utility.c revision 053b865412d1982ad1dc0e840898d82527deeb99
1/* system/debuggerd/utility.c
2**
3** Copyright 2008, The Android Open Source Project
4**
5** Licensed under the Apache License, Version 2.0 (the "License");
6** you may not use this file except in compliance with the License.
7** You may obtain a copy of the License at
8**
9**     http://www.apache.org/licenses/LICENSE-2.0
10**
11** Unless required by applicable law or agreed to in writing, software
12** distributed under the License is distributed on an "AS IS" BASIS,
13** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14** See the License for the specific language governing permissions and
15** limitations under the License.
16*/
17
18#include <stddef.h>
19#include <stdbool.h>
20#include <stdio.h>
21#include <string.h>
22#include <errno.h>
23#include <unistd.h>
24#include <signal.h>
25#include <cutils/logd.h>
26#include <sys/ptrace.h>
27#include <sys/wait.h>
28
29#include "utility.h"
30
31const int sleep_time_usec = 50000;         /* 0.05 seconds */
32const int max_total_sleep_usec = 10000000; /* 10 seconds */
33
34void _LOG(log_t* log, bool in_tombstone_only, const char *fmt, ...) {
35    char buf[512];
36
37    va_list ap;
38    va_start(ap, fmt);
39
40    if (log && log->tfd >= 0) {
41        int len;
42        vsnprintf(buf, sizeof(buf), fmt, ap);
43        len = strlen(buf);
44        write(log->tfd, buf, len);
45    }
46
47    if (!in_tombstone_only && (!log || !log->quiet)) {
48        __android_log_vprint(ANDROID_LOG_INFO, "DEBUG", fmt, ap);
49    }
50    va_end(ap);
51}
52
53int wait_for_signal(pid_t tid, int* total_sleep_time_usec) {
54    for (;;) {
55        int status;
56        pid_t n = waitpid(tid, &status, __WALL | WNOHANG);
57        if (n < 0) {
58            if(errno == EAGAIN) continue;
59            LOG("waitpid failed: %s\n", strerror(errno));
60            return -1;
61        } else if (n > 0) {
62            XLOG("waitpid: n=%d status=%08x\n", n, status);
63            if (WIFSTOPPED(status)) {
64                return WSTOPSIG(status);
65            } else {
66                LOG("unexpected waitpid response: n=%d, status=%08x\n", n, status);
67                return -1;
68            }
69        }
70
71        if (*total_sleep_time_usec > max_total_sleep_usec) {
72            LOG("timed out waiting for tid=%d to die\n", tid);
73            return -1;
74        }
75
76        /* not ready yet */
77        XLOG("not ready yet\n");
78        usleep(sleep_time_usec);
79        *total_sleep_time_usec += sleep_time_usec;
80    }
81}
82
83void wait_for_stop(pid_t tid, int* total_sleep_time_usec) {
84    siginfo_t si;
85    while (TEMP_FAILURE_RETRY(ptrace(PTRACE_GETSIGINFO, tid, 0, &si)) < 0 && errno == ESRCH) {
86        if (*total_sleep_time_usec > max_total_sleep_usec) {
87            LOG("timed out waiting for tid=%d to stop\n", tid);
88            break;
89        }
90
91        usleep(sleep_time_usec);
92        *total_sleep_time_usec += sleep_time_usec;
93    }
94}
95