+++ /dev/null
-/*
- * SPDX-License-Identifier: LGPL-2.1-only
- *
- * Copyright (C) 2005-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * Ring Buffer Library Synchronization Header (API).
- *
- * See ring_buffer_frontend.c for more information on wait-free algorithms.
- */
-
-#ifndef _LTTNG_RING_BUFFER_FRONTEND_H
-#define _LTTNG_RING_BUFFER_FRONTEND_H
-
-#include <stddef.h>
-#include <stdint.h>
-
-#include <urcu/compiler.h>
-#include <urcu/uatomic.h>
-
-#include "smp.h"
-
-/* Internal helpers */
-#include "frontend_internal.h"
-
-/* Buffer creation/removal and setup operations */
-
-/*
- * switch_timer_interval is the time interval (in us) to fill sub-buffers with
- * padding to let readers get those sub-buffers. Used for live streaming.
- *
- * read_timer_interval is the time interval (in us) to wake up pending readers.
- *
- * buf_addr is a pointer the the beginning of the preallocated buffer contiguous
- * address mapping. It is used only by RING_BUFFER_STATIC configuration. It can
- * be set to NULL for other backends.
- *
- * private data is a memory area for configuration data. This memory is
- * managed by lib ring buffer. priv_data_align is the alignment required
- * for the private data area.
- */
-
-extern
-struct lttng_ust_shm_handle *channel_create(const struct lttng_ust_lib_ring_buffer_config *config,
- const char *name,
- size_t priv_data_align,
- size_t priv_data_size,
- void *priv_data_init,
- void *priv,
- void *buf_addr,
- size_t subbuf_size, size_t num_subbuf,
- unsigned int switch_timer_interval,
- unsigned int read_timer_interval,
- const int *stream_fds, int nr_stream_fds,
- int64_t blocking_timeout)
- __attribute__((visibility("hidden")));
-
-/*
- * channel_destroy finalizes all channel's buffers, waits for readers to
- * release all references, and destroys the channel.
- */
-void channel_destroy(struct lttng_ust_lib_ring_buffer_channel *chan,
- struct lttng_ust_shm_handle *handle,
- int consumer)
- __attribute__((visibility("hidden")));
-
-
-/* Buffer read operations */
-
-/*
- * Iteration on channel cpumask needs to issue a read barrier to match the write
- * barrier in cpu hotplug. It orders the cpumask read before read of per-cpu
- * buffer data. The per-cpu buffer is never removed by cpu hotplug; teardown is
- * only performed at channel destruction.
- */
-#define for_each_channel_cpu(cpu, chan) \
- for_each_possible_cpu(cpu)
-
-extern struct lttng_ust_lib_ring_buffer *channel_get_ring_buffer(
- const struct lttng_ust_lib_ring_buffer_config *config,
- struct lttng_ust_lib_ring_buffer_channel *chan, int cpu,
- struct lttng_ust_shm_handle *handle,
- int *shm_fd, int *wait_fd,
- int *wakeup_fd,
- uint64_t *memory_map_size)
- __attribute__((visibility("hidden")));
-
-extern
-int ring_buffer_channel_close_wait_fd(const struct lttng_ust_lib_ring_buffer_config *config,
- struct lttng_ust_lib_ring_buffer_channel *chan,
- struct lttng_ust_shm_handle *handle)
- __attribute__((visibility("hidden")));
-
-extern
-int ring_buffer_channel_close_wakeup_fd(const struct lttng_ust_lib_ring_buffer_config *config,
- struct lttng_ust_lib_ring_buffer_channel *chan,
- struct lttng_ust_shm_handle *handle)
- __attribute__((visibility("hidden")));
-
-extern
-int ring_buffer_stream_close_wait_fd(const struct lttng_ust_lib_ring_buffer_config *config,
- struct lttng_ust_lib_ring_buffer_channel *chan,
- struct lttng_ust_shm_handle *handle,
- int cpu)
- __attribute__((visibility("hidden")));
-
-extern
-int ring_buffer_stream_close_wakeup_fd(const struct lttng_ust_lib_ring_buffer_config *config,
- struct lttng_ust_lib_ring_buffer_channel *chan,
- struct lttng_ust_shm_handle *handle,
- int cpu)
- __attribute__((visibility("hidden")));
-
-extern int lib_ring_buffer_open_read(struct lttng_ust_lib_ring_buffer *buf,
- struct lttng_ust_shm_handle *handle)
- __attribute__((visibility("hidden")));
-
-extern void lib_ring_buffer_release_read(struct lttng_ust_lib_ring_buffer *buf,
- struct lttng_ust_shm_handle *handle)
- __attribute__((visibility("hidden")));
-
-/*
- * Initialize signals for ring buffer. Should be called early e.g. by
- * main() in the program to affect all threads.
- */
-void lib_ringbuffer_signal_init(void)
- __attribute__((visibility("hidden")));
-
-/*
- * Read sequence: snapshot, many get_subbuf/put_subbuf, move_consumer.
- */
-extern int lib_ring_buffer_snapshot(struct lttng_ust_lib_ring_buffer *buf,
- unsigned long *consumed,
- unsigned long *produced,
- struct lttng_ust_shm_handle *handle)
- __attribute__((visibility("hidden")));
-
-extern int lib_ring_buffer_snapshot_sample_positions(
- struct lttng_ust_lib_ring_buffer *buf,
- unsigned long *consumed,
- unsigned long *produced,
- struct lttng_ust_shm_handle *handle)
- __attribute__((visibility("hidden")));
-
-extern void lib_ring_buffer_move_consumer(struct lttng_ust_lib_ring_buffer *buf,
- unsigned long consumed_new,
- struct lttng_ust_shm_handle *handle)
- __attribute__((visibility("hidden")));
-
-extern int lib_ring_buffer_get_subbuf(struct lttng_ust_lib_ring_buffer *buf,
- unsigned long consumed,
- struct lttng_ust_shm_handle *handle)
- __attribute__((visibility("hidden")));
-
-extern void lib_ring_buffer_put_subbuf(struct lttng_ust_lib_ring_buffer *buf,
- struct lttng_ust_shm_handle *handle)
- __attribute__((visibility("hidden")));
-
-/*
- * lib_ring_buffer_get_next_subbuf/lib_ring_buffer_put_next_subbuf are helpers
- * to read sub-buffers sequentially.
- */
-static inline int lib_ring_buffer_get_next_subbuf(struct lttng_ust_lib_ring_buffer *buf,
- struct lttng_ust_shm_handle *handle)
-{
- int ret;
-
- ret = lib_ring_buffer_snapshot(buf, &buf->cons_snapshot,
- &buf->prod_snapshot, handle);
- if (ret)
- return ret;
- ret = lib_ring_buffer_get_subbuf(buf, buf->cons_snapshot, handle);
- return ret;
-}
-
-static inline
-void lib_ring_buffer_put_next_subbuf(struct lttng_ust_lib_ring_buffer *buf,
- struct lttng_ust_shm_handle *handle)
-{
- struct lttng_ust_lib_ring_buffer_channel *chan;
-
- chan = shmp(handle, buf->backend.chan);
- if (!chan)
- return;
- lib_ring_buffer_put_subbuf(buf, handle);
- lib_ring_buffer_move_consumer(buf, subbuf_align(buf->cons_snapshot, chan),
- handle);
-}
-
-extern void channel_reset(struct lttng_ust_lib_ring_buffer_channel *chan)
- __attribute__((visibility("hidden")));
-
-extern void lib_ring_buffer_reset(struct lttng_ust_lib_ring_buffer *buf,
- struct lttng_ust_shm_handle *handle)
- __attribute__((visibility("hidden")));
-
-static inline
-unsigned long lib_ring_buffer_get_offset(const struct lttng_ust_lib_ring_buffer_config *config,
- struct lttng_ust_lib_ring_buffer *buf)
-{
- return v_read(config, &buf->offset);
-}
-
-static inline
-unsigned long lib_ring_buffer_get_consumed(
- const struct lttng_ust_lib_ring_buffer_config *config __attribute__((unused)),
- struct lttng_ust_lib_ring_buffer *buf)
-{
- return uatomic_read(&buf->consumed);
-}
-
-/*
- * Must call lib_ring_buffer_is_finalized before reading counters (memory
- * ordering enforced with respect to trace teardown).
- */
-static inline
-int lib_ring_buffer_is_finalized(
- const struct lttng_ust_lib_ring_buffer_config *config __attribute__((unused)),
- struct lttng_ust_lib_ring_buffer *buf)
-{
- int finalized = CMM_ACCESS_ONCE(buf->finalized);
- /*
- * Read finalized before counters.
- */
- cmm_smp_rmb();
- return finalized;
-}
-
-static inline
-int lib_ring_buffer_channel_is_finalized(const struct lttng_ust_lib_ring_buffer_channel *chan)
-{
- return chan->finalized;
-}
-
-static inline
-int lib_ring_buffer_channel_is_disabled(const struct lttng_ust_lib_ring_buffer_channel *chan)
-{
- return uatomic_read(&chan->record_disabled);
-}
-
-static inline
-unsigned long lib_ring_buffer_get_read_data_size(
- const struct lttng_ust_lib_ring_buffer_config *config,
- struct lttng_ust_lib_ring_buffer *buf,
- struct lttng_ust_shm_handle *handle)
-{
- return subbuffer_get_read_data_size(config, &buf->backend, handle);
-}
-
-static inline
-unsigned long lib_ring_buffer_get_records_count(
- const struct lttng_ust_lib_ring_buffer_config *config,
- struct lttng_ust_lib_ring_buffer *buf)
-{
- return v_read(config, &buf->records_count);
-}
-
-static inline
-unsigned long lib_ring_buffer_get_records_overrun(
- const struct lttng_ust_lib_ring_buffer_config *config,
- struct lttng_ust_lib_ring_buffer *buf)
-{
- return v_read(config, &buf->records_overrun);
-}
-
-static inline
-unsigned long lib_ring_buffer_get_records_lost_full(
- const struct lttng_ust_lib_ring_buffer_config *config,
- struct lttng_ust_lib_ring_buffer *buf)
-{
- return v_read(config, &buf->records_lost_full);
-}
-
-static inline
-unsigned long lib_ring_buffer_get_records_lost_wrap(
- const struct lttng_ust_lib_ring_buffer_config *config,
- struct lttng_ust_lib_ring_buffer *buf)
-{
- return v_read(config, &buf->records_lost_wrap);
-}
-
-static inline
-unsigned long lib_ring_buffer_get_records_lost_big(
- const struct lttng_ust_lib_ring_buffer_config *config,
- struct lttng_ust_lib_ring_buffer *buf)
-{
- return v_read(config, &buf->records_lost_big);
-}
-
-static inline
-unsigned long lib_ring_buffer_get_records_read(
- const struct lttng_ust_lib_ring_buffer_config *config,
- struct lttng_ust_lib_ring_buffer *buf)
-{
- return v_read(config, &buf->backend.records_read);
-}
-
-#endif /* _LTTNG_RING_BUFFER_FRONTEND_H */
projects / lttng-ust.git / blobdiff