X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=libringbuffer%2Ffrontend_internal.h;h=6d1a75bdceef83e06d982097b94e4cdc8d8bcf59;hb=e92f3e285939848f248af08f11a39a04a7fcf852;hp=02cb4d4a75d37c4b70f1f515be7fe5a1e18443d9;hpb=4746ae29409b78e96543a3b207c91a3c510c6476;p=lttng-ust.git diff --git a/libringbuffer/frontend_internal.h b/libringbuffer/frontend_internal.h index 02cb4d4a..6d1a75bd 100644 --- a/libringbuffer/frontend_internal.h +++ b/libringbuffer/frontend_internal.h @@ -1,13 +1,28 @@ -#ifndef _LINUX_RING_BUFFER_FRONTEND_INTERNAL_H -#define _LINUX_RING_BUFFER_FRONTEND_INTERNAL_H +#ifndef _LTTNG_RING_BUFFER_FRONTEND_INTERNAL_H +#define _LTTNG_RING_BUFFER_FRONTEND_INTERNAL_H /* - * linux/ringbuffer/frontend_internal.h - * - * (C) Copyright 2005-2010 - Mathieu Desnoyers + * libringbuffer/frontend_internal.h * * Ring Buffer Library Synchronization Header (internal helpers). * + * Copyright (C) 2005-2012 Mathieu Desnoyers + * + * 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 + * + * * Author: * Mathieu Desnoyers * @@ -18,7 +33,7 @@ #include -#include +#include #include "backend_types.h" #include "frontend_types.h" #include "shm.h" @@ -85,8 +100,8 @@ unsigned long subbuf_index(unsigned long offset, struct channel *chan) #if (CAA_BITS_PER_LONG == 32) static inline -void save_last_tsc(const struct lib_ring_buffer_config *config, - struct lib_ring_buffer *buf, u64 tsc) +void save_last_tsc(const struct lttng_ust_lib_ring_buffer_config *config, + struct lttng_ust_lib_ring_buffer *buf, uint64_t tsc) { if (config->tsc_bits == 0 || config->tsc_bits == 64) return; @@ -98,8 +113,8 @@ void save_last_tsc(const struct lib_ring_buffer_config *config, } static inline -int last_tsc_overflow(const struct lib_ring_buffer_config *config, - struct lib_ring_buffer *buf, u64 tsc) +int last_tsc_overflow(const struct lttng_ust_lib_ring_buffer_config *config, + struct lttng_ust_lib_ring_buffer *buf, uint64_t tsc) { unsigned long tsc_shifted; @@ -107,7 +122,7 @@ int last_tsc_overflow(const struct lib_ring_buffer_config *config, return 0; tsc_shifted = (unsigned long)(tsc >> config->tsc_bits); - if (unlikely(tsc_shifted + if (caa_unlikely(tsc_shifted - (unsigned long)v_read(config, &buf->last_tsc))) return 1; else @@ -115,8 +130,8 @@ int last_tsc_overflow(const struct lib_ring_buffer_config *config, } #else static inline -void save_last_tsc(const struct lib_ring_buffer_config *config, - struct lib_ring_buffer *buf, u64 tsc) +void save_last_tsc(const struct lttng_ust_lib_ring_buffer_config *config, + struct lttng_ust_lib_ring_buffer *buf, uint64_t tsc) { if (config->tsc_bits == 0 || config->tsc_bits == 64) return; @@ -125,13 +140,13 @@ void save_last_tsc(const struct lib_ring_buffer_config *config, } static inline -int last_tsc_overflow(const struct lib_ring_buffer_config *config, - struct lib_ring_buffer *buf, u64 tsc) +int last_tsc_overflow(const struct lttng_ust_lib_ring_buffer_config *config, + struct lttng_ust_lib_ring_buffer *buf, uint64_t tsc) { if (config->tsc_bits == 0 || config->tsc_bits == 64) return 0; - if (unlikely((tsc - v_read(config, &buf->last_tsc)) + if (caa_unlikely((tsc - v_read(config, &buf->last_tsc)) >> config->tsc_bits)) return 1; else @@ -140,17 +155,17 @@ int last_tsc_overflow(const struct lib_ring_buffer_config *config, #endif extern -int lib_ring_buffer_reserve_slow(struct lib_ring_buffer_ctx *ctx); +int lib_ring_buffer_reserve_slow(struct lttng_ust_lib_ring_buffer_ctx *ctx); extern -void lib_ring_buffer_switch_slow(struct lib_ring_buffer *buf, +void lib_ring_buffer_switch_slow(struct lttng_ust_lib_ring_buffer *buf, enum switch_mode mode, - struct shm_handle *handle); + struct lttng_ust_shm_handle *handle); /* Buffer write helpers */ static inline -void lib_ring_buffer_reserve_push_reader(struct lib_ring_buffer *buf, +void lib_ring_buffer_reserve_push_reader(struct lttng_ust_lib_ring_buffer *buf, struct channel *chan, unsigned long offset) { @@ -167,32 +182,32 @@ void lib_ring_buffer_reserve_push_reader(struct lib_ring_buffer *buf, * write position sub-buffer index in the buffer being the one * which will win this loop. */ - if (unlikely(subbuf_trunc(offset, chan) + if (caa_unlikely(subbuf_trunc(offset, chan) - subbuf_trunc(consumed_old, chan) >= chan->backend.buf_size)) consumed_new = subbuf_align(consumed_old, chan); else return; - } while (unlikely(uatomic_cmpxchg(&buf->consumed, consumed_old, + } while (caa_unlikely(uatomic_cmpxchg(&buf->consumed, consumed_old, consumed_new) != consumed_old)); } static inline -void lib_ring_buffer_vmcore_check_deliver(const struct lib_ring_buffer_config *config, - struct lib_ring_buffer *buf, +void lib_ring_buffer_vmcore_check_deliver(const struct lttng_ust_lib_ring_buffer_config *config, + struct lttng_ust_lib_ring_buffer *buf, unsigned long commit_count, unsigned long idx, - struct shm_handle *handle) + struct lttng_ust_shm_handle *handle) { if (config->oops == RING_BUFFER_OOPS_CONSISTENCY) v_set(config, &shmp_index(handle, buf->commit_hot, idx)->seq, commit_count); } static inline -int lib_ring_buffer_poll_deliver(const struct lib_ring_buffer_config *config, - struct lib_ring_buffer *buf, +int lib_ring_buffer_poll_deliver(const struct lttng_ust_lib_ring_buffer_config *config, + struct lttng_ust_lib_ring_buffer *buf, struct channel *chan, - struct shm_handle *handle) + struct lttng_ust_shm_handle *handle) { unsigned long consumed_old, consumed_idx, commit_count, write_offset; @@ -232,18 +247,18 @@ int lib_ring_buffer_poll_deliver(const struct lib_ring_buffer_config *config, } static inline -int lib_ring_buffer_pending_data(const struct lib_ring_buffer_config *config, - struct lib_ring_buffer *buf, +int lib_ring_buffer_pending_data(const struct lttng_ust_lib_ring_buffer_config *config, + struct lttng_ust_lib_ring_buffer *buf, struct channel *chan) { return !!subbuf_offset(v_read(config, &buf->offset), chan); } static inline -unsigned long lib_ring_buffer_get_data_size(const struct lib_ring_buffer_config *config, - struct lib_ring_buffer *buf, +unsigned long lib_ring_buffer_get_data_size(const struct lttng_ust_lib_ring_buffer_config *config, + struct lttng_ust_lib_ring_buffer *buf, unsigned long idx, - struct shm_handle *handle) + struct lttng_ust_shm_handle *handle) { return subbuffer_get_data_size(config, &buf->backend, idx, handle); } @@ -254,10 +269,10 @@ unsigned long lib_ring_buffer_get_data_size(const struct lib_ring_buffer_config * This is a very specific ftrace use-case, so we keep this as "internal" API. */ static inline -int lib_ring_buffer_reserve_committed(const struct lib_ring_buffer_config *config, - struct lib_ring_buffer *buf, +int lib_ring_buffer_reserve_committed(const struct lttng_ust_lib_ring_buffer_config *config, + struct lttng_ust_lib_ring_buffer *buf, struct channel *chan, - struct shm_handle *handle) + struct lttng_ust_shm_handle *handle) { unsigned long offset, idx, commit_count; @@ -283,20 +298,20 @@ int lib_ring_buffer_reserve_committed(const struct lib_ring_buffer_config *confi } static inline -void lib_ring_buffer_check_deliver(const struct lib_ring_buffer_config *config, - struct lib_ring_buffer *buf, +void lib_ring_buffer_check_deliver(const struct lttng_ust_lib_ring_buffer_config *config, + struct lttng_ust_lib_ring_buffer *buf, struct channel *chan, unsigned long offset, unsigned long commit_count, unsigned long idx, - struct shm_handle *handle) + struct lttng_ust_shm_handle *handle) { unsigned long old_commit_count = commit_count - chan->backend.subbuf_size; - u64 tsc; + uint64_t tsc; /* Check if all commits have been done */ - if (unlikely((buf_trunc(offset, chan) >> chan->backend.num_subbuf_order) + if (caa_unlikely((buf_trunc(offset, chan) >> chan->backend.num_subbuf_order) - (old_commit_count & chan->commit_count_mask) == 0)) { /* * If we succeeded at updating cc_sb below, we are the subbuffer @@ -324,7 +339,7 @@ void lib_ring_buffer_check_deliver(const struct lib_ring_buffer_config *config, * The subbuffer size is least 2 bytes (minimum size: 1 page). * This guarantees that old_commit_count + 1 != commit_count. */ - if (likely(v_cmpxchg(config, &shmp_index(handle, buf->commit_cold, idx)->cc_sb, + if (caa_likely(v_cmpxchg(config, &shmp_index(handle, buf->commit_cold, idx)->cc_sb, old_commit_count, old_commit_count + 1) == old_commit_count)) { /* @@ -376,7 +391,8 @@ void lib_ring_buffer_check_deliver(const struct lib_ring_buffer_config *config, * RING_BUFFER_WAKEUP_BY_WRITER wakeup is not lock-free. */ if (config->wakeup == RING_BUFFER_WAKEUP_BY_WRITER - && uatomic_read(&buf->active_readers) + && (uatomic_read(&buf->active_readers) + || uatomic_read(&buf->active_shadow_readers)) && lib_ring_buffer_poll_deliver(config, buf, chan, handle)) { int wakeup_fd = shm_get_wakeup_fd(handle, &buf->self._ref); @@ -386,6 +402,20 @@ void lib_ring_buffer_check_deliver(const struct lib_ring_buffer_config *config, * Wake-up the other end by * writing a null byte in the * pipe (non-blocking). + * Important note: Because + * writing into the pipe is + * non-blocking (and therefore + * we allow dropping wakeup + * data, as long as there is + * wakeup data present in the + * pipe buffer to wake up the + * consumer), the consumer + * should perform the following + * sequence for waiting: + * 1) empty the pipe (reads). + * 2) check if there is data in + * the buffer. + * 3) wait on the pipe (poll). */ do { ret = write(wakeup_fd, "", 1); @@ -406,14 +436,14 @@ void lib_ring_buffer_check_deliver(const struct lib_ring_buffer_config *config, * useful for crash dump. */ static inline -void lib_ring_buffer_write_commit_counter(const struct lib_ring_buffer_config *config, - struct lib_ring_buffer *buf, +void lib_ring_buffer_write_commit_counter(const struct lttng_ust_lib_ring_buffer_config *config, + struct lttng_ust_lib_ring_buffer *buf, struct channel *chan, unsigned long idx, unsigned long buf_offset, unsigned long commit_count, size_t slot_size, - struct shm_handle *handle) + struct lttng_ust_shm_handle *handle) { unsigned long offset, commit_seq_old; @@ -428,7 +458,7 @@ void lib_ring_buffer_write_commit_counter(const struct lib_ring_buffer_config *c * buffer full/empty mismatch because offset is never zero here * (subbuffer header and record headers have non-zero length). */ - if (unlikely(subbuf_offset(offset - commit_count, chan))) + if (caa_unlikely(subbuf_offset(offset - commit_count, chan))) return; commit_seq_old = v_read(config, &shmp_index(handle, buf->commit_hot, idx)->seq); @@ -437,14 +467,14 @@ void lib_ring_buffer_write_commit_counter(const struct lib_ring_buffer_config *c commit_seq_old, commit_count); } -extern int lib_ring_buffer_create(struct lib_ring_buffer *buf, +extern int lib_ring_buffer_create(struct lttng_ust_lib_ring_buffer *buf, struct channel_backend *chanb, int cpu, - struct shm_handle *handle, + struct lttng_ust_shm_handle *handle, struct shm_object *shmobj); -extern void lib_ring_buffer_free(struct lib_ring_buffer *buf, - struct shm_handle *handle); +extern void lib_ring_buffer_free(struct lttng_ust_lib_ring_buffer *buf, + struct lttng_ust_shm_handle *handle); /* Keep track of trap nesting inside ring buffer code */ extern __thread unsigned int lib_ring_buffer_nesting; -#endif /* _LINUX_RING_BUFFER_FRONTEND_INTERNAL_H */ +#endif /* _LTTNG_RING_BUFFER_FRONTEND_INTERNAL_H */