Merge "[ravenwood] Better log redirection to stdout" into main (d891e96b) · Commits · e / os / android_frameworks_base

ravenwood/runtime-jni/ravenwood_initializer.cpp

+73 −4

Original line number	Diff line number	Diff line
		@@ -26,6 +26,10 @@
		#include <fcntl.h>

		#include <set>
		#include <fstream>
		#include <iostream>
		#include <string>
		#include <cstdlib>

		#include "jni_helper.h"

		@@ -182,17 +186,82 @@ static jboolean removeSystemProperty(JNIEnv* env, jclass, jstring javaKey) {
		}
		}

		// Find the PPID of child_pid using /proc/N/stat. The 4th field is the PPID.
		// Also returns child_pid's process name (2nd field).
		static pid_t getppid_of(pid_t child_pid, std::string& out_process_name) {
		if (child_pid < 0) {
		return -1;
		}
		std::string stat_file = "/proc/" + std::to_string(child_pid) + "/stat";
		std::ifstream stat_stream(stat_file);
		if (!stat_stream.is_open()) {
		ALOGW("Unable to open '%s': %s", stat_file.c_str(), strerror(errno));
		return -1;
		}

		std::string field;
		int field_count = 0;
		while (std::getline(stat_stream, field, ' ')) {
		if (++field_count == 4) {
		return atoi(field.c_str());
		}
		if (field_count == 2) {
		out_process_name = field;
		}
		}
		ALOGW("Unexpected format in '%s'", stat_file.c_str());
		return -1;
		}

		// Find atest's PID. Climb up the process tree, and find "atest-py3".
		static pid_t find_atest_pid() {
		auto ret = getpid(); // self (isolation runner process)

		while (ret != -1) {
		std::string proc;
		ret = getppid_of(ret, proc);
		if (proc == "(atest-py3)") {
		return ret;
		}
		}

		return ret;
		}

		// If $RAVENWOOD_LOG_OUT is set, redirect stdout/err to this file.
		// Originally it was added to allow to monitor log in realtime, with
		// RAVENWOOD_LOG_OUT=$(tty) atest...
		//
		// As a special case, if $RAVENWOOD_LOG_OUT is set to "-", we try to find
		// atest's process and send the output to its stdout. It's sort of hacky, but
		// this allows shell redirection to work on Ravenwood output too,
		// so e.g. `atest ... \|tee atest.log` would work on Ravenwood's output.
		// (which wouldn't work with `RAVENWOOD_LOG_OUT=$(tty)`).
		//
		// Otherwise -- if $RAVENWOOD_LOG_OUT isn't set -- atest/tradefed just writes
		// the test's output to its own log file.
		static void maybeRedirectLog() {
		auto ravenwoodLogOut = getenv("RAVENWOOD_LOG_OUT");
		if (ravenwoodLogOut == NULL) {
		if (ravenwoodLogOut == NULL \|\| *ravenwoodLogOut == '\0') {
		return;
		}
		ALOGI("RAVENWOOD_LOG_OUT set. Redirecting output to %s", ravenwoodLogOut);
		std::string path;
		if (strcmp("-", ravenwoodLogOut) == 0) {
		pid_t ppid = find_atest_pid();
		if (ppid < 0) {
		ALOGI("RAVENWOOD_LOG_OUT set to '-', but unable to find atest's PID");
		return;
		}
		path = std::format("/proc/{}/fd/1", ppid);
		} else {
		path = ravenwoodLogOut;
		}
		ALOGI("RAVENWOOD_LOG_OUT set. Redirecting output to '%s'", path.c_str());

		// Redirect stdin / stdout to /dev/tty.
		int ttyFd = open(ravenwoodLogOut, O_WRONLY \| O_APPEND);
		int ttyFd = open(path.c_str(), O_WRONLY \| O_APPEND);
		if (ttyFd == -1) {
		ALOGW("$RAVENWOOD_LOG_OUT is set to %s, but failed to open: %s ", ravenwoodLogOut,
		ALOGW("$RAVENWOOD_LOG_OUT is set, but failed to open '%s': %s ", path.c_str(),
		strerror(errno));
		return;
		}