bootstat: Refactor init/utils/boot_clock into base/chrono_utils.

Use this for bootstat and init. This replaces the custom uptime parser in
bootstat.

This is a reland of aosp/338325 with a stubbed implementation for Darwin.

This change also has clang_format fixes (automatic).

Bug: 34352037
Test: chrono_utils_test
Change-Id: I72a62a3ca1ccfc0a4ccc6294ff1776c263144686

base/Android.bp

@@ -42,24 +42,36 @@ cc_library {
             srcs: [
                 "errors_unix.cpp",
                 "properties.cpp",
+                "chrono_utils.cpp",
             ],
             cppflags: ["-Wexit-time-destructors"],
             sanitize: {
                 misc_undefined: ["integer"],
             },
+
         },
         darwin: {
-            srcs: ["errors_unix.cpp"],
+            srcs: [
+                "chrono_utils.cpp",
+                "errors_unix.cpp",
+            ],
             cppflags: ["-Wexit-time-destructors"],
         },
         linux_bionic: {
-            srcs: ["errors_unix.cpp"],
+            srcs: [
+                "chrono_utils.cpp",
+                "errors_unix.cpp",
+            ],
             cppflags: ["-Wexit-time-destructors"],
             enabled: true,
         },
         linux: {
-            srcs: ["errors_unix.cpp"],
+            srcs: [
+                "chrono_utils.cpp",
+                "errors_unix.cpp",
+            ],
             cppflags: ["-Wexit-time-destructors"],
+            host_ldlibs: ["-lrt"],
         },
         windows: {
             srcs: [
@@ -92,11 +104,18 @@ cc_test {
     ],
     target: {
         android: {
-            srcs: ["properties_test.cpp"],
+            srcs: [
+                "chrono_utils_test.cpp",
+                "properties_test.cpp"
+            ],
             sanitize: {
                 misc_undefined: ["integer"],
             },
         },
+        linux: {
+            srcs: ["chrono_utils_test.cpp"],
+            host_ldlibs: ["-lrt"],
+        },
         windows: {
             srcs: ["utf8_test.cpp"],
             enabled: true,

base/chrono_utils.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2016 The Android Open Source Project
+ * Copyright (C) 2017 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.
@@ -14,25 +14,24 @@
  * limitations under the License.
  */
 
-#include "uptime_parser.h"
+#include "android-base/chrono_utils.h"
 
 #include <time.h>
-#include <cstdlib>
-#include <string>
-#include <android-base/file.h>
-#include <android-base/logging.h>
 
-namespace bootstat {
+namespace android {
+namespace base {
 
-time_t ParseUptime() {
-  std::string uptime_str;
-  if (!android::base::ReadFileToString("/proc/uptime", &uptime_str)) {
-    PLOG(ERROR) << "Failed to read /proc/uptime";
-    return -1;
-  }
-
-  // Cast intentionally rounds down.
-  return static_cast<time_t>(strtod(uptime_str.c_str(), NULL));
+boot_clock::time_point boot_clock::now() {
+#ifdef __ANDROID__
+  timespec ts;
+  clock_gettime(CLOCK_BOOTTIME, &ts);
+  return boot_clock::time_point(std::chrono::seconds(ts.tv_sec) +
+                                std::chrono::nanoseconds(ts.tv_nsec));
+#else
+  // Darwin does not support clock_gettime.
+  return boot_clock::time_point();
+#endif  // __ANDROID__
 }
 
-}  // namespace bootstat
+}  // namespace base
+}  // namespace android

base/chrono_utils_test.cpp

@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2017 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 "android-base/chrono_utils.h"
+
+#include <time.h>
+
+#include <chrono>
+
+#include <gtest/gtest.h>
+
+namespace android {
+namespace base {
+
+std::chrono::seconds GetBootTimeSeconds() {
+  struct timespec now;
+  clock_gettime(CLOCK_BOOTTIME, &now);
+
+  auto now_tp = boot_clock::time_point(std::chrono::seconds(now.tv_sec) +
+                                       std::chrono::nanoseconds(now.tv_nsec));
+  return std::chrono::duration_cast<std::chrono::seconds>(now_tp.time_since_epoch());
+}
+
+// Tests (at least) the seconds accuracy of the boot_clock::now() method.
+TEST(ChronoUtilsTest, BootClockNowSeconds) {
+  auto now = GetBootTimeSeconds();
+  auto boot_seconds =
+      std::chrono::duration_cast<std::chrono::seconds>(boot_clock::now().time_since_epoch());
+  EXPECT_EQ(now, boot_seconds);
+}
+
+}  // namespace base
+}  // namespace android

base/include/android-base/chrono_utils.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2016 The Android Open Source Project
+ * Copyright (C) 2017 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.
@@ -14,16 +14,24 @@
  * limitations under the License.
  */
 
-#ifndef UPTIME_PARSER_H_
-#define UPTIME_PARSER_H_
+#ifndef ANDROID_BASE_CHRONO_UTILS_H
+#define ANDROID_BASE_CHRONO_UTILS_H
 
-#include <time.h>
+#include <chrono>
 
-namespace bootstat {
+namespace android {
+namespace base {
 
-// Returns the number of seconds the system has been on since reboot.
-time_t ParseUptime();
+// A std::chrono clock based on CLOCK_BOOTTIME.
+class boot_clock {
+ public:
+  typedef std::chrono::nanoseconds duration;
+  typedef std::chrono::time_point<boot_clock, duration> time_point;
 
-}  // namespace bootstat
+  static time_point now();
+};
 
-#endif  // UPTIME_PARSER_H_
+}  // namespace base
+}  // namespace android
+
+#endif  // ANDROID_BASE_CHRONO_UTILS_H

bootstat/Android.bp

@@ -16,7 +16,6 @@
 
 bootstat_lib_src_files = [
     "boot_event_record_store.cpp",
-    "uptime_parser.cpp",
 ]
 
 cc_defaults {

bootstat/boot_event_record_store.cpp

@@ -20,13 +20,16 @@
 #include <fcntl.h>
 #include <sys/stat.h>
 #include <utime.h>
+
+#include <chrono>
 #include <cstdlib>
 #include <string>
 #include <utility>
+
+#include <android-base/chrono_utils.h>
 #include <android-base/file.h>
 #include <android-base/logging.h>
 #include <android-base/parseint.h>
-#include "uptime_parser.h"
 
 namespace {
 
@@ -55,7 +58,9 @@ BootEventRecordStore::BootEventRecordStore() {
 }
 
 void BootEventRecordStore::AddBootEvent(const std::string& event) {
-  AddBootEventWithValue(event, bootstat::ParseUptime());
+    auto uptime = std::chrono::duration_cast<std::chrono::seconds>(
+        android::base::boot_clock::now().time_since_epoch());
+    AddBootEventWithValue(event, uptime.count());
 }
 
 // The implementation of AddBootEventValue makes use of the mtime file

bootstat/boot_event_record_store_test.cpp

@@ -21,15 +21,18 @@
 #include <sys/stat.h>
 #include <sys/time.h>
 #include <unistd.h>
+
+#include <chrono>
 #include <cstdint>
 #include <cstdlib>
+
+#include <android-base/chrono_utils.h>
 #include <android-base/file.h>
 #include <android-base/logging.h>
 #include <android-base/test_utils.h>
 #include <android-base/unique_fd.h>
-#include <gtest/gtest.h>
 #include <gmock/gmock.h>
-#include "uptime_parser.h"
+#include <gtest/gtest.h>
 
 using testing::UnorderedElementsAreArray;
 
@@ -89,6 +92,13 @@ void DeleteDirectory(const std::string& path) {
   rmdir(path.c_str());
 }
 
+// Returns the time in seconds since boot.
+time_t GetUptimeSeconds() {
+    return std::chrono::duration_cast<std::chrono::seconds>(
+               android::base::boot_clock::now().time_since_epoch())
+        .count();
+}
+
 class BootEventRecordStoreTest : public ::testing::Test {
  public:
   BootEventRecordStoreTest() {
@@ -126,7 +136,7 @@ TEST_F(BootEventRecordStoreTest, AddSingleBootEvent) {
   BootEventRecordStore store;
   store.SetStorePath(GetStorePathForTesting());
 
-  time_t uptime = bootstat::ParseUptime();
+  time_t uptime = GetUptimeSeconds();
   ASSERT_NE(-1, uptime);
 
   store.AddBootEvent("cenozoic");
@@ -141,7 +151,7 @@ TEST_F(BootEventRecordStoreTest, AddMultipleBootEvents) {
   BootEventRecordStore store;
   store.SetStorePath(GetStorePathForTesting());
 
-  time_t uptime = bootstat::ParseUptime();
+  time_t uptime = GetUptimeSeconds();
   ASSERT_NE(-1, uptime);
 
   store.AddBootEvent("cretaceous");

bootstat/bootstat.cpp

@@ -21,6 +21,7 @@
 #include <getopt.h>
 #include <unistd.h>
 
+#include <chrono>
 #include <cmath>
 #include <cstddef>
 #include <cstdio>
@@ -30,15 +31,15 @@
 #include <string>
 #include <vector>
 
-#include <android/log.h>
+#include <android-base/chrono_utils.h>
 #include <android-base/logging.h>
 #include <android-base/parseint.h>
 #include <android-base/strings.h>
+#include <android/log.h>
 #include <cutils/properties.h>
 #include <metricslogger/metrics_logger.h>
 
 #include "boot_event_record_store.h"
-#include "uptime_parser.h"
 
 namespace {
 
@@ -255,7 +256,8 @@ void RecordBootComplete() {
   BootEventRecordStore boot_event_store;
   BootEventRecordStore::BootEventRecord record;
 
-  time_t uptime = bootstat::ParseUptime();
+  auto uptime = std::chrono::duration_cast<std::chrono::seconds>(
+      android::base::boot_clock::now().time_since_epoch());
   time_t current_time_utc = time(nullptr);
 
   if (boot_event_store.GetBootEvent("last_boot_time_utc", &record)) {
@@ -282,22 +284,21 @@ void RecordBootComplete() {
     // Log the amount of time elapsed until the device is decrypted, which
     // includes the variable amount of time the user takes to enter the
     // decryption password.
-    boot_event_store.AddBootEventWithValue("boot_decryption_complete", uptime);
+    boot_event_store.AddBootEventWithValue("boot_decryption_complete", uptime.count());
 
     // Subtract the decryption time to normalize the boot cycle timing.
-    time_t boot_complete = uptime - record.second;
+    std::chrono::seconds boot_complete = std::chrono::seconds(uptime.count() - record.second);
     boot_event_store.AddBootEventWithValue(boot_complete_prefix + "_post_decrypt",
-                                           boot_complete);
-
+                                           boot_complete.count());
 
   } else {
-    boot_event_store.AddBootEventWithValue(boot_complete_prefix + "_no_encryption",
-                                           uptime);
+      boot_event_store.AddBootEventWithValue(boot_complete_prefix + "_no_encryption",
+                                             uptime.count());
   }
 
   // Record the total time from device startup to boot complete, regardless of
   // encryption state.
-  boot_event_store.AddBootEventWithValue(boot_complete_prefix, uptime);
+  boot_event_store.AddBootEventWithValue(boot_complete_prefix, uptime.count());
 
   RecordInitBootTimeProp(&boot_event_store, "ro.boottime.init");
   RecordInitBootTimeProp(&boot_event_store, "ro.boottime.init.selinux");

init/init.cpp

@@ -40,6 +40,7 @@
 #include <selinux/label.h>
 #include <selinux/android.h>
 
+#include <android-base/chrono_utils.h>
 #include <android-base/file.h>
 #include <android-base/properties.h>
 #include <android-base/stringprintf.h>
@@ -69,6 +70,7 @@
 #include "util.h"
 #include "watchdogd.h"
 
+using android::base::boot_clock;
 using android::base::GetProperty;
 using android::base::StringPrintf;
 

init/service.cpp

@@ -32,6 +32,7 @@
 
 #include <selinux/selinux.h>
 
+#include <android-base/chrono_utils.h>
 #include <android-base/file.h>
 #include <android-base/parseint.h>
 #include <android-base/properties.h>
@@ -48,6 +49,7 @@
 #include "property_service.h"
 #include "util.h"
 
+using android::base::boot_clock;
 using android::base::ParseInt;
 using android::base::StringPrintf;
 using android::base::WriteStringToFile;

init/service.h

@@ -26,6 +26,8 @@
 #include <string>
 #include <vector>
 
+#include <android-base/chrono_utils.h>
+
 #include "action.h"
 #include "capabilities.h"
 #include "descriptors.h"
@@ -144,8 +146,8 @@ class Service {
 
     unsigned flags_;
     pid_t pid_;
-    boot_clock::time_point time_started_; // time of last start
-    boot_clock::time_point time_crashed_; // first crash within inspection window
+    android::base::boot_clock::time_point time_started_;  // time of last start
+    android::base::boot_clock::time_point time_crashed_;  // first crash within inspection window
     int crash_count_;                     // number of times crashed within window
 
     uid_t uid_;

init/util.cpp

@@ -52,6 +52,8 @@
 #include "reboot.h"
 #include "util.h"
 
+using android::base::boot_clock;
+
 static unsigned int do_decode_uid(const char *s)
 {
     unsigned int v;
@@ -198,13 +200,6 @@ bool write_file(const char* path, const char* content) {
     return success;
 }
 
-boot_clock::time_point boot_clock::now() {
-  timespec ts;
-  clock_gettime(CLOCK_BOOTTIME, &ts);
-  return boot_clock::time_point(std::chrono::seconds(ts.tv_sec) +
-                                std::chrono::nanoseconds(ts.tv_nsec));
-}
-
 int mkdir_recursive(const char *pathname, mode_t mode)
 {
     char buf[128];

init/util.h

@@ -25,8 +25,11 @@
 #include <ostream>
 #include <string>
 
+#include <android-base/chrono_utils.h>
+
 #define COLDBOOT_DONE "/dev/.coldboot_done"
 
+using android::base::boot_clock;
 using namespace std::chrono_literals;
 
 int create_socket(const char *name, int type, mode_t perm,
@@ -35,32 +38,22 @@ int create_socket(const char *name, int type, mode_t perm,
 bool read_file(const char* path, std::string* content);
 bool write_file(const char* path, const char* content);
 
-// A std::chrono clock based on CLOCK_BOOTTIME.
-class boot_clock {
- public:
-  typedef std::chrono::nanoseconds duration;
-  typedef std::chrono::time_point<boot_clock, duration> time_point;
-  static constexpr bool is_steady = true;
-
-  static time_point now();
-};
-
 class Timer {
- public:
-  Timer() : start_(boot_clock::now()) {
-  }
+  public:
+    Timer() : start_(boot_clock::now()) {}
 
-  double duration_s() const {
-    typedef std::chrono::duration<double> double_duration;
-    return std::chrono::duration_cast<double_duration>(boot_clock::now() - start_).count();
-  }
+    double duration_s() const {
+        typedef std::chrono::duration<double> double_duration;
+        return std::chrono::duration_cast<double_duration>(boot_clock::now() - start_).count();
+    }
 
-  int64_t duration_ms() const {
-    return std::chrono::duration_cast<std::chrono::milliseconds>(boot_clock::now() - start_).count();
-  }
+    int64_t duration_ms() const {
+        return std::chrono::duration_cast<std::chrono::milliseconds>(boot_clock::now() - start_)
+            .count();
+    }
 
- private:
-  boot_clock::time_point start_;
+  private:
+    android::base::boot_clock::time_point start_;
 };
 
 std::ostream& operator<<(std::ostream& os, const Timer& t);