dumpsys: use a socket for dumping, add timeout support. am: 4b8f6f9adb (7f60e002) · Commits · e / os / android_frameworks_native

cmds/dumpsys/Android.mk

+2 −1

Original line number	Diff line number	Diff line
		@@ -5,6 +5,7 @@ LOCAL_SRC_FILES:= \
		dumpsys.cpp

		LOCAL_SHARED_LIBRARIES := \
		libbase \
		libutils \
		liblog \
		libbinder

cmds/dumpsys/dumpsys.cpp

+110 −13

Original line number	Diff line number	Diff line
		@@ -5,21 +5,33 @@

		#define LOG_TAG "dumpsys"

		#include <utils/Log.h>
		#include <algorithm>
		#include <chrono>
		#include <thread>

		#include <android-base/file.h>
		#include <android-base/unique_fd.h>
		#include <binder/IServiceManager.h>
		#include <binder/Parcel.h>
		#include <binder/ProcessState.h>
		#include <binder/IServiceManager.h>
		#include <binder/TextOutput.h>
		#include <utils/Log.h>
		#include <utils/Vector.h>

		#include <fcntl.h>
		#include <getopt.h>
		#include <stdlib.h>
		#include <stdio.h>
		#include <stdlib.h>
		#include <string.h>
		#include <unistd.h>
		#include <sys/poll.h>
		#include <sys/socket.h>
		#include <sys/time.h>
		#include <sys/types.h>
		#include <unistd.h>

		using namespace android;
		using android::base::unique_fd;
		using android::base::WriteFully;

		static int sort_func(const String16* lhs, const String16* rhs)
		{
		@@ -122,22 +134,107 @@ int main(int argc, char* const argv[])
		}

		for (size_t i = 0; i < N; i++) {
		if (IsSkipped(skippedServices, services[i])) continue;
		String16 service_name = std::move(services[i]);
		if (IsSkipped(skippedServices, service_name)) continue;

		sp<IBinder> service = sm->checkService(services[i]);
		sp<IBinder> service = sm->checkService(service_name);
		if (service != NULL) {
		int sfd[2];

		// Use a socketpair instead of a pipe to avoid sending SIGPIPE to services that timeout.
		if (socketpair(AF_UNIX, SOCK_STREAM, 0, sfd) != 0) {
		aerr << "Failed to create socketpair to dump service info for " << service_name
		<< ": " << strerror(errno) << endl;
		continue;
		}

		unique_fd local_end(sfd[0]);
		unique_fd remote_end(sfd[1]);
		sfd[0] = sfd[1] = -1;

		if (N > 1) {
		aout << "------------------------------------------------------------"
		"-------------------" << endl;
		aout << "DUMP OF SERVICE " << services[i] << ":" << endl;
		aout << "DUMP OF SERVICE " << service_name << ":" << endl;
		}
		int err = service->dump(STDOUT_FILENO, args);

		// dump blocks until completion, so spawn a thread..
		std::thread dump_thread([=, remote_end { std::move(remote_end) }]() mutable {
		int err = service->dump(remote_end.get(), args);

		// It'd be nice to be able to close the remote end of the socketpair before the dump
		// call returns, to terminate our reads if the other end closes their copy of the
		// file descriptor, but then hangs for some reason. There doesn't seem to be a good
		// way to do this, though.
		remote_end.clear();

		if (err != 0) {
		aerr << "Error dumping service info: (" << strerror(err)
		<< ") " << services[i] << endl;
		aerr << "Error dumping service info: (" << strerror(err) << ") " << service_name
		<< endl;
		}
		});

		// TODO: Make this configurable at runtime.
		constexpr auto timeout = std::chrono::seconds(10);
		auto end = std::chrono::steady_clock::now() + timeout;

		struct pollfd pfd = {
		.fd = local_end.get(),
		.events = POLLIN
		};

		bool timed_out = false;
		bool error = false;
		while (true) {
		// Wrap this in a lambda so that TEMP_FAILURE_RETRY recalculates the timeout.
		auto time_left_ms = [end]() {
		auto now = std::chrono::steady_clock::now();
		auto diff = std::chrono::duration_cast<std::chrono::milliseconds>(end - now);
		return std::max(diff.count(), 0ll);
		};

		int rc = TEMP_FAILURE_RETRY(poll(&pfd, 1, time_left_ms()));
		if (rc < 0) {
		aerr << "Error in poll while dumping service " << service_name << " : "
		<< strerror(errno) << endl;
		error = true;
		break;
		} else if (rc == 0) {
		timed_out = true;
		break;
		}

		char buf[4096];
		rc = TEMP_FAILURE_RETRY(read(local_end.get(), buf, sizeof(buf)));
		if (rc < 0) {
		aerr << "Failed to read while dumping service " << service_name << ": "
		<< strerror(errno) << endl;
		error = true;
		break;
		} else if (rc == 0) {
		// EOF.
		break;
		}

		if (!WriteFully(STDOUT_FILENO, buf, rc)) {
		aerr << "Failed to write while dumping service " << service_name << ": "
		<< strerror(errno) << endl;
		error = true;
		break;
		}
		}

		if (timed_out) {
		aout << endl << "* SERVICE DUMP TIMEOUT EXPIRED *" << endl << endl;
		}

		if (timed_out \|\| error) {
		dump_thread.detach();
		} else {
		dump_thread.join();
		}
		} else {
		aerr << "Can't find service: " << services[i] << endl;
		aerr << "Can't find service: " << service_name << endl;
		}
		}