/*
* ring_buffer_frontend.c
*
- * (C) Copyright 2005-2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * Copyright (C) 2005-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; only
+ * version 2.1 of the License.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ *
*
* Ring buffer wait-free buffer synchronization. Producer-consumer and flight
* recorder (overwrite) modes. See thesis:
* - splice one subbuffer worth of data to a pipe
* - splice the data from pipe to disk/network
* - put_subbuf
- *
- * Dual LGPL v2.1/GPL v2 license.
*/
#define _GNU_SOURCE
#include <sys/types.h>
#include <sys/mman.h>
#include <sys/stat.h>
+#include <unistd.h>
#include <fcntl.h>
+#include <signal.h>
+#include <time.h>
#include <urcu/compiler.h>
#include <urcu/ref.h>
+#include <urcu/tls-compat.h>
#include <helper.h>
#include "smp.h"
#include "backend.h"
#include "frontend.h"
#include "shm.h"
+#include "tlsfixup.h"
+#include "../liblttng-ust/compat.h" /* For ENODATA */
#ifndef max
#define max(a, b) ((a) > (b) ? (a) : (b))
/* Print DBG() messages about events lost only every 1048576 hits */
#define DBG_PRINT_NR_LOST (1UL << 20)
+#define LTTNG_UST_RB_SIG_FLUSH SIGRTMIN
+#define LTTNG_UST_RB_SIG_READ SIGRTMIN + 1
+#define LTTNG_UST_RB_SIG_TEARDOWN SIGRTMIN + 2
+#define CLOCKID CLOCK_MONOTONIC
+
/*
* Use POSIX SHM: shm_open(3) and shm_unlink(3).
* close(2) to close the fd returned by shm_open.
switch_old_end:1;
};
-__thread unsigned int lib_ring_buffer_nesting;
+DEFINE_URCU_TLS(unsigned int, lib_ring_buffer_nesting);
/*
- * TODO: this is unused. Errors are saved within the ring buffer.
- * Eventually, allow consumerd to print these errors.
+ * wakeup_fd_mutex protects wakeup fd use by timer from concurrent
+ * close.
*/
+static pthread_mutex_t wakeup_fd_mutex = PTHREAD_MUTEX_INITIALIZER;
+
static
void lib_ring_buffer_print_errors(struct channel *chan,
- struct lttng_ust_lib_ring_buffer *buf, int cpu,
- struct lttng_ust_shm_handle *handle)
- __attribute__((unused));
+ struct lttng_ust_lib_ring_buffer *buf, int cpu,
+ struct lttng_ust_shm_handle *handle);
+
+/*
+ * Handle timer teardown race wrt memory free of private data by
+ * ring buffer signals are handled by a single thread, which permits
+ * a synchronization point between handling of each signal.
+ * Protected by the ust mutex.
+ */
+struct timer_signal_data {
+ pthread_t tid; /* thread id managing signals */
+ int setup_done;
+ int qs_done;
+};
+
+static struct timer_signal_data timer_signal;
/**
* lib_ring_buffer_reset - Reset ring buffer to initial values.
return ret;
}
-#if 0
-static void switch_buffer_timer(unsigned long data)
+static
+void lib_ring_buffer_channel_switch_timer(int sig, siginfo_t *si, void *uc)
{
- struct lttng_ust_lib_ring_buffer *buf = (struct lttng_ust_lib_ring_buffer *)data;
- struct channel *chan = shmp(handle, buf->backend.chan);
- const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config;
+ const struct lttng_ust_lib_ring_buffer_config *config;
+ struct lttng_ust_shm_handle *handle;
+ struct channel *chan;
+ int cpu;
+
+ assert(CMM_LOAD_SHARED(timer_signal.tid) == pthread_self());
+
+ chan = si->si_value.sival_ptr;
+ handle = chan->handle;
+ config = &chan->backend.config;
+
+ DBG("Switch timer for channel %p\n", chan);
/*
* Only flush buffers periodically if readers are active.
*/
- if (uatomic_read(&buf->active_readers) || uatomic_read(&buf->active_shadow_readers))
- lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE, handle);
-
- //TODO timers
- //if (config->alloc == RING_BUFFER_ALLOC_PER_CPU)
- // mod_timer_pinned(&buf->switch_timer,
- // jiffies + chan->switch_timer_interval);
- //else
- // mod_timer(&buf->switch_timer,
- // jiffies + chan->switch_timer_interval);
+ pthread_mutex_lock(&wakeup_fd_mutex);
+ if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
+ for_each_possible_cpu(cpu) {
+ struct lttng_ust_lib_ring_buffer *buf =
+ shmp(handle, chan->backend.buf[cpu].shmp);
+ if (uatomic_read(&buf->active_readers))
+ lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE,
+ chan->handle);
+ }
+ } else {
+ struct lttng_ust_lib_ring_buffer *buf =
+ shmp(handle, chan->backend.buf[0].shmp);
+
+ if (uatomic_read(&buf->active_readers))
+ lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE,
+ chan->handle);
+ }
+ pthread_mutex_unlock(&wakeup_fd_mutex);
+ return;
}
-#endif //0
-static void lib_ring_buffer_start_switch_timer(struct lttng_ust_lib_ring_buffer *buf,
- struct lttng_ust_shm_handle *handle)
+static
+void lib_ring_buffer_channel_do_read(struct channel *chan)
{
- struct channel *chan = shmp(handle, buf->backend.chan);
- //const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config;
+ const struct lttng_ust_lib_ring_buffer_config *config;
+ struct lttng_ust_shm_handle *handle;
+ int cpu;
+
+ handle = chan->handle;
+ config = &chan->backend.config;
+
+ /*
+ * Only flush buffers periodically if readers are active.
+ */
+ pthread_mutex_lock(&wakeup_fd_mutex);
+ if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
+ for_each_possible_cpu(cpu) {
+ struct lttng_ust_lib_ring_buffer *buf =
+ shmp(handle, chan->backend.buf[cpu].shmp);
+
+ if (uatomic_read(&buf->active_readers)
+ && lib_ring_buffer_poll_deliver(config, buf,
+ chan, handle)) {
+ lib_ring_buffer_wakeup(buf, handle);
+ }
+ }
+ } else {
+ struct lttng_ust_lib_ring_buffer *buf =
+ shmp(handle, chan->backend.buf[0].shmp);
+
+ if (uatomic_read(&buf->active_readers)
+ && lib_ring_buffer_poll_deliver(config, buf,
+ chan, handle)) {
+ lib_ring_buffer_wakeup(buf, handle);
+ }
+ }
+ pthread_mutex_unlock(&wakeup_fd_mutex);
+}
+
+static
+void lib_ring_buffer_channel_read_timer(int sig, siginfo_t *si, void *uc)
+{
+ struct channel *chan;
+
+ assert(CMM_LOAD_SHARED(timer_signal.tid) == pthread_self());
+ chan = si->si_value.sival_ptr;
+ DBG("Read timer for channel %p\n", chan);
+ lib_ring_buffer_channel_do_read(chan);
+ return;
+}
+
+static
+void rb_setmask(sigset_t *mask)
+{
+ int ret;
+
+ ret = sigemptyset(mask);
+ if (ret) {
+ PERROR("sigemptyset");
+ }
+ ret = sigaddset(mask, LTTNG_UST_RB_SIG_FLUSH);
+ if (ret) {
+ PERROR("sigaddset");
+ }
+ ret = sigaddset(mask, LTTNG_UST_RB_SIG_READ);
+ if (ret) {
+ PERROR("sigaddset");
+ }
+ ret = sigaddset(mask, LTTNG_UST_RB_SIG_TEARDOWN);
+ if (ret) {
+ PERROR("sigaddset");
+ }
+}
+
+static
+void *sig_thread(void *arg)
+{
+ sigset_t mask;
+ siginfo_t info;
+ int signr;
+
+ /* Only self thread will receive signal mask. */
+ rb_setmask(&mask);
+ CMM_STORE_SHARED(timer_signal.tid, pthread_self());
+
+ for (;;) {
+ signr = sigwaitinfo(&mask, &info);
+ if (signr == -1) {
+ if (errno != EINTR)
+ PERROR("sigwaitinfo");
+ continue;
+ }
+ if (signr == LTTNG_UST_RB_SIG_FLUSH) {
+ lib_ring_buffer_channel_switch_timer(info.si_signo,
+ &info, NULL);
+ } else if (signr == LTTNG_UST_RB_SIG_READ) {
+ lib_ring_buffer_channel_read_timer(info.si_signo,
+ &info, NULL);
+ } else if (signr == LTTNG_UST_RB_SIG_TEARDOWN) {
+ cmm_smp_mb();
+ CMM_STORE_SHARED(timer_signal.qs_done, 1);
+ cmm_smp_mb();
+ } else {
+ ERR("Unexptected signal %d\n", info.si_signo);
+ }
+ }
+ return NULL;
+}
+
+/*
+ * Called with ust_lock() held.
+ * Ensure only a single thread listens on the timer signal.
+ */
+static
+void lib_ring_buffer_setup_timer_thread(void)
+{
+ pthread_t thread;
+ int ret;
- if (!chan->switch_timer_interval || buf->switch_timer_enabled)
+ if (timer_signal.setup_done)
return;
- //TODO
- //init_timer(&buf->switch_timer);
- //buf->switch_timer.function = switch_buffer_timer;
- //buf->switch_timer.expires = jiffies + chan->switch_timer_interval;
- //buf->switch_timer.data = (unsigned long)buf;
- //if (config->alloc == RING_BUFFER_ALLOC_PER_CPU)
- // add_timer_on(&buf->switch_timer, buf->backend.cpu);
- //else
- // add_timer(&buf->switch_timer);
- buf->switch_timer_enabled = 1;
+
+ ret = pthread_create(&thread, NULL, &sig_thread, NULL);
+ if (ret) {
+ errno = ret;
+ PERROR("pthread_create");
+ }
+ ret = pthread_detach(thread);
+ if (ret) {
+ errno = ret;
+ PERROR("pthread_detach");
+ }
+ timer_signal.setup_done = 1;
}
-static void lib_ring_buffer_stop_switch_timer(struct lttng_ust_lib_ring_buffer *buf,
- struct lttng_ust_shm_handle *handle)
+/*
+ * Called with ust_lock() held.
+ */
+static
+void lib_ring_buffer_channel_switch_timer_start(struct channel *chan)
{
- struct channel *chan = shmp(handle, buf->backend.chan);
+ struct sigevent sev;
+ struct itimerspec its;
+ int ret;
- if (!chan->switch_timer_interval || !buf->switch_timer_enabled)
+ if (!chan->switch_timer_interval || chan->switch_timer_enabled)
return;
- //TODO
- //del_timer_sync(&buf->switch_timer);
- buf->switch_timer_enabled = 0;
+ chan->switch_timer_enabled = 1;
+
+ lib_ring_buffer_setup_timer_thread();
+
+ sev.sigev_notify = SIGEV_SIGNAL;
+ sev.sigev_signo = LTTNG_UST_RB_SIG_FLUSH;
+ sev.sigev_value.sival_ptr = chan;
+ ret = timer_create(CLOCKID, &sev, &chan->switch_timer);
+ if (ret == -1) {
+ PERROR("timer_create");
+ }
+
+ its.it_value.tv_sec = chan->switch_timer_interval / 1000000;
+ its.it_value.tv_nsec = chan->switch_timer_interval % 1000000;
+ its.it_interval.tv_sec = its.it_value.tv_sec;
+ its.it_interval.tv_nsec = its.it_value.tv_nsec;
+
+ ret = timer_settime(chan->switch_timer, 0, &its, NULL);
+ if (ret == -1) {
+ PERROR("timer_settime");
+ }
}
-#if 0
/*
- * Polling timer to check the channels for data.
+ * Called with ust_lock() held.
*/
-static void read_buffer_timer(unsigned long data)
+static
+void lib_ring_buffer_channel_switch_timer_stop(struct channel *chan)
{
- struct lttng_ust_lib_ring_buffer *buf = (struct lttng_ust_lib_ring_buffer *)data;
- struct channel *chan = shmp(handle, buf->backend.chan);
- const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config;
+ sigset_t pending_set;
+ int ret;
+
+ if (!chan->switch_timer_interval || !chan->switch_timer_enabled)
+ return;
- CHAN_WARN_ON(chan, !buf->backend.allocated);
+ ret = timer_delete(chan->switch_timer);
+ if (ret == -1) {
+ PERROR("timer_delete");
+ }
- if (uatomic_read(&buf->active_readers) || uatomic_read(&buf->active_shadow_readers))
- && lib_ring_buffer_poll_deliver(config, buf, chan)) {
- //TODO
- //wake_up_interruptible(&buf->read_wait);
- //wake_up_interruptible(&chan->read_wait);
+ /*
+ * Ensure we don't have any signal queued for this channel.
+ */
+ for (;;) {
+ ret = sigemptyset(&pending_set);
+ if (ret == -1) {
+ PERROR("sigemptyset");
+ }
+ ret = sigpending(&pending_set);
+ if (ret == -1) {
+ PERROR("sigpending");
+ }
+ if (!sigismember(&pending_set, LTTNG_UST_RB_SIG_FLUSH))
+ break;
+ caa_cpu_relax();
}
- //TODO
- //if (config->alloc == RING_BUFFER_ALLOC_PER_CPU)
- // mod_timer_pinned(&buf->read_timer,
- // jiffies + chan->read_timer_interval);
- //else
- // mod_timer(&buf->read_timer,
- // jiffies + chan->read_timer_interval);
+ /*
+ * From this point, no new signal handler will be fired that
+ * would try to access "chan". However, we still need to wait
+ * for any currently executing handler to complete.
+ */
+ cmm_smp_mb();
+ CMM_STORE_SHARED(timer_signal.qs_done, 0);
+ cmm_smp_mb();
+
+ /*
+ * Kill with LTTNG_UST_RB_SIG_TEARDOWN, so signal management
+ * thread wakes up.
+ */
+ kill(getpid(), LTTNG_UST_RB_SIG_TEARDOWN);
+
+ while (!CMM_LOAD_SHARED(timer_signal.qs_done))
+ caa_cpu_relax();
+ cmm_smp_mb();
+
+ chan->switch_timer = 0;
+ chan->switch_timer_enabled = 0;
}
-#endif //0
-static void lib_ring_buffer_start_read_timer(struct lttng_ust_lib_ring_buffer *buf,
- struct lttng_ust_shm_handle *handle)
+/*
+ * Called with ust_lock() held.
+ */
+static
+void lib_ring_buffer_channel_read_timer_start(struct channel *chan)
{
- struct channel *chan = shmp(handle, buf->backend.chan);
const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config;
+ struct sigevent sev;
+ struct itimerspec its;
+ int ret;
if (config->wakeup != RING_BUFFER_WAKEUP_BY_TIMER
- || !chan->read_timer_interval
- || buf->read_timer_enabled)
+ || !chan->read_timer_interval || chan->read_timer_enabled)
return;
- //TODO
- //init_timer(&buf->read_timer);
- //buf->read_timer.function = read_buffer_timer;
- //buf->read_timer.expires = jiffies + chan->read_timer_interval;
- //buf->read_timer.data = (unsigned long)buf;
-
- //if (config->alloc == RING_BUFFER_ALLOC_PER_CPU)
- // add_timer_on(&buf->read_timer, buf->backend.cpu);
- //else
- // add_timer(&buf->read_timer);
- buf->read_timer_enabled = 1;
+ chan->read_timer_enabled = 1;
+
+ lib_ring_buffer_setup_timer_thread();
+
+ sev.sigev_notify = SIGEV_SIGNAL;
+ sev.sigev_signo = LTTNG_UST_RB_SIG_READ;
+ sev.sigev_value.sival_ptr = chan;
+ ret = timer_create(CLOCKID, &sev, &chan->read_timer);
+ if (ret == -1) {
+ PERROR("timer_create");
+ }
+
+ its.it_value.tv_sec = chan->read_timer_interval / 1000000;
+ its.it_value.tv_nsec = chan->read_timer_interval % 1000000;
+ its.it_interval.tv_sec = its.it_value.tv_sec;
+ its.it_interval.tv_nsec = its.it_value.tv_nsec;
+
+ ret = timer_settime(chan->read_timer, 0, &its, NULL);
+ if (ret == -1) {
+ PERROR("timer_settime");
+ }
}
-static void lib_ring_buffer_stop_read_timer(struct lttng_ust_lib_ring_buffer *buf,
- struct lttng_ust_shm_handle *handle)
+/*
+ * Called with ust_lock() held.
+ */
+static
+void lib_ring_buffer_channel_read_timer_stop(struct channel *chan)
{
- struct channel *chan = shmp(handle, buf->backend.chan);
const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config;
+ sigset_t pending_set;
+ int ret;
if (config->wakeup != RING_BUFFER_WAKEUP_BY_TIMER
- || !chan->read_timer_interval
- || !buf->read_timer_enabled)
+ || !chan->read_timer_interval || !chan->read_timer_enabled)
return;
- //TODO
- //del_timer_sync(&buf->read_timer);
+ ret = timer_delete(chan->read_timer);
+ if (ret == -1) {
+ PERROR("timer_delete");
+ }
+
/*
* do one more check to catch data that has been written in the last
* timer period.
*/
- if (lib_ring_buffer_poll_deliver(config, buf, chan, handle)) {
- //TODO
- //wake_up_interruptible(&buf->read_wait);
- //wake_up_interruptible(&chan->read_wait);
+ lib_ring_buffer_channel_do_read(chan);
+
+
+ /*
+ * Ensure we don't have any signal queued for this channel.
+ */
+ for (;;) {
+ ret = sigemptyset(&pending_set);
+ if (ret == -1) {
+ PERROR("sigemptyset");
+ }
+ ret = sigpending(&pending_set);
+ if (ret == -1) {
+ PERROR("sigpending");
+ }
+ if (!sigismember(&pending_set, LTTNG_UST_RB_SIG_READ))
+ break;
+ caa_cpu_relax();
}
- buf->read_timer_enabled = 0;
+
+ /*
+ * From this point, no new signal handler will be fired that
+ * would try to access "chan". However, we still need to wait
+ * for any currently executing handler to complete.
+ */
+ cmm_smp_mb();
+ CMM_STORE_SHARED(timer_signal.qs_done, 0);
+ cmm_smp_mb();
+
+ /*
+ * Kill with LTTNG_UST_RB_SIG_TEARDOWN, so signal management
+ * thread wakes up.
+ */
+ kill(getpid(), LTTNG_UST_RB_SIG_TEARDOWN);
+
+ while (!CMM_LOAD_SHARED(timer_signal.qs_done))
+ caa_cpu_relax();
+ cmm_smp_mb();
+
+ chan->read_timer = 0;
+ chan->read_timer_enabled = 0;
}
static void channel_unregister_notifiers(struct channel *chan,
struct lttng_ust_shm_handle *handle)
{
- const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config;
+ lib_ring_buffer_channel_switch_timer_stop(chan);
+ lib_ring_buffer_channel_read_timer_stop(chan);
+}
+
+static void channel_print_errors(struct channel *chan,
+ struct lttng_ust_shm_handle *handle)
+{
+ const struct lttng_ust_lib_ring_buffer_config *config =
+ &chan->backend.config;
int cpu;
if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
for_each_possible_cpu(cpu) {
- struct lttng_ust_lib_ring_buffer *buf = shmp(handle, chan->backend.buf[cpu].shmp);
-
- lib_ring_buffer_stop_switch_timer(buf, handle);
- lib_ring_buffer_stop_read_timer(buf, handle);
+ struct lttng_ust_lib_ring_buffer *buf =
+ shmp(handle, chan->backend.buf[cpu].shmp);
+ lib_ring_buffer_print_errors(chan, buf, cpu, handle);
}
} else {
- struct lttng_ust_lib_ring_buffer *buf = shmp(handle, chan->backend.buf[0].shmp);
+ struct lttng_ust_lib_ring_buffer *buf =
+ shmp(handle, chan->backend.buf[0].shmp);
- lib_ring_buffer_stop_switch_timer(buf, handle);
- lib_ring_buffer_stop_read_timer(buf, handle);
+ lib_ring_buffer_print_errors(chan, buf, -1, handle);
}
- //channel_backend_unregister_notifiers(&chan->backend);
}
-static void channel_free(struct channel *chan, struct lttng_ust_shm_handle *handle,
- int shadow)
+static void channel_free(struct channel *chan,
+ struct lttng_ust_shm_handle *handle)
{
- if (!shadow)
- channel_backend_free(&chan->backend, handle);
+ channel_backend_free(&chan->backend, handle);
/* chan is freed by shm teardown */
shm_object_table_destroy(handle->table);
free(handle);
void *priv_data_init,
void *buf_addr, size_t subbuf_size,
size_t num_subbuf, unsigned int switch_timer_interval,
- unsigned int read_timer_interval,
- int **shm_fd, int **wait_fd, uint64_t **memory_map_size)
+ unsigned int read_timer_interval)
{
- int ret, cpu;
+ int ret;
size_t shmsize, chansize;
struct channel *chan;
struct lttng_ust_shm_handle *handle;
struct shm_object *shmobj;
- struct shm_ref *ref;
+ unsigned int nr_streams;
+
+ if (config->alloc == RING_BUFFER_ALLOC_PER_CPU)
+ nr_streams = num_possible_cpus();
+ else
+ nr_streams = 1;
if (lib_ring_buffer_check_config(config, switch_timer_interval,
read_timer_interval))
/* Calculate the shm allocation layout */
shmsize = sizeof(struct channel);
shmsize += offset_align(shmsize, __alignof__(struct lttng_ust_lib_ring_buffer_shmp));
- if (config->alloc == RING_BUFFER_ALLOC_PER_CPU)
- shmsize += sizeof(struct lttng_ust_lib_ring_buffer_shmp) * num_possible_cpus();
- else
- shmsize += sizeof(struct lttng_ust_lib_ring_buffer_shmp);
+ shmsize += sizeof(struct lttng_ust_lib_ring_buffer_shmp) * nr_streams;
chansize = shmsize;
- shmsize += offset_align(shmsize, priv_data_align);
+ if (priv_data_align)
+ shmsize += offset_align(shmsize, priv_data_align);
shmsize += priv_data_size;
- shmobj = shm_object_table_append(handle->table, shmsize);
+ /* Allocate normal memory for channel (not shared) */
+ shmobj = shm_object_table_alloc(handle->table, shmsize, SHM_OBJECT_MEM);
if (!shmobj)
goto error_append;
/* struct channel is at object 0, offset 0 (hardcoded) */
chan = shmp(handle, handle->chan);
if (!chan)
goto error_append;
+ chan->nr_streams = nr_streams;
/* space for private data */
if (priv_data_size) {
memcpy(*priv_data, priv_data_init, priv_data_size);
} else {
chan->priv_data_offset = -1;
- *priv_data = NULL;
+ if (priv_data)
+ *priv_data = NULL;
}
ret = channel_backend_init(&chan->backend, name, config,
if (ret)
goto error_backend_init;
+ chan->handle = handle;
chan->commit_count_mask = (~0UL >> chan->backend.num_subbuf_order);
- //TODO
- //chan->switch_timer_interval = usecs_to_jiffies(switch_timer_interval);
- //chan->read_timer_interval = usecs_to_jiffies(read_timer_interval);
- //TODO
- //init_waitqueue_head(&chan->read_wait);
- //init_waitqueue_head(&chan->hp_wait);
- if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
- /*
- * In case of non-hotplug cpu, if the ring-buffer is allocated
- * in early initcall, it will not be notified of secondary cpus.
- * In that off case, we need to allocate for all possible cpus.
- */
- for_each_possible_cpu(cpu) {
- struct lttng_ust_lib_ring_buffer *buf = shmp(handle, chan->backend.buf[cpu].shmp);
- lib_ring_buffer_start_switch_timer(buf, handle);
- lib_ring_buffer_start_read_timer(buf, handle);
- }
- } else {
- struct lttng_ust_lib_ring_buffer *buf = shmp(handle, chan->backend.buf[0].shmp);
+ chan->switch_timer_interval = switch_timer_interval;
+ chan->read_timer_interval = read_timer_interval;
+ lib_ring_buffer_channel_switch_timer_start(chan);
+ lib_ring_buffer_channel_read_timer_start(chan);
- lib_ring_buffer_start_switch_timer(buf, handle);
- lib_ring_buffer_start_read_timer(buf, handle);
- }
- ref = &handle->chan._ref;
- shm_get_object_data(handle, ref, shm_fd, wait_fd, memory_map_size);
return handle;
error_backend_init:
return NULL;
}
-struct lttng_ust_shm_handle *channel_handle_create(int shm_fd, int wait_fd,
- uint64_t memory_map_size)
+struct lttng_ust_shm_handle *channel_handle_create(void *data,
+ uint64_t memory_map_size,
+ int wakeup_fd)
{
struct lttng_ust_shm_handle *handle;
struct shm_object *object;
if (!handle->table)
goto error_table_alloc;
/* Add channel object */
- object = shm_object_table_append_shadow(handle->table,
- shm_fd, wait_fd, memory_map_size);
+ object = shm_object_table_append_mem(handle->table, data,
+ memory_map_size, wakeup_fd);
if (!object)
goto error_table_object;
/* struct channel is at object 0, offset 0 (hardcoded) */
}
int channel_handle_add_stream(struct lttng_ust_shm_handle *handle,
- int shm_fd, int wait_fd, uint64_t memory_map_size)
+ int shm_fd, int wakeup_fd, uint32_t stream_nr,
+ uint64_t memory_map_size)
{
struct shm_object *object;
/* Add stream object */
- object = shm_object_table_append_shadow(handle->table,
- shm_fd, wait_fd, memory_map_size);
+ object = shm_object_table_append_shm(handle->table,
+ shm_fd, wakeup_fd, stream_nr,
+ memory_map_size);
if (!object)
- return -1;
+ return -EINVAL;
return 0;
}
+unsigned int channel_handle_get_nr_streams(struct lttng_ust_shm_handle *handle)
+{
+ assert(handle->table);
+ return handle->table->allocated_len - 1;
+}
+
static
-void channel_release(struct channel *chan, struct lttng_ust_shm_handle *handle,
- int shadow)
+void channel_release(struct channel *chan, struct lttng_ust_shm_handle *handle)
{
- channel_free(chan, handle, shadow);
+ channel_free(chan, handle);
}
/**
* They should release their handle at that point.
*/
void channel_destroy(struct channel *chan, struct lttng_ust_shm_handle *handle,
- int shadow)
+ int consumer)
{
- if (shadow) {
- channel_release(chan, handle, shadow);
- return;
+ if (consumer) {
+ /*
+ * Note: the consumer takes care of finalizing and
+ * switching the buffers.
+ */
+ channel_unregister_notifiers(chan, handle);
+ /*
+ * The consumer prints errors.
+ */
+ channel_print_errors(chan, handle);
}
- channel_unregister_notifiers(chan, handle);
-
- /*
- * Note: the consumer takes care of finalizing and switching the
- * buffers.
- */
-
/*
* sessiond/consumer are keeping a reference on the shm file
* descriptor directly. No need to refcount.
*/
- channel_release(chan, handle, shadow);
+ channel_release(chan, handle);
return;
}
const struct lttng_ust_lib_ring_buffer_config *config,
struct channel *chan, int cpu,
struct lttng_ust_shm_handle *handle,
- int **shm_fd, int **wait_fd,
- uint64_t **memory_map_size)
+ int *shm_fd, int *wait_fd,
+ int *wakeup_fd,
+ uint64_t *memory_map_size)
{
struct shm_ref *ref;
if (config->alloc == RING_BUFFER_ALLOC_GLOBAL) {
- ref = &chan->backend.buf[0].shmp._ref;
- shm_get_object_data(handle, ref, shm_fd, wait_fd,
- memory_map_size);
- return shmp(handle, chan->backend.buf[0].shmp);
+ cpu = 0;
} else {
if (cpu >= num_possible_cpus())
return NULL;
- ref = &chan->backend.buf[cpu].shmp._ref;
- shm_get_object_data(handle, ref, shm_fd, wait_fd,
- memory_map_size);
- return shmp(handle, chan->backend.buf[cpu].shmp);
}
+ ref = &chan->backend.buf[cpu].shmp._ref;
+ *shm_fd = shm_get_shm_fd(handle, ref);
+ *wait_fd = shm_get_wait_fd(handle, ref);
+ *wakeup_fd = shm_get_wakeup_fd(handle, ref);
+ if (shm_get_shm_size(handle, ref, memory_map_size))
+ return NULL;
+ return shmp(handle, chan->backend.buf[cpu].shmp);
}
-int lib_ring_buffer_open_read(struct lttng_ust_lib_ring_buffer *buf,
- struct lttng_ust_shm_handle *handle,
- int shadow)
+int ring_buffer_channel_close_wait_fd(const struct lttng_ust_lib_ring_buffer_config *config,
+ struct channel *chan,
+ struct lttng_ust_shm_handle *handle)
{
- if (shadow) {
- if (uatomic_cmpxchg(&buf->active_shadow_readers, 0, 1) != 0)
- return -EBUSY;
- cmm_smp_mb();
- return 0;
+ struct shm_ref *ref;
+
+ ref = &handle->chan._ref;
+ return shm_close_wait_fd(handle, ref);
+}
+
+int ring_buffer_channel_close_wakeup_fd(const struct lttng_ust_lib_ring_buffer_config *config,
+ struct channel *chan,
+ struct lttng_ust_shm_handle *handle)
+{
+ struct shm_ref *ref;
+
+ ref = &handle->chan._ref;
+ return shm_close_wakeup_fd(handle, ref);
+}
+
+int ring_buffer_stream_close_wait_fd(const struct lttng_ust_lib_ring_buffer_config *config,
+ struct channel *chan,
+ struct lttng_ust_shm_handle *handle,
+ int cpu)
+{
+ struct shm_ref *ref;
+
+ if (config->alloc == RING_BUFFER_ALLOC_GLOBAL) {
+ cpu = 0;
+ } else {
+ if (cpu >= num_possible_cpus())
+ return -EINVAL;
}
+ ref = &chan->backend.buf[cpu].shmp._ref;
+ return shm_close_wait_fd(handle, ref);
+}
+
+int ring_buffer_stream_close_wakeup_fd(const struct lttng_ust_lib_ring_buffer_config *config,
+ struct channel *chan,
+ struct lttng_ust_shm_handle *handle,
+ int cpu)
+{
+ struct shm_ref *ref;
+ int ret;
+
+ if (config->alloc == RING_BUFFER_ALLOC_GLOBAL) {
+ cpu = 0;
+ } else {
+ if (cpu >= num_possible_cpus())
+ return -EINVAL;
+ }
+ ref = &chan->backend.buf[cpu].shmp._ref;
+ pthread_mutex_lock(&wakeup_fd_mutex);
+ ret = shm_close_wakeup_fd(handle, ref);
+ pthread_mutex_unlock(&wakeup_fd_mutex);
+ return ret;
+}
+
+int lib_ring_buffer_open_read(struct lttng_ust_lib_ring_buffer *buf,
+ struct lttng_ust_shm_handle *handle)
+{
if (uatomic_cmpxchg(&buf->active_readers, 0, 1) != 0)
return -EBUSY;
cmm_smp_mb();
}
void lib_ring_buffer_release_read(struct lttng_ust_lib_ring_buffer *buf,
- struct lttng_ust_shm_handle *handle,
- int shadow)
+ struct lttng_ust_shm_handle *handle)
{
struct channel *chan = shmp(handle, buf->backend.chan);
- if (shadow) {
- CHAN_WARN_ON(chan, uatomic_read(&buf->active_shadow_readers) != 1);
- cmm_smp_mb();
- uatomic_dec(&buf->active_shadow_readers);
- return;
- }
CHAN_WARN_ON(chan, uatomic_read(&buf->active_readers) != 1);
cmm_smp_mb();
uatomic_dec(&buf->active_readers);
}
/**
- * lib_ring_buffer_put_snapshot - move consumed counter forward
+ * lib_ring_buffer_move_consumer - move consumed counter forward
* @buf: ring buffer
* @consumed_new: new consumed count value
*/
struct channel *chan = shmp(handle, bufb->chan);
unsigned long consumed;
- CHAN_WARN_ON(chan, uatomic_read(&buf->active_readers) != 1
- && uatomic_read(&buf->active_shadow_readers) != 1);
+ CHAN_WARN_ON(chan, uatomic_read(&buf->active_readers) != 1);
/*
* Only push the consumed value forward.
const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config;
unsigned long read_sb_bindex, consumed_idx, consumed;
- CHAN_WARN_ON(chan, uatomic_read(&buf->active_readers) != 1
- && uatomic_read(&buf->active_shadow_readers) != 1);
+ CHAN_WARN_ON(chan, uatomic_read(&buf->active_readers) != 1);
if (!buf->get_subbuf) {
/*
static
void lib_ring_buffer_print_errors(struct channel *chan,
- struct lttng_ust_lib_ring_buffer *buf, int cpu,
- struct lttng_ust_shm_handle *handle)
+ struct lttng_ust_lib_ring_buffer *buf, int cpu,
+ struct lttng_ust_shm_handle *handle)
{
const struct lttng_ust_lib_ring_buffer_config *config = &chan->backend.config;
void *priv = channel_get_private(chan);
- DBG("ring buffer %s, cpu %d: %lu records written, "
- "%lu records overrun\n",
- chan->backend.name, cpu,
- v_read(config, &buf->records_count),
- v_read(config, &buf->records_overrun));
-
- if (v_read(config, &buf->records_lost_full)
- || v_read(config, &buf->records_lost_wrap)
- || v_read(config, &buf->records_lost_big))
- DBG("ring buffer %s, cpu %d: records were lost. Caused by:\n"
- " [ %lu buffer full, %lu nest buffer wrap-around, "
- "%lu event too big ]\n",
- chan->backend.name, cpu,
- v_read(config, &buf->records_lost_full),
- v_read(config, &buf->records_lost_wrap),
- v_read(config, &buf->records_lost_big));
-
+ if (!strcmp(chan->backend.name, "relay-metadata-mmap")) {
+ DBG("ring buffer %s: %lu records written, "
+ "%lu records overrun\n",
+ chan->backend.name,
+ v_read(config, &buf->records_count),
+ v_read(config, &buf->records_overrun));
+ } else {
+ DBG("ring buffer %s, cpu %d: %lu records written, "
+ "%lu records overrun\n",
+ chan->backend.name, cpu,
+ v_read(config, &buf->records_count),
+ v_read(config, &buf->records_overrun));
+
+ if (v_read(config, &buf->records_lost_full)
+ || v_read(config, &buf->records_lost_wrap)
+ || v_read(config, &buf->records_lost_big))
+ DBG("ring buffer %s, cpu %d: records were lost. Caused by:\n"
+ " [ %lu buffer full, %lu nest buffer wrap-around, "
+ "%lu event too big ]\n",
+ chan->backend.name, cpu,
+ v_read(config, &buf->records_lost_full),
+ v_read(config, &buf->records_lost_wrap),
+ v_read(config, &buf->records_lost_big));
+ }
lib_ring_buffer_print_buffer_errors(buf, chan, priv, cpu, handle);
}
*/
if (mode == SWITCH_FLUSH || off > 0) {
if (caa_unlikely(off == 0)) {
+ /*
+ * A final flush that encounters an empty
+ * sub-buffer cannot switch buffer if a
+ * reader is located within this sub-buffer.
+ * Anyway, the purpose of final flushing of a
+ * sub-buffer at offset 0 is to handle the case
+ * of entirely empty stream.
+ */
+ if (caa_unlikely(subbuf_trunc(offsets->begin, chan)
+ - subbuf_trunc((unsigned long)
+ uatomic_read(&buf->consumed), chan)
+ >= chan->backend.buf_size))
+ return -1;
/*
* The client does not save any header information.
* Don't switch empty subbuffer on finalize, because it
ctx->buf_offset = offsets.begin + offsets.pre_header_padding;
return 0;
}
+
+/*
+ * Force a read (imply TLS fixup for dlopen) of TLS variables.
+ */
+void lttng_fixup_ringbuffer_tls(void)
+{
+ asm volatile ("" : : "m" (URCU_TLS(lib_ring_buffer_nesting)));
+}
+
+void lib_ringbuffer_signal_init(void)
+{
+ sigset_t mask;
+ int ret;
+
+ /*
+ * Block signal for entire process, so only our thread processes
+ * it.
+ */
+ rb_setmask(&mask);
+ ret = pthread_sigmask(SIG_BLOCK, &mask, NULL);
+ if (ret) {
+ errno = ret;
+ PERROR("pthread_sigmask");
+ }
+}
projects / lttng-ust.git / blobdiff