X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=liblttng-ust%2Flttng-context.c;h=6cab7dc1721a57dbbd004cd84f5db4deed32072b;hb=refs%2Fheads%2Fstable-2.5;hp=16894ec1032b722407ce578d43f47051a62bbc60;hpb=7dd08bec735b428479201f9f84d59c78deabdf57;p=lttng-ust.git

diff --git a/liblttng-ust/lttng-context.c b/liblttng-ust/lttng-context.c
index 16894ec1..6cab7dc1 100644
--- a/liblttng-ust/lttng-context.c
+++ b/liblttng-ust/lttng-context.c
@@ -23,10 +23,21 @@
 
 #include <lttng/ust-events.h>
 #include <lttng/ust-tracer.h>
+#include <usterr-signal-safe.h>
 #include <helper.h>
 #include <string.h>
 #include <assert.h>
 
+/*
+ * The filter implementation requires that two consecutive "get" for the
+ * same context performed by the same thread return the same result.
+ */
+
+/*
+ * Static array of contexts, for $ctx filters.
+ */
+struct lttng_ctx *lttng_static_ctx;
+
 int lttng_find_context(struct lttng_ctx *ctx, const char *name)
 {
 	unsigned int i;
@@ -41,6 +52,22 @@ int lttng_find_context(struct lttng_ctx *ctx, const char *name)
 	return 0;
 }
 
+int lttng_get_context_index(struct lttng_ctx *ctx, const char *name)
+{
+	unsigned int i;
+
+	if (!ctx)
+		return -1;
+	for (i = 0; i < ctx->nr_fields; i++) {
+		/* Skip allocated (but non-initialized) contexts */
+		if (!ctx->fields[i].event_field.name)
+			continue;
+		if (!strcmp(ctx->fields[i].event_field.name, name))
+			return i;
+	}
+	return -1;
+}
+
 /*
  * Note: as we append context information, the pointer location may change.
  */
@@ -53,6 +80,7 @@ struct lttng_ctx_field *lttng_append_context(struct lttng_ctx **ctx_p)
 		*ctx_p = zmalloc(sizeof(struct lttng_ctx));
 		if (!*ctx_p)
 			return NULL;
+		(*ctx_p)->largest_align = 1;
 	}
 	ctx = *ctx_p;
 	if (ctx->nr_fields + 1 > ctx->allocated_fields) {
@@ -72,6 +100,94 @@ struct lttng_ctx_field *lttng_append_context(struct lttng_ctx **ctx_p)
 	return field;
 }
 
+/*
+ * lttng_context_update() should be called at least once between context
+ * modification and trace start.
+ */
+void lttng_context_update(struct lttng_ctx *ctx)
+{
+	int i;
+	size_t largest_align = 8;	/* in bits */
+
+	for (i = 0; i < ctx->nr_fields; i++) {
+		struct lttng_type *type;
+		size_t field_align = 8;
+
+		type = &ctx->fields[i].event_field.type;
+		switch (type->atype) {
+		case atype_integer:
+			field_align = type->u.basic.integer.alignment;
+			break;
+		case atype_array:
+		{
+			struct lttng_basic_type *btype;
+
+			btype = &type->u.array.elem_type;
+			switch (btype->atype) {
+			case atype_integer:
+				field_align = btype->u.basic.integer.alignment;
+				break;
+			case atype_string:
+				break;
+
+			case atype_array:
+			case atype_sequence:
+			default:
+				WARN_ON_ONCE(1);
+				break;
+			}
+			break;
+		}
+		case atype_sequence:
+		{
+			struct lttng_basic_type *btype;
+
+			btype = &type->u.sequence.length_type;
+			switch (btype->atype) {
+			case atype_integer:
+				field_align = btype->u.basic.integer.alignment;
+				break;
+
+			case atype_string:
+			case atype_array:
+			case atype_sequence:
+			default:
+				WARN_ON_ONCE(1);
+				break;
+			}
+
+			btype = &type->u.sequence.elem_type;
+			switch (btype->atype) {
+			case atype_integer:
+				field_align = max_t(size_t,
+					field_align,
+					btype->u.basic.integer.alignment);
+				break;
+
+			case atype_string:
+				break;
+
+			case atype_array:
+			case atype_sequence:
+			default:
+				WARN_ON_ONCE(1);
+				break;
+			}
+			break;
+		}
+		case atype_string:
+			break;
+
+		case atype_enum:
+		default:
+			WARN_ON_ONCE(1);
+			break;
+		}
+		largest_align = max_t(size_t, largest_align, field_align);
+	}
+	ctx->largest_align = largest_align >> 3;	/* bits to bytes */
+}
+
 /*
  * Remove last context field.
  */
@@ -99,3 +215,31 @@ void lttng_destroy_context(struct lttng_ctx *ctx)
 	free(ctx->fields);
 	free(ctx);
 }
+
+void lttng_context_init(void)
+{
+	int ret;
+
+	ret = lttng_add_pthread_id_to_ctx(&lttng_static_ctx);
+	if (ret) {
+		WARN("Cannot add context lttng_add_pthread_id_to_ctx");
+	}
+	ret = lttng_add_vtid_to_ctx(&lttng_static_ctx);
+	if (ret) {
+		WARN("Cannot add context lttng_add_vtid_to_ctx");
+	}
+	ret = lttng_add_vpid_to_ctx(&lttng_static_ctx);
+	if (ret) {
+		WARN("Cannot add context lttng_add_vpid_to_ctx");
+	}
+	ret = lttng_add_procname_to_ctx(&lttng_static_ctx);
+	if (ret) {
+		WARN("Cannot add context lttng_add_procname_to_ctx");
+	}
+}
+
+void lttng_context_exit(void)
+{
+	lttng_destroy_context(lttng_static_ctx);
+	lttng_static_ctx = NULL;
+}