win32: adb start-server shows stdout/stderr output from actual server
When launching the adb server (typically from adb start-server),
redirect stdout/stderr to anonymous pipes which are read by threads in
the parent process, to make error diagnosis easier.
If there is an error during adb start-server, the output looks like:
> adb start-server
* daemon not running. starting it now on port 5037 *
error: could not blah # from server process
could not read ok from ADB Server # from launch_server
* failed to start daemon * # from adb_connect
error: cannot connect to daemon # from adb_commandline
Fix handle-leaks in launch_server by using new unique_handle class
that is based on std::unique_ptr.
In the server, close stdin and redirect to adb.log *before* sending the
ACK, so that any errors are reported early instead of after the ACK.
Change-Id: I943881210a0ea9458fc36851339f916c3d6a0830
Signed-off-by: Spencer Low <CompareAndSwap@gmail.com>
diff --git a/adb/adb.cpp b/adb/adb.cpp
index a0501a6..48973cb 100644
--- a/adb/adb.cpp
+++ b/adb/adb.cpp
@@ -580,6 +580,105 @@
#if ADB_HOST
+#ifdef _WIN32
+
+static bool _make_handle_noninheritable(HANDLE h) {
+ if (h != INVALID_HANDLE_VALUE && h != NULL) {
+ if (!SetHandleInformation(h, HANDLE_FLAG_INHERIT, 0)) {
+ // Show the handle value to give us a clue in case we have problems
+ // with pseudo-handle values.
+ fprintf(stderr, "Cannot make handle 0x%p non-inheritable: %s\n",
+ h, SystemErrorCodeToString(GetLastError()).c_str());
+ return false;
+ }
+ }
+
+ return true;
+}
+
+// Create anonymous pipe, preventing inheritance of the read pipe and setting
+// security of the write pipe to sa.
+static bool _create_anonymous_pipe(unique_handle* pipe_read_out,
+ unique_handle* pipe_write_out,
+ SECURITY_ATTRIBUTES* sa) {
+ HANDLE pipe_read_raw = NULL;
+ HANDLE pipe_write_raw = NULL;
+ if (!CreatePipe(&pipe_read_raw, &pipe_write_raw, sa, 0)) {
+ fprintf(stderr, "Cannot create pipe: %s\n",
+ SystemErrorCodeToString(GetLastError()).c_str());
+ return false;
+ }
+
+ unique_handle pipe_read(pipe_read_raw);
+ pipe_read_raw = NULL;
+ unique_handle pipe_write(pipe_write_raw);
+ pipe_write_raw = NULL;
+
+ if (!_make_handle_noninheritable(pipe_read.get())) {
+ return false;
+ }
+
+ *pipe_read_out = std::move(pipe_read);
+ *pipe_write_out = std::move(pipe_write);
+
+ return true;
+}
+
+// Read from a pipe (that we take ownership of) and write what is returned to
+// GetStdHandle(nStdHandle). Return on error or when the pipe is closed.
+static unsigned _redirect_pipe_thread(HANDLE h, DWORD nStdHandle) {
+ // Take ownership of the HANDLE and close when we're done.
+ unique_handle read_pipe(h);
+ const HANDLE write_handle = GetStdHandle(nStdHandle);
+ const char* output_name = nStdHandle == STD_OUTPUT_HANDLE ?
+ "stdout" : "stderr";
+
+ while (true) {
+ char buf[64 * 1024];
+ DWORD bytes_read = 0;
+ if (!ReadFile(read_pipe.get(), buf, sizeof(buf), &bytes_read, NULL)) {
+ const DWORD err = GetLastError();
+ // ERROR_BROKEN_PIPE is expected when the subprocess closes
+ // the other end of the pipe.
+ if (err == ERROR_BROKEN_PIPE) {
+ return EXIT_SUCCESS;
+ } else {
+ fprintf(stderr, "Failed to read from %s: %s\n", output_name,
+ SystemErrorCodeToString(err).c_str());
+ return EXIT_FAILURE;
+ }
+ }
+
+ // Don't try to write if our stdout/stderr was not setup by the
+ // parent process.
+ if (write_handle != NULL && write_handle != INVALID_HANDLE_VALUE) {
+ DWORD bytes_written = 0;
+ if (!WriteFile(write_handle, buf, bytes_read, &bytes_written,
+ NULL)) {
+ fprintf(stderr, "Failed to write to %s: %s\n", output_name,
+ SystemErrorCodeToString(GetLastError()).c_str());
+ return EXIT_FAILURE;
+ }
+
+ if (bytes_written != bytes_read) {
+ fprintf(stderr, "Only wrote %lu of %lu bytes to %s\n",
+ bytes_written, bytes_read, output_name);
+ return EXIT_FAILURE;
+ }
+ }
+ }
+}
+
+static unsigned __stdcall _redirect_stdout_thread(HANDLE h) {
+ return _redirect_pipe_thread(h, STD_OUTPUT_HANDLE);
+}
+
+static unsigned __stdcall _redirect_stderr_thread(HANDLE h) {
+ return _redirect_pipe_thread(h, STD_ERROR_HANDLE);
+}
+
+#endif
+
int launch_server(int server_port)
{
#if defined(_WIN32)
@@ -587,58 +686,42 @@
/* we create a PIPE that will be used to wait for the server's "OK" */
/* message since the pipe handles must be inheritable, we use a */
/* security attribute */
- HANDLE nul_read, nul_write;
- HANDLE pipe_read, pipe_write;
- HANDLE stdout_handle, stderr_handle;
SECURITY_ATTRIBUTES sa;
- STARTUPINFOW startup;
- PROCESS_INFORMATION pinfo;
- WCHAR program_path[ MAX_PATH ];
- int ret;
-
sa.nLength = sizeof(sa);
sa.lpSecurityDescriptor = NULL;
sa.bInheritHandle = TRUE;
- /* Redirect stdin and stderr to Windows /dev/null. If we instead pass our
- * stdin/stderr handles and they are console handles, when the adb server
- * starts up, the C Runtime will see console handles for a process that
- * isn't connected to a console and it will configure stderr to be closed.
- * At that point, freopen() could be used to reopen stderr, but it would
- * take more massaging to fixup the file descriptor number that freopen()
- * uses. It's simplest to avoid all of this complexity by just redirecting
- * stdin/stderr to `nul' and then the C Runtime acts as expected.
- */
- nul_read = CreateFileW(L"nul", GENERIC_READ,
- FILE_SHARE_READ | FILE_SHARE_WRITE, &sa,
- OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
- if (nul_read == INVALID_HANDLE_VALUE) {
- fprintf(stderr, "CreateFileW(nul, GENERIC_READ) failed: %s\n",
+ // Redirect stdin to Windows /dev/null. If we instead pass an original
+ // stdin/stdout/stderr handle and it is a console handle, when the adb
+ // server starts up, the C Runtime will see a console handle for a process
+ // that isn't connected to a console and it will configure
+ // stdin/stdout/stderr to be closed. At that point, freopen() could be used
+ // to reopen stderr/out, but it would take more massaging to fixup the file
+ // descriptor number that freopen() uses. It's simplest to avoid all of this
+ // complexity by just redirecting stdin to `nul' and then the C Runtime acts
+ // as expected.
+ unique_handle nul_read(CreateFileW(L"nul", GENERIC_READ,
+ FILE_SHARE_READ | FILE_SHARE_WRITE, &sa, OPEN_EXISTING,
+ FILE_ATTRIBUTE_NORMAL, NULL));
+ if (nul_read.get() == INVALID_HANDLE_VALUE) {
+ fprintf(stderr, "Cannot open 'nul': %s\n",
SystemErrorCodeToString(GetLastError()).c_str());
return -1;
}
- nul_write = CreateFileW(L"nul", GENERIC_WRITE,
- FILE_SHARE_READ | FILE_SHARE_WRITE, &sa,
- OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
- if (nul_write == INVALID_HANDLE_VALUE) {
- fprintf(stderr, "CreateFileW(nul, GENERIC_WRITE) failed: %s\n",
- SystemErrorCodeToString(GetLastError()).c_str());
- CloseHandle(nul_read);
+ // create pipes with non-inheritable read handle, inheritable write handle
+ unique_handle ack_read, ack_write;
+ if (!_create_anonymous_pipe(&ack_read, &ack_write, &sa)) {
return -1;
}
-
- /* create pipe, and ensure its read handle isn't inheritable */
- ret = CreatePipe( &pipe_read, &pipe_write, &sa, 0 );
- if (!ret) {
- fprintf(stderr, "CreatePipe() failed: %s\n",
- SystemErrorCodeToString(GetLastError()).c_str());
- CloseHandle(nul_read);
- CloseHandle(nul_write);
+ unique_handle stdout_read, stdout_write;
+ if (!_create_anonymous_pipe(&stdout_read, &stdout_write, &sa)) {
return -1;
}
-
- SetHandleInformation( pipe_read, HANDLE_FLAG_INHERIT, 0 );
+ unique_handle stderr_read, stderr_write;
+ if (!_create_anonymous_pipe(&stderr_read, &stderr_write, &sa)) {
+ return -1;
+ }
/* Some programs want to launch an adb command and collect its output by
* calling CreateProcess with inheritable stdout/stderr handles, then
@@ -650,52 +733,64 @@
* the calling process is stuck while read()-ing from the stdout/stderr
* descriptors, because they're connected to corresponding handles in the
* adb server process (even if the latter never uses/writes to them).
+ * Note that even if we don't pass these handles in the STARTUPINFO struct,
+ * if they're marked inheritable, they're still inherited, requiring us to
+ * deal with this.
+ *
+ * If we're still having problems with inheriting random handles in the
+ * future, consider using PROC_THREAD_ATTRIBUTE_HANDLE_LIST to explicitly
+ * specify which handles should be inherited: http://blogs.msdn.com/b/oldnewthing/archive/2011/12/16/10248328.aspx
*/
- stdout_handle = GetStdHandle( STD_OUTPUT_HANDLE );
- stderr_handle = GetStdHandle( STD_ERROR_HANDLE );
- if (stdout_handle != INVALID_HANDLE_VALUE) {
- SetHandleInformation( stdout_handle, HANDLE_FLAG_INHERIT, 0 );
+ if (!_make_handle_noninheritable(GetStdHandle(STD_INPUT_HANDLE))) {
+ return -1;
}
- if (stderr_handle != INVALID_HANDLE_VALUE) {
- SetHandleInformation( stderr_handle, HANDLE_FLAG_INHERIT, 0 );
+ if (!_make_handle_noninheritable(GetStdHandle(STD_OUTPUT_HANDLE))) {
+ return -1;
+ }
+ if (!_make_handle_noninheritable(GetStdHandle(STD_ERROR_HANDLE))) {
+ return -1;
}
+ STARTUPINFOW startup;
ZeroMemory( &startup, sizeof(startup) );
startup.cb = sizeof(startup);
- startup.hStdInput = nul_read;
- startup.hStdOutput = nul_write;
- startup.hStdError = nul_write;
+ startup.hStdInput = nul_read.get();
+ startup.hStdOutput = stdout_write.get();
+ startup.hStdError = stderr_write.get();
startup.dwFlags = STARTF_USESTDHANDLES;
- ZeroMemory( &pinfo, sizeof(pinfo) );
+ // Verify that the pipe_write handle value can be passed on the command line
+ // as %d and that the rest of adb code can pass it around in an int.
+ const int ack_write_as_int = cast_handle_to_int(ack_write.get());
+ if (cast_int_to_handle(ack_write_as_int) != ack_write.get()) {
+ // If this fires, either handle values are larger than 32-bits or else
+ // there is a bug in our casting.
+ // https://msdn.microsoft.com/en-us/library/windows/desktop/aa384203%28v=vs.85%29.aspx
+ fprintf(stderr, "Cannot fit pipe handle value into 32-bits: 0x%p\n",
+ ack_write.get());
+ return -1;
+ }
- /* get path of current program */
- DWORD module_result = GetModuleFileNameW(NULL, program_path,
- arraysize(program_path));
- if ((module_result == arraysize(program_path)) || (module_result == 0)) {
+ // get path of current program
+ WCHAR program_path[MAX_PATH];
+ const DWORD module_result = GetModuleFileNameW(NULL, program_path,
+ arraysize(program_path));
+ if ((module_result >= arraysize(program_path)) || (module_result == 0)) {
// String truncation or some other error.
- fprintf(stderr, "GetModuleFileNameW() failed: %s\n",
+ fprintf(stderr, "Cannot get executable path: %s\n",
SystemErrorCodeToString(GetLastError()).c_str());
return -1;
}
- // Verify that the pipe_write handle value can be passed on the command line
- // as %d and that the rest of adb code can pass it around in an int.
- const int pipe_write_as_int = cast_handle_to_int(pipe_write);
- if (cast_int_to_handle(pipe_write_as_int) != pipe_write) {
- // If this fires, either handle values are larger than 32-bits or else
- // there is a bug in our casting.
- // https://msdn.microsoft.com/en-us/library/windows/desktop/aa384203%28v=vs.85%29.aspx
- fprintf(stderr, "CreatePipe handle value too large: 0x%p\n",
- pipe_write);
- return -1;
- }
-
- WCHAR args[64];
+ WCHAR args[64];
snwprintf(args, arraysize(args),
L"adb -P %d fork-server server --reply-fd %d", server_port,
- pipe_write_as_int);
- ret = CreateProcessW(
+ ack_write_as_int);
+
+ PROCESS_INFORMATION pinfo;
+ ZeroMemory(&pinfo, sizeof(pinfo));
+
+ if (!CreateProcessW(
program_path, /* program path */
args,
/* the fork-server argument will set the
@@ -707,38 +802,113 @@
NULL, /* use parent's environment block */
NULL, /* use parent's starting directory */
&startup, /* startup info, i.e. std handles */
- &pinfo );
-
- CloseHandle( nul_read );
- CloseHandle( nul_write );
- CloseHandle( pipe_write );
-
- if (!ret) {
- fprintf(stderr, "CreateProcess failed: %s\n",
+ &pinfo )) {
+ fprintf(stderr, "Cannot create process: %s\n",
SystemErrorCodeToString(GetLastError()).c_str());
- CloseHandle( pipe_read );
return -1;
}
- CloseHandle( pinfo.hProcess );
- CloseHandle( pinfo.hThread );
+ unique_handle process_handle(pinfo.hProcess);
+ pinfo.hProcess = NULL;
- /* wait for the "OK\n" message */
+ // Close handles that we no longer need to complete the rest.
+ CloseHandle(pinfo.hThread);
+ pinfo.hThread = NULL;
+
+ nul_read.reset();
+ ack_write.reset();
+ stdout_write.reset();
+ stderr_write.reset();
+
+ // Start threads to read from subprocess stdout/stderr and write to ours
+ // to make subprocess errors easier to diagnose.
+
+ // In the past, reading from a pipe before the child process's C Runtime
+ // started up and called GetFileType() caused a hang: http://blogs.msdn.com/b/oldnewthing/archive/2011/12/02/10243553.aspx#10244216
+ // This is reportedly fixed in Windows Vista: https://support.microsoft.com/en-us/kb/2009703
+ // I was unable to reproduce the problem on Windows XP. It sounds like a
+ // Windows Update may have fixed this: https://www.duckware.com/tech/peeknamedpipe.html
+ unique_handle stdout_thread(reinterpret_cast<HANDLE>(
+ _beginthreadex(NULL, 0, _redirect_stdout_thread, stdout_read.get(),
+ 0, NULL)));
+ if (stdout_thread.get() == nullptr) {
+ fprintf(stderr, "Cannot create thread: %s\n", strerror(errno));
+ return -1;
+ }
+ stdout_read.release(); // Transfer ownership to new thread
+
+ unique_handle stderr_thread(reinterpret_cast<HANDLE>(
+ _beginthreadex(NULL, 0, _redirect_stderr_thread, stderr_read.get(),
+ 0, NULL)));
+ if (stderr_thread.get() == nullptr) {
+ fprintf(stderr, "Cannot create thread: %s\n", strerror(errno));
+ return -1;
+ }
+ stderr_read.release(); // Transfer ownership to new thread
+
+ bool got_ack = false;
+
+ // Wait for the "OK\n" message, for the pipe to be closed, or other error.
{
- char temp[3];
- DWORD count;
+ char temp[3];
+ DWORD count = 0;
- ret = ReadFile( pipe_read, temp, 3, &count, NULL );
- CloseHandle( pipe_read );
- if ( !ret ) {
- fprintf(stderr, "could not read ok from ADB Server, error: %s\n",
- SystemErrorCodeToString(GetLastError()).c_str());
- return -1;
+ if (ReadFile(ack_read.get(), temp, sizeof(temp), &count, NULL)) {
+ const CHAR expected[] = "OK\n";
+ const DWORD expected_length = arraysize(expected) - 1;
+ if (count == expected_length &&
+ memcmp(temp, expected, expected_length) == 0) {
+ got_ack = true;
+ } else {
+ fprintf(stderr, "ADB server didn't ACK\n");
+ }
+ } else {
+ const DWORD err = GetLastError();
+ // If the ACK was not written and the process exited, GetLastError()
+ // is probably ERROR_BROKEN_PIPE, in which case that info is not
+ // useful to the user.
+ fprintf(stderr, "could not read ok from ADB Server%s\n",
+ err == ERROR_BROKEN_PIPE ? "" :
+ android::base::StringPrintf(": %s",
+ SystemErrorCodeToString(err).c_str()).c_str());
}
- if (count != 3 || temp[0] != 'O' || temp[1] != 'K' || temp[2] != '\n') {
- fprintf(stderr, "ADB server didn't ACK\n" );
- return -1;
+ }
+
+ // Always try to wait a bit for threads reading stdout/stderr to finish.
+ // If the process started ok, it should close the pipes causing the threads
+ // to finish. If the process had an error, it should exit, also causing
+ // the pipes to be closed. In that case we want to read all of the output
+ // and write it out so that the user can diagnose failures.
+ const DWORD thread_timeout_ms = 15 * 1000;
+ const HANDLE threads[] = { stdout_thread.get(), stderr_thread.get() };
+ const DWORD wait_result = WaitForMultipleObjects(arraysize(threads),
+ threads, TRUE, thread_timeout_ms);
+ if (wait_result == WAIT_TIMEOUT) {
+ // Threads did not finish after waiting a little while. Perhaps the
+ // server didn't close pipes, or it is hung.
+ fprintf(stderr, "Timed-out waiting for threads to finish reading from "
+ "ADB Server\n");
+ // Process handles are signaled when the process exits, so if we wait
+ // on the handle for 0 seconds and it returns 'timeout', that means that
+ // the process is still running.
+ if (WaitForSingleObject(process_handle.get(), 0) == WAIT_TIMEOUT) {
+ // We could TerminateProcess(), but that seems somewhat presumptive.
+ fprintf(stderr, "ADB Server is running: process id %lu\n",
+ pinfo.dwProcessId);
}
+ return -1;
+ }
+
+ if (wait_result != WAIT_OBJECT_0) {
+ fprintf(stderr, "Unexpected result waiting for threads: %lu: %s\n",
+ wait_result, SystemErrorCodeToString(GetLastError()).c_str());
+ return -1;
+ }
+
+ // For now ignore the thread exit codes and assume they worked properly.
+
+ if (!got_ack) {
+ return -1;
}
#else /* !defined(_WIN32) */
char path[PATH_MAX];