#include "task.h" #include <errno.h> #include <fcntl.h> #include <log/log.h> #include <stdio.h> #include <cctype> #include <cstdlib> #include <memory> #include <sstream> #include <android-base/unique_fd.h> #include "stdio_filebuf.h" #include "string_trim.h" namespace { const char kProcBase[] = "/proc"; android::base::unique_fd OpenTaskDirectory(pid_t task_id) { std::ostringstream stream; stream << kProcBase << "/" << task_id; return android::base::unique_fd( open(stream.str().c_str(), O_RDONLY | O_DIRECTORY)); } void ParseUidStatusField(const std::string& value, std::array<int, 4>& ids) { const char* start = value.c_str(); ids[0] = std::strtol(start, const_cast<char**>(&start), 10); ids[1] = std::strtol(start, const_cast<char**>(&start), 10); ids[2] = std::strtol(start, const_cast<char**>(&start), 10); ids[3] = std::strtol(start, const_cast<char**>(&start), 10); } } // anonymous namespace namespace android { namespace dvr { Task::Task(pid_t task_id) : task_id_(task_id), thread_group_id_(-1), parent_process_id_(-1), thread_count_(0), cpus_allowed_mask_(0) { task_fd_ = OpenTaskDirectory(task_id_); ALOGE_IF(task_fd_.get() < 0, "Task::Task: Failed to open task directory for task_id=%d: %s", task_id, strerror(errno)); ReadStatusFields(); ALOGD_IF(TRACE, "Task::Task: task_id=%d name=%s tgid=%d ppid=%d cpu_mask=%x", task_id_, name_.c_str(), thread_group_id_, parent_process_id_, cpus_allowed_mask_); } base::unique_fd Task::OpenTaskFile(const std::string& name) const { const std::string relative_path = "./" + name; return base::unique_fd( openat(task_fd_.get(), relative_path.c_str(), O_RDONLY)); } UniqueFile Task::OpenTaskFilePointer(const std::string& name) const { const std::string relative_path = "./" + name; base::unique_fd fd(openat(task_fd_.get(), relative_path.c_str(), O_RDONLY)); if (fd.get() < 0) { ALOGE("Task::OpenTaskFilePointer: Failed to open /proc/%d/%s: %s", task_id_, name.c_str(), strerror(errno)); return nullptr; } UniqueFile fp(fdopen(fd.release(), "r")); if (!fp) ALOGE("Task::OpenTaskFilePointer: Failed to fdopen /proc/%d/%s: %s", task_id_, name.c_str(), strerror(errno)); return fp; } std::string Task::GetStatusField(const std::string& field) const { if (auto file = OpenTaskFilePointer("status")) { stdio_filebuf<char> filebuf(file.get()); std::istream file_stream(&filebuf); for (std::string line; std::getline(file_stream, line);) { auto offset = line.find(field); ALOGD_IF(TRACE, "Task::GetStatusField: field=\"%s\" line=\"%s\" offset=%zd", field.c_str(), line.c_str(), offset); if (offset == std::string::npos) continue; // The status file has lines with the format <field>:<value>. Extract the // value after the colon. return Trim(line.substr(offset + field.size() + 1)); } } return "[unknown]"; } void Task::ReadStatusFields() { if (auto file = OpenTaskFilePointer("status")) { stdio_filebuf<char> filebuf(file.get()); std::istream file_stream(&filebuf); for (std::string line; std::getline(file_stream, line);) { auto offset = line.find(":"); if (offset == std::string::npos) { ALOGW("ReadStatusFields: Failed to find delimiter \":\" in line=\"%s\"", line.c_str()); continue; } std::string key = line.substr(0, offset); std::string value = Trim(line.substr(offset + 1)); ALOGD_IF(TRACE, "Task::ReadStatusFields: key=\"%s\" value=\"%s\"", key.c_str(), value.c_str()); if (key == "Name") name_ = value; else if (key == "Tgid") thread_group_id_ = std::strtol(value.c_str(), nullptr, 10); else if (key == "PPid") parent_process_id_ = std::strtol(value.c_str(), nullptr, 10); else if (key == "Uid") ParseUidStatusField(value, user_id_); else if (key == "Gid") ParseUidStatusField(value, group_id_); else if (key == "Threads") thread_count_ = std::strtoul(value.c_str(), nullptr, 10); else if (key == "Cpus_allowed") cpus_allowed_mask_ = std::strtoul(value.c_str(), nullptr, 16); else if (key == "Cpus_allowed_list") cpus_allowed_list_ = value; } } } std::string Task::GetCpuSetPath() const { if (auto file = OpenTaskFilePointer("cpuset")) { stdio_filebuf<char> filebuf(file.get()); std::istream file_stream(&filebuf); std::string line = ""; std::getline(file_stream, line); return Trim(line); } else { return ""; } } } // namespace dvr } // namespace android