X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=ltt-ring-buffer-client.h;h=dc6bbd0bb51480a78141ba7bb82be8b89e0fcd3e;hb=c539a324b020171c10d0fcb100892ac93c17e9e7;hp=39587dd0b15f2054454a57bda420cc78ec680a62;hpb=2db1399a47bc5a86dade078994cd1060d6d56f64;p=lttng-modules.git

diff --git a/ltt-ring-buffer-client.h b/ltt-ring-buffer-client.h
index 39587dd0..dc6bbd0b 100644
--- a/ltt-ring-buffer-client.h
+++ b/ltt-ring-buffer-client.h
@@ -22,6 +22,14 @@
  * you ever add/remove a field from this header. Packed attribute is not used
  * because gcc generates poor code on at least powerpc and mips. Don't ever
  * let gcc add padding between the structure elements.
+ *
+ * The guarantee we have with timestamps is that all the events in a
+ * packet are included (inclusive) within the begin/end timestamps of
+ * the packet. Another guarantee we have is that the "timestamp begin",
+ * as well as the event timestamps, are monotonically increasing (never
+ * decrease) when moving forward in a stream (physically). But this
+ * guarantee does not apply to "timestamp end", because it is sampled at
+ * commit time, which is not ordered with respect to space reservation.
  */
 
 struct packet_header {
@@ -137,6 +145,7 @@ unsigned char record_header_size(const struct lib_ring_buffer_config *config,
 		}
 		break;
 	default:
+		padding = 0;
 		WARN_ON_ONCE(1);
 	}
 	offset += ctx_get_size(offset, event->ctx);
@@ -148,7 +157,7 @@ unsigned char record_header_size(const struct lib_ring_buffer_config *config,
 
 #include "wrapper/ringbuffer/api.h"
 
-extern
+static
 void ltt_write_event_header_slow(const struct lib_ring_buffer_config *config,
 				 struct lib_ring_buffer_ctx *ctx,
 				 uint32_t event_id);
@@ -197,8 +206,8 @@ void ltt_write_event_header(const struct lib_ring_buffer_config *config,
 		WARN_ON_ONCE(1);
 	}
 
-	ctx_record(ctx, ltt_chan, event->ctx);
 	ctx_record(ctx, ltt_chan, ltt_chan->ctx);
+	ctx_record(ctx, ltt_chan, event->ctx);
 
 	return;
 
@@ -206,6 +215,7 @@ slow_path:
 	ltt_write_event_header_slow(config, ctx, event_id);
 }
 
+static
 void ltt_write_event_header_slow(const struct lib_ring_buffer_config *config,
 				 struct lib_ring_buffer_ctx *ctx,
 				 uint32_t event_id)
@@ -259,8 +269,8 @@ void ltt_write_event_header_slow(const struct lib_ring_buffer_config *config,
 	default:
 		WARN_ON_ONCE(1);
 	}
-	ctx_record(ctx, ltt_chan, event->ctx);
 	ctx_record(ctx, ltt_chan, ltt_chan->ctx);
+	ctx_record(ctx, ltt_chan, event->ctx);
 }
 
 static const struct lib_ring_buffer_config client_config;
@@ -399,6 +409,20 @@ struct lib_ring_buffer *ltt_buffer_read_open(struct channel *chan)
 	return NULL;
 }
 
+static
+int ltt_buffer_has_read_closed_stream(struct channel *chan)
+{
+	struct lib_ring_buffer *buf;
+	int cpu;
+
+	for_each_channel_cpu(cpu, chan) {
+		buf = channel_get_ring_buffer(&client_config, chan, cpu);
+		if (!atomic_long_read(&buf->active_readers))
+			return 1;
+	}
+	return 0;
+}
+
 static
 void ltt_buffer_read_close(struct lib_ring_buffer *buf)
 {
@@ -455,9 +479,11 @@ void ltt_event_write(struct lib_ring_buffer_ctx *ctx, const void *src,
 }
 
 static
-wait_queue_head_t *ltt_get_reader_wait_queue(struct channel *chan)
+wait_queue_head_t *ltt_get_writer_buf_wait_queue(struct channel *chan, int cpu)
 {
-	return &chan->read_wait;
+	struct lib_ring_buffer *buf = channel_get_ring_buffer(&client_config,
+					chan, cpu);
+	return &buf->write_wait;
 }
 
 static
@@ -485,12 +511,14 @@ static struct ltt_transport ltt_relay_transport = {
 		.channel_create = _channel_create,
 		.channel_destroy = ltt_channel_destroy,
 		.buffer_read_open = ltt_buffer_read_open,
+		.buffer_has_read_closed_stream =
+			ltt_buffer_has_read_closed_stream,
 		.buffer_read_close = ltt_buffer_read_close,
 		.event_reserve = ltt_event_reserve,
 		.event_commit = ltt_event_commit,
 		.event_write = ltt_event_write,
 		.packet_avail_size = NULL,	/* Would be racy anyway */
-		.get_reader_wait_queue = ltt_get_reader_wait_queue,
+		.get_writer_buf_wait_queue = ltt_get_writer_buf_wait_queue,
 		.get_hp_wait_queue = ltt_get_hp_wait_queue,
 		.is_finalized = ltt_is_finalized,
 		.is_disabled = ltt_is_disabled,