Move include/ust/ to include/lttng/

[ust.git] / include / lttng / ringbuffer-abi.h

diff --git a/include/lttng/ringbuffer-abi.h b/include/lttng/ringbuffer-abi.h
new file mode 100644 (file)
index 0000000..25bc194
--- /dev/null
+++ b/include/lttng/ringbuffer-abi.h
@@ -0,0 +1,67 @@
+#ifndef _UST_RING_BUFFER_ABI_H
+#define _UST_RING_BUFFER_ABI_H
+
+/*
+ * ust/ringbuffer-abi.h
+ *
+ * (C) Copyright 2005-2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * Wait-free ring buffer ABI.
+ *
+ * Author:
+ *     Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#define _UST_CMD(minor)                                (minor)
+#define _UST_CMDR(minor, type)                 (minor)
+#define _UST_CMDW(minor, type)                 (minor)
+
+/*
+ * Use RING_BUFFER_GET_NEXT_SUBBUF / RING_BUFFER_PUT_NEXT_SUBBUF to read and
+ * consume sub-buffers sequentially.
+ *
+ * Reading sub-buffers without consuming them can be performed with:
+ *
+ * RING_BUFFER_SNAPSHOT
+ * RING_BUFFER_SNAPSHOT_GET_CONSUMED
+ * RING_BUFFER_SNAPSHOT_GET_PRODUCED
+ *
+ * to get the offset range to consume, and then by passing each sub-buffer
+ * offset to RING_BUFFER_GET_SUBBUF, read the sub-buffer, and then release it
+ * with RING_BUFFER_PUT_SUBBUF.
+ *
+ * Note that the "snapshot" API can be used to read the sub-buffer in reverse
+ * order, which is useful for flight recorder snapshots.
+ */
+
+/* Get a snapshot of the current ring buffer producer and consumer positions */
+#define RING_BUFFER_SNAPSHOT                   _UST_CMD(0x00)
+/* Get the consumer position (iteration start) */
+#define RING_BUFFER_SNAPSHOT_GET_CONSUMED      _UST_CMDR(0x01, unsigned long)
+/* Get the producer position (iteration end) */
+#define RING_BUFFER_SNAPSHOT_GET_PRODUCED      _UST_CMDR(0x02, unsigned long)
+/* Get exclusive read access to the specified sub-buffer position */
+#define RING_BUFFER_GET_SUBBUF                 _UST_CMDW(0x03, unsigned long)
+/* Release exclusive sub-buffer access */
+#define RING_BUFFER_PUT_SUBBUF                 _UST_CMD(0x04)
+
+/* Get exclusive read access to the next sub-buffer that can be read. */
+#define RING_BUFFER_GET_NEXT_SUBBUF            _UST_CMD(0x05)
+/* Release exclusive sub-buffer access, move consumer forward. */
+#define RING_BUFFER_PUT_NEXT_SUBBUF            _UST_CMD(0x06)
+/* returns the size of the current sub-buffer, without padding (for mmap). */
+#define RING_BUFFER_GET_SUBBUF_SIZE            _UST_CMDR(0x07, unsigned long)
+/* returns the size of the current sub-buffer, with padding (for splice). */
+#define RING_BUFFER_GET_PADDED_SUBBUF_SIZE     _UST_CMDR(0x08, unsigned long)
+/* returns the maximum size for sub-buffers. */
+#define RING_BUFFER_GET_MAX_SUBBUF_SIZE                _UST_CMDR(0x09, unsigned long)
+/* returns the length to mmap. */
+#define RING_BUFFER_GET_MMAP_LEN               _UST_CMDR(0x0A, unsigned long)
+/* returns the offset of the subbuffer belonging to the mmap reader. */
+#define RING_BUFFER_GET_MMAP_READ_OFFSET       _UST_CMDR(0x0B, unsigned long)
+/* flush the current sub-buffer */
+#define RING_BUFFER_FLUSH                      _UST_CMD(0x0C)
+
+#endif /* _UST_RING_BUFFER_ABI_H */