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PipeWindows.cpp
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1//===-- PipeWindows.cpp ---------------------------------------------------===//
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
10
11#include "llvm/ADT/SmallString.h"
12#include "llvm/Support/Process.h"
13#include "llvm/Support/raw_ostream.h"
14
15#include <fcntl.h>
16#include <io.h>
17#include <rpc.h>
18
19#include <atomic>
20#include <string>
21
22using namespace lldb;
23using namespace lldb_private;
24
25static std::atomic<uint32_t> g_pipe_serial(0);
26static constexpr llvm::StringLiteral g_pipe_name_prefix = "\\\\.\\Pipe\\";
27
29 : m_read(INVALID_HANDLE_VALUE), m_write(INVALID_HANDLE_VALUE),
30 m_read_fd(PipeWindows::kInvalidDescriptor),
31 m_write_fd(PipeWindows::kInvalidDescriptor) {
32 ZeroMemory(&m_read_overlapped, sizeof(m_read_overlapped));
33 ZeroMemory(&m_write_overlapped, sizeof(m_write_overlapped));
34}
35
37 : m_read((HANDLE)read), m_write((HANDLE)write),
38 m_read_fd(PipeWindows::kInvalidDescriptor),
39 m_write_fd(PipeWindows::kInvalidDescriptor) {
40 assert(read != LLDB_INVALID_PIPE || write != LLDB_INVALID_PIPE);
41
42 // Don't risk in passing file descriptors and getting handles from them by
43 // _get_osfhandle since the retrieved handles are highly likely unrecognized
44 // in the current process and usually crashes the program. Pass handles
45 // instead since the handle can be inherited.
46
47 if (read != LLDB_INVALID_PIPE) {
48 m_read_fd = _open_osfhandle((intptr_t)read, _O_RDONLY);
49 // Make sure the fd and native handle are consistent.
50 if (m_read_fd < 0)
51 m_read = INVALID_HANDLE_VALUE;
52 }
53
54 if (write != LLDB_INVALID_PIPE) {
55 m_write_fd = _open_osfhandle((intptr_t)write, _O_WRONLY);
56 if (m_write_fd < 0)
57 m_write = INVALID_HANDLE_VALUE;
58 }
59
60 ZeroMemory(&m_read_overlapped, sizeof(m_read_overlapped));
61 ZeroMemory(&m_write_overlapped, sizeof(m_write_overlapped));
62}
63
65
66Status PipeWindows::CreateNew(bool child_process_inherit) {
67 // Create an anonymous pipe with the specified inheritance.
68 SECURITY_ATTRIBUTES sa{sizeof(SECURITY_ATTRIBUTES), 0,
69 child_process_inherit ? TRUE : FALSE};
70 BOOL result = ::CreatePipe(&m_read, &m_write, &sa, 1024);
71 if (result == FALSE)
72 return Status(::GetLastError(), eErrorTypeWin32);
73
74 m_read_fd = _open_osfhandle((intptr_t)m_read, _O_RDONLY);
75 ZeroMemory(&m_read_overlapped, sizeof(m_read_overlapped));
76 m_read_overlapped.hEvent = ::CreateEventA(nullptr, TRUE, FALSE, nullptr);
77
78 m_write_fd = _open_osfhandle((intptr_t)m_write, _O_WRONLY);
79 ZeroMemory(&m_write_overlapped, sizeof(m_write_overlapped));
80
81 return Status();
82}
83
84Status PipeWindows::CreateNewNamed(bool child_process_inherit) {
85 // Even for anonymous pipes, we open a named pipe. This is because you
86 // cannot get overlapped i/o on Windows without using a named pipe. So we
87 // synthesize a unique name.
88 uint32_t serial = g_pipe_serial.fetch_add(1);
89 std::string pipe_name;
90 llvm::raw_string_ostream pipe_name_stream(pipe_name);
91 pipe_name_stream << "lldb.pipe." << ::GetCurrentProcessId() << "." << serial;
92 pipe_name_stream.flush();
93
94 return CreateNew(pipe_name.c_str(), child_process_inherit);
95}
96
97Status PipeWindows::CreateNew(llvm::StringRef name,
98 bool child_process_inherit) {
99 if (name.empty())
100 return Status(ERROR_INVALID_PARAMETER, eErrorTypeWin32);
101
102 if (CanRead() || CanWrite())
103 return Status(ERROR_ALREADY_EXISTS, eErrorTypeWin32);
104
105 std::string pipe_path = g_pipe_name_prefix.str();
106 pipe_path.append(name.str());
107
108 // Always open for overlapped i/o. We implement blocking manually in Read
109 // and Write.
110 DWORD read_mode = FILE_FLAG_OVERLAPPED;
111 m_read = ::CreateNamedPipeA(
112 pipe_path.c_str(), PIPE_ACCESS_INBOUND | read_mode,
113 PIPE_TYPE_BYTE | PIPE_WAIT, 1, 1024, 1024, 120 * 1000, NULL);
114 if (INVALID_HANDLE_VALUE == m_read)
115 return Status(::GetLastError(), eErrorTypeWin32);
116 m_read_fd = _open_osfhandle((intptr_t)m_read, _O_RDONLY);
117 ZeroMemory(&m_read_overlapped, sizeof(m_read_overlapped));
118 m_read_overlapped.hEvent = ::CreateEvent(nullptr, TRUE, FALSE, nullptr);
119
120 // Open the write end of the pipe. Note that closing either the read or
121 // write end of the pipe could directly close the pipe itself.
122 Status result = OpenNamedPipe(name, child_process_inherit, false);
123 if (!result.Success()) {
125 return result;
126 }
127
128 return result;
129}
130
132 bool child_process_inherit,
134 llvm::SmallString<128> pipe_name;
136 ::UUID unique_id;
137 RPC_CSTR unique_string;
138 RPC_STATUS status = ::UuidCreate(&unique_id);
139 if (status == RPC_S_OK || status == RPC_S_UUID_LOCAL_ONLY)
140 status = ::UuidToStringA(&unique_id, &unique_string);
141 if (status == RPC_S_OK) {
142 pipe_name = prefix;
143 pipe_name += "-";
144 pipe_name += reinterpret_cast<char *>(unique_string);
145 ::RpcStringFreeA(&unique_string);
146 error = CreateNew(pipe_name, child_process_inherit);
147 } else {
148 error.SetError(status, eErrorTypeWin32);
149 }
150 if (error.Success())
151 name = pipe_name;
152 return error;
153}
154
156 bool child_process_inherit) {
157 if (CanRead())
158 return Status(ERROR_ALREADY_EXISTS, eErrorTypeWin32);
159
160 return OpenNamedPipe(name, child_process_inherit, true);
161}
162
163Status
165 bool child_process_inherit,
166 const std::chrono::microseconds &timeout) {
167 if (CanWrite())
168 return Status(ERROR_ALREADY_EXISTS, eErrorTypeWin32);
169
170 return OpenNamedPipe(name, child_process_inherit, false);
171}
172
174 bool child_process_inherit, bool is_read) {
175 if (name.empty())
176 return Status(ERROR_INVALID_PARAMETER, eErrorTypeWin32);
177
178 assert(is_read ? !CanRead() : !CanWrite());
179
180 SECURITY_ATTRIBUTES attributes = {};
181 attributes.bInheritHandle = child_process_inherit;
182
183 std::string pipe_path = g_pipe_name_prefix.str();
184 pipe_path.append(name.str());
185
186 if (is_read) {
187 m_read = ::CreateFileA(pipe_path.c_str(), GENERIC_READ, 0, &attributes,
188 OPEN_EXISTING, FILE_FLAG_OVERLAPPED, NULL);
189 if (INVALID_HANDLE_VALUE == m_read)
190 return Status(::GetLastError(), eErrorTypeWin32);
191
192 m_read_fd = _open_osfhandle((intptr_t)m_read, _O_RDONLY);
193
194 ZeroMemory(&m_read_overlapped, sizeof(m_read_overlapped));
195 m_read_overlapped.hEvent = ::CreateEvent(nullptr, TRUE, FALSE, nullptr);
196 } else {
197 m_write = ::CreateFileA(pipe_path.c_str(), GENERIC_WRITE, 0, &attributes,
198 OPEN_EXISTING, FILE_FLAG_OVERLAPPED, NULL);
199 if (INVALID_HANDLE_VALUE == m_write)
200 return Status(::GetLastError(), eErrorTypeWin32);
201
202 m_write_fd = _open_osfhandle((intptr_t)m_write, _O_WRONLY);
203
204 ZeroMemory(&m_write_overlapped, sizeof(m_write_overlapped));
205 }
206
207 return Status();
208}
209
211
213
215 if (!CanRead())
217 int result = m_read_fd;
219 if (m_read_overlapped.hEvent)
220 ::CloseHandle(m_read_overlapped.hEvent);
221 m_read = INVALID_HANDLE_VALUE;
222 ZeroMemory(&m_read_overlapped, sizeof(m_read_overlapped));
223 return result;
224}
225
227 if (!CanWrite())
229 int result = m_write_fd;
231 m_write = INVALID_HANDLE_VALUE;
232 ZeroMemory(&m_write_overlapped, sizeof(m_write_overlapped));
233 return result;
234}
235
237 if (!CanRead())
238 return;
239
240 if (m_read_overlapped.hEvent)
241 ::CloseHandle(m_read_overlapped.hEvent);
242
243 _close(m_read_fd);
244 m_read = INVALID_HANDLE_VALUE;
246 ZeroMemory(&m_read_overlapped, sizeof(m_read_overlapped));
247}
248
250 if (!CanWrite())
251 return;
252
253 _close(m_write_fd);
254 m_write = INVALID_HANDLE_VALUE;
256 ZeroMemory(&m_write_overlapped, sizeof(m_write_overlapped));
257}
258
262}
263
264Status PipeWindows::Delete(llvm::StringRef name) { return Status(); }
265
266bool PipeWindows::CanRead() const { return (m_read != INVALID_HANDLE_VALUE); }
267
268bool PipeWindows::CanWrite() const { return (m_write != INVALID_HANDLE_VALUE); }
269
270HANDLE
272
273HANDLE
275
277 const std::chrono::microseconds &duration,
278 size_t &bytes_read) {
279 if (!CanRead())
280 return Status(ERROR_INVALID_HANDLE, eErrorTypeWin32);
281
282 bytes_read = 0;
283 DWORD sys_bytes_read = size;
284 BOOL result = ::ReadFile(m_read, buf, sys_bytes_read, &sys_bytes_read,
286 if (!result && GetLastError() != ERROR_IO_PENDING)
287 return Status(::GetLastError(), eErrorTypeWin32);
288
289 DWORD timeout = (duration == std::chrono::microseconds::zero())
290 ? INFINITE
291 : duration.count() * 1000;
292 DWORD wait_result = ::WaitForSingleObject(m_read_overlapped.hEvent, timeout);
293 if (wait_result != WAIT_OBJECT_0) {
294 // The operation probably failed. However, if it timed out, we need to
295 // cancel the I/O. Between the time we returned from WaitForSingleObject
296 // and the time we call CancelIoEx, the operation may complete. If that
297 // hapens, CancelIoEx will fail and return ERROR_NOT_FOUND. If that
298 // happens, the original operation should be considered to have been
299 // successful.
300 bool failed = true;
301 DWORD failure_error = ::GetLastError();
302 if (wait_result == WAIT_TIMEOUT) {
303 BOOL cancel_result = CancelIoEx(m_read, &m_read_overlapped);
304 if (!cancel_result && GetLastError() == ERROR_NOT_FOUND)
305 failed = false;
306 }
307 if (failed)
308 return Status(failure_error, eErrorTypeWin32);
309 }
310
311 // Now we call GetOverlappedResult setting bWait to false, since we've
312 // already waited as long as we're willing to.
313 if (!GetOverlappedResult(m_read, &m_read_overlapped, &sys_bytes_read, FALSE))
314 return Status(::GetLastError(), eErrorTypeWin32);
315
316 bytes_read = sys_bytes_read;
317 return Status();
318}
319
320Status PipeWindows::Write(const void *buf, size_t num_bytes,
321 size_t &bytes_written) {
322 if (!CanWrite())
323 return Status(ERROR_INVALID_HANDLE, eErrorTypeWin32);
324
325 DWORD sys_bytes_written = 0;
326 BOOL write_result = ::WriteFile(m_write, buf, num_bytes, &sys_bytes_written,
328 if (!write_result && GetLastError() != ERROR_IO_PENDING)
329 return Status(::GetLastError(), eErrorTypeWin32);
330
331 BOOL result = GetOverlappedResult(m_write, &m_write_overlapped,
332 &sys_bytes_written, TRUE);
333 if (!result)
334 return Status(::GetLastError(), eErrorTypeWin32);
335 return Status();
336}
static llvm::raw_ostream & error(Stream &strm)
static std::atomic< uint32_t > g_pipe_serial(0)
static constexpr llvm::StringLiteral g_pipe_name_prefix
Definition: PipeWindows.cpp:26
bool CanWrite() const override
Status Write(const void *buf, size_t size, size_t &bytes_written) override
Status OpenAsReader(llvm::StringRef name, bool child_process_inherit) override
Status CreateWithUniqueName(llvm::StringRef prefix, bool child_process_inherit, llvm::SmallVectorImpl< char > &name) override
Status Delete(llvm::StringRef name) override
int ReleaseReadFileDescriptor() override
void CloseReadFileDescriptor() override
OVERLAPPED m_write_overlapped
Definition: PipeWindows.h:84
Status ReadWithTimeout(void *buf, size_t size, const std::chrono::microseconds &timeout, size_t &bytes_read) override
void CloseWriteFileDescriptor() override
Status CreateNewNamed(bool child_process_inherit)
Definition: PipeWindows.cpp:84
OVERLAPPED m_read_overlapped
Definition: PipeWindows.h:83
static const int kInvalidDescriptor
Definition: PipeWindows.h:24
Status CreateNew(bool child_process_inherit) override
Definition: PipeWindows.cpp:66
Status OpenNamedPipe(llvm::StringRef name, bool child_process_inherit, bool is_read)
Status OpenAsWriterWithTimeout(llvm::StringRef name, bool child_process_inherit, const std::chrono::microseconds &timeout) override
int ReleaseWriteFileDescriptor() override
int GetWriteFileDescriptor() const override
int GetReadFileDescriptor() const override
bool CanRead() const override
An error handling class.
Definition: Status.h:44
bool Success() const
Test for success condition.
Definition: Status.cpp:287
#define LLDB_INVALID_PIPE
Definition: lldb-types.h:80
A class that represents a running process on the host machine.
Definition: SBAddress.h:15
int pipe_t
Definition: lldb-types.h:64
@ eErrorTypeWin32
Standard Win32 error codes.