Refactoring: hide internal fields of ring buffer context

[lttng-ust.git] / libringbuffer / frontend_types.h

diff --git a/libringbuffer/frontend_types.h b/libringbuffer/frontend_types.h
index 835647683ba78e8d1a9e642dd922f17f98c4cd7c..106c1e1208634f2fd969fcd311b38a01299a5626 100644 (file)
--- a/libringbuffer/frontend_types.h
+++ b/libringbuffer/frontend_types.h
@@ -26,6 +26,8 @@
 #include "shm_types.h"
 #include "vatomic.h"
 
+#define LIB_RING_BUFFER_MAX_NESTING    5
+
 /*
  * A switch is done during tracing or as a final flush after tracing (so it
  * won't write in the new sub-buffer).
@@ -223,6 +225,43 @@ struct lttng_ust_lib_ring_buffer {
        char padding[RB_RING_BUFFER_PADDING];
 } __attribute__((aligned(CAA_CACHE_LINE_SIZE)));
 
+/*
+ * ring buffer private context
+ *
+ * Private context passed to lib_ring_buffer_reserve(), lib_ring_buffer_commit(),
+ * lib_ring_buffer_try_discard_reserve(), lttng_ust_lib_ring_buffer_align_ctx() and
+ * lib_ring_buffer_write().
+ *
+ * This context is allocated on an internal shadow-stack by a successful reserve
+ * operation, used by align/write, and freed by commit.
+ */
+
+struct lttng_ust_lib_ring_buffer_ctx_private {
+       /* input received by lib_ring_buffer_reserve(). */
+       struct lttng_ust_lib_ring_buffer_ctx *pub;
+       struct lttng_ust_lib_ring_buffer_channel *chan; /* channel */
+
+       /* output from lib_ring_buffer_reserve() */
+       int reserve_cpu;                        /* processor id updated by the reserve */
+       size_t slot_size;                       /* size of the reserved slot */
+       unsigned long buf_offset;               /* offset following the record header */
+       unsigned long pre_offset;               /*
+                                                * Initial offset position _before_
+                                                * the record is written. Positioned
+                                                * prior to record header alignment
+                                                * padding.
+                                                */
+       uint64_t tsc;                           /* time-stamp counter value */
+       unsigned int rflags;                    /* reservation flags */
+       void *ip;                               /* caller ip address */
+
+       struct lttng_ust_lib_ring_buffer *buf;  /*
+                                                * buffer corresponding to processor id
+                                                * for this channel
+                                                */
+       struct lttng_ust_lib_ring_buffer_backend_pages *backend_pages;
+};
+
 static inline
 void *channel_get_private_config(struct lttng_ust_lib_ring_buffer_channel *chan)
 {
@@ -270,4 +309,21 @@ void channel_set_private(struct lttng_ust_lib_ring_buffer_channel *chan, void *p
                _____ret = _____ret; /* For clang "unused result". */   \
        })
 
+/**
+ * lttng_ust_lib_ring_buffer_align_ctx - Align context offset on "alignment"
+ * @ctx: ring buffer context.
+ */
+static inline lttng_ust_notrace
+void lttng_ust_lib_ring_buffer_align_ctx(struct lttng_ust_lib_ring_buffer_ctx *ctx,
+                          size_t alignment);
+static inline
+void lttng_ust_lib_ring_buffer_align_ctx(struct lttng_ust_lib_ring_buffer_ctx *ctx,
+                          size_t alignment)
+{
+       struct lttng_ust_lib_ring_buffer_ctx_private *ctx_private = ctx->priv;
+
+       ctx_private->buf_offset += lttng_ust_lib_ring_buffer_align(ctx_private->buf_offset,
+                                                alignment);
+}
+
 #endif /* _LTTNG_RING_BUFFER_FRONTEND_TYPES_H */