Enable agent application contexts if filter has such dependencies

[lttng-tools.git] / src / bin / lttng-sessiond / event.c

diff --git a/src/bin/lttng-sessiond/event.c b/src/bin/lttng-sessiond/event.c
index e4c79df74a4dca37f132478408caacd92d9f2577..b7b80d366c6ed60d9027ffcfd1e3320c60cc18d0 100644 (file)
--- a/src/bin/lttng-sessiond/event.c
+++ b/src/bin/lttng-sessiond/event.c
@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
+ * Copyright (C) 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License, version 2 only,
@@ -23,6 +24,8 @@
 #include <lttng/lttng.h>
 #include <common/error.h>
 #include <common/sessiond-comm/sessiond-comm.h>
+#include <common/filter.h>
+#include <common/context.h>
 
 #include "channel.h"
 #include "event.h"
@@ -416,6 +419,67 @@ error:
        return ret;
 }
 
+/*
+ * Check if this event's filter requires the activation of application contexts
+ * and enable them in the agent.
+ */
+static int add_filter_app_ctx(struct lttng_filter_bytecode *bytecode,
+               const char *filter_expression, struct agent *agt)
+{
+       int ret = LTTNG_OK;
+       char *provider_name = NULL, *ctx_name = NULL;
+       struct bytecode_symbol_iterator *it =
+                       bytecode_symbol_iterator_create(bytecode);
+
+       if (!it) {
+               ret = LTTNG_ERR_NOMEM;
+               goto end;
+       }
+
+       do {
+               struct lttng_event_context ctx;
+               const char *symbol_name =
+                               bytecode_symbol_iterator_get_name(it);
+
+               if (parse_application_context(symbol_name, &provider_name,
+                               &ctx_name)) {
+                       /* Not an application context. */
+                       continue;
+               }
+
+               ctx.ctx = LTTNG_EVENT_CONTEXT_APP_CONTEXT;
+               ctx.u.app_ctx.provider_name = provider_name;
+               ctx.u.app_ctx.ctx_name = ctx_name;
+
+               /* Recognized an application context. */
+               DBG("Enabling event with filter expression \"%s\" requires enabling the %s:%s application context.",
+                               filter_expression, provider_name, ctx_name);
+
+               ret = agent_add_context(&ctx, agt);
+               if (ret != LTTNG_OK) {
+                       ERR("Failed to add application context %s:%s.",
+                                       provider_name, ctx_name);
+                       goto end;
+               }
+
+               ret = agent_enable_context(&ctx, agt->domain);
+               if (ret != LTTNG_OK) {
+                       ERR("Failed to enable application context %s:%s.",
+                                       provider_name, ctx_name);
+                       goto end;
+               }
+
+               free(provider_name);
+               free(ctx_name);
+               provider_name = ctx_name = NULL;
+       } while (bytecode_symbol_iterator_next(it) == 0);
+end:
+       free(provider_name);
+       free(ctx_name);
+       bytecode_symbol_iterator_destroy(it);
+       return ret;
+}
+
 /*
  * Enable a single agent event for a given UST session.
  *
@@ -439,7 +503,7 @@ int event_agent_enable(struct ltt_ust_session *usess,
                        filter_expression ? filter_expression : "NULL");
 
        aevent = agent_find_event(event->name, event->loglevel_type,
-               event->loglevel, filter_expression, agt);
+                       event->loglevel, filter_expression, agt);
        if (!aevent) {
                aevent = agent_create_event(event->name, event->loglevel_type,
                                event->loglevel, filter,
@@ -448,6 +512,7 @@ int event_agent_enable(struct ltt_ust_session *usess,
                        ret = LTTNG_ERR_NOMEM;
                        goto error;
                }
+
                created = 1;
        }
 
@@ -456,6 +521,13 @@ int event_agent_enable(struct ltt_ust_session *usess,
                goto end;
        }
 
+       if (created && filter) {
+               ret = add_filter_app_ctx(filter, filter_expression, agt);
+               if (ret != LTTNG_OK) {
+                       goto error;
+               }
+       }
+
        ret = agent_enable_event(aevent, agt->domain);
        if (ret != LTTNG_OK) {
                goto error;