-#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 <mathieu.desnoyers@efficios.com>
+ * libringbuffer/frontend_internal.h
*
* Ring Buffer Library Synchronization Header (internal helpers).
*
+ * 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
+ *
+ *
* Author:
* Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*
*/
#include <urcu/compiler.h>
+#include <signal.h>
+#include <pthread.h>
-#include <ust/ringbuffer-config.h>
+#include <lttng/ringbuffer-config.h>
#include "backend_types.h"
#include "frontend_types.h"
#include "shm.h"
#if (CAA_BITS_PER_LONG == 32)
static inline
void save_last_tsc(const struct lttng_ust_lib_ring_buffer_config *config,
- struct lttng_ust_lib_ring_buffer *buf, u64 tsc)
+ struct lttng_ust_lib_ring_buffer *buf, uint64_t tsc)
{
if (config->tsc_bits == 0 || config->tsc_bits == 64)
return;
static inline
int last_tsc_overflow(const struct lttng_ust_lib_ring_buffer_config *config,
- struct lttng_ust_lib_ring_buffer *buf, u64 tsc)
+ struct lttng_ust_lib_ring_buffer *buf, uint64_t tsc)
{
unsigned long tsc_shifted;
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
#else
static inline
void save_last_tsc(const struct lttng_ust_lib_ring_buffer_config *config,
- struct lttng_ust_lib_ring_buffer *buf, u64 tsc)
+ struct lttng_ust_lib_ring_buffer *buf, uint64_t tsc)
{
if (config->tsc_bits == 0 || config->tsc_bits == 64)
return;
static inline
int last_tsc_overflow(const struct lttng_ust_lib_ring_buffer_config *config,
- struct lttng_ust_lib_ring_buffer *buf, u64 tsc)
+ 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
* 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));
}
{
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
* 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)) {
/*
int wakeup_fd = shm_get_wakeup_fd(handle, &buf->self._ref);
if (wakeup_fd >= 0) {
- int ret;
+ sigset_t sigpipe_set, pending_set, old_set;
+ int ret, sigpipe_was_pending = 0;
+
/*
* Wake-up the other end by
* writing a null byte in the
* 2) check if there is data in
* the buffer.
* 3) wait on the pipe (poll).
+ *
+ * Discard the SIGPIPE from write(), not
+ * disturbing any SIGPIPE that might be
+ * already pending. If a bogus SIGPIPE
+ * is sent to the entire process
+ * concurrently by a malicious user, it
+ * may be simply discarded.
+ */
+ ret = sigemptyset(&pending_set);
+ assert(!ret);
+ /*
+ * sigpending returns the mask
+ * of signals that are _both_
+ * blocked for the thread _and_
+ * pending for either the thread
+ * or the entire process.
*/
+ ret = sigpending(&pending_set);
+ assert(!ret);
+ sigpipe_was_pending = sigismember(&pending_set, SIGPIPE);
+ /*
+ * If sigpipe was pending, it
+ * means it was already blocked,
+ * so no need to block it.
+ */
+ if (!sigpipe_was_pending) {
+ ret = sigemptyset(&sigpipe_set);
+ assert(!ret);
+ ret = sigaddset(&sigpipe_set, SIGPIPE);
+ assert(!ret);
+ ret = pthread_sigmask(SIG_BLOCK, &sigpipe_set, &old_set);
+ assert(!ret);
+ }
do {
ret = write(wakeup_fd, "", 1);
} while (ret == -1L && errno == EINTR);
+ if (ret == -1L && errno == EPIPE && !sigpipe_was_pending) {
+ struct timespec timeout = { 0, 0 };
+ do {
+ ret = sigtimedwait(&sigpipe_set, NULL,
+ &timeout);
+ } while (ret == -1L && errno == EINTR);
+ }
+ if (!sigpipe_was_pending) {
+ ret = pthread_sigmask(SIG_SETMASK, &old_set, NULL);
+ assert(!ret);
+ }
}
}
-
}
}
}
* 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);
/* 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 */
projects / lttng-ust.git / blobdiff