = false; |
79 | std::future<void> *future = |
80 | new std::future<void>(std::async(policy: std::launch::async, fn: [&]() { |
81 | std::ofstream writer(m_fifo_file, std::ofstream::out); |
82 | writer << JSONToString(json) << std::endl; |
83 | done = true; |
84 | })); |
85 | if (future->wait_for(rel: timeout) == std::future_status::timeout || !done) { |
86 | // Indeed this is a leak, but it's intentional. "future" obj destructor will |
87 | // block on waiting for the worker thread to join. And the worker thread |
88 | // might be stuck in blocking I/O. Intentionally leaking the obj as a hack |
89 | // to avoid blocking main thread, and adding annotation to supress static |
90 | // code inspection warnings" |
91 | |
92 | // coverity[leaked_storage] |
93 | return createStringError(EC: inconvertibleErrorCode(), |
94 | S: "Timed out trying to send messages to the " + |
95 | m_other_endpoint_name); |
96 | } |
97 | delete future; |
98 | return Error::success(); |
99 | } |
100 | |
101 | } // namespace lldb_dap |
102 | |