libprocessgroup: Add support for task profiles

Abstract usage of cgroups into task profiles that allows for changes
in cgroup hierarchy and version without affecting framework codebase.
Rework current processgroup and sched_policy API function implementations
to use task profiles instead of hardcoded paths and attributes.
Mount cgroups using information from cgroups.json rather than from init.rc

Exempt-From-Owner-Approval: already approved in internal master

Bug: 111307099
Test: builds, boots

Change-Id: If5532d6dc570add825cebd5b5148e00c7d688e32
Merged-In: If5532d6dc570add825cebd5b5148e00c7d688e32
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
diff --git a/libprocessgroup/task_profiles.h b/libprocessgroup/task_profiles.h
new file mode 100644
index 0000000..684762a
--- /dev/null
+++ b/libprocessgroup/task_profiles.h
@@ -0,0 +1,140 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <sys/cdefs.h>
+#include <sys/types.h>
+#include <map>
+#include <string>
+#include <vector>
+
+#include <android-base/unique_fd.h>
+#include <cgroup_map.h>
+
+class ProfileAttribute {
+  public:
+    ProfileAttribute(const CgroupController* controller, const std::string& file_name)
+        : controller_(controller), file_name_(file_name) {}
+
+    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_;
+    std::string file_name_;
+};
+
+// Abstract profile element
+class ProfileAction {
+  public:
+    virtual ~ProfileAction() {}
+
+    // Default implementations will fail
+    virtual bool ExecuteForProcess(uid_t, pid_t) const { return -1; };
+    virtual bool ExecuteForTask(int) const { return -1; };
+};
+
+// Profile actions
+class SetClampsAction : public ProfileAction {
+  public:
+    SetClampsAction(int boost, int clamp) noexcept : boost_(boost), clamp_(clamp) {}
+
+    virtual bool ExecuteForProcess(uid_t uid, pid_t pid) const;
+    virtual bool ExecuteForTask(int tid) const;
+
+  protected:
+    int boost_;
+    int clamp_;
+};
+
+class SetTimerSlackAction : public ProfileAction {
+  public:
+    SetTimerSlackAction(unsigned long slack) noexcept : slack_(slack) {}
+
+    virtual bool ExecuteForTask(int tid) const;
+
+  private:
+    unsigned long slack_;
+
+    static bool IsTimerSlackSupported(int tid);
+};
+
+// Set attribute profile element
+class SetAttributeAction : public ProfileAction {
+  public:
+    SetAttributeAction(const ProfileAttribute* attribute, const std::string& value)
+        : attribute_(attribute), value_(value) {}
+
+    virtual bool ExecuteForProcess(uid_t uid, pid_t pid) const;
+    virtual bool ExecuteForTask(int tid) const;
+
+  private:
+    const ProfileAttribute* attribute_;
+    std::string value_;
+};
+
+// Set cgroup profile element
+class SetCgroupAction : public ProfileAction {
+  public:
+    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_; }
+    std::string path() const { return path_; }
+
+  private:
+    const CgroupController* controller_;
+    std::string path_;
+    android::base::unique_fd fd_;
+
+    static bool IsAppDependentPath(const std::string& path);
+    static bool AddTidToCgroup(int tid, int fd);
+};
+
+class TaskProfile {
+  public:
+    TaskProfile() {}
+
+    void Add(std::unique_ptr<ProfileAction> e) { elements_.push_back(std::move(e)); }
+
+    bool ExecuteForProcess(uid_t uid, pid_t pid) const;
+    bool ExecuteForTask(int tid) const;
+
+  private:
+    std::vector<std::unique_ptr<ProfileAction>> elements_;
+};
+
+class TaskProfiles {
+  public:
+    // Should be used by all users
+    static TaskProfiles& GetInstance();
+
+    const TaskProfile* GetProfile(const std::string& name) const;
+    const ProfileAttribute* GetAttribute(const std::string& name) const;
+
+  private:
+    std::map<std::string, std::unique_ptr<TaskProfile>> profiles_;
+    std::map<std::string, std::unique_ptr<ProfileAttribute>> attributes_;
+
+    TaskProfiles();
+
+    bool Load(const CgroupMap& cg_map);
+};