summaryrefslogtreecommitdiffstats
blob: f054de98b3930551443f1c8f9ded32afecd607d7 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
/*
 * Copyright (C) 2013 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.
 */

#define LOG_TAG "ProcessCallStack"
// #define LOG_NDEBUG 0

#include <utils/ProcessCallStack.h>

#include <dirent.h>
#include <unistd.h>

#include <memory>

#include <utils/Printer.h>

namespace android {

enum {
    // Max sizes for various dynamically generated strings
    MAX_TIME_STRING = 64,
    MAX_PROC_PATH = 1024,

    // Dump related prettiness constants
    IGNORE_DEPTH_CURRENT_THREAD = 2,
};

static const char* CALL_STACK_PREFIX = "  ";
static const char* PATH_THREAD_NAME = "/proc/self/task/%d/comm";
static const char* PATH_SELF_TASK = "/proc/self/task";

static void dumpProcessHeader(Printer& printer, pid_t pid, const char* timeStr) {
    if (timeStr == nullptr) {
        ALOGW("%s: timeStr was NULL", __FUNCTION__);
        return;
    }

    char path[PATH_MAX];
    char procNameBuf[MAX_PROC_PATH];
    char* procName = nullptr;
    FILE* fp;

    snprintf(path, sizeof(path), "/proc/%d/cmdline", pid);
    if ((fp = fopen(path, "r"))) {
        procName = fgets(procNameBuf, sizeof(procNameBuf), fp);
        fclose(fp);
    }

    if (!procName) {
        procName = const_cast<char*>("<unknown>");
    }

    printer.printLine();
    printer.printLine();
    printer.printFormatLine("----- pid %d at %s -----", pid, timeStr);
    printer.printFormatLine("Cmd line: %s", procName);
}

static void dumpProcessFooter(Printer& printer, pid_t pid) {
    printer.printLine();
    printer.printFormatLine("----- end %d -----", pid);
    printer.printLine();
}

static String8 getThreadName(pid_t tid) {
    char path[PATH_MAX];
    char* procName = nullptr;
    char procNameBuf[MAX_PROC_PATH];
    FILE* fp;

    snprintf(path, sizeof(path), PATH_THREAD_NAME, tid);
    if ((fp = fopen(path, "r"))) {
        procName = fgets(procNameBuf, sizeof(procNameBuf), fp);
        fclose(fp);
    } else {
        ALOGE("%s: Failed to open %s", __FUNCTION__, path);
    }

    if (procName == nullptr) {
        // Reading /proc/self/task/%d/comm failed due to a race
        return String8::format("[err-unknown-tid-%d]", tid);
    }

    // Strip ending newline
    strtok(procName, "\n");

    return String8(procName);
}

static String8 getTimeString(struct tm tm) {
    char timestr[MAX_TIME_STRING];
    // i.e. '2013-10-22 14:42:05'
    strftime(timestr, sizeof(timestr), "%F %T", &tm);

    return String8(timestr);
}

/*
 * Implementation of ProcessCallStack
 */
ProcessCallStack::ProcessCallStack() {
}

ProcessCallStack::ProcessCallStack(const ProcessCallStack& rhs) :
        mThreadMap(rhs.mThreadMap),
        mTimeUpdated(rhs.mTimeUpdated) {
}

ProcessCallStack::~ProcessCallStack() {
}

void ProcessCallStack::clear() {
    mThreadMap.clear();
    mTimeUpdated = tm();
}

void ProcessCallStack::update() {
    std::unique_ptr<DIR, decltype(&closedir)> dp(opendir(PATH_SELF_TASK), closedir);
    if (dp == nullptr) {
        ALOGE("%s: Failed to update the process's call stacks: %s",
              __FUNCTION__, strerror(errno));
        return;
    }

    pid_t selfPid = getpid();

    clear();

    // Get current time.
    {
        time_t t = time(nullptr);
        struct tm tm;
        localtime_r(&t, &tm);

        mTimeUpdated = tm;
    }

    /*
     * Each tid is a directory inside of /proc/self/task
     * - Read every file in directory => get every tid
     */
    dirent* ep;
    while ((ep = readdir(dp.get())) != nullptr) {
        pid_t tid = -1;
        sscanf(ep->d_name, "%d", &tid);

        if (tid < 0) {
            // Ignore '.' and '..'
            ALOGV("%s: Failed to read tid from %s/%s",
                  __FUNCTION__, PATH_SELF_TASK, ep->d_name);
            continue;
        }

        ssize_t idx = mThreadMap.add(tid, ThreadInfo());
        if (idx < 0) { // returns negative error value on error
            ALOGE("%s: Failed to add new ThreadInfo: %s",
                  __FUNCTION__, strerror(-idx));
            continue;
        }

        ThreadInfo& threadInfo = mThreadMap.editValueAt(static_cast<size_t>(idx));

        /*
         * Ignore CallStack::update and ProcessCallStack::update for current thread
         * - Every other thread doesn't need this since we call update off-thread
         */
        int ignoreDepth = (selfPid == tid) ? IGNORE_DEPTH_CURRENT_THREAD : 0;

        // Update thread's call stacks
        threadInfo.callStack.update(ignoreDepth, tid);

        // Read/save thread name
        threadInfo.threadName = getThreadName(tid);

        ALOGV("%s: Got call stack for tid %d (size %zu)",
              __FUNCTION__, tid, threadInfo.callStack.size());
    }
}

void ProcessCallStack::log(const char* logtag, android_LogPriority priority,
                           const char* prefix) const {
    LogPrinter printer(logtag, priority, prefix, /*ignoreBlankLines*/false);
    print(printer);
}

void ProcessCallStack::print(Printer& printer) const {
    /*
     * Print the header/footer with the regular printer.
     * Print the callstack with an additional two spaces as the prefix for legibility.
     */
    PrefixPrinter csPrinter(printer, CALL_STACK_PREFIX);
    printInternal(printer, csPrinter);
}

void ProcessCallStack::printInternal(Printer& printer, Printer& csPrinter) const {
    dumpProcessHeader(printer, getpid(),
                      getTimeString(mTimeUpdated).string());

    for (size_t i = 0; i < mThreadMap.size(); ++i) {
        pid_t tid = mThreadMap.keyAt(i);
        const ThreadInfo& threadInfo = mThreadMap.valueAt(i);
        const String8& threadName = threadInfo.threadName;

        printer.printLine("");
        printer.printFormatLine("\"%s\" sysTid=%d", threadName.string(), tid);

        threadInfo.callStack.print(csPrinter);
    }

    dumpProcessFooter(printer, getpid());
}

void ProcessCallStack::dump(int fd, int indent, const char* prefix) const {

    if (indent < 0) {
        ALOGW("%s: Bad indent (%d)", __FUNCTION__, indent);
        return;
    }

    FdPrinter printer(fd, static_cast<unsigned int>(indent), prefix);
    print(printer);
}

String8 ProcessCallStack::toString(const char* prefix) const {

    String8 dest;
    String8Printer printer(&dest, prefix);
    print(printer);

    return dest;
}

size_t ProcessCallStack::size() const {
    return mThreadMap.size();
}

}; //namespace android