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
|
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2014 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
*
*/
#include <stdio.h>
#include <poll.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/time.h>
#include <sys/types.h>
#include "trace-local.h"
/*
* Stream runs for a single machine. We are going to cheat
* and use the trace-output and trace-input code to create
* our pevent. First just create a trace.dat file and then read
* it to create the pevent and handle.
*/
struct tracecmd_input *
trace_stream_init(struct buffer_instance *instance, int cpu, int fd, int cpus,
struct hook_list *hooks,
tracecmd_handle_init_func handle_init, int global)
{
struct tracecmd_output *trace_output;
struct tracecmd_input *trace_input;
static FILE *fp = NULL;
static int tfd;
long flags;
if (instance->handle) {
trace_input = instance->handle;
goto make_pipe;
}
if (!fp) {
fp = tmpfile();
if (!fp)
return NULL;
tfd = fileno(fp);
trace_output = tracecmd_output_create_fd(tfd);
if (!trace_output)
goto fail;
tracecmd_output_write_headers(trace_output, NULL);
tracecmd_output_flush(trace_output);
/* Don't close the descriptor, use it for reading */
tracecmd_output_free(trace_output);
}
lseek(tfd, 0, SEEK_SET);
trace_input = tracecmd_alloc_fd(tfd, 0);
if (!trace_input)
goto fail;
if (tracecmd_read_headers(trace_input, TRACECMD_FILE_PRINTK) < 0)
goto fail_free_input;
if (handle_init)
handle_init(trace_input, hooks, global);
make_pipe:
/* Do not block on this pipe */
flags = fcntl(fd, F_GETFL);
fcntl(fd, F_SETFL, flags | O_NONBLOCK);
if (tracecmd_make_pipe(trace_input, cpu, fd, cpus) < 0)
goto fail_free_input;
instance->handle = trace_input;
return trace_input;
fail_free_input:
tracecmd_close(trace_input);
fail:
fclose(fp);
fp = NULL; /* Try again later? */
return NULL;
}
int trace_stream_read(struct pid_record_data *pids, int nr_pids, long sleep_us)
{
struct pid_record_data *last_pid;
struct pid_record_data *pid;
struct tep_record *record;
struct pollfd pollfd[nr_pids];
long sleep_ms = sleep_us > 0 ? (sleep_us + 999) / 1000 : sleep_us;
int ret;
int i;
if (!nr_pids)
return 0;
last_pid = NULL;
again:
for (i = 0; i < nr_pids; i++) {
pid = &pids[i];
if (!pid->record)
pid->record = tracecmd_read_data(pid->instance->handle, pid->cpu);
record = pid->record;
if (!record && errno == EINVAL)
/* pipe has closed */
pid->closed = 1;
if (record &&
(!last_pid || record->ts < last_pid->record->ts))
last_pid = pid;
}
if (last_pid) {
trace_show_data(last_pid->instance->handle, last_pid->record);
tracecmd_free_record(last_pid->record);
last_pid->record = NULL;
return 1;
}
for (i = 0; i < nr_pids; i++) {
/* Do not process closed pipes */
if (pids[i].closed) {
memset(pollfd + i, 0, sizeof(*pollfd));
continue;
}
pollfd[i].fd = pids[i].brass[0];
pollfd[i].events = POLLIN;
}
ret = poll(pollfd, nr_pids, sleep_ms);
if (ret > 0)
goto again;
return ret;
}
|
