X-Git-Url: http://git.lttng.org./?a=blobdiff_plain;ds=sidebyside;f=libringbuffer%2Fbackend.h;h=fff4f9ec7b11ffdc69d75f3f418e92452c814a98;hb=3b2e18579fd7ae05607a7c1ba1265848736f98e3;hp=e95bb7bc13deabcb0b00bb3cc15d5a376e51d7b9;hpb=ddabe860f4cf41a4206a8157d83e6b9354f85cb5;p=lttng-ust.git

diff --git a/libringbuffer/backend.h b/libringbuffer/backend.h
index e95bb7bc..fff4f9ec 100644
--- a/libringbuffer/backend.h
+++ b/libringbuffer/backend.h
@@ -68,9 +68,10 @@ void lib_ring_buffer_write(const struct lttng_ust_lib_ring_buffer_config *config
 			   struct lttng_ust_lib_ring_buffer_ctx *ctx,
 			   const void *src, size_t len)
 {
-	struct channel_backend *chanb = &ctx->chan->backend;
-	struct lttng_ust_shm_handle *handle = ctx->handle;
-	size_t offset = ctx->buf_offset;
+	struct lttng_ust_lib_ring_buffer_ctx_private *ctx_private = ctx->priv;
+	struct channel_backend *chanb = &ctx_private->chan->backend;
+	struct lttng_ust_shm_handle *handle = ctx_private->chan->handle;
+	size_t offset = ctx_private->buf_offset;
 	struct lttng_ust_lib_ring_buffer_backend_pages *backend_pages;
 	void *p;
 
@@ -90,7 +91,7 @@ void lib_ring_buffer_write(const struct lttng_ust_lib_ring_buffer_config *config
 	if (caa_unlikely(!p))
 		return;
 	lib_ring_buffer_do_copy(config, p, src, len);
-	ctx->buf_offset += len;
+	ctx_private->buf_offset += len;
 }
 
 /*
@@ -137,12 +138,13 @@ 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_lib_ring_buffer_ctx_private *ctx_private = ctx->priv;
+	struct channel_backend *chanb = &ctx_private->chan->backend;
+	struct lttng_ust_shm_handle *handle = ctx_private->chan->handle;
 	size_t count;
-	size_t offset = ctx->buf_offset;
+	size_t offset = ctx_private->buf_offset;
 	struct lttng_ust_lib_ring_buffer_backend_pages *backend_pages;
 	void *p;
 
@@ -179,7 +181,66 @@ void lib_ring_buffer_strcpy(const struct lttng_ust_lib_ring_buffer_config *confi
 	if (caa_unlikely(!p))
 		return;
 	lib_ring_buffer_do_memset(p, '\0', 1);
-	ctx->buf_offset += len;
+	ctx_private->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 lttng_ust_lib_ring_buffer_ctx_private *ctx_private = ctx->priv;
+	struct channel_backend *chanb = &ctx_private->chan->backend;
+	struct lttng_ust_shm_handle *handle = ctx_private->chan->handle;
+	size_t count;
+	size_t offset = ctx_private->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_private->buf_offset += len;
 }
 
 /*
@@ -196,7 +257,7 @@ 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)