X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=liblttng-ustconsumer%2Flttng-ustconsumer.c;h=ed4a27c9da927d47ed52cadf129a6592d17fca48;hp=951ef78812e3661980bc95b7a3b31674969146e5;hb=d5cd1f3415b6d3cafa347b8e0068de2245014f25;hpb=1316184615e422526ef4fae68f980443414969c1

diff --git a/liblttng-ustconsumer/lttng-ustconsumer.c b/liblttng-ustconsumer/lttng-ustconsumer.c
index 951ef7881..ed4a27c9d 100644
--- a/liblttng-ustconsumer/lttng-ustconsumer.c
+++ b/liblttng-ustconsumer/lttng-ustconsumer.c
@@ -29,9 +29,9 @@
 #include <sys/types.h>
 #include <unistd.h>
 
-#include <ust/lttng-ust-ctl.h>
 #include <lttng-sessiond-comm.h>
 #include <lttng/lttng-ustconsumer.h>
+#include <lttng/ust-ctl.h>
 #include <lttngerr.h>
 
 extern struct lttng_consumer_global_data consumer_data;
@@ -208,6 +208,7 @@ int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 
 		DBG("consumer_add_stream %s (%d,%d)", msg.u.stream.path_name,
 			fds[0], fds[1]);
+		assert(msg.u.stream.output == LTTNG_EVENT_MMAP);
 		new_stream = consumer_allocate_stream(msg.u.stream.channel_key,
 				msg.u.stream.stream_key,
 				fds[0], fds[1],
@@ -271,9 +272,20 @@ int lttng_ustconsumer_allocate_channel(struct lttng_consumer_channel *chan)
 	if (!chan->handle) {
 		return -ENOMEM;
 	}
+	/*
+	 * The channel fds are passed to ustctl, we only keep a copy.
+	 */
+	chan->shm_fd_is_copy = 1;
+	chan->wait_fd_is_copy = 1;
+
 	return 0;
 }
 
+void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream *stream)
+{
+	ustctl_flush_buffer(stream->chan->handle, stream->buf, 0);
+}
+
 void lttng_ustconsumer_del_channel(struct lttng_consumer_channel *chan)
 {
 	ustctl_unmap_channel(chan->handle);
@@ -298,6 +310,12 @@ int lttng_ustconsumer_allocate_stream(struct lttng_consumer_stream *stream)
 	if (!stream->mmap_base) {
 		return -EINVAL;
 	}
+	/*
+	 * The stream fds are passed to ustctl, we only keep a copy.
+	 */
+	stream->shm_fd_is_copy = 1;
+	stream->wait_fd_is_copy = 1;
+
 	return 0;
 }
 
@@ -305,3 +323,98 @@ void lttng_ustconsumer_del_stream(struct lttng_consumer_stream *stream)
 {
 	ustctl_close_stream_read(stream->chan->handle, stream->buf);
 }
+
+
+int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
+		struct lttng_consumer_local_data *ctx)
+{
+	unsigned long len;
+	int err;
+	long ret = 0;
+	struct lttng_ust_shm_handle *handle;
+	struct lttng_ust_lib_ring_buffer *buf;
+	char dummy;
+	ssize_t readlen;
+
+	DBG("In read_subbuffer (wait_fd: %d, stream key: %d)",
+		stream->wait_fd, stream->key);
+
+	/* We can consume the 1 byte written into the wait_fd by UST */
+	do {
+		readlen = read(stream->wait_fd, &dummy, 1);
+	} while (readlen == -1 && errno == -EINTR);
+	if (readlen == -1) {
+		ret = readlen;
+		goto end;
+	}
+
+	buf = stream->buf;
+	handle = stream->chan->handle;
+	/* Get the next subbuffer */
+	err = ustctl_get_next_subbuf(handle, buf);
+	if (err != 0) {
+		ret = errno;
+		/*
+		 * This is a debug message even for single-threaded consumer,
+		 * because poll() have more relaxed criterions than get subbuf,
+		 * so get_subbuf may fail for short race windows where poll()
+		 * would issue wakeups.
+		 */
+		DBG("Reserving sub buffer failed (everything is normal, "
+				"it is due to concurrency)");
+		goto end;
+	}
+	assert(stream->output == LTTNG_EVENT_MMAP);
+	/* read the used subbuffer size */
+	err = ustctl_get_padded_subbuf_size(handle, buf, &len);
+	if (err != 0) {
+		ret = errno;
+		perror("Getting sub-buffer len failed.");
+		goto end;
+	}
+	/* write the subbuffer to the tracefile */
+	ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, len);
+	if (ret < 0) {
+		/*
+		 * display the error but continue processing to try
+		 * to release the subbuffer
+		 */
+		ERR("Error writing to tracefile");
+	}
+	err = ustctl_put_next_subbuf(handle, buf);
+	if (err != 0) {
+		ret = errno;
+		if (errno == EFAULT) {
+			perror("Error in unreserving sub buffer\n");
+		} else if (errno == EIO) {
+			/* Should never happen with newer LTTng versions */
+			perror("Reader has been pushed by the writer, last sub-buffer corrupted.");
+		}
+		goto end;
+	}
+end:
+	return ret;
+}
+
+int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream *stream)
+{
+	int ret;
+
+	/* Opening the tracefile in write mode */
+	if (stream->path_name != NULL) {
+		ret = open(stream->path_name,
+				O_WRONLY|O_CREAT|O_TRUNC, S_IRWXU|S_IRWXG|S_IRWXO);
+		if (ret < 0) {
+			ERR("Opening %s", stream->path_name);
+			perror("open");
+			goto error;
+		}
+		stream->out_fd = ret;
+	}
+
+	/* we return 0 to let the library handle the FD internally */
+	return 0;
+
+error:
+	return ret;
+}