Implement health check for app registration dispatch

[lttng-tools.git] / src / bin / lttng-sessiond / health.h

diff --git a/src/bin/lttng-sessiond/health.h b/src/bin/lttng-sessiond/health.h
index 19880fa377d0d61e192853a52c6154e301fdeaac..d04d18b78ff4b436f59dae699892638f98e8c565 100644 (file)
--- a/src/bin/lttng-sessiond/health.h
+++ b/src/bin/lttng-sessiond/health.h
@@ -20,7 +20,10 @@
 
 #include <assert.h>
 #include <time.h>
+#include <pthread.h>
+#include <urcu/tls-compat.h>
 #include <urcu/uatomic.h>
+#include <urcu/list.h>
 
 /*
  * These are the value added to the current state depending of the position in
@@ -32,8 +35,24 @@
 #define HEALTH_IS_IN_POLL(x)   ((x) & HEALTH_POLL_VALUE)
 
 enum health_flags {
-       HEALTH_EXIT =  (1U << 0),
-       HEALTH_ERROR = (1U << 1),
+       HEALTH_ERROR = (1U << 0),
+};
+
+enum health_type {
+       HEALTH_TYPE_CMD                 = 0,
+       HEALTH_TYPE_APP_MANAGE  = 1,
+       HEALTH_TYPE_APP_REG             = 2,
+       HEALTH_TYPE_KERNEL              = 3,
+       HEALTH_TYPE_CONSUMER    = 4,
+       HEALTH_TYPE_HT_CLEANUP          = 5,
+       HEALTH_TYPE_APP_MANAGE_NOTIFY   = 6,
+       HEALTH_TYPE_APP_REG_DISPATCH    = 7,
+
+       HEALTH_NUM_TYPE,
+};
+
+struct health_tls_state_list {
+       struct cds_list_head head;
 };
 
 struct health_state {
@@ -49,71 +68,61 @@ struct health_state {
         */
        unsigned long current;          /* progress counter, updated atomically */
        enum health_flags flags;        /* other flags, updated atomically */
+       enum health_type type;          /* Indicates the nature of the thread. */
+       /* Node of the global TLS state list. */
+       struct cds_list_head node;
 };
 
-/* Health state counters for the client command thread */
-extern struct health_state health_thread_cmd;
-
-/* Health state counters for the application management thread */
-extern struct health_state health_thread_app_manage;
-
-/* Health state counters for the application registration thread */
-extern struct health_state health_thread_app_reg;
-
-/* Health state counters for the kernel thread */
-extern struct health_state health_thread_kernel;
+/* Declare TLS health state. */
+extern DECLARE_URCU_TLS(struct health_state, health_state);
 
 /*
- * Update current counter by 1 to indicate that the thread entered or
- * left a blocking state caused by a poll().
+ * Update current counter by 1 to indicate that the thread entered or left a
+ * blocking state caused by a poll(). If the counter's value is not an even
+ * number (meaning a code execution flow), an assert() is raised.
  */
-static inline void health_poll_update(struct health_state *state)
+static inline void health_poll_entry(void)
 {
-       assert(state);
-       uatomic_add(&state->current, HEALTH_POLL_VALUE);
-}
+       /* Code MUST be in code execution state which is an even number. */
+       assert(!(uatomic_read(&URCU_TLS(health_state).current)
+                               & HEALTH_POLL_VALUE));
 
-/*
- * Update current counter by 2 indicates progress in execution of a
- * thread.
- */
-static inline void health_code_update(struct health_state *state)
-{
-       assert(state);
-       uatomic_add(&state->current, HEALTH_CODE_VALUE);
+       uatomic_add(&URCU_TLS(health_state).current, HEALTH_POLL_VALUE);
 }
 
 /*
- * Set health "exit" flag.
+ * Update current counter by 1 indicating the exit of a poll or blocking call.
+ * If the counter's value is not an odd number (a poll execution), an assert()
+ * is raised.
  */
-static inline void health_exit(struct health_state *state)
+static inline void health_poll_exit(void)
 {
-       assert(state);
-       uatomic_or(&state->flags, HEALTH_EXIT);
+       /* Code MUST be in poll execution state which is an odd number. */
+       assert(uatomic_read(&URCU_TLS(health_state).current)
+                               & HEALTH_POLL_VALUE);
+
+       uatomic_add(&URCU_TLS(health_state).current, HEALTH_POLL_VALUE);
 }
 
 /*
- * Set health "error" flag.
+ * Update current counter by 2 indicates progress in execution of a
+ * thread.
  */
-static inline void health_error(struct health_state *state)
+static inline void health_code_update(void)
 {
-       assert(state);
-       uatomic_or(&state->flags, HEALTH_ERROR);
+       uatomic_add(&URCU_TLS(health_state).current, HEALTH_CODE_VALUE);
 }
 
 /*
- * Init health state.
+ * Set health "error" flag.
  */
-static inline void health_init(struct health_state *state)
+static inline void health_error(void)
 {
-       assert(state);
-       state->last = 0;
-       state->last_time.tv_sec = 0;
-       state->last_time.tv_nsec = 0;
-       uatomic_set(&state->current, 0);
-       uatomic_set(&state->flags, 0);
+       uatomic_or(&URCU_TLS(health_state).flags, HEALTH_ERROR);
 }
 
-int health_check_state(struct health_state *state);
+int health_check_state(enum health_type type);
+void health_register(enum health_type type);
+void health_unregister(void);
 
 #endif /* _HEALTH_H */