commit fa7a05fe5f7a166baefb07298b4908ebc9b90075
author Suren Baghdasaryan <surenb@google.com> Wed May 08 17:59:55 2019 -0700
committer Suren Baghdasaryan <surenb@google.com> Tue May 21 10:03:21 2019 -0700
tree f2c98c45fa117e7857a3ad85a65ee92488f33f50
parent 7dc7c3a9c66cc5f934e57a57415dae33c4830841

libprocessgroup: add flags to indicate when a controller failed to mount

Controllers listed in cgroups.json file might fail to mount if kernel is
not configured to support them. We need a way to indicate whether a
controller was successfully mounted and is usable to avoid logging errors
and warnings when a controller that failed to mount is being used. Add
flags bitmask to cgrouprc controller descriptor and use a bit to indicate
that controller is successfully mounted. Modify cpusets_enabled() and
schedboost_enabled() functions to use this bit and report the actual
availability of the controller.

Bug: 124080437
Test: libcutils_test with cpuset and schedtune controllers disabled
Change-Id: I770cc39fe50465146e3205aacf77dc3c56923c5d
Signed-off-by: Suren Baghdasaryan <surenb@google.com>

libprocessgroup/cgrouprc/Android.bp

diff --git a/libprocessgroup/cgrouprc/Android.bp b/libprocessgroup/cgrouprc/Android.bp
index 24652fb..0af75bb 100644
--- a/libprocessgroup/cgrouprc/Android.bp
+++ b/libprocessgroup/cgrouprc/Android.bp
@@ -43,19 +43,19 @@
         "libcgrouprc_format",
     ],
     stubs: {
-        symbol_file: "libcgrouprc.map.txt",
+        symbol_file: "libcgrouprc.llndk.txt",
         versions: ["29"],
     },
     target: {
         linux: {
-            version_script: "libcgrouprc.map.txt",
+            version_script: "libcgrouprc.llndk.txt",
         },
     },
 }
 
 llndk_library {
     name: "libcgrouprc",
-    symbol_file: "libcgrouprc.map.txt",
+    symbol_file: "libcgrouprc.llndk.txt",
     native_bridge_supported: true,
     export_include_dirs: [
         "include",

libprocessgroup/cgrouprc/cgroup_controller.cpp

diff --git a/libprocessgroup/cgrouprc/cgroup_controller.cpp b/libprocessgroup/cgrouprc/cgroup_controller.cpp
index d064d31..5a326e5 100644
--- a/libprocessgroup/cgrouprc/cgroup_controller.cpp
+++ b/libprocessgroup/cgrouprc/cgroup_controller.cpp
@@ -27,6 +27,11 @@
     return controller->version();
 }
 
+uint32_t ACgroupController_getFlags(const ACgroupController* controller) {
+    CHECK(controller != nullptr);
+    return controller->flags();
+}
+
 const char* ACgroupController_getName(const ACgroupController* controller) {
     CHECK(controller != nullptr);
     return controller->name();

libprocessgroup/cgrouprc/include/android/cgrouprc.h

diff --git a/libprocessgroup/cgrouprc/include/android/cgrouprc.h b/libprocessgroup/cgrouprc/include/android/cgrouprc.h
index 4edd239..ffc9f0b 100644
--- a/libprocessgroup/cgrouprc/include/android/cgrouprc.h
+++ b/libprocessgroup/cgrouprc/include/android/cgrouprc.h
@@ -66,6 +66,18 @@
         __INTRODUCED_IN(29);
 
 /**
+ * Flag bitmask used in ACgroupController_getFlags
+ */
+#define CGROUPRC_CONTROLLER_FLAG_MOUNTED 0x1
+
+/**
+ * Returns the flags bitmask of the given controller.
+ * If the given controller is null, return 0.
+ */
+__attribute__((warn_unused_result)) uint32_t ACgroupController_getFlags(const ACgroupController*)
+        __INTRODUCED_IN(29);
+
+/**
  * Returns the name of the given controller.
  * If the given controller is null, return nullptr.
  */

libprocessgroup/cgrouprc/libcgrouprc.llndk.txt

diff --git a/libprocessgroup/cgrouprc/libcgrouprc.map.txt b/libprocessgroup/cgrouprc/libcgrouprc.llndk.txt
similarity index 88%
rename from libprocessgroup/cgrouprc/libcgrouprc.map.txt
rename to libprocessgroup/cgrouprc/libcgrouprc.llndk.txt
index 91df392..ea3df33 100644
--- a/libprocessgroup/cgrouprc/libcgrouprc.map.txt
+++ b/libprocessgroup/cgrouprc/libcgrouprc.llndk.txt
@@ -4,6 +4,7 @@
     ACgroupFile_getControllerCount;
     ACgroupFile_getController;
     ACgroupController_getVersion;
+    ACgroupController_getFlags;
     ACgroupController_getName;
     ACgroupController_getPath;
   local: