adb: win32: fix start-server to properly display UTF-8 on the console
fwrite() is a macro that maps to adb_fwrite(), which can write UTF-8 to
the console. Use it to write the output that comes from the subprocess
adb server.
To do this, dup the stdout/stderr file descriptor and make a duplicate
FILE* stream, in binary mode (since we're reading raw bytes from the
subprocess), and unbuffered.
Change-Id: I480761bae0bd576dc9e03fa4d31266f4e49635ed
Signed-off-by: Spencer Low <CompareAndSwap@gmail.com>
diff --git a/adb/adb.cpp b/adb/adb.cpp
index 35e5945..58ccd0a 100644
--- a/adb/adb.cpp
+++ b/adb/adb.cpp
@@ -509,14 +509,60 @@
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.
+// Read from a pipe (that we take ownership of) and write the result to stdout/stderr. Return on
+// error or when the pipe is closed. Internally makes inheritable handles, so this should not be
+// called if subprocesses may be started concurrently.
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";
+ const char* output_name = nStdHandle == STD_OUTPUT_HANDLE ? "stdout" : "stderr";
+ const int original_fd = fileno(nStdHandle == STD_OUTPUT_HANDLE ? stdout : stderr);
+ std::unique_ptr<FILE, decltype(&fclose)> stream(nullptr, fclose);
+
+ if (original_fd == -1) {
+ fprintf(stderr, "Failed to get file descriptor for %s: %s\n", output_name, strerror(errno));
+ return EXIT_FAILURE;
+ }
+
+ // If fileno() is -2, stdout/stderr is not associated with an output stream, so we should read,
+ // but don't write. Otherwise, make a FILE* identical to stdout/stderr except that it is in
+ // binary mode with no CR/LR translation since we're reading raw.
+ if (original_fd >= 0) {
+ // This internally makes a duplicate file handle that is inheritable, so callers should not
+ // call this function if subprocesses may be started concurrently.
+ const int fd = dup(original_fd);
+ if (fd == -1) {
+ fprintf(stderr, "Failed to duplicate file descriptor for %s: %s\n", output_name,
+ strerror(errno));
+ return EXIT_FAILURE;
+ }
+
+ // Note that although we call fdopen() below with a binary flag, it may not adhere to that
+ // flag, so we have to set the mode manually.
+ if (_setmode(fd, _O_BINARY) == -1) {
+ fprintf(stderr, "Failed to set binary mode for duplicate of %s: %s\n", output_name,
+ strerror(errno));
+ unix_close(fd);
+ return EXIT_FAILURE;
+ }
+
+ stream.reset(fdopen(fd, "wb"));
+ if (stream.get() == nullptr) {
+ fprintf(stderr, "Failed to open duplicate stream for %s: %s\n", output_name,
+ strerror(errno));
+ unix_close(fd);
+ return EXIT_FAILURE;
+ }
+
+ // Unbuffer the stream because it will be buffered by default and we want subprocess output
+ // to be shown immediately.
+ if (setvbuf(stream.get(), NULL, _IONBF, 0) == -1) {
+ fprintf(stderr, "Failed to unbuffer %s: %s\n", output_name, strerror(errno));
+ return EXIT_FAILURE;
+ }
+
+ // fd will be closed when stream is closed.
+ }
while (true) {
char buf[64 * 1024];
@@ -534,20 +580,13 @@
}
}
- // 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,
- android::base::SystemErrorCodeToString(GetLastError()).c_str());
- return EXIT_FAILURE;
- }
-
+ // Don't try to write if our stdout/stderr was not setup by the parent process.
+ if (stream) {
+ // fwrite() actually calls adb_fwrite() which can write UTF-8 to the console.
+ const size_t bytes_written = fwrite(buf, 1, bytes_read, stream.get());
if (bytes_written != bytes_read) {
- fprintf(stderr, "Only wrote %lu of %lu bytes to %s\n",
- bytes_written, bytes_read, output_name);
+ fprintf(stderr, "Only wrote %zu of %lu bytes to %s\n", bytes_written, bytes_read,
+ output_name);
return EXIT_FAILURE;
}
}
@@ -596,7 +635,10 @@
return -1;
}
- // create pipes with non-inheritable read handle, inheritable write handle
+ // Create pipes with non-inheritable read handle, inheritable write handle. We need to connect
+ // the subprocess to pipes instead of just letting the subprocess inherit our existing
+ // stdout/stderr handles because a DETACHED_PROCESS cannot write to a console that it is not
+ // attached to.
unique_handle ack_read, ack_write;
if (!_create_anonymous_pipe(&ack_read, &ack_write, &sa)) {
return -1;
@@ -704,8 +746,9 @@
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.
+ // Start threads to read from subprocess stdout/stderr and write to ours to make subprocess
+ // errors easier to diagnose. Note that the threads internally create inheritable handles, but
+ // that is ok because we've already spawned the subprocess.
// 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