libprocessgroup: use libcgrouprc to read cgroup.rc
Use the LL-NDK library to read cgroup.rc.
As a side-effect, the CgroupController class is changed
to a wrapper of ACgroupController* from the library. The
class itself essentially becomes the pointer, and can be
trivially copied. Modify all client code for this change.
Test: builds and boots
Bug: 123664216
Change-Id: I635d9885db62e82f37421f6d20f59c84a6f4cbb2
diff --git a/libcutils/Android.bp b/libcutils/Android.bp
index a27ecef..619bc56 100644
--- a/libcutils/Android.bp
+++ b/libcutils/Android.bp
@@ -235,6 +235,7 @@
"libbase",
"libjsoncpp",
"libprocessgroup",
+ "libcgrouprc",
]
cc_test {
@@ -249,7 +250,10 @@
name: "libcutils_test_static",
test_suites: ["device-tests"],
defaults: ["libcutils_test_default"],
- static_libs: ["libc"] + test_libraries,
+ static_libs: [
+ "libc",
+ "libcgrouprc_format",
+ ] + test_libraries,
stl: "libc++_static",
target: {
diff --git a/libprocessgroup/Android.bp b/libprocessgroup/Android.bp
index 07cbce9..78a02e5 100644
--- a/libprocessgroup/Android.bp
+++ b/libprocessgroup/Android.bp
@@ -31,6 +31,7 @@
},
shared_libs: [
"libbase",
+ "libcgrouprc",
"libjsoncpp",
],
// for cutils/android_filesystem_config.h
diff --git a/libprocessgroup/cgroup_map.cpp b/libprocessgroup/cgroup_map.cpp
index 3b852ae..6cd6b6e 100644
--- a/libprocessgroup/cgroup_map.cpp
+++ b/libprocessgroup/cgroup_map.cpp
@@ -48,28 +48,38 @@
static constexpr const char* CGROUP_TASKS_FILE = "/tasks";
static constexpr const char* CGROUP_TASKS_FILE_V2 = "/cgroup.tasks";
-CgroupController::CgroupController(uint32_t version, const std::string& name,
- const std::string& path) {
- version_ = version;
- strncpy(name_, name.c_str(), sizeof(name_) - 1);
- name_[sizeof(name_) - 1] = '\0';
- strncpy(path_, path.c_str(), sizeof(path_) - 1);
- path_[sizeof(path_) - 1] = '\0';
+uint32_t CgroupController::version() const {
+ CHECK(HasValue());
+ return ACgroupController_getVersion(controller_);
}
-std::string CgroupController::GetTasksFilePath(const std::string& path) const {
- std::string tasks_path = path_;
+const char* CgroupController::name() const {
+ CHECK(HasValue());
+ return ACgroupController_getName(controller_);
+}
- if (!path.empty()) {
- tasks_path += "/" + path;
+const char* CgroupController::path() const {
+ CHECK(HasValue());
+ return ACgroupController_getPath(controller_);
+}
+
+bool CgroupController::HasValue() const {
+ return controller_ != nullptr;
+}
+
+std::string CgroupController::GetTasksFilePath(const std::string& rel_path) const {
+ std::string tasks_path = path();
+
+ if (!rel_path.empty()) {
+ tasks_path += "/" + rel_path;
}
- return (version_ == 1) ? tasks_path + CGROUP_TASKS_FILE : tasks_path + CGROUP_TASKS_FILE_V2;
+ return (version() == 1) ? tasks_path + CGROUP_TASKS_FILE : tasks_path + CGROUP_TASKS_FILE_V2;
}
-std::string CgroupController::GetProcsFilePath(const std::string& path, uid_t uid,
+std::string CgroupController::GetProcsFilePath(const std::string& rel_path, uid_t uid,
pid_t pid) const {
- std::string proc_path(path_);
- proc_path.append("/").append(path);
+ std::string proc_path(path());
+ proc_path.append("/").append(rel_path);
proc_path = regex_replace(proc_path, std::regex("<uid>"), std::to_string(uid));
proc_path = regex_replace(proc_path, std::regex("<pid>"), std::to_string(pid));
@@ -90,7 +100,7 @@
return true;
}
- std::string cg_tag = StringPrintf(":%s:", name_);
+ std::string cg_tag = StringPrintf(":%s:", name());
size_t start_pos = content.find(cg_tag);
if (start_pos == std::string::npos) {
return false;
@@ -107,20 +117,12 @@
return true;
}
-CgroupMap::CgroupMap() : cg_file_data_(nullptr), cg_file_size_(0) {
+CgroupMap::CgroupMap() {
if (!LoadRcFile()) {
LOG(ERROR) << "CgroupMap::LoadRcFile called for [" << getpid() << "] failed";
}
}
-CgroupMap::~CgroupMap() {
- if (cg_file_data_) {
- munmap(cg_file_data_, cg_file_size_);
- cg_file_data_ = nullptr;
- cg_file_size_ = 0;
- }
-}
-
CgroupMap& CgroupMap::GetInstance() {
// Deliberately leak this object to avoid a race between destruction on
// process exit and concurrent access from another thread.
@@ -129,85 +131,46 @@
}
bool CgroupMap::LoadRcFile() {
- struct stat sb;
-
- if (cg_file_data_) {
- // Data already initialized
- return true;
+ if (!loaded_) {
+ loaded_ = (ACgroupFile_getVersion() != 0);
}
-
- unique_fd fd(TEMP_FAILURE_RETRY(open(CGROUPS_RC_PATH, O_RDONLY | O_CLOEXEC)));
- if (fd < 0) {
- PLOG(ERROR) << "open() failed for " << CGROUPS_RC_PATH;
- return false;
- }
-
- if (fstat(fd, &sb) < 0) {
- PLOG(ERROR) << "fstat() failed for " << CGROUPS_RC_PATH;
- return false;
- }
-
- size_t file_size = sb.st_size;
- if (file_size < sizeof(CgroupFile)) {
- LOG(ERROR) << "Invalid file format " << CGROUPS_RC_PATH;
- return false;
- }
-
- CgroupFile* file_data = (CgroupFile*)mmap(nullptr, file_size, PROT_READ, MAP_SHARED, fd, 0);
- if (file_data == MAP_FAILED) {
- PLOG(ERROR) << "Failed to mmap " << CGROUPS_RC_PATH;
- return false;
- }
-
- if (file_data->version_ != CgroupFile::FILE_CURR_VERSION) {
- LOG(ERROR) << CGROUPS_RC_PATH << " file version mismatch";
- munmap(file_data, file_size);
- return false;
- }
-
- if (file_size != sizeof(CgroupFile) + file_data->controller_count_ * sizeof(CgroupController)) {
- LOG(ERROR) << CGROUPS_RC_PATH << " file has invalid size";
- munmap(file_data, file_size);
- return false;
- }
-
- cg_file_data_ = file_data;
- cg_file_size_ = file_size;
-
- return true;
+ return loaded_;
}
void CgroupMap::Print() const {
- if (!cg_file_data_) {
+ if (!loaded_) {
LOG(ERROR) << "CgroupMap::Print called for [" << getpid()
<< "] failed, RC file was not initialized properly";
return;
}
- LOG(INFO) << "File version = " << cg_file_data_->version_;
- LOG(INFO) << "File controller count = " << cg_file_data_->controller_count_;
+ LOG(INFO) << "File version = " << ACgroupFile_getVersion();
+ LOG(INFO) << "File controller count = " << ACgroupFile_getControllerCount();
LOG(INFO) << "Mounted cgroups:";
- CgroupController* controller = (CgroupController*)(cg_file_data_ + 1);
- for (int i = 0; i < cg_file_data_->controller_count_; i++, controller++) {
- LOG(INFO) << "\t" << controller->name() << " ver " << controller->version() << " path "
- << controller->path();
+
+ auto controller_count = ACgroupFile_getControllerCount();
+ for (uint32_t i = 0; i < controller_count; ++i) {
+ const ACgroupController* controller = ACgroupFile_getController(i);
+ LOG(INFO) << "\t" << ACgroupController_getName(controller) << " ver "
+ << ACgroupController_getVersion(controller) << " path "
+ << ACgroupController_getPath(controller);
}
}
-const CgroupController* CgroupMap::FindController(const std::string& name) const {
- if (!cg_file_data_) {
+CgroupController CgroupMap::FindController(const std::string& name) const {
+ if (!loaded_) {
LOG(ERROR) << "CgroupMap::FindController called for [" << getpid()
<< "] failed, RC file was not initialized properly";
- return nullptr;
+ return CgroupController(nullptr);
}
- // skip the file header to get to the first controller
- CgroupController* controller = (CgroupController*)(cg_file_data_ + 1);
- for (int i = 0; i < cg_file_data_->controller_count_; i++, controller++) {
- if (name == controller->name()) {
- return controller;
+ auto controller_count = ACgroupFile_getControllerCount();
+ for (uint32_t i = 0; i < controller_count; ++i) {
+ const ACgroupController* controller = ACgroupFile_getController(i);
+ if (name == ACgroupController_getName(controller)) {
+ return CgroupController(controller);
}
}
- return nullptr;
+ return CgroupController(nullptr);
}
diff --git a/libprocessgroup/cgroup_map.h b/libprocessgroup/cgroup_map.h
index 044510b..d765e60 100644
--- a/libprocessgroup/cgroup_map.h
+++ b/libprocessgroup/cgroup_map.h
@@ -20,39 +20,30 @@
#include <sys/types.h>
#include <map>
+#include <memory>
#include <mutex>
#include <string>
+#include <vector>
-// Minimal controller description to be mmapped into process address space
+#include <android/cgrouprc.h>
+
+// Convenient wrapper of an ACgroupController pointer.
class CgroupController {
public:
- CgroupController() {}
- CgroupController(uint32_t version, const std::string& name, const std::string& path);
+ // Does not own controller
+ explicit CgroupController(const ACgroupController* controller) : controller_(controller) {}
- uint32_t version() const { return version_; }
- const char* name() const { return name_; }
- const char* path() const { return path_; }
+ uint32_t version() const;
+ const char* name() const;
+ const char* path() const;
+
+ bool HasValue() const;
std::string GetTasksFilePath(const std::string& path) const;
std::string GetProcsFilePath(const std::string& path, uid_t uid, pid_t pid) const;
bool GetTaskGroup(int tid, std::string* group) const;
-
private:
- static constexpr size_t CGROUP_NAME_BUF_SZ = 16;
- static constexpr size_t CGROUP_PATH_BUF_SZ = 32;
-
- uint32_t version_;
- char name_[CGROUP_NAME_BUF_SZ];
- char path_[CGROUP_PATH_BUF_SZ];
-};
-
-struct CgroupFile {
- static constexpr uint32_t FILE_VERSION_1 = 1;
- static constexpr uint32_t FILE_CURR_VERSION = FILE_VERSION_1;
-
- uint32_t version_;
- uint32_t controller_count_;
- CgroupController controllers_[];
+ const ACgroupController* controller_ = nullptr;
};
class CgroupMap {
@@ -61,16 +52,11 @@
static bool SetupCgroups();
static CgroupMap& GetInstance();
-
- const CgroupController* FindController(const std::string& name) const;
+ CgroupController FindController(const std::string& name) const;
private:
- struct CgroupFile* cg_file_data_;
- size_t cg_file_size_;
-
+ bool loaded_ = false;
CgroupMap();
- ~CgroupMap();
-
bool LoadRcFile();
void Print() const;
};
diff --git a/libprocessgroup/cgrouprc/Android.bp b/libprocessgroup/cgrouprc/Android.bp
index f5ff7eb..774738d 100644
--- a/libprocessgroup/cgrouprc/Android.bp
+++ b/libprocessgroup/cgrouprc/Android.bp
@@ -12,10 +12,15 @@
// See the License for the specific language governing permissions and
// limitations under the License.
-cc_library_shared {
+cc_library {
name: "libcgrouprc",
host_supported: true,
recovery_available: true,
+ // Do not ever mark this as vendor_available; otherwise, vendor modules
+ // that links to the static library will behave unexpectedly. All on-device
+ // modules should use libprocessgroup which links to the LL-NDK library
+ // defined below. The static library is built for tests.
+ vendor_available: false,
srcs: [
"cgroup_controller.cpp",
"cgroup_file.cpp",
diff --git a/libprocessgroup/processgroup.cpp b/libprocessgroup/processgroup.cpp
index 3f6b2d7..abe63dd 100644
--- a/libprocessgroup/processgroup.cpp
+++ b/libprocessgroup/processgroup.cpp
@@ -56,14 +56,14 @@
#define PROCESSGROUP_CGROUP_PROCS_FILE "/cgroup.procs"
bool CgroupGetControllerPath(const std::string& cgroup_name, std::string* path) {
- const CgroupController* controller = CgroupMap::GetInstance().FindController(cgroup_name);
+ auto controller = CgroupMap::GetInstance().FindController(cgroup_name);
- if (controller == nullptr) {
+ if (!controller.HasValue()) {
return false;
}
if (path) {
- *path = controller->path();
+ *path = controller.path();
}
return true;
@@ -107,7 +107,7 @@
static bool isMemoryCgroupSupported() {
std::string cgroup_name;
- static bool memcg_supported = (CgroupMap::GetInstance().FindController("memory") != nullptr);
+ static bool memcg_supported = CgroupMap::GetInstance().FindController("memory").HasValue();
return memcg_supported;
}
diff --git a/libprocessgroup/sched_policy.cpp b/libprocessgroup/sched_policy.cpp
index 1eefada..c7d0cca 100644
--- a/libprocessgroup/sched_policy.cpp
+++ b/libprocessgroup/sched_policy.cpp
@@ -152,21 +152,21 @@
}
bool cpusets_enabled() {
- static bool enabled = (CgroupMap::GetInstance().FindController("cpuset") != nullptr);
+ static bool enabled = (CgroupMap::GetInstance().FindController("cpuset").HasValue());
return enabled;
}
bool schedboost_enabled() {
- static bool enabled = (CgroupMap::GetInstance().FindController("schedtune") != nullptr);
+ static bool enabled = (CgroupMap::GetInstance().FindController("schedtune").HasValue());
return enabled;
}
static int getCGroupSubsys(int tid, const char* subsys, std::string& subgroup) {
- const CgroupController* controller = CgroupMap::GetInstance().FindController(subsys);
+ auto controller = CgroupMap::GetInstance().FindController(subsys);
- if (!controller) return -1;
+ if (!controller.HasValue()) return -1;
- if (!controller->GetTaskGroup(tid, &subgroup)) {
+ if (!controller.GetTaskGroup(tid, &subgroup)) {
LOG(ERROR) << "Failed to find cgroup for tid " << tid;
return -1;
}
diff --git a/libprocessgroup/task_profiles.cpp b/libprocessgroup/task_profiles.cpp
index 9362c03..4b45c87 100644
--- a/libprocessgroup/task_profiles.cpp
+++ b/libprocessgroup/task_profiles.cpp
@@ -46,7 +46,7 @@
bool ProfileAttribute::GetPathForTask(int tid, std::string* path) const {
std::string subgroup;
- if (!controller_->GetTaskGroup(tid, &subgroup)) {
+ if (!controller()->GetTaskGroup(tid, &subgroup)) {
return false;
}
@@ -55,9 +55,10 @@
}
if (subgroup.empty()) {
- *path = StringPrintf("%s/%s", controller_->path(), file_name_.c_str());
+ *path = StringPrintf("%s/%s", controller()->path(), file_name_.c_str());
} else {
- *path = StringPrintf("%s/%s/%s", controller_->path(), subgroup.c_str(), file_name_.c_str());
+ *path = StringPrintf("%s/%s/%s", controller()->path(), subgroup.c_str(),
+ file_name_.c_str());
}
return true;
}
@@ -135,7 +136,7 @@
return path.find("<uid>", 0) != std::string::npos || path.find("<pid>", 0) != std::string::npos;
}
-SetCgroupAction::SetCgroupAction(const CgroupController* c, const std::string& p)
+SetCgroupAction::SetCgroupAction(const CgroupController& c, const std::string& p)
: controller_(c), path_(p) {
#ifdef CACHE_FILE_DESCRIPTORS
// cache file descriptor only if path is app independent
@@ -145,7 +146,7 @@
return;
}
- std::string tasks_path = c->GetTasksFilePath(p.c_str());
+ std::string tasks_path = c.GetTasksFilePath(p);
if (access(tasks_path.c_str(), W_OK) != 0) {
// file is not accessible
@@ -199,7 +200,7 @@
}
// this is app-dependent path, file descriptor is not cached
- std::string procs_path = controller_->GetProcsFilePath(path_, uid, pid);
+ std::string procs_path = controller()->GetProcsFilePath(path_, uid, pid);
unique_fd tmp_fd(TEMP_FAILURE_RETRY(open(procs_path.c_str(), O_WRONLY | O_CLOEXEC)));
if (tmp_fd < 0) {
PLOG(WARNING) << "Failed to open " << procs_path;
@@ -212,7 +213,7 @@
return true;
#else
- std::string procs_path = controller_->GetProcsFilePath(path_, uid, pid);
+ std::string procs_path = controller()->GetProcsFilePath(path_, uid, pid);
unique_fd tmp_fd(TEMP_FAILURE_RETRY(open(procs_path.c_str(), O_WRONLY | O_CLOEXEC)));
if (tmp_fd < 0) {
// no permissions to access the file, ignore
@@ -247,7 +248,7 @@
LOG(ERROR) << "Application profile can't be applied to a thread";
return false;
#else
- std::string tasks_path = controller_->GetTasksFilePath(path_);
+ std::string tasks_path = controller()->GetTasksFilePath(path_);
unique_fd tmp_fd(TEMP_FAILURE_RETRY(open(tasks_path.c_str(), O_WRONLY | O_CLOEXEC)));
if (tmp_fd < 0) {
// no permissions to access the file, ignore
@@ -326,8 +327,8 @@
std::string file_attr = attr[i]["File"].asString();
if (attributes_.find(name) == attributes_.end()) {
- const CgroupController* controller = cg_map.FindController(controller_name);
- if (controller) {
+ auto controller = cg_map.FindController(controller_name);
+ if (controller.HasValue()) {
attributes_[name] = std::make_unique<ProfileAttribute>(controller, file_attr);
} else {
LOG(WARNING) << "Controller " << controller_name << " is not found";
@@ -355,8 +356,8 @@
std::string controller_name = params_val["Controller"].asString();
std::string path = params_val["Path"].asString();
- const CgroupController* controller = cg_map.FindController(controller_name);
- if (controller) {
+ auto controller = cg_map.FindController(controller_name);
+ if (controller.HasValue()) {
profile->Add(std::make_unique<SetCgroupAction>(controller, path));
} else {
LOG(WARNING) << "JoinCgroup: controller " << controller_name << " is not found";
diff --git a/libprocessgroup/task_profiles.h b/libprocessgroup/task_profiles.h
index 9ee81c1..37cc305 100644
--- a/libprocessgroup/task_profiles.h
+++ b/libprocessgroup/task_profiles.h
@@ -27,16 +27,16 @@
class ProfileAttribute {
public:
- ProfileAttribute(const CgroupController* controller, const std::string& file_name)
+ ProfileAttribute(const CgroupController& controller, const std::string& file_name)
: controller_(controller), file_name_(file_name) {}
- const CgroupController* controller() const { return controller_; }
+ const CgroupController* controller() const { return &controller_; }
const std::string& file_name() const { return file_name_; }
bool GetPathForTask(int tid, std::string* path) const;
private:
- const CgroupController* controller_;
+ CgroupController controller_;
std::string file_name_;
};
@@ -106,16 +106,16 @@
// Set cgroup profile element
class SetCgroupAction : public ProfileAction {
public:
- SetCgroupAction(const CgroupController* c, const std::string& p);
+ SetCgroupAction(const CgroupController& c, const std::string& p);
virtual bool ExecuteForProcess(uid_t uid, pid_t pid) const;
virtual bool ExecuteForTask(int tid) const;
- const CgroupController* controller() const { return controller_; }
+ const CgroupController* controller() const { return &controller_; }
std::string path() const { return path_; }
private:
- const CgroupController* controller_;
+ CgroupController controller_;
std::string path_;
#ifdef CACHE_FILE_DESCRIPTORS
android::base::unique_fd fd_;