X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=libringbuffer%2Ffrontend_api.h;h=77a269184fcf1f3dbc26380f7e2e201cd25bd497;hb=36cb884cbb186c5b280f3427066294a2350a944a;hp=49f6e4c27274a32c2c59b05e414714b780770b9e;hpb=35897f8b2d311b756b81657dad9c53ef1c0fad8a;p=lttng-ust.git diff --git a/libringbuffer/frontend_api.h b/libringbuffer/frontend_api.h index 49f6e4c2..77a26918 100644 --- a/libringbuffer/frontend_api.h +++ b/libringbuffer/frontend_api.h @@ -1,20 +1,33 @@ -#ifndef _LINUX_RING_BUFFER_FRONTEND_API_H -#define _LINUX_RING_BUFFER_FRONTEND_API_H +#ifndef _LTTNG_RING_BUFFER_FRONTEND_API_H +#define _LTTNG_RING_BUFFER_FRONTEND_API_H /* - * linux/ringbuffer/frontend_api.h + * libringbuffer/frontend_api.h * - * (C) Copyright 2005-2010 - Mathieu Desnoyers + * 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 * * Ring Buffer Library Synchronization Header (buffer write API). * * Author: - * Mathieu Desnoyers - * - * See ring_buffer_frontend.c for more information on wait-free algorithms. - * See linux/ringbuffer/frontend.h for channel allocation and read-side API. + * Mathieu Desnoyers * - * Dual LGPL v2.1/GPL v2 license. + * See ring_buffer_frontend.c for more information on wait-free + * algorithms. + * See frontend.h for channel allocation and read-side API. */ #include "frontend.h" @@ -24,10 +37,10 @@ /** * lib_ring_buffer_get_cpu - Precedes ring buffer reserve/commit. * - * Grabs RCU read-side lock and keeps a ring buffer nesting count as - * supplementary safety net to ensure tracer client code will never - * trigger an endless recursion. Returns the processor ID on success, - * -EPERM on failure (nesting count too high). + * Keeps a ring buffer nesting count as supplementary safety net to + * ensure tracer client code will never trigger an endless recursion. + * Returns the processor ID on success, -EPERM on failure (nesting count + * too high). * * asm volatile and "memory" clobber prevent the compiler from moving * instructions out of the ring buffer nesting count. This is required to ensure @@ -40,14 +53,13 @@ int lib_ring_buffer_get_cpu(const struct lttng_ust_lib_ring_buffer_config *confi { int cpu, nesting; - rcu_read_lock(); cpu = lttng_ust_get_cpu(); - nesting = ++lib_ring_buffer_nesting; /* TLS */ + nesting = ++URCU_TLS(lib_ring_buffer_nesting); cmm_barrier(); if (caa_unlikely(nesting > 4)) { WARN_ON_ONCE(1); - lib_ring_buffer_nesting--; /* TLS */ + URCU_TLS(lib_ring_buffer_nesting)--; rcu_read_unlock(); return -EPERM; } else @@ -61,8 +73,7 @@ static inline void lib_ring_buffer_put_cpu(const struct lttng_ust_lib_ring_buffer_config *config) { cmm_barrier(); - lib_ring_buffer_nesting--; /* TLS */ - rcu_read_unlock(); + URCU_TLS(lib_ring_buffer_nesting)--; /* TLS */ } /* @@ -275,14 +286,13 @@ void lib_ring_buffer_commit(const struct lttng_ust_lib_ring_buffer_config *confi commit_count = v_read(config, &shmp_index(handle, buf->commit_hot, endidx)->cc); lib_ring_buffer_check_deliver(config, buf, chan, offset_end - 1, - commit_count, endidx, handle); + commit_count, endidx, handle, ctx->tsc); /* * Update used size at each commit. It's needed only for extracting * ring_buffer buffers from vmcore, after crash. */ lib_ring_buffer_write_commit_counter(config, buf, chan, endidx, - ctx->buf_offset, commit_count, - ctx->slot_size, handle); + offset_end, commit_count, handle); } /** @@ -351,4 +361,4 @@ void lib_ring_buffer_record_enable(const struct lttng_ust_lib_ring_buffer_config uatomic_dec(&buf->record_disabled); } -#endif /* _LINUX_RING_BUFFER_FRONTEND_API_H */ +#endif /* _LTTNG_RING_BUFFER_FRONTEND_API_H */