Refactoring: Channel structures

[lttng-ust.git] / include / lttng / ust-events.h

diff --git a/include/lttng/ust-events.h b/include/lttng/ust-events.h
index 59446c4b783c77715e8048f85546a8846f03874e..4ef3301c12ae42c807aa67b94b51056ffcc150df 100644 (file)
--- a/include/lttng/ust-events.h
+++ b/include/lttng/ust-events.h
@@ -36,7 +36,7 @@ extern "C" {
 #define LTTNG_UST_PROVIDER_MAJOR       2
 #define LTTNG_UST_PROVIDER_MINOR       0
 
-struct lttng_channel;
+struct lttng_ust_channel_buffer;
 struct lttng_ust_session;
 struct lttng_ust_lib_ring_buffer_ctx;
 struct lttng_ust_event_field;
@@ -405,7 +405,7 @@ struct lttng_ust_event_recorder {
        struct lttng_ust_event_recorder_private *priv;  /* Private event record interface */
 
        unsigned int id;
-       struct lttng_channel *chan;
+       struct lttng_ust_channel_buffer *chan;
        struct lttng_ust_ctx *ctx;
 
        /* End of base ABI. Fields below should be used after checking struct_size. */
@@ -441,7 +441,6 @@ struct lttng_ust_event_notifier {
 };
 
 struct lttng_ust_lib_ring_buffer_channel;
-struct lttng_ust_shm_handle;
 struct lttng_ust_channel_ops_private;
 
 /*
@@ -469,34 +468,58 @@ struct lttng_ust_channel_ops {
        /* End of base ABI. Fields below should be used after checking struct_size. */
 };
 
+enum lttng_ust_channel_type {
+       LTTNG_UST_CHANNEL_TYPE_BUFFER = 0,
+};
+
+struct lttng_ust_channel_common_private;
+
 /*
  * IMPORTANT: this structure is part of the ABI between the probe and
  * UST. Fields need to be only added at the end, never reordered, never
  * removed.
+ *
+ * The field @struct_size should be used to determine the size of the
+ * structure. It should be queried before using additional fields added
+ * at the end of the structure.
  */
-struct lttng_channel {
-       /*
-        * The pointers located in this private data are NOT safe to be
-        * dereferenced by the consumer. The only operations the
-        * consumer process is designed to be allowed to do is to read
-        * and perform subbuffer flush.
-        */
-       struct lttng_ust_lib_ring_buffer_channel *chan; /* Channel buffers */
+struct lttng_ust_channel_common {
+       uint32_t struct_size;                           /* Size of this structure. */
+
+       struct lttng_ust_channel_common_private *priv;  /* Private channel interface */
+
+       enum lttng_ust_channel_type type;
+       void *child;                                    /* Pointer to child, for inheritance by aggregation. */
+
        int enabled;
-       struct lttng_ust_ctx *ctx;
-       /* Event ID management */
        struct lttng_ust_session *session;
-       int objd;                       /* Object associated to channel */
-       struct cds_list_head node;      /* Channel list in session */
+
+       /* End of base ABI. Fields below should be used after checking struct_size. */
+};
+
+struct lttng_ust_channel_buffer_private;
+
+/*
+ * IMPORTANT: this structure is part of the ABI between the probe and
+ * UST. Fields need to be only added at the end, never reordered, never
+ * removed.
+ *
+ * The field @struct_size should be used to determine the size of the
+ * structure. It should be queried before using additional fields added
+ * at the end of the structure.
+ */
+struct lttng_ust_channel_buffer {
+       uint32_t struct_size;                           /* Size of this structure. */
+
+       struct lttng_ust_channel_common *parent;        /* Inheritance by aggregation. */
+       struct lttng_ust_channel_buffer_private *priv;  /* Private channel buffer interface */
+
+       struct lttng_ust_ctx *ctx;
        struct lttng_ust_channel_ops *ops;
-       int header_type;                /* 0: unset, 1: compact, 2: large */
-       struct lttng_ust_shm_handle *handle;    /* shared-memory handle */
+       struct lttng_ust_lib_ring_buffer_channel *chan; /* Channel buffers */
+       struct lttng_ust_shm_handle *handle;            /* shared-memory handle */
 
-       /* Channel ID */
-       unsigned int id;
-       enum lttng_ust_abi_chan_type type;
-       unsigned char uuid[LTTNG_UST_UUID_LEN]; /* Trace session unique ID */
-       int tstate:1;                   /* Transient enable state */
+       /* End of base ABI. Fields below should be used after checking struct_size. */
 };
 
 /*