Merge "debuggerd: simplify output handling" (34de7475) · Commits · e / os / android_system_core

debuggerd/client/debuggerd_client.cpp

+7 −0

Original line number	Diff line number	Diff line
		@@ -276,6 +276,13 @@ bool debuggerd_trigger_dump(pid_t tid, DebuggerdDumpType dump_type, unsigned int
		return false;
		}

		// WARNING: It's not possible to replace the below with a splice call.
		// Due to the way debuggerd does many small writes across the pipe,
		// this would cause splice to copy a page for each write. The second
		// pipe fills up based on the number of pages being copied, even
		// though there is not much data being transferred per page. When
		// the second pipe is full, everything stops since there is nothing
		// reading the second pipe to clear it.
		char buf[1024];
		rc = TEMP_FAILURE_RETRY(read(pipe_read.get(), buf, sizeof(buf)));
		if (rc == 0) {

+4 −24

Original line number	Diff line number	Diff line
		@@ -41,22 +41,6 @@ static void usage(int exit_code) {
		_exit(exit_code);
		}

		static std::thread spawn_redirect_thread(unique_fd fd) {
		return std::thread([fd{ std::move(fd) }]() {
		while (true) {
		char buf[BUFSIZ];
		ssize_t rc = TEMP_FAILURE_RETRY(read(fd.get(), buf, sizeof(buf)));
		if (rc <= 0) {
		return;
		}

		if (!android::base::WriteFully(STDOUT_FILENO, buf, rc)) {
		return;
		}
		}
		});
		}

		int main(int argc, char* argv[]) {
		if (argc <= 1) usage(0);
		if (argc > 3) usage(1);
		@@ -107,14 +91,11 @@ int main(int argc, char* argv[]) {
		}
		}

		unique_fd piperead, pipewrite;
		if (!Pipe(&piperead, &pipewrite)) {
		err(1, "failed to create pipe");
		unique_fd output_fd(fcntl(STDOUT_FILENO, F_DUPFD_CLOEXEC, 0));
		if (output_fd.get() == -1) {
		err(1, "failed to fcntl dup stdout");
		}

		std::thread redirect_thread = spawn_redirect_thread(std::move(piperead));
		if (!debuggerd_trigger_dump(proc_info.pid, dump_type, 0, std::move(pipewrite))) {
		redirect_thread.join();
		if (!debuggerd_trigger_dump(proc_info.pid, dump_type, 0, std::move(output_fd))) {
		if (pid == proc_info.pid) {
		errx(1, "failed to dump process %d", pid);
		} else {
		@@ -122,6 +103,5 @@ int main(int argc, char* argv[]) {
		}
		}

		redirect_thread.join();
		return 0;
		}