Add critical log level

[lttng-ust.git] / src / common / logging.c

diff --git a/src/common/logging.c b/src/common/logging.c
index eb610833676d46519cd7e7437e36d00df3f84654..39b515ff9a9368f4c6b19cc4fd186b5b237954b7 100644 (file)
--- a/src/common/logging.c
+++ b/src/common/logging.c
@@ -4,24 +4,110 @@
  * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  */
 
+#include <urcu/compiler.h>
+#include <urcu/system.h>
+
 #include "common/logging.h"
 
-volatile enum lttng_ust_log_level lttng_ust_log_level;
+int lttng_ust_log_level = LTTNG_UST_LOG_LEVEL_UNKNOWN;
+int lttng_ust_log_critical_action = LTTNG_UST_LOG_CRITICAL_ACTION_UNKNOWN;
 
-void lttng_ust_logging_init(void)
+/*
+ * Initialize the global log level from the "LTTNG_UST_DEBUG" environment
+ * variable.
+ *
+ * This could end up being called concurrently by multiple threads but doesn't
+ * require a mutex since the input is invariant across threads and the result
+ * will be the same.
+ */
+static
+void lttng_ust_logging_log_level_init(void)
 {
        char *lttng_ust_debug;
+       int current_log_level;
+
+       current_log_level = CMM_LOAD_SHARED(lttng_ust_log_level);
+
+       /*
+        * Check early if we are initialized, this is unlikely as it's already tested
+        * in lttng_ust_logging_debug_enabled before performing lazy initialization.
+        */
+       if (caa_unlikely(current_log_level != LTTNG_UST_LOG_LEVEL_UNKNOWN))
+               return;
 
-       if (lttng_ust_log_level == LTTNG_UST_LOG_LEVEL_UNKNOWN) {
-               /*
-                * This getenv is not part of lttng_ust_getenv() because it
-                * is required to print ERR() performed during getenv
-                * initialization.
-                */
-               lttng_ust_debug = getenv("LTTNG_UST_DEBUG");
-               if (lttng_ust_debug)
-                       lttng_ust_log_level = LTTNG_UST_LOG_LEVEL_DEBUG;
-               else
-                       lttng_ust_log_level = LTTNG_UST_LOG_LEVEL_NORMAL;
-       }
+       /*
+        * This getenv is not part of lttng_ust_getenv() because logging is
+        * used in the getenv initialization and thus logging must be
+        * initialized prior to getenv.
+        */
+       lttng_ust_debug = getenv("LTTNG_UST_DEBUG");
+
+       /*
+        * If the LTTNG_UST_DEBUG environment variable is defined, print all
+        * messages, otherwise print nothing.
+        */
+       if (lttng_ust_debug)
+               current_log_level = LTTNG_UST_LOG_LEVEL_DEBUG;
+       else
+               current_log_level = LTTNG_UST_LOG_LEVEL_SILENT;
+
+       /* Initialize the log level */
+       CMM_STORE_SHARED(lttng_ust_log_level, current_log_level);
+}
+
+/*
+ * Initialize the global log critical action from the "LTTNG_UST_ABORT_ON_CRITICAL"
+ * environment variable.
+ *
+ * This could end up being called concurrently by multiple threads but doesn't
+ * require a mutex since the input is invariant across threads and the result
+ * will be the same.
+ */
+static
+void lttng_ust_logging_log_critical_action_init(void)
+{
+       char *lttng_ust_abort_on_critical;
+       int current_log_critical_action;
+
+       current_log_critical_action = CMM_LOAD_SHARED(lttng_ust_log_critical_action);
+
+       /*
+        * Check early if we are initialized, this is unlikely as it's already tested
+        * in lttng_ust_logging_abort_on_critical_enabled before performing lazy initialization.
+        */
+       if (caa_unlikely(current_log_critical_action != LTTNG_UST_LOG_CRITICAL_ACTION_UNKNOWN))
+               return;
+
+       /*
+        * This getenv is not part of lttng_ust_getenv() because logging is
+        * used in the getenv initialization and thus logging must be
+        * initialized prior to getenv.
+        */
+       lttng_ust_abort_on_critical = getenv("LTTNG_UST_ABORT_ON_CRITICAL");
+
+       /*
+        * If the LTTNG_UST_ABORT_ON_CRITICAL environment variable is defined,
+        * call abort() on CRIT(), otherwise take no action.
+        */
+       if (lttng_ust_abort_on_critical)
+               current_log_critical_action = LTTNG_UST_LOG_CRITICAL_ACTION_ABORT;
+       else
+               current_log_critical_action = LTTNG_UST_LOG_CRITICAL_ACTION_NONE;
+
+       /* Initialize the log critical action */
+       CMM_STORE_SHARED(lttng_ust_log_critical_action, current_log_critical_action);
+}
+
+/*
+ * Initialize the global log level from the "LTTNG_UST_DEBUG" environment
+ * variable and the global log critical action from "LTTNG_UST_ABORT_ON_CRITICAL".
+ *
+ * This could end up being called concurrently by multiple threads but doesn't
+ * require a mutex since the input is invariant across threads and the result
+ * will be the same.
+ */
+void lttng_ust_logging_init(void)
+{
+       lttng_ust_logging_log_level_init();
+       lttng_ust_logging_log_critical_action_init();
 }