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/*
* Copyright (C) 2014 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License (not later!)
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses>
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
#include <stdio.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_input *trace_input;
struct tracecmd_output *trace_output;
static FILE *fp = NULL;
static int tfd;
static int ofd;
long flags;
if (instance->handle) {
trace_input = instance->handle;
goto make_pipe;
}
if (!fp) {
fp = tmpfile();
if (!fp)
return NULL;
tfd = fileno(fp);
ofd = dup(tfd);
trace_output = tracecmd_create_init_fd(ofd);
if (!trace_output) {
fclose(fp);
return NULL;
}
tracecmd_output_free(trace_output);
}
lseek(ofd, 0, SEEK_SET);
trace_input = tracecmd_alloc_fd(ofd);
if (!trace_input) {
close(ofd);
goto fail;
}
if (tracecmd_read_headers(trace_input) < 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);
return NULL;
}
int trace_stream_read(struct pid_record_data *pids, int nr_pids, struct timeval *tv)
{
struct pevent_record *record;
struct pid_record_data *pid;
struct pid_record_data *last_pid;
fd_set rfds;
int top_rfd = 0;
int ret;
int i;
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);
free_record(last_pid->record);
last_pid->record = NULL;
return 1;
}
FD_ZERO(&rfds);
for (i = 0; i < nr_pids; i++) {
/* Do not process closed pipes */
if (pids[i].closed)
continue;
if (pids[i].brass[0] > top_rfd)
top_rfd = pids[i].brass[0];
FD_SET(pids[i].brass[0], &rfds);
}
ret = select(top_rfd + 1, &rfds, NULL, NULL, tv);
if (ret > 0)
goto again;
return ret;
}
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