X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=src%2Flttng-context.c;h=4b948ef8001277b53346d651ee08efc0497f8ef8;hb=69bd2039594fa6ef366381ed7406582cb1d4e522;hp=eb5e5d113cd6bad3bc65a6c77f758ec9e9828ccb;hpb=cfa6cc1d0f01c2cfcc1a679abf3a6572d411c309;p=lttng-modules.git

diff --git a/src/lttng-context.c b/src/lttng-context.c
index eb5e5d11..4b948ef8 100644
--- a/src/lttng-context.c
+++ b/src/lttng-context.c
@@ -29,6 +29,8 @@ int lttng_find_context(struct lttng_ctx *ctx, const char *name)
 {
 	unsigned int i;
 
+	if (!ctx)
+		return 0;
 	for (i = 0; i < ctx->nr_fields; i++) {
 		/* Skip allocated (but non-initialized) contexts */
 		if (!ctx->fields[i].event_field.name)
@@ -63,18 +65,27 @@ int lttng_get_context_index(struct lttng_ctx *ctx, const char *name)
 }
 EXPORT_SYMBOL_GPL(lttng_get_context_index);
 
+struct lttng_ctx_field *lttng_get_context_field_from_index(struct lttng_ctx *ctx,
+		size_t index)
+{
+	if (index >= ctx->nr_fields)
+		return NULL;
+	return &ctx->fields[index];
+}
+EXPORT_SYMBOL_GPL(lttng_get_context_field_from_index);
+
 /*
  * Note: as we append context information, the pointer location may change.
  */
-struct lttng_ctx_field *lttng_append_context(struct lttng_ctx **ctx_p)
+ssize_t lttng_append_context_index(struct lttng_ctx **ctx_p)
 {
-	struct lttng_ctx_field *field;
 	struct lttng_ctx *ctx;
+	ssize_t pos = -1;
 
 	if (!*ctx_p) {
 		*ctx_p = kzalloc(sizeof(struct lttng_ctx), GFP_KERNEL);
 		if (!*ctx_p)
-			return NULL;
+			goto end;
 		(*ctx_p)->largest_align = 1;
 	}
 	ctx = *ctx_p;
@@ -84,15 +95,29 @@ struct lttng_ctx_field *lttng_append_context(struct lttng_ctx **ctx_p)
 		ctx->allocated_fields = max_t(size_t, 1, 2 * ctx->allocated_fields);
 		new_fields = lttng_kvzalloc(ctx->allocated_fields * sizeof(struct lttng_ctx_field), GFP_KERNEL);
 		if (!new_fields)
-			return NULL;
+			goto end;
 		if (ctx->fields)
 			memcpy(new_fields, ctx->fields, sizeof(*ctx->fields) * ctx->nr_fields);
 		lttng_kvfree(ctx->fields);
 		ctx->fields = new_fields;
 	}
-	field = &ctx->fields[ctx->nr_fields];
-	ctx->nr_fields++;
-	return field;
+	pos = ctx->nr_fields++;
+end:
+	return pos;
+}
+EXPORT_SYMBOL_GPL(lttng_append_context_index);
+
+/*
+ * Note: as we append context information, the pointer location may change.
+ */
+struct lttng_ctx_field *lttng_append_context(struct lttng_ctx **ctx_p)
+{
+	ssize_t pos;
+
+	pos = lttng_append_context_index(ctx_p);
+	if (pos < 0)
+		return NULL;
+	return &(*ctx_p)->fields[pos];
 }
 EXPORT_SYMBOL_GPL(lttng_append_context);
 
@@ -180,6 +205,22 @@ void lttng_context_update(struct lttng_ctx *ctx)
 	ctx->largest_align = largest_align >> 3;	/* bits to bytes */
 }
 
+/* Keep same order. */
+void lttng_remove_context_field_index(struct lttng_ctx **ctx_p, size_t index)
+{
+	struct lttng_ctx *ctx = *ctx_p;
+
+	WARN_ON_ONCE(ctx->nr_fields >= index);
+	if (index != ctx->nr_fields - 1) {
+		memmove(&ctx->fields[index], &ctx->fields[index + 1],
+			(ctx->nr_fields - index - 1) * sizeof(struct lttng_ctx_field));
+	}
+	/* Clear last item. */
+	memset(&ctx->fields[ctx->nr_fields - 1], 0, sizeof(struct lttng_ctx_field));
+	ctx->nr_fields--;
+}
+EXPORT_SYMBOL_GPL(lttng_remove_context_field_index);
+
 /*
  * Remove last context field.
  */
@@ -301,6 +342,10 @@ int lttng_context_init(void)
 	if (ret && ret != -ENOSYS) {
 		printk(KERN_WARNING "Cannot add context lttng_add_uts_ns_to_ctx");
 	}
+	ret = lttng_add_time_ns_to_ctx(&lttng_static_ctx);
+	if (ret && ret != -ENOSYS) {
+		printk(KERN_WARNING "Cannot add context lttng_add_time_ns_to_ctx");
+	}
 	/* TODO: perf counters for filtering */
 	return 0;
 }