Merge "libprocinfo: return error msg instead of printing it." (220c1d55) · Commits · e / os / android_system_core

libprocinfo/include/procinfo/process.h

+17 −9

Original line number	Diff line number	Diff line
		@@ -56,23 +56,25 @@ struct ProcessInfo {
		};

		// Parse the contents of /proc/<tid>/status into \|process_info\|.
		bool GetProcessInfo(pid_t tid, ProcessInfo* process_info);
		bool GetProcessInfo(pid_t tid, ProcessInfo* process_info, std::string* error = nullptr);

		// Parse the contents of <fd>/status into \|process_info\|.
		// \|fd\| should be an fd pointing at a /proc/<pid> directory.
		bool GetProcessInfoFromProcPidFd(int fd, ProcessInfo* process_info);
		bool GetProcessInfoFromProcPidFd(int fd, ProcessInfo* process_info, std::string* error = nullptr);

		// Fetch the list of threads from a given process's /proc/<pid> directory.
		// \|fd\| should be an fd pointing at a /proc/<pid> directory.
		template <typename Collection>
		auto GetProcessTidsFromProcPidFd(int fd, Collection* out) ->
		auto GetProcessTidsFromProcPidFd(int fd, Collection* out, std::string* error = nullptr) ->
		typename std::enable_if<sizeof(typename Collection::value_type) >= sizeof(pid_t), bool>::type {
		out->clear();

		int task_fd = openat(fd, "task", O_DIRECTORY \| O_RDONLY \| O_CLOEXEC);
		std::unique_ptr<DIR, int ()(DIR)> dir(fdopendir(task_fd), closedir);
		if (!dir) {
		PLOG(ERROR) << "failed to open task directory";
		if (error != nullptr) {
		*error = "failed to open task directory";
		}
		return false;
		}

		@@ -81,7 +83,9 @@ auto GetProcessTidsFromProcPidFd(int fd, Collection* out) ->
		if (strcmp(dent->d_name, ".") != 0 && strcmp(dent->d_name, "..") != 0) {
		pid_t tid;
		if (!android::base::ParseInt(dent->d_name, &tid, 1, std::numeric_limits<pid_t>::max())) {
		LOG(ERROR) << "failed to parse task id: " << dent->d_name;
		if (error != nullptr) {
		*error = std::string("failed to parse task id: ") + dent->d_name;
		}
		return false;
		}

		@@ -93,21 +97,25 @@ auto GetProcessTidsFromProcPidFd(int fd, Collection* out) ->
		}

		template <typename Collection>
		auto GetProcessTids(pid_t pid, Collection* out) ->
		auto GetProcessTids(pid_t pid, Collection* out, std::string* error = nullptr) ->
		typename std::enable_if<sizeof(typename Collection::value_type) >= sizeof(pid_t), bool>::type {
		char task_path[PATH_MAX];
		if (snprintf(task_path, PATH_MAX, "/proc/%d", pid) >= PATH_MAX) {
		LOG(ERROR) << "task path overflow (pid = " << pid << ")";
		if (error != nullptr) {
		*error = "task path overflow (pid = " + std::to_string(pid) + ")";
		}
		return false;
		}

		android::base::unique_fd fd(open(task_path, O_DIRECTORY \| O_RDONLY \| O_CLOEXEC));
		if (fd == -1) {
		PLOG(ERROR) << "failed to open " << task_path;
		if (error != nullptr) {
		*error = std::string("failed to open ") + task_path;
		}
		return false;
		}

		return GetProcessTidsFromProcPidFd(fd.get(), out);
		return GetProcessTidsFromProcPidFd(fd.get(), out, error);
		}

		#endif

libprocinfo/process.cpp

+12 −6

Original line number	Diff line number	Diff line
		@@ -31,17 +31,19 @@ using android::base::unique_fd;
		namespace android {
		namespace procinfo {

		bool GetProcessInfo(pid_t tid, ProcessInfo* process_info) {
		bool GetProcessInfo(pid_t tid, ProcessInfo* process_info, std::string* error) {
		char path[PATH_MAX];
		snprintf(path, sizeof(path), "/proc/%d", tid);

		unique_fd dirfd(open(path, O_DIRECTORY \| O_RDONLY));
		if (dirfd == -1) {
		PLOG(ERROR) << "failed to open " << path;
		if (error != nullptr) {
		*error = std::string("failed to open ") + path;
		}
		return false;
		}

		return GetProcessInfoFromProcPidFd(dirfd.get(), process_info);
		return GetProcessInfoFromProcPidFd(dirfd.get(), process_info, error);
		}

		static ProcessState parse_state(const char* state) {
		@@ -62,17 +64,21 @@ static ProcessState parse_state(const char* state) {
		}
		}

		bool GetProcessInfoFromProcPidFd(int fd, ProcessInfo* process_info) {
		bool GetProcessInfoFromProcPidFd(int fd, ProcessInfo* process_info, std::string* error) {
		int status_fd = openat(fd, "status", O_RDONLY \| O_CLOEXEC);

		if (status_fd == -1) {
		PLOG(ERROR) << "failed to open status fd in GetProcessInfoFromProcPidFd";
		if (error != nullptr) {
		*error = "failed to open status fd in GetProcessInfoFromProcPidFd";
		}
		return false;
		}

		std::unique_ptr<FILE, decltype(&fclose)> fp(fdopen(status_fd, "r"), fclose);
		if (!fp) {
		PLOG(ERROR) << "failed to open status file in GetProcessInfoFromProcPidFd";
		if (error != nullptr) {
		*error = "failed to open status file in GetProcessInfoFromProcPidFd";
		}
		close(status_fd);
		return false;
		}