/*
* buffers.h
+ * LTTng userspace tracer buffering system
*
* Copyright (C) 2009 - Pierre-Marc Fournier (pierre-marc dot fournier at polymtl dot ca)
* Copyright (C) 2008 - Mathieu Desnoyers (mathieu.desnoyers@polymtl.ca)
*
+ * 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; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * 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
*/
#ifndef _UST_BUFFERS_H
#define _UST_BUFFERS_H
-#include <kcompat/kref.h>
#include <assert.h>
-#include "channels.h"
-#include "buffers.h"
-/* Return the size of the minimum number of pages that can contain x. */
-#define FIX_SIZE(x) ((((x) - 1) & PAGE_MASK) + PAGE_SIZE)
+#include <ust/core.h>
+#include <ust/clock.h>
+
+#include "usterr_signal_safe.h"
+#include "channels.h"
+#include "tracerconst.h"
+#include "tracercore.h"
/*
* BUFFER_TRUNC zeroes the subbuffer offset and the subbuffer number parts of
*/
#define UST_CHANNEL_VERSION 8
+/**************************************/
+
+/*
+ * TODO: using "long" type for struct ust_buffer (control structure
+ * shared between traced apps and the consumer) is a very bad idea when
+ * we get to systems with mixed 32/64-bit processes.
+ *
+ * But on 64-bit system, we want the full power of 64-bit counters,
+ * which wraps less often. Therefore, it's not as easy as "use 32-bit
+ * types everywhere".
+ *
+ * One way to deal with this is to:
+ * 1) Design 64-bit consumer so it can detect 32-bit and 64-bit apps.
+ * 2) The 32-bit consumer only supports 32-bit apps.
+ */
+
+struct commit_counters {
+ long cc; /* ATOMIC */
+ long cc_sb; /* ATOMIC - Incremented _once_ at sb switch */
+};
+
struct ust_buffer {
/* First 32 bytes cache-hot cacheline */
- local_t offset; /* Current offset in the buffer */
- local_t *commit_count; /* Commit count per sub-buffer */
- atomic_long_t consumed; /*
- * Current offset in the buffer
- * standard atomic access (shared)
- */
+ long offset; /* Current offset in the buffer *atomic* */
+ struct commit_counters *commit_count; /* Commit count per sub-buffer */
+ long consumed; /* Current offset in the buffer *atomic* access (shared) */
unsigned long last_tsc; /*
* Last timestamp written in the buffer.
*/
/* End of first 32 bytes cacheline */
- atomic_long_t active_readers; /*
- * Active readers count
- * standard atomic access (shared)
- */
- local_t events_lost;
- local_t corrupted_subbuffers;
+ long active_readers; /* ATOMIC - Active readers count standard atomic access (shared) */
+ long events_lost; /* ATOMIC */
+ long corrupted_subbuffers; /* *ATOMIC* */
/* one byte is written to this pipe when data is available, in order
to wake the consumer */
/* portability: Single byte writes must be as quick as possible. The kernel-side
int data_ready_fd_write;
/* the reading end of the pipe */
int data_ready_fd_read;
+ /*
+ * List of buffers with an open pipe, used for fork and forced subbuffer
+ * switch.
+ */
+ struct cds_list_head open_buffers_list;
+
+ unsigned int finalized;
+//ust// struct timer_list switch_timer; /* timer for periodical switch */
+ unsigned long switch_timer_interval; /* 0 = unset */
struct ust_channel *chan;
- struct kref kref;
+
+ struct urcu_ref urcu_ref;
void *buf_data;
size_t buf_size;
int shmid;
unsigned int cpu;
/* commit count per subbuffer; must be at end of struct */
- local_t commit_seq[0] ____cacheline_aligned;
+ long commit_seq[0]; /* ATOMIC */
} ____cacheline_aligned;
-extern void _ust_buffers_write(struct ust_buffer *buf, size_t offset,
- const void *src, size_t len, ssize_t cpy);
+/*
+ * A switch is either done during tracing (FORCE_ACTIVE) or as a final
+ * flush after tracing (with FORCE_FLUSH). FORCE_FLUSH ensures we won't
+ * write in the new sub-buffer).
+ */
+enum force_switch_mode { FORCE_ACTIVE, FORCE_FLUSH };
+
+extern int ltt_reserve_slot_lockless_slow(struct ust_channel *chan,
+ struct ust_trace *trace, size_t data_size,
+ int largest_align, int cpu,
+ struct ust_buffer **ret_buf,
+ size_t *slot_size, long *buf_offset,
+ u64 *tsc, unsigned int *rflags);
+
+extern void ltt_force_switch_lockless_slow(struct ust_buffer *buf,
+ enum force_switch_mode mode);
+
+#ifndef HAVE_EFFICIENT_UNALIGNED_ACCESS
/*
- * Return the address where a given offset is located.
- * Should be used to get the current subbuffer header pointer. Given we know
- * it's never on a page boundary, it's safe to write directly to this address,
- * as long as the write is never bigger than a page size.
+ * Calculate the offset needed to align the type.
+ * size_of_type must be non-zero.
*/
-extern void *ust_buffers_offset_address(struct ust_buffer *buf,
- size_t offset);
+static inline unsigned int ltt_align(size_t align_drift, size_t size_of_type)
+{
+ size_t alignment = min(sizeof(void *), size_of_type);
+ return (alignment - align_drift) & (alignment - 1);
+}
+/* Default arch alignment */
+#define LTT_ALIGN
+
+static inline int ltt_get_alignment(void)
+{
+ return sizeof(void *);
+}
+
+#else /* HAVE_EFFICIENT_UNALIGNED_ACCESS */
+
+static inline unsigned int ltt_align(size_t align_drift,
+ size_t size_of_type)
+{
+ return 0;
+}
+
+#define LTT_ALIGN __attribute__((packed))
+
+static inline int ltt_get_alignment(void)
+{
+ return 0;
+}
+#endif /* HAVE_EFFICIENT_UNALIGNED_ACCESS */
-/* FIXME: lttng has a version for systems with inefficient unaligned access */
static __inline__ void ust_buffers_do_copy(void *dest, const void *src, size_t len)
{
union {
} u = { .src = src };
switch (len) {
- case 0: break;
- case 1: *(u8 *)dest = *u.src8;
+ case 0: break;
+ case 1: *(u8 *)dest = *u.src8;
break;
- case 2: *(u16 *)dest = *u.src16;
+ case 2: *(u16 *)dest = *u.src16;
break;
- case 4: *(u32 *)dest = *u.src32;
+ case 4: *(u32 *)dest = *u.src32;
break;
- case 8: *(u64 *)dest = *u.src64;
+ case 8: *(u64 *)dest = *u.src64;
break;
default:
memcpy(dest, src, len);
}
}
-/* FIXME: there is both a static inline and a '_' non static inline version ?? */
+static __inline__ void *ust_buffers_offset_address(struct ust_buffer *buf, size_t offset)
+{
+ return ((char *)buf->buf_data)+offset;
+}
+
+/*
+ * Last TSC comparison functions. Check if the current TSC overflows
+ * LTT_TSC_BITS bits from the last TSC read. Reads and writes last_tsc
+ * atomically.
+ */
+
+/* FIXME: does this test work properly? */
+#if (BITS_PER_LONG == 32)
+static __inline__ void save_last_tsc(struct ust_buffer *ltt_buf,
+ u64 tsc)
+{
+ ltt_buf->last_tsc = (unsigned long)(tsc >> LTT_TSC_BITS);
+}
+
+static __inline__ int last_tsc_overflow(struct ust_buffer *ltt_buf,
+ u64 tsc)
+{
+ unsigned long tsc_shifted = (unsigned long)(tsc >> LTT_TSC_BITS);
+
+ if (unlikely((tsc_shifted - ltt_buf->last_tsc)))
+ return 1;
+ else
+ return 0;
+}
+#else
+static __inline__ void save_last_tsc(struct ust_buffer *ltt_buf,
+ u64 tsc)
+{
+ ltt_buf->last_tsc = (unsigned long)tsc;
+}
+
+static __inline__ int last_tsc_overflow(struct ust_buffer *ltt_buf,
+ u64 tsc)
+{
+ if (unlikely((tsc - ltt_buf->last_tsc) >> LTT_TSC_BITS))
+ return 1;
+ else
+ return 0;
+}
+#endif
+
+/*
+ * ust_get_header_size
+ *
+ * Calculate alignment offset to 32-bits. This is the alignment offset of the
+ * event header.
+ *
+ * Important note :
+ * The event header must be 32-bits. The total offset calculated here :
+ *
+ * Alignment of header struct on 32 bits (min arch size, header size)
+ * + sizeof(header struct) (32-bits)
+ * + (opt) u16 (ext. event id)
+ * + (opt) u16 (event_size) (if event_size == 0xFFFFUL, has ext. event size)
+ * + (opt) u32 (ext. event size)
+ * + (opt) u64 full TSC (aligned on min(64-bits, arch size))
+ *
+ * The payload must itself determine its own alignment from the biggest type it
+ * contains.
+ * */
+static __inline__ unsigned char ust_get_header_size(
+ struct ust_channel *channel,
+ size_t offset,
+ size_t data_size,
+ size_t *before_hdr_pad,
+ unsigned int rflags)
+{
+ size_t orig_offset = offset;
+ size_t padding;
+
+ padding = ltt_align(offset, sizeof(struct ltt_event_header));
+ offset += padding;
+ offset += sizeof(struct ltt_event_header);
+
+ if(unlikely(rflags)) {
+ switch (rflags) {
+ case LTT_RFLAG_ID_SIZE_TSC:
+ offset += sizeof(u16) + sizeof(u16);
+ if (data_size >= 0xFFFFU)
+ offset += sizeof(u32);
+ offset += ltt_align(offset, sizeof(u64));
+ offset += sizeof(u64);
+ break;
+ case LTT_RFLAG_ID_SIZE:
+ offset += sizeof(u16) + sizeof(u16);
+ if (data_size >= 0xFFFFU)
+ offset += sizeof(u32);
+ break;
+ case LTT_RFLAG_ID:
+ offset += sizeof(u16);
+ break;
+ }
+ }
+
+ *before_hdr_pad = padding;
+ return offset - orig_offset;
+}
+
+static __inline__ void ltt_reserve_push_reader(
+ struct ust_channel *rchan,
+ struct ust_buffer *buf,
+ long offset)
+{
+ long consumed_old, consumed_new;
+
+ do {
+ consumed_old = uatomic_read(&buf->consumed);
+ /*
+ * If buffer is in overwrite mode, push the reader consumed
+ * count if the write position has reached it and we are not
+ * at the first iteration (don't push the reader farther than
+ * the writer). This operation can be done concurrently by many
+ * writers in the same buffer, the writer being at the farthest
+ * write position sub-buffer index in the buffer being the one
+ * which will win this loop.
+ * If the buffer is not in overwrite mode, pushing the reader
+ * only happens if a sub-buffer is corrupted.
+ */
+ if (unlikely((SUBBUF_TRUNC(offset, buf->chan)
+ - SUBBUF_TRUNC(consumed_old, buf->chan))
+ >= rchan->alloc_size))
+ consumed_new = SUBBUF_ALIGN(consumed_old, buf->chan);
+ else
+ return;
+ } while (unlikely(uatomic_cmpxchg(&buf->consumed, consumed_old,
+ consumed_new) != consumed_old));
+}
+
+static __inline__ void ltt_vmcore_check_deliver(
+ struct ust_buffer *buf,
+ long commit_count, long idx)
+{
+ uatomic_set(&buf->commit_seq[idx], commit_count);
+}
+
+static __inline__ void ltt_check_deliver(struct ust_channel *chan,
+ struct ust_buffer *buf,
+ long offset, long commit_count, long idx)
+{
+ long old_commit_count = commit_count - chan->subbuf_size;
+
+ /* Check if all commits have been done */
+ if (unlikely((BUFFER_TRUNC(offset, chan)
+ >> chan->n_subbufs_order)
+ - (old_commit_count
+ & chan->commit_count_mask) == 0)) {
+ /*
+ * If we succeeded in updating the cc_sb, we are delivering
+ * the subbuffer. Deals with concurrent updates of the "cc"
+ * value without adding a add_return atomic operation to the
+ * fast path.
+ */
+ if (likely(uatomic_cmpxchg(&buf->commit_count[idx].cc_sb,
+ old_commit_count, commit_count)
+ == old_commit_count)) {
+ int result;
+
+ /*
+ * Set noref flag for this subbuffer.
+ */
+//ust// ltt_set_noref_flag(rchan, buf, idx);
+ ltt_vmcore_check_deliver(buf, commit_count, idx);
+
+ /* wakeup consumer */
+ result = write(buf->data_ready_fd_write, "1", 1);
+ if(result == -1) {
+ PERROR("write (in ltt_relay_buffer_flush)");
+ ERR("this should never happen!");
+ }
+ }
+ }
+}
+
+static __inline__ int ltt_poll_deliver(struct ust_channel *chan, struct ust_buffer *buf)
+{
+ long consumed_old, consumed_idx, commit_count, write_offset;
+
+ consumed_old = uatomic_read(&buf->consumed);
+ consumed_idx = SUBBUF_INDEX(consumed_old, buf->chan);
+ commit_count = uatomic_read(&buf->commit_count[consumed_idx].cc_sb);
+ /*
+ * No memory cmm_barrier here, since we are only interested
+ * in a statistically correct polling result. The next poll will
+ * get the data is we are racing. The mb() that ensures correct
+ * memory order is in get_subbuf.
+ */
+ write_offset = uatomic_read(&buf->offset);
+
+ /*
+ * Check that the subbuffer we are trying to consume has been
+ * already fully committed.
+ */
+
+ if (((commit_count - chan->subbuf_size)
+ & chan->commit_count_mask)
+ - (BUFFER_TRUNC(consumed_old, buf->chan)
+ >> chan->n_subbufs_order)
+ != 0)
+ return 0;
+
+ /*
+ * Check that we are not about to read the same subbuffer in
+ * which the writer head is.
+ */
+ if ((SUBBUF_TRUNC(write_offset, buf->chan)
+ - SUBBUF_TRUNC(consumed_old, buf->chan))
+ == 0)
+ return 0;
+
+ return 1;
+
+}
+
+/*
+ * returns 0 if reserve ok, or 1 if the slow path must be taken.
+ */
+static __inline__ int ltt_relay_try_reserve(
+ struct ust_channel *chan,
+ struct ust_buffer *buf,
+ size_t data_size,
+ u64 *tsc, unsigned int *rflags, int largest_align,
+ long *o_begin, long *o_end, long *o_old,
+ size_t *before_hdr_pad, size_t *size)
+{
+ *o_begin = uatomic_read(&buf->offset);
+ *o_old = *o_begin;
+
+ *tsc = trace_clock_read64();
+
+ if (last_tsc_overflow(buf, *tsc))
+ *rflags = LTT_RFLAG_ID_SIZE_TSC;
+
+ if (unlikely(SUBBUF_OFFSET(*o_begin, buf->chan) == 0))
+ return 1;
+
+ *size = ust_get_header_size(chan,
+ *o_begin, data_size,
+ before_hdr_pad, *rflags);
+ *size += ltt_align(*o_begin + *size, largest_align) + data_size;
+ if (unlikely((SUBBUF_OFFSET(*o_begin, buf->chan) + *size)
+ > buf->chan->subbuf_size))
+ return 1;
+
+ /*
+ * Event fits in the current buffer and we are not on a switch
+ * boundary. It's safe to write.
+ */
+ *o_end = *o_begin + *size;
+
+ if (unlikely((SUBBUF_OFFSET(*o_end, buf->chan)) == 0))
+ /*
+ * The offset_end will fall at the very beginning of the next
+ * subbuffer.
+ */
+ return 1;
+
+ return 0;
+}
+
+static __inline__ int ltt_reserve_slot(struct ust_channel *chan,
+ struct ust_trace *trace, size_t data_size,
+ int largest_align, int cpu,
+ struct ust_buffer **ret_buf,
+ size_t *slot_size, long *buf_offset, u64 *tsc,
+ unsigned int *rflags)
+{
+ struct ust_buffer *buf = *ret_buf = chan->buf[cpu];
+ long o_begin, o_end, o_old;
+ size_t before_hdr_pad;
+
+ /*
+ * Perform retryable operations.
+ */
+ if (unlikely(CMM_LOAD_SHARED(ltt_nesting) > 4)) {
+ DBG("Dropping event because nesting is too deep.");
+ uatomic_inc(&buf->events_lost);
+ return -EPERM;
+ }
+
+ if (unlikely(ltt_relay_try_reserve(chan, buf,
+ data_size, tsc, rflags,
+ largest_align, &o_begin, &o_end, &o_old,
+ &before_hdr_pad, slot_size)))
+ goto slow_path;
+
+ if (unlikely(uatomic_cmpxchg(&buf->offset, o_old, o_end) != o_old))
+ goto slow_path;
+
+ /*
+ * Atomically update last_tsc. This update races against concurrent
+ * atomic updates, but the race will always cause supplementary full TSC
+ * events, never the opposite (missing a full TSC event when it would be
+ * needed).
+ */
+ save_last_tsc(buf, *tsc);
+
+ /*
+ * Push the reader if necessary
+ */
+ ltt_reserve_push_reader(chan, buf, o_end - 1);
+
+ *buf_offset = o_begin + before_hdr_pad;
+ return 0;
+slow_path:
+ return ltt_reserve_slot_lockless_slow(chan, trace, data_size,
+ largest_align, cpu, ret_buf,
+ slot_size, buf_offset, tsc,
+ rflags);
+}
+
+/*
+ * Force a sub-buffer switch for a per-cpu buffer. This operation is
+ * completely reentrant : can be called while tracing is active with
+ * absolutely no lock held.
+ */
+static __inline__ void ltt_force_switch(struct ust_buffer *buf,
+ enum force_switch_mode mode)
+{
+ return ltt_force_switch_lockless_slow(buf, mode);
+}
+
+/*
+ * for flight recording. must be called after relay_commit.
+ * This function increments the subbuffers's commit_seq counter each time the
+ * commit count reaches back the reserve offset (module subbuffer size). It is
+ * useful for crash dump.
+ */
+static __inline__ void ltt_write_commit_counter(struct ust_channel *chan,
+ struct ust_buffer *buf, long idx, long buf_offset,
+ long commit_count, size_t data_size)
+{
+ long offset;
+ long commit_seq_old;
+
+ offset = buf_offset + data_size;
+
+ /*
+ * SUBBUF_OFFSET includes commit_count_mask. We can simply
+ * compare the offsets within the subbuffer without caring about
+ * buffer full/empty mismatch because offset is never zero here
+ * (subbuffer header and event headers have non-zero length).
+ */
+ if (unlikely(SUBBUF_OFFSET(offset - commit_count, buf->chan)))
+ return;
+
+ commit_seq_old = uatomic_read(&buf->commit_seq[idx]);
+ while (commit_seq_old < commit_count)
+ commit_seq_old = uatomic_cmpxchg(&buf->commit_seq[idx],
+ commit_seq_old, commit_count);
+
+ DBG("commit_seq for channel %s_%d, subbuf %ld is now %ld", buf->chan->channel_name, buf->cpu, idx, commit_count);
+}
+
+/*
+ * Atomic unordered slot commit. Increments the commit count in the
+ * specified sub-buffer, and delivers it if necessary.
+ *
+ * Parameters:
+ *
+ * @ltt_channel : channel structure
+ * @transport_data: transport-specific data
+ * @buf_offset : offset following the event header.
+ * @data_size : size of the event data.
+ * @slot_size : size of the reserved slot.
+ */
+static __inline__ void ltt_commit_slot(
+ struct ust_channel *chan,
+ struct ust_buffer *buf, long buf_offset,
+ size_t data_size, size_t slot_size)
+{
+ long offset_end = buf_offset;
+ long endidx = SUBBUF_INDEX(offset_end - 1, chan);
+ long commit_count;
+
+ cmm_smp_wmb();
+
+ uatomic_add(&buf->commit_count[endidx].cc, slot_size);
+ /*
+ * commit count read can race with concurrent OOO commit count updates.
+ * This is only needed for ltt_check_deliver (for non-polling delivery
+ * only) and for ltt_write_commit_counter. The race can only cause the
+ * counter to be read with the same value more than once, which could
+ * cause :
+ * - Multiple delivery for the same sub-buffer (which is handled
+ * gracefully by the reader code) if the value is for a full
+ * sub-buffer. It's important that we can never miss a sub-buffer
+ * delivery. Re-reading the value after the uatomic_add ensures this.
+ * - Reading a commit_count with a higher value that what was actually
+ * added to it for the ltt_write_commit_counter call (again caused by
+ * a concurrent committer). It does not matter, because this function
+ * is interested in the fact that the commit count reaches back the
+ * reserve offset for a specific sub-buffer, which is completely
+ * independent of the order.
+ */
+ commit_count = uatomic_read(&buf->commit_count[endidx].cc);
+
+ ltt_check_deliver(chan, buf, offset_end - 1, commit_count, endidx);
+ /*
+ * Update data_size for each commit. It's needed only for extracting
+ * ltt buffers from vmcore, after crash.
+ */
+ ltt_write_commit_counter(chan, buf, endidx, buf_offset, commit_count, data_size);
+}
+
+void _ust_buffers_strncpy_fixup(struct ust_buffer *buf, size_t offset,
+ size_t len, size_t copied, int terminated);
+
static __inline__ int ust_buffers_write(struct ust_buffer *buf, size_t offset,
- const void *src, size_t len)
+ const void *src, size_t len)
{
- size_t cpy;
size_t buf_offset = BUFFER_OFFSET(offset, buf->chan);
assert(buf_offset < buf->chan->subbuf_size*buf->chan->subbuf_cnt);
+ assert(buf_offset + len
+ <= buf->chan->subbuf_size*buf->chan->subbuf_cnt);
+
+ ust_buffers_do_copy(buf->buf_data + buf_offset, src, len);
- cpy = min_t(size_t, len, buf->buf_size - buf_offset);
- ust_buffers_do_copy(buf->buf_data + buf_offset, src, cpy);
-
- if (unlikely(len != cpy))
- _ust_buffers_write(buf, buf_offset, src, len, cpy);
return len;
}
-int ust_buffers_channel_open(struct ust_channel *chan, size_t subbuf_size, size_t n_subbufs);
-extern void ust_buffers_channel_close(struct ust_channel *chan);
+/*
+ * ust_buffers_do_memset - write character into dest.
+ * @dest: destination
+ * @src: source character
+ * @len: length to write
+ */
+static __inline__
+void ust_buffers_do_memset(void *dest, char src, size_t len)
+{
+ /*
+ * What we really want here is an __inline__ memset, but we
+ * don't have constants, so gcc generally uses a function call.
+ */
+ for (; len > 0; len--)
+ *(u8 *)dest++ = src;
+}
-extern int ust_buffers_do_get_subbuf(struct ust_buffer *buf, long *pconsumed_old);
+/*
+ * ust_buffers_do_strncpy - copy a string up to a certain number of bytes
+ * @dest: destination
+ * @src: source
+ * @len: max. length to copy
+ * @terminated: output string ends with \0 (output)
+ *
+ * returns the number of bytes copied. Does not finalize with \0 if len is
+ * reached.
+ */
+static __inline__
+size_t ust_buffers_do_strncpy(void *dest, const void *src, size_t len,
+ int *terminated)
+{
+ size_t orig_len = len;
-extern int ust_buffers_do_put_subbuf(struct ust_buffer *buf, u32 uconsumed_old);
+ *terminated = 0;
+ /*
+ * What we really want here is an __inline__ strncpy, but we
+ * don't have constants, so gcc generally uses a function call.
+ */
+ for (; len > 0; len--) {
+ *(u8 *)dest = CMM_LOAD_SHARED(*(const u8 *)src);
+ /* Check with dest, because src may be modified concurrently */
+ if (*(const u8 *)dest == '\0') {
+ len--;
+ *terminated = 1;
+ break;
+ }
+ dest++;
+ src++;
+ }
+ return orig_len - len;
+}
-extern void init_ustrelay_transport(void);
+static __inline__
+int ust_buffers_strncpy(struct ust_buffer *buf, size_t offset, const void *src,
+ size_t len)
+{
+ size_t buf_offset = BUFFER_OFFSET(offset, buf->chan);
+ ssize_t copied;
+ int terminated;
-/*static*/ /* inline */ notrace void ltt_commit_slot(
- struct ust_channel *channel,
- void **transport_data, long buf_offset,
- size_t data_size, size_t slot_size);
+ assert(buf_offset < buf->chan->subbuf_size*buf->chan->subbuf_cnt);
+ assert(buf_offset + len
+ <= buf->chan->subbuf_size*buf->chan->subbuf_cnt);
+
+ copied = ust_buffers_do_strncpy(buf->buf_data + buf_offset,
+ src, len, &terminated);
+ if (unlikely(copied < len || !terminated))
+ _ust_buffers_strncpy_fixup(buf, offset, len, copied,
+ terminated);
+ return len;
+}
+
+extern int ust_buffers_get_subbuf(struct ust_buffer *buf, long *consumed);
+extern int ust_buffers_put_subbuf(struct ust_buffer *buf, unsigned long uconsumed_old);
+
+extern void init_ustrelay_transport(void);
#endif /* _UST_BUFFERS_H */
projects / ust.git / blobdiff