1 /*
2 * Copyright (c) 2020, The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #define LOG_TAG "carwatchdogd"
18
19 #include "UidIoStatsCollector.h"
20
21 #include <android-base/file.h>
22 #include <android-base/parseint.h>
23 #include <android-base/stringprintf.h>
24 #include <android-base/strings.h>
25 #include <log/log.h>
26
27 #include <inttypes.h>
28
29 #include <string>
30 #include <unordered_map>
31 #include <utility>
32 #include <vector>
33
34 namespace android {
35 namespace automotive {
36 namespace watchdog {
37
38 using ::android::base::Error;
39 using ::android::base::ParseInt;
40 using ::android::base::ParseUint;
41 using ::android::base::ReadFileToString;
42 using ::android::base::Result;
43 using ::android::base::Split;
44 using ::android::base::StringPrintf;
45
46 namespace {
47
parseUidIoStats(const std::string & data,UidIoStats * stats,uid_t * uid)48 bool parseUidIoStats(const std::string& data, UidIoStats* stats, uid_t* uid) {
49 std::vector<std::string> fields = Split(data, " ");
50 if (fields.size() < 11 || !ParseUint(fields[0], uid) ||
51 !ParseInt(fields[3], &stats->metrics[READ_BYTES][FOREGROUND]) ||
52 !ParseInt(fields[4], &stats->metrics[WRITE_BYTES][FOREGROUND]) ||
53 !ParseInt(fields[7], &stats->metrics[READ_BYTES][BACKGROUND]) ||
54 !ParseInt(fields[8], &stats->metrics[WRITE_BYTES][BACKGROUND]) ||
55 !ParseInt(fields[9], &stats->metrics[FSYNC_COUNT][FOREGROUND]) ||
56 !ParseInt(fields[10], &stats->metrics[FSYNC_COUNT][BACKGROUND])) {
57 ALOGW("Invalid uid I/O stats: \"%s\"", data.c_str());
58 return false;
59 }
60 return true;
61 }
62
63 } // namespace
64
operator -=(const UidIoStats & rhs)65 UidIoStats& UidIoStats::operator-=(const UidIoStats& rhs) {
66 const auto diff = [](int64_t lhs, int64_t rhs) -> int64_t { return lhs > rhs ? lhs - rhs : 0; };
67 metrics[READ_BYTES][FOREGROUND] =
68 diff(metrics[READ_BYTES][FOREGROUND], rhs.metrics[READ_BYTES][FOREGROUND]);
69 metrics[READ_BYTES][BACKGROUND] =
70 diff(metrics[READ_BYTES][BACKGROUND], rhs.metrics[READ_BYTES][BACKGROUND]);
71 metrics[WRITE_BYTES][FOREGROUND] =
72 diff(metrics[WRITE_BYTES][FOREGROUND], rhs.metrics[WRITE_BYTES][FOREGROUND]);
73 metrics[WRITE_BYTES][BACKGROUND] =
74 diff(metrics[WRITE_BYTES][BACKGROUND], rhs.metrics[WRITE_BYTES][BACKGROUND]);
75 metrics[FSYNC_COUNT][FOREGROUND] =
76 diff(metrics[FSYNC_COUNT][FOREGROUND], rhs.metrics[FSYNC_COUNT][FOREGROUND]);
77 metrics[FSYNC_COUNT][BACKGROUND] =
78 diff(metrics[FSYNC_COUNT][BACKGROUND], rhs.metrics[FSYNC_COUNT][BACKGROUND]);
79 return *this;
80 }
81
isZero() const82 bool UidIoStats::isZero() const {
83 for (int i = 0; i < METRIC_TYPES; i++) {
84 for (int j = 0; j < UID_STATES; j++) {
85 if (metrics[i][j]) {
86 return false;
87 }
88 }
89 }
90 return true;
91 }
92
toString() const93 std::string UidIoStats::toString() const {
94 return StringPrintf("FgRdBytes:%" PRIi64 " BgRdBytes:%" PRIi64 " FgWrBytes:%" PRIi64
95 " BgWrBytes:%" PRIi64 " FgFsync:%" PRIi64 " BgFsync:%" PRIi64,
96 metrics[READ_BYTES][FOREGROUND], metrics[READ_BYTES][BACKGROUND],
97 metrics[WRITE_BYTES][FOREGROUND], metrics[WRITE_BYTES][BACKGROUND],
98 metrics[FSYNC_COUNT][FOREGROUND], metrics[FSYNC_COUNT][BACKGROUND]);
99 }
100
collect()101 Result<void> UidIoStatsCollector::collect() {
102 if (!mEnabled) {
103 return Error() << "Can not access " << kPath;
104 }
105
106 Mutex::Autolock lock(mMutex);
107 const auto& uidIoStatsByUid = readUidIoStatsLocked();
108 if (!uidIoStatsByUid.ok() || uidIoStatsByUid->empty()) {
109 return Error() << "Failed to get UID IO stats: " << uidIoStatsByUid.error();
110 }
111
112 mDeltaStats.clear();
113 for (const auto& [uid, uidIoStats] : *uidIoStatsByUid) {
114 if (uidIoStats.isZero()) {
115 continue;
116 }
117 UidIoStats deltaStats = uidIoStats;
118 if (const auto it = mLatestStats.find(uid); it != mLatestStats.end()) {
119 if (deltaStats -= it->second; deltaStats.isZero()) {
120 continue;
121 }
122 }
123 mDeltaStats[uid] = deltaStats;
124 }
125 mLatestStats = *uidIoStatsByUid;
126 return {};
127 }
128
readUidIoStatsLocked() const129 Result<std::unordered_map<uid_t, UidIoStats>> UidIoStatsCollector::readUidIoStatsLocked() const {
130 std::string buffer;
131 if (!ReadFileToString(kPath, &buffer)) {
132 return Error() << "ReadFileToString failed for " << kPath;
133 }
134 std::unordered_map<uid_t, UidIoStats> uidIoStatsByUid;
135 std::vector<std::string> lines = Split(std::move(buffer), "\n");
136 for (const auto& line : lines) {
137 if (line.empty() || !line.compare(0, 4, "task")) {
138 /* Skip per-task stats as CONFIG_UID_SYS_STATS_DEBUG is not set in the kernel and
139 * the collected data is aggregated only per-UID.
140 */
141 continue;
142 }
143 uid_t uid;
144 UidIoStats uidIoStats;
145 if (!parseUidIoStats(line, &uidIoStats, &uid)) {
146 return Error() << "Failed to parse the contents of " << kPath;
147 }
148 uidIoStatsByUid[uid] = uidIoStats;
149 }
150 return uidIoStatsByUid;
151 }
152
153 } // namespace watchdog
154 } // namespace automotive
155 } // namespace android
156