/*
- * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#include "timeval.h"
#include <assert.h>
#include <errno.h>
+#if HAVE_EXECINFO_H
+#include <execinfo.h>
+#endif
#include <poll.h>
#include <signal.h>
#include <stdlib.h>
#include <unistd.h>
#include "coverage.h"
#include "dummy.h"
+#include "dynamic-string.h"
#include "fatal-signal.h"
#include "signals.h"
#include "unixctl.h"
#include "util.h"
#include "vlog.h"
+#ifndef HAVE_EXECINFO_H
+#define HAVE_EXECINFO_H 0
+#endif
+
VLOG_DEFINE_THIS_MODULE(timeval);
/* The clock to use for measuring time intervals. This is CLOCK_MONOTONIC by
* to CLOCK_REALTIME. */
static clockid_t monotonic_clock;
-/* Has a timer tick occurred?
+/* Has a timer tick occurred? Only relevant if CACHE_TIME is true.
*
* We initialize these to true to force time_init() to get called on the first
* call to time_msec() or another function that queries the current time. */
static struct timespec warp_offset; /* Offset added to monotonic_time. */
static bool time_stopped; /* Disables real-time updates, if true. */
-/* Time at which to die with SIGALRM (if not TIME_MIN). */
-static time_t deadline = TIME_MIN;
+/* Time in milliseconds at which to die with SIGALRM (if not LLONG_MAX). */
+static long long int deadline = LLONG_MAX;
+
+struct trace {
+ void *backtrace[32]; /* Populated by backtrace(). */
+ size_t n_frames; /* Number of frames in 'backtrace'. */
+};
+
+#define MAX_TRACES 50
+static struct unixctl_conn *backtrace_conn = NULL;
+static struct trace *traces = NULL;
+static size_t n_traces = 0;
static void set_up_timer(void);
static void set_up_signal(int flags);
static void sigalrm_handler(int);
static void refresh_wall_if_ticked(void);
static void refresh_monotonic_if_ticked(void);
-static time_t time_add(time_t, time_t);
static void block_sigalrm(sigset_t *);
static void unblock_sigalrm(const sigset_t *);
static void log_poll_interval(long long int last_wakeup);
static void refresh_rusage(void);
static void timespec_add(struct timespec *sum,
const struct timespec *a, const struct timespec *b);
+static void trace_run(void);
+static unixctl_cb_func backtrace_cb;
/* Initializes the timetracking module, if not already initialized. */
static void
time_init(void)
{
static bool inited;
+
+ /* The best place to do this is probably a timeval_run() function.
+ * However, none exists and this function is usually so fast that doing it
+ * here seems fine for now. */
+ trace_run();
+
if (inited) {
return;
}
inited = true;
+ if (HAVE_EXECINFO_H && CACHE_TIME) {
+ unixctl_command_register("backtrace", "", 0, 0, backtrace_cb, NULL);
+ }
+
coverage_init();
if (!clock_gettime(CLOCK_MONOTONIC, &monotonic_time)) {
set_up_signal(SA_RESTART);
set_up_timer();
+
boot_time = time_msec();
}
static timer_t timer_id; /* "static" to avoid apparent memory leak. */
struct itimerspec itimer;
+ if (!CACHE_TIME) {
+ return;
+ }
+
if (timer_create(monotonic_clock, NULL, &timer_id)) {
VLOG_FATAL("timer_create failed (%s)", strerror(errno));
}
/* Forces a refresh of the current time from the kernel. It is not usually
* necessary to call this function, since the time will be refreshed
- * automatically at least every TIME_UPDATE_INTERVAL milliseconds. */
+ * automatically at least every TIME_UPDATE_INTERVAL milliseconds. If
+ * CACHE_TIME is false, we will always refresh the current time so this
+ * function has no effect. */
void
time_refresh(void)
{
return monotonic_time.tv_sec;
}
-/* Same as time_now() except does not write to static variables, for use in
- * signal handlers. */
-static time_t
-time_now_sig(void)
-{
- struct timespec cur_time;
-
- clock_gettime(monotonic_clock, &cur_time);
- return cur_time.tv_sec;
-}
-
/* Returns the current time, in seconds. */
time_t
time_wall(void)
void
time_alarm(unsigned int secs)
{
+ long long int now;
+ long long int msecs;
+
sigset_t oldsigs;
time_init();
+ time_refresh();
+
+ now = time_msec();
+ msecs = secs * 1000;
+
block_sigalrm(&oldsigs);
- deadline = secs ? time_add(time_now(), secs) : TIME_MIN;
+ deadline = now < LLONG_MAX - msecs ? now + msecs : LLONG_MAX;
unblock_sigalrm(&oldsigs);
}
coverage_clear();
start = time_msec();
blocked = false;
+
+ timeout_when = MIN(timeout_when, deadline);
+
for (;;) {
long long int now = time_msec();
int time_left;
if (retval < 0) {
retval = -errno;
}
+
time_refresh();
+ if (deadline <= time_msec()) {
+ fatal_signal_handler(SIGALRM);
+ if (retval < 0) {
+ retval = 0;
+ }
+ break;
+ }
+
if (retval != -EINTR) {
break;
}
- if (!blocked && deadline == TIME_MIN) {
+ if (!blocked && CACHE_TIME && !backtrace_conn) {
block_sigalrm(&oldsigs);
blocked = true;
}
return retval;
}
-/* Returns the sum of 'a' and 'b', with saturation on overflow or underflow. */
-static time_t
-time_add(time_t a, time_t b)
-{
- return (a >= 0
- ? (b > TIME_MAX - a ? TIME_MAX : a + b)
- : (b < TIME_MIN - a ? TIME_MIN : a + b));
-}
-
static void
-sigalrm_handler(int sig_nr)
+sigalrm_handler(int sig_nr OVS_UNUSED)
{
wall_tick = true;
monotonic_tick = true;
- if (deadline != TIME_MIN && time_now_sig() > deadline) {
- fatal_signal_handler(sig_nr);
+
+#if HAVE_EXECINFO_H
+ if (backtrace_conn && n_traces < MAX_TRACES) {
+ struct trace *trace = &traces[n_traces++];
+ trace->n_frames = backtrace(trace->backtrace,
+ ARRAY_SIZE(trace->backtrace));
}
+#endif
}
static void
refresh_wall_if_ticked(void)
{
- if (wall_tick) {
+ if (!CACHE_TIME || wall_tick) {
refresh_wall();
}
}
static void
refresh_monotonic_if_ticked(void)
{
- if (monotonic_tick) {
+ if (!CACHE_TIME || monotonic_tick) {
refresh_monotonic();
}
}
{
return cpu_usage;
}
+
+static void
+trace_run(void)
+{
+#if HAVE_EXECINFO_H
+ if (backtrace_conn && n_traces >= MAX_TRACES) {
+ struct unixctl_conn *reply_conn = backtrace_conn;
+ struct ds ds = DS_EMPTY_INITIALIZER;
+ sigset_t oldsigs;
+ size_t i;
+
+ block_sigalrm(&oldsigs);
+
+ for (i = 0; i < n_traces; i++) {
+ struct trace *trace = &traces[i];
+ char **frame_strs;
+ size_t j;
+
+ frame_strs = backtrace_symbols(trace->backtrace, trace->n_frames);
+
+ ds_put_format(&ds, "Backtrace %zu\n", i + 1);
+ for (j = 0; j < trace->n_frames; j++) {
+ ds_put_format(&ds, "%s\n", frame_strs[j]);
+ }
+ ds_put_cstr(&ds, "\n");
+
+ free(frame_strs);
+ }
+
+ free(traces);
+ traces = NULL;
+ n_traces = 0;
+ backtrace_conn = NULL;
+
+ unblock_sigalrm(&oldsigs);
+
+ unixctl_command_reply(reply_conn, ds_cstr(&ds));
+ ds_destroy(&ds);
+ }
+#endif
+}
\f
/* Unixctl interface. */
unixctl_command_reply(conn, "warped");
}
+static void
+backtrace_cb(struct unixctl_conn *conn,
+ int argc OVS_UNUSED, const char *argv[] OVS_UNUSED,
+ void *aux OVS_UNUSED)
+{
+ sigset_t oldsigs;
+
+ assert(HAVE_EXECINFO_H && CACHE_TIME);
+
+ if (backtrace_conn) {
+ unixctl_command_reply_error(conn, "In Use");
+ return;
+ }
+ assert(!traces);
+
+ block_sigalrm(&oldsigs);
+ backtrace_conn = conn;
+ traces = xmalloc(MAX_TRACES * sizeof *traces);
+ n_traces = 0;
+ unblock_sigalrm(&oldsigs);
+}
+
void
timeval_dummy_register(void)
{
projects / openvswitch / blobdiff