summaryrefslogtreecommitdiffstats
blob: f7df275580f7b64cea00329199ce06b91d3191a2 (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
/*
 * Copyright (C) 2012-2013 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.
 */

#include <ctype.h>
#include <poll.h>
#include <sys/prctl.h>
#include <sys/socket.h>

#include <cutils/sockets.h>

#include "LogReader.h"
#include "FlushCommand.h"

LogReader::LogReader(LogBuffer *logbuf)
        : SocketListener(getLogSocket(), true)
        , mLogbuf(*logbuf)
{ }

// When we are notified a new log entry is available, inform
// all of our listening sockets.
void LogReader::notifyNewLog() {
    FlushCommand command(*this);
    runOnEachSocket(&command);
}

bool LogReader::onDataAvailable(SocketClient *cli) {
    prctl(PR_SET_NAME, "logd.reader");

    char buffer[255];

    int len = read(cli->getSocket(), buffer, sizeof(buffer) - 1);
    if (len <= 0) {
        doSocketDelete(cli);
        return false;
    }
    buffer[len] = '\0';

    unsigned long tail = 0;
    static const char _tail[] = " tail=";
    char *cp = strstr(buffer, _tail);
    if (cp) {
        tail = atol(cp + sizeof(_tail) - 1);
    }

    log_time start(log_time::EPOCH);
    static const char _start[] = " start=";
    cp = strstr(buffer, _start);
    if (cp) {
        // Parse errors will result in current time
        start.strptime(cp + sizeof(_start) - 1, "%s.%q");
    }

    unsigned int logMask = -1;
    static const char _logIds[] = " lids=";
    cp = strstr(buffer, _logIds);
    if (cp) {
        logMask = 0;
        cp += sizeof(_logIds) - 1;
        while (*cp && *cp != '\0') {
            int val = 0;
            while (isdigit(*cp)) {
                val = val * 10 + *cp - '0';
                ++cp;
            }
            logMask |= 1 << val;
            if (*cp != ',') {
                break;
            }
            ++cp;
        }
    }

    pid_t pid = 0;
    static const char _pid[] = " pid=";
    cp = strstr(buffer, _pid);
    if (cp) {
        pid = atol(cp + sizeof(_pid) - 1);
    }

    bool nonBlock = false;
    if (strncmp(buffer, "dumpAndClose", 12) == 0) {
        // Allow writer to get some cycles, and wait for pending notifications
        sched_yield();
        LogTimeEntry::lock();
        LogTimeEntry::unlock();
        sched_yield();
        nonBlock = true;
    }

    uint64_t sequence = 1;
    // Convert realtime to sequence number
    if (start != log_time::EPOCH) {
        class LogFindStart {
            const pid_t mPid;
            const unsigned mLogMask;
            bool startTimeSet;
            log_time &start;
            uint64_t &sequence;
            uint64_t last;

        public:
            LogFindStart(unsigned logMask, pid_t pid, log_time &start, uint64_t &sequence)
                    : mPid(pid)
                    , mLogMask(logMask)
                    , startTimeSet(false)
                    , start(start)
                    , sequence(sequence)
                    , last(sequence)
            { }

            static int callback(const LogBufferElement *element, void *obj) {
                LogFindStart *me = reinterpret_cast<LogFindStart *>(obj);
                if ((!me->mPid || (me->mPid == element->getPid()))
                        && (me->mLogMask & (1 << element->getLogId()))) {
                    if (me->start == element->getRealTime()) {
                        me->sequence = element->getSequence();
                        me->startTimeSet = true;
                        return -1;
                    } else {
                        if (me->start < element->getRealTime()) {
                            me->sequence = me->last;
                            me->startTimeSet = true;
                            return -1;
                        }
                        me->last = element->getSequence();
                    }
                }
                return false;
            }

            bool found() { return startTimeSet; }
        } logFindStart(logMask, pid, start, sequence);

        logbuf().flushTo(cli, sequence, FlushCommand::hasReadLogs(cli),
                         logFindStart.callback, &logFindStart);

        if (!logFindStart.found()) {
            if (nonBlock) {
                doSocketDelete(cli);
                return false;
            }
            sequence = LogBufferElement::getCurrentSequence();
        }
    }

    FlushCommand command(*this, nonBlock, tail, logMask, pid, sequence);
    command.runSocketCommand(cli);
    return true;
}

void LogReader::doSocketDelete(SocketClient *cli) {
    LastLogTimes &times = mLogbuf.mTimes;
    LogTimeEntry::lock();
    LastLogTimes::iterator it = times.begin();
    while(it != times.end()) {
        LogTimeEntry *entry = (*it);
        if (entry->mClient == cli) {
            times.erase(it);
            entry->release_Locked();
            break;
        }
        it++;
    }
    LogTimeEntry::unlock();
}

int LogReader::getLogSocket() {
    static const char socketName[] = "logdr";
    int sock = android_get_control_socket(socketName);

    if (sock < 0) {
        sock = socket_local_server(socketName,
                                   ANDROID_SOCKET_NAMESPACE_RESERVED,
                                   SOCK_SEQPACKET);
    }

    return sock;
}