X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=libringbuffer%2Fbackend.h;h=2fe06cefd56f2c146b128762f9268c85101c5946;hb=50d2bb48d09d5b6ae23185e8f916152e2371d04a;hp=98c194ca5bf988603646071b778ac936b1add00d;hpb=c0c0989ab70574e09b2f7e8b48c2da6af664a849;p=lttng-ust.git

diff --git a/libringbuffer/backend.h b/libringbuffer/backend.h
index 98c194ca..2fe06cef 100644
--- a/libringbuffer/backend.h
+++ b/libringbuffer/backend.h
@@ -23,10 +23,12 @@
 
 /* Ring buffer backend access (read/write) */
 
+__attribute__((visibility("hidden")))
 extern size_t lib_ring_buffer_read(struct lttng_ust_lib_ring_buffer_backend *bufb,
 				   size_t offset, void *dest, size_t len,
 				   struct lttng_ust_shm_handle *handle);
 
+__attribute__((visibility("hidden")))
 extern int lib_ring_buffer_read_cstr(struct lttng_ust_lib_ring_buffer_backend *bufb,
 				     size_t offset, void *dest, size_t len,
 				     struct lttng_ust_shm_handle *handle);
@@ -37,10 +39,13 @@ extern int lib_ring_buffer_read_cstr(struct lttng_ust_lib_ring_buffer_backend *b
  * it's never on a page boundary, it's safe to write directly to this address,
  * as long as the write is never bigger than a page size.
  */
+__attribute__((visibility("hidden")))
 extern void *
 lib_ring_buffer_offset_address(struct lttng_ust_lib_ring_buffer_backend *bufb,
 			       size_t offset,
 			       struct lttng_ust_shm_handle *handle);
+
+__attribute__((visibility("hidden")))
 extern void *
 lib_ring_buffer_read_offset_address(struct lttng_ust_lib_ring_buffer_backend *bufb,
 				    size_t offset,
@@ -64,7 +69,7 @@ void lib_ring_buffer_write(const struct lttng_ust_lib_ring_buffer_config *config
 			   const void *src, size_t len)
 {
 	struct channel_backend *chanb = &ctx->chan->backend;
-	struct lttng_ust_shm_handle *handle = ctx->handle;
+	struct lttng_ust_shm_handle *handle = ctx->chan->handle;
 	size_t offset = ctx->buf_offset;
 	struct lttng_ust_lib_ring_buffer_backend_pages *backend_pages;
 	void *p;
@@ -132,10 +137,10 @@ size_t lib_ring_buffer_do_strcpy(const struct lttng_ust_lib_ring_buffer_config *
 static inline __attribute__((always_inline))
 void lib_ring_buffer_strcpy(const struct lttng_ust_lib_ring_buffer_config *config,
 			   struct lttng_ust_lib_ring_buffer_ctx *ctx,
-			   const char *src, size_t len, int pad)
+			   const char *src, size_t len, char pad)
 {
 	struct channel_backend *chanb = &ctx->chan->backend;
-	struct lttng_ust_shm_handle *handle = ctx->handle;
+	struct lttng_ust_shm_handle *handle = ctx->chan->handle;
 	size_t count;
 	size_t offset = ctx->buf_offset;
 	struct lttng_ust_lib_ring_buffer_backend_pages *backend_pages;
@@ -177,6 +182,64 @@ void lib_ring_buffer_strcpy(const struct lttng_ust_lib_ring_buffer_config *confi
 	ctx->buf_offset += len;
 }
 
+/**
+ * lib_ring_buffer_pstrcpy - write to a buffer backend P-string
+ * @config : ring buffer instance configuration
+ * @ctx: ring buffer context. (input arguments only)
+ * @src : source pointer to copy from
+ * @len : length of data to copy
+ * @pad : character to use for padding
+ *
+ * This function copies up to @len bytes of data from a source pointer
+ * to a Pascal String into the buffer backend. If a terminating '\0'
+ * character is found in @src before @len characters are copied, pad the
+ * buffer with @pad characters (e.g.  '\0').
+ *
+ * The length of the pascal strings in the ring buffer is explicit: it
+ * is either the array or sequence length.
+ */
+static inline __attribute__((always_inline))
+void lib_ring_buffer_pstrcpy(const struct lttng_ust_lib_ring_buffer_config *config,
+			   struct lttng_ust_lib_ring_buffer_ctx *ctx,
+			   const char *src, size_t len, char pad)
+{
+	struct channel_backend *chanb = &ctx->chan->backend;
+	struct lttng_ust_shm_handle *handle = ctx->chan->handle;
+	size_t count;
+	size_t offset = ctx->buf_offset;
+	struct lttng_ust_lib_ring_buffer_backend_pages *backend_pages;
+	void *p;
+
+	if (caa_unlikely(!len))
+		return;
+	/*
+	 * Underlying layer should never ask for writes across
+	 * subbuffers.
+	 */
+	CHAN_WARN_ON(chanb, (offset & (chanb->buf_size - 1)) + len > chanb->buf_size);
+	backend_pages = lib_ring_buffer_get_backend_pages_from_ctx(config, ctx);
+	if (caa_unlikely(!backend_pages)) {
+		if (lib_ring_buffer_backend_get_pages(config, ctx, &backend_pages))
+			return;
+	}
+	p = shmp_index(handle, backend_pages->p, offset & (chanb->subbuf_size - 1));
+	if (caa_unlikely(!p))
+		return;
+
+	count = lib_ring_buffer_do_strcpy(config, p, src, len);
+	offset += count;
+	/* Padding */
+	if (caa_unlikely(count < len)) {
+		size_t pad_len = len - count;
+
+		p = shmp_index(handle, backend_pages->p, offset & (chanb->subbuf_size - 1));
+		if (caa_unlikely(!p))
+			return;
+		lib_ring_buffer_do_memset(p, pad, pad_len);
+	}
+	ctx->buf_offset += len;
+}
+
 /*
  * This accessor counts the number of unread records in a buffer.
  * It only provides a consistent value if no reads not writes are performed
@@ -191,7 +254,7 @@ unsigned long lib_ring_buffer_get_records_unread(
 	struct lttng_ust_lib_ring_buffer_backend *bufb = &buf->backend;
 	unsigned long records_unread = 0, sb_bindex;
 	unsigned int i;
-	struct channel *chan;
+	struct lttng_ust_lib_ring_buffer_channel *chan;
 
 	chan = shmp(handle, bufb->chan);
 	if (!chan)