+++ /dev/null
-/*
- * SPDX-License-Identifier: LGPL-2.1-only
- *
- * Copyright (C) 2005-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * Ring Buffer Library Synchronization Header (types).
- *
- * See ring_buffer_frontend.c for more information on wait-free algorithms.
- */
-
-#ifndef _LTTNG_RING_BUFFER_FRONTEND_TYPES_H
-#define _LTTNG_RING_BUFFER_FRONTEND_TYPES_H
-
-#include <stdint.h>
-#include <string.h>
-#include <time.h> /* for timer_t */
-
-#include <urcu/list.h>
-#include <urcu/uatomic.h>
-
-#include <lttng/ringbuffer-context.h>
-#include "ringbuffer-config.h"
-#include <usterr-signal-safe.h>
-#include "backend_types.h"
-#include "shm_internal.h"
-#include "shm_types.h"
-#include "vatomic.h"
-
-#define LIB_RING_BUFFER_MAX_NESTING 5
-
-/*
- * A switch is done during tracing or as a final flush after tracing (so it
- * won't write in the new sub-buffer).
- */
-enum switch_mode { SWITCH_ACTIVE, SWITCH_FLUSH };
-
-/* channel: collection of per-cpu ring buffers. */
-#define RB_CHANNEL_PADDING 32
-struct lttng_ust_lib_ring_buffer_channel {
- int record_disabled;
- unsigned long commit_count_mask; /*
- * Commit count mask, removing
- * the MSBs corresponding to
- * bits used to represent the
- * subbuffer index.
- */
-
- unsigned long switch_timer_interval; /* Buffer flush (us) */
- timer_t switch_timer;
- int switch_timer_enabled;
-
- unsigned long read_timer_interval; /* Reader wakeup (us) */
- timer_t read_timer;
- int read_timer_enabled;
-
- int finalized; /* Has channel been finalized */
- size_t priv_data_offset; /* Offset of private data channel config */
- unsigned int nr_streams; /* Number of streams */
- struct lttng_ust_shm_handle *handle;
- /* Extended options. */
- union {
- struct {
- int32_t blocking_timeout_ms;
- void *priv; /* Private data pointer. */
- } s;
- char padding[RB_CHANNEL_PADDING];
- } u;
- /*
- * Associated backend contains a variable-length array. Needs to
- * be last member.
- */
- struct channel_backend backend; /* Associated backend */
-} __attribute__((aligned(CAA_CACHE_LINE_SIZE)));
-
-/* Per-subbuffer commit counters used on the hot path */
-#define RB_COMMIT_COUNT_HOT_PADDING 16
-struct commit_counters_hot {
- union v_atomic cc; /* Commit counter */
- union v_atomic seq; /* Consecutive commits */
- char padding[RB_COMMIT_COUNT_HOT_PADDING];
-} __attribute__((aligned(CAA_CACHE_LINE_SIZE)));
-
-/* Per-subbuffer commit counters used only on cold paths */
-#define RB_COMMIT_COUNT_COLD_PADDING 24
-struct commit_counters_cold {
- union v_atomic cc_sb; /* Incremented _once_ at sb switch */
- char padding[RB_COMMIT_COUNT_COLD_PADDING];
-} __attribute__((aligned(CAA_CACHE_LINE_SIZE)));
-
-/* ring buffer state */
-#define RB_CRASH_DUMP_ABI_LEN 256
-#define RB_RING_BUFFER_PADDING 60
-
-#define RB_CRASH_DUMP_ABI_MAGIC_LEN 16
-
-/*
- * The 128-bit magic number is xor'd in the process data so it does not
- * cause a false positive when searching for buffers by scanning memory.
- * The actual magic number is:
- * 0x17, 0x7B, 0xF1, 0x77, 0xBF, 0x17, 0x7B, 0xF1,
- * 0x77, 0xBF, 0x17, 0x7B, 0xF1, 0x77, 0xBF, 0x17,
- */
-#define RB_CRASH_DUMP_ABI_MAGIC_XOR \
- { \
- 0x17 ^ 0xFF, 0x7B ^ 0xFF, 0xF1 ^ 0xFF, 0x77 ^ 0xFF, \
- 0xBF ^ 0xFF, 0x17 ^ 0xFF, 0x7B ^ 0xFF, 0xF1 ^ 0xFF, \
- 0x77 ^ 0xFF, 0xBF ^ 0xFF, 0x17 ^ 0xFF, 0x7B ^ 0xFF, \
- 0xF1 ^ 0xFF, 0x77 ^ 0xFF, 0xBF ^ 0xFF, 0x17 ^ 0xFF, \
- }
-
-#define RB_CRASH_ENDIAN 0x1234
-
-#define RB_CRASH_DUMP_ABI_MAJOR 0
-#define RB_CRASH_DUMP_ABI_MINOR 0
-
-enum lttng_crash_type {
- LTTNG_CRASH_TYPE_UST = 0,
- LTTNG_CRASH_TYPE_KERNEL = 1,
-};
-
-struct lttng_crash_abi {
- uint8_t magic[RB_CRASH_DUMP_ABI_MAGIC_LEN];
- uint64_t mmap_length; /* Overall lenght of crash record */
- uint16_t endian; /*
- * { 0x12, 0x34 }: big endian
- * { 0x34, 0x12 }: little endian
- */
- uint16_t major; /* Major number. */
- uint16_t minor; /* Minor number. */
- uint8_t word_size; /* Word size (bytes). */
- uint8_t layout_type; /* enum lttng_crash_type */
-
- struct {
- uint32_t prod_offset;
- uint32_t consumed_offset;
- uint32_t commit_hot_array;
- uint32_t commit_hot_seq;
- uint32_t buf_wsb_array;
- uint32_t buf_wsb_id;
- uint32_t sb_array;
- uint32_t sb_array_shmp_offset;
- uint32_t sb_backend_p_offset;
- uint32_t content_size;
- uint32_t packet_size;
- } __attribute__((packed)) offset;
- struct {
- uint8_t prod_offset;
- uint8_t consumed_offset;
- uint8_t commit_hot_seq;
- uint8_t buf_wsb_id;
- uint8_t sb_array_shmp_offset;
- uint8_t sb_backend_p_offset;
- uint8_t content_size;
- uint8_t packet_size;
- } __attribute__((packed)) length;
- struct {
- uint32_t commit_hot_array;
- uint32_t buf_wsb_array;
- uint32_t sb_array;
- } __attribute__((packed)) stride;
-
- uint64_t buf_size; /* Size of the buffer */
- uint64_t subbuf_size; /* Sub-buffer size */
- uint64_t num_subbuf; /* Number of sub-buffers for writer */
- uint32_t mode; /* Buffer mode: 0: overwrite, 1: discard */
-} __attribute__((packed));
-
-struct lttng_ust_lib_ring_buffer {
- /* First 32 bytes are for the buffer crash dump ABI */
- struct lttng_crash_abi crash_abi;
-
- /* 32 bytes cache-hot cacheline */
- union v_atomic __attribute__((aligned(32))) offset;
- /* Current offset in the buffer */
- DECLARE_SHMP(struct commit_counters_hot, commit_hot);
- /* Commit count per sub-buffer */
- long consumed; /*
- * Current offset in the buffer
- * standard atomic access (shared)
- */
- int record_disabled;
- /* End of cache-hot 32 bytes cacheline */
-
- union v_atomic last_tsc; /*
- * Last timestamp written in the buffer.
- */
-
- struct lttng_ust_lib_ring_buffer_backend backend;
- /* Associated backend */
-
- DECLARE_SHMP(struct commit_counters_cold, commit_cold);
- /* Commit count per sub-buffer */
- DECLARE_SHMP(uint64_t, ts_end); /*
- * timestamp_end per sub-buffer.
- * Time is sampled by the
- * switch_*_end() callbacks
- * which are the last space
- * reservation performed in the
- * sub-buffer before it can be
- * fully committed and
- * delivered. This time value is
- * then read by the deliver
- * callback, performed by the
- * last commit before the buffer
- * becomes readable.
- */
- long active_readers; /*
- * Active readers count
- * standard atomic access (shared)
- */
- /* Dropped records */
- union v_atomic records_lost_full; /* Buffer full */
- union v_atomic records_lost_wrap; /* Nested wrap-around */
- union v_atomic records_lost_big; /* Events too big */
- union v_atomic records_count; /* Number of records written */
- union v_atomic records_overrun; /* Number of overwritten records */
- //wait_queue_head_t read_wait; /* reader buffer-level wait queue */
- int finalized; /* buffer has been finalized */
- unsigned long get_subbuf_consumed; /* Read-side consumed */
- unsigned long prod_snapshot; /* Producer count snapshot */
- unsigned long cons_snapshot; /* Consumer count snapshot */
- unsigned int get_subbuf:1; /* Sub-buffer being held by reader */
- /* shmp pointer to self */
- DECLARE_SHMP(struct lttng_ust_lib_ring_buffer, self);
- char padding[RB_RING_BUFFER_PADDING];
-} __attribute__((aligned(CAA_CACHE_LINE_SIZE)));
-
-/*
- * ring buffer private context
- *
- * Private context passed to lib_ring_buffer_reserve(), lib_ring_buffer_commit(),
- * lib_ring_buffer_try_discard_reserve(), lttng_ust_lib_ring_buffer_align_ctx() and
- * lib_ring_buffer_write().
- *
- * This context is allocated on an internal shadow-stack by a successful reserve
- * operation, used by align/write, and freed by commit.
- */
-
-struct lttng_ust_lib_ring_buffer_ctx_private {
- /* input received by lib_ring_buffer_reserve(). */
- struct lttng_ust_lib_ring_buffer_ctx *pub;
- struct lttng_ust_lib_ring_buffer_channel *chan; /* channel */
-
- /* output from lib_ring_buffer_reserve() */
- int reserve_cpu; /* processor id updated by the reserve */
- size_t slot_size; /* size of the reserved slot */
- unsigned long buf_offset; /* offset following the record header */
- unsigned long pre_offset; /*
- * Initial offset position _before_
- * the record is written. Positioned
- * prior to record header alignment
- * padding.
- */
- uint64_t tsc; /* time-stamp counter value */
- unsigned int rflags; /* reservation flags */
- void *ip; /* caller ip address */
-
- struct lttng_ust_lib_ring_buffer *buf; /*
- * buffer corresponding to processor id
- * for this channel
- */
- struct lttng_ust_lib_ring_buffer_backend_pages *backend_pages;
-};
-
-static inline
-void *channel_get_private_config(struct lttng_ust_lib_ring_buffer_channel *chan)
-{
- return ((char *) chan) + chan->priv_data_offset;
-}
-
-static inline
-void *channel_get_private(struct lttng_ust_lib_ring_buffer_channel *chan)
-{
- return chan->u.s.priv;
-}
-
-static inline
-void channel_set_private(struct lttng_ust_lib_ring_buffer_channel *chan, void *priv)
-{
- chan->u.s.priv = priv;
-}
-
-#ifndef __rb_same_type
-#define __rb_same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
-#endif
-
-/*
- * Issue warnings and disable channels upon internal error.
- * Can receive struct lttng_ust_lib_ring_buffer or struct lttng_ust_lib_ring_buffer_backend
- * parameters.
- */
-#define CHAN_WARN_ON(c, cond) \
- ({ \
- struct lttng_ust_lib_ring_buffer_channel *__chan; \
- int _____ret = caa_unlikely(cond); \
- if (_____ret) { \
- if (__rb_same_type(*(c), struct channel_backend)) \
- __chan = caa_container_of((void *) (c), \
- struct lttng_ust_lib_ring_buffer_channel, \
- backend); \
- else if (__rb_same_type(*(c), \
- struct lttng_ust_lib_ring_buffer_channel)) \
- __chan = (void *) (c); \
- else \
- BUG_ON(1); \
- uatomic_inc(&__chan->record_disabled); \
- WARN_ON(1); \
- } \
- _____ret = _____ret; /* For clang "unused result". */ \
- })
-
-/**
- * lttng_ust_lib_ring_buffer_align_ctx - Align context offset on "alignment"
- * @ctx: ring buffer context.
- */
-static inline
-void lttng_ust_lib_ring_buffer_align_ctx(struct lttng_ust_lib_ring_buffer_ctx *ctx,
- size_t alignment)
- lttng_ust_notrace;
-static inline
-void lttng_ust_lib_ring_buffer_align_ctx(struct lttng_ust_lib_ring_buffer_ctx *ctx,
- size_t alignment)
-{
- struct lttng_ust_lib_ring_buffer_ctx_private *ctx_private = ctx->priv;
-
- ctx_private->buf_offset += lttng_ust_lib_ring_buffer_align(ctx_private->buf_offset,
- alignment);
-}
-
-#endif /* _LTTNG_RING_BUFFER_FRONTEND_TYPES_H */
projects / lttng-ust.git / blobdiff