libtimeinstate: add more tests

Check reported values to confirm that getUidCpuFreqTimes() and
getUidsCpuFreqTimes() are behaving reasonably.

Also revise RemoveUid test to create and then delete map entries for
an unused UID rather than UID 0. getUidCpuFreqTimes() is only meant to
be called when an app is uninstalled, and calling it with a UID that
has running tasks creates data inconsistencies that can cause the new
tests to fail. Since the revised test needs to directly manipulate the
BPF map in order to add a fake entry, move some definitions from
cputimeinstate.cpp into a header file to make them available for the
test.

Test: libtimeinstate_test passes
Bug: 78498733
Change-Id: I1587b1c7db870343ff863f2156b2a810d8ace915
Signed-off-by: Connor O'Brien <connoro@google.com>

4 files changed, 136 insertions, 20 deletions

diff --git a/libs/cputimeinstate/Android.bp b/libs/cputimeinstate/Android.bp
index 28cb13827d..9080ce13db 100644
--- a/libs/cputimeinstate/Android.bp
+++ b/libs/cputimeinstate/Android.bp
@@ -19,7 +19,11 @@ cc_test {
     name: "libtimeinstate_test",
     srcs: ["testtimeinstate.cpp"],
     shared_libs: [
+        "libbase",
+        "libbpf",
+        "libbpf_android",
         "libtimeinstate",
+        "libnetdutils",
     ],
     cflags: [
         "-Werror",
diff --git a/libs/cputimeinstate/cputimeinstate.cpp b/libs/cputimeinstate/cputimeinstate.cpp
index 41cbde1c18..0e68e628b6 100644
--- a/libs/cputimeinstate/cputimeinstate.cpp
+++ b/libs/cputimeinstate/cputimeinstate.cpp
@@ -17,6 +17,7 @@
 #define LOG_TAG "libtimeinstate"
 
 #include "cputimeinstate.h"
+#include "timeinstate.h"
 
 #include <dirent.h>
 #include <errno.h>
@@ -38,23 +39,12 @@
 #include <libbpf.h>
 #include <log/log.h>
 
-#define BPF_FS_PATH "/sys/fs/bpf/"
-
 using android::base::StringPrintf;
 using android::base::unique_fd;
 
 namespace android {
 namespace bpf {
 
-struct time_key_t {
-    uint32_t uid;
-    uint32_t freq;
-};
-
-struct val_t {
-    uint64_t ar[100];
-};
-
 static std::mutex gInitializedMutex;
 static bool gInitialized = false;
 static uint32_t gNPolicies = 0;
diff --git a/libs/cputimeinstate/testtimeinstate.cpp b/libs/cputimeinstate/testtimeinstate.cpp
index d4b87386e0..6347de166a 100644
--- a/libs/cputimeinstate/testtimeinstate.cpp
+++ b/libs/cputimeinstate/testtimeinstate.cpp
@@ -1,14 +1,24 @@
 
+#include "timeinstate.h"
+
+#include <sys/sysinfo.h>
+
 #include <unordered_map>
 #include <vector>
 
 #include <gtest/gtest.h>
 
+#include <android-base/unique_fd.h>
+#include <bpf/BpfMap.h>
 #include <cputimeinstate.h>
+#include <libbpf.h>
 
 namespace android {
 namespace bpf {
 
+static constexpr uint64_t NSEC_PER_SEC = 1000000000;
+static constexpr uint64_t NSEC_PER_YEAR = NSEC_PER_SEC * 60 * 60 * 24 * 365;
+
 using std::vector;
 
 TEST(TimeInStateTest, SingleUid) {
@@ -33,8 +43,95 @@ TEST(TimeInStateTest, AllUid) {
     }
 }
 
+TEST(TimeInStateTest, SingleAndAllUidConsistent) {
+    auto map = getUidsCpuFreqTimes();
+    ASSERT_TRUE(map.has_value());
+    ASSERT_FALSE(map->empty());
+
+    for (const auto &kv : *map) {
+        uint32_t uid = kv.first;
+        auto times1 = kv.second;
+        auto times2 = getUidCpuFreqTimes(uid);
+        ASSERT_TRUE(times2.has_value());
+
+        ASSERT_EQ(times1.size(), times2->size());
+        for (uint32_t i = 0; i < times1.size(); ++i) {
+            ASSERT_EQ(times1[i].size(), (*times2)[i].size());
+            for (uint32_t j = 0; j < times1[i].size(); ++j) {
+                ASSERT_LE((*times2)[i][j] - times1[i][j], NSEC_PER_SEC);
+            }
+        }
+    }
+}
+
+void TestCheckDelta(uint64_t before, uint64_t after) {
+    // Times should never decrease
+    ASSERT_LE(before, after);
+    // UID can't have run for more than ~1s on each CPU
+    ASSERT_LE(after - before, NSEC_PER_SEC * 2 * get_nprocs_conf());
+}
+
+TEST(TimeInStateTest, AllUidMonotonic) {
+    auto map1 = getUidsCpuFreqTimes();
+    ASSERT_TRUE(map1.has_value());
+    sleep(1);
+    auto map2 = getUidsCpuFreqTimes();
+    ASSERT_TRUE(map2.has_value());
+
+    for (const auto &kv : *map1) {
+        uint32_t uid = kv.first;
+        auto times = kv.second;
+        ASSERT_NE(map2->find(uid), map2->end());
+        for (uint32_t policy = 0; policy < times.size(); ++policy) {
+            for (uint32_t freqIdx = 0; freqIdx < times[policy].size(); ++freqIdx) {
+                auto before = times[policy][freqIdx];
+                auto after = (*map2)[uid][policy][freqIdx];
+                ASSERT_NO_FATAL_FAILURE(TestCheckDelta(before, after));
+            }
+        }
+    }
+}
+
+TEST(TimeInStateTest, AllUidSanityCheck) {
+    auto map = getUidsCpuFreqTimes();
+    ASSERT_TRUE(map.has_value());
+
+    bool foundLargeValue = false;
+    for (const auto &kv : *map) {
+        for (const auto &timeVec : kv.second) {
+            for (const auto &time : timeVec) {
+                ASSERT_LE(time, NSEC_PER_YEAR);
+                if (time > UINT32_MAX) foundLargeValue = true;
+            }
+        }
+    }
+    // UINT32_MAX nanoseconds is less than 5 seconds, so if every part of our pipeline is using
+    // uint64_t as expected, we should have some times higher than that.
+    ASSERT_TRUE(foundLargeValue);
+}
+
 TEST(TimeInStateTest, RemoveUid) {
-    auto times = getUidCpuFreqTimes(0);
+    uint32_t uid = 0;
+    {
+        // Find an unused UID
+        auto times = getUidsCpuFreqTimes();
+        ASSERT_TRUE(times.has_value());
+        ASSERT_FALSE(times->empty());
+        for (const auto &kv : *times) uid = std::max(uid, kv.first);
+        ++uid;
+    }
+    {
+        // Add a map entry for our fake UID by copying a real map entry
+        android::base::unique_fd fd{bpf_obj_get(BPF_FS_PATH "map_time_in_state_uid_times_map")};
+        ASSERT_GE(fd, 0);
+        time_key_t k;
+        ASSERT_FALSE(getFirstMapKey(fd, &k));
+        val_t val;
+        ASSERT_FALSE(findMapEntry(fd, &k, &val));
+        k.uid = uid;
+        ASSERT_FALSE(writeToMapEntry(fd, &k, &val, BPF_NOEXIST));
+    }
+    auto times = getUidCpuFreqTimes(uid);
     ASSERT_TRUE(times.has_value());
     ASSERT_FALSE(times->empty());
 
@@ -44,15 +141,12 @@ TEST(TimeInStateTest, RemoveUid) {
     }
     ASSERT_GT(sum, (uint64_t)0);
 
-    ASSERT_TRUE(clearUidCpuFreqTimes(0));
+    ASSERT_TRUE(clearUidCpuFreqTimes(uid));
 
-    auto times2 = getUidCpuFreqTimes(0);
-    ASSERT_TRUE(times2.has_value());
-    ASSERT_EQ(times2->size(), times->size());
-    for (size_t i = 0; i < times->size(); ++i) {
-        ASSERT_EQ((*times2)[i].size(), (*times)[i].size());
-        for (size_t j = 0; j < (*times)[i].size(); ++j) ASSERT_LE((*times2)[i][j], (*times)[i][j]);
-    }
+    auto allTimes = getUidsCpuFreqTimes();
+    ASSERT_TRUE(allTimes.has_value());
+    ASSERT_FALSE(allTimes->empty());
+    ASSERT_EQ(allTimes->find(uid), allTimes->end());
 }
 
 } // namespace bpf
diff --git a/libs/cputimeinstate/timeinstate.h b/libs/cputimeinstate/timeinstate.h
new file mode 100644
index 0000000000..cf66ae7077
--- /dev/null
+++ b/libs/cputimeinstate/timeinstate.h
@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+#include <inttypes.h>
+
+#define BPF_FS_PATH "/sys/fs/bpf/"
+
+struct time_key_t {
+    uint32_t uid;
+    uint32_t freq;
+};
+
+struct val_t {
+    uint64_t ar[100];
+};