Namespace lttng_context_procname_reset public symbol

[lttng-ust.git] / include / lttng / ust-events.h

diff --git a/include/lttng/ust-events.h b/include/lttng/ust-events.h
index c9c118c26e1389c96ce9fcd358ece78b4b421b73..41dcbaf307d27a068ea970d8dd2e34b0b8deeb42 100644 (file)
--- a/include/lttng/ust-events.h
+++ b/include/lttng/ust-events.h
@@ -362,14 +362,18 @@ struct lttng_interpreter_output;
 struct lttng_ust_bytecode_runtime_private;
 
 /*
- * This structure is used in the probes. More specifically, the
- * `interpreter_funcs` and `node` fields are explicity used in the
- * probes. When modifying this structure we must not change the layout
- * of these two fields as it is considered ABI.
+ * IMPORTANT: this structure is part of the ABI between the probe and
+ * UST. Fields need to be only added at the end, never reordered, never
+ * removed.
+ *
+ * The field @struct_size should be used to determine the size of the
+ * structure. It should be queried before using additional fields added
+ * at the end of the structure.
  */
-struct lttng_bytecode_runtime {
-       struct lttng_ust_bytecode_runtime_private *priv;
+struct lttng_ust_bytecode_runtime {
+       uint32_t struct_size;                   /* Size of this structure. */
 
+       struct lttng_ust_bytecode_runtime_private *priv;
        /* Associated bytecode */
        union {
                uint64_t (*filter)(void *interpreter_data,
@@ -379,6 +383,8 @@ struct lttng_bytecode_runtime {
                                struct lttng_interpreter_output *interpreter_output);
        } interpreter_funcs;
        struct cds_list_head node;      /* list of bytecode runtime in event */
+
+       /* End of base ABI. Fields below should be used after checking struct_size. */
 };
 
 /*
@@ -421,7 +427,7 @@ struct lttng_ust_event_common {
 
        int enabled;
        int has_enablers_without_bytecode;
-       /* list of struct lttng_bytecode_runtime, sorted by seqnum */
+       /* list of struct lttng_ust_bytecode_runtime, sorted by seqnum */
        struct cds_list_head filter_bytecode_runtime_head;
 
        /* End of base ABI. Fields below should be used after checking struct_size. */
@@ -560,32 +566,23 @@ struct lttng_channel {
        int tstate:1;                   /* Transient enable state */
 };
 
-#define LTTNG_UST_STACK_CTX_PADDING    32
-struct lttng_stack_ctx {
+/*
+ * IMPORTANT: this structure is part of the ABI between the probe and
+ * UST. Fields need to be only added at the end, never reordered, never
+ * removed.
+ *
+ * The field @struct_size should be used to determine the size of the
+ * structure. It should be queried before using additional fields added
+ * at the end of the structure.
+ */
+struct lttng_ust_stack_ctx {
+       uint32_t struct_size;                   /* Size of this structure */
+
        struct lttng_ust_event_recorder *event_recorder;
        struct lttng_ctx *chan_ctx;     /* RCU dereferenced. */
        struct lttng_ctx *event_ctx;    /* RCU dereferenced. */
-       char padding[LTTNG_UST_STACK_CTX_PADDING];
-};
 
-#define LTTNG_UST_EVENT_HT_BITS                12
-#define LTTNG_UST_EVENT_HT_SIZE                (1U << LTTNG_UST_EVENT_HT_BITS)
-
-struct lttng_ust_event_ht {
-       struct cds_hlist_head table[LTTNG_UST_EVENT_HT_SIZE];
-};
-
-#define LTTNG_UST_EVENT_NOTIFIER_HT_BITS               12
-#define LTTNG_UST_EVENT_NOTIFIER_HT_SIZE               (1U << LTTNG_UST_EVENT_NOTIFIER_HT_BITS)
-struct lttng_ust_event_notifier_ht {
-       struct cds_hlist_head table[LTTNG_UST_EVENT_NOTIFIER_HT_SIZE];
-};
-
-#define LTTNG_UST_ENUM_HT_BITS         12
-#define LTTNG_UST_ENUM_HT_SIZE         (1U << LTTNG_UST_ENUM_HT_BITS)
-
-struct lttng_ust_enum_ht {
-       struct cds_hlist_head table[LTTNG_UST_ENUM_HT_SIZE];
+       /* End of base ABI. Fields below should be used after checking struct_size. */
 };
 
 struct lttng_ust_session_private;
@@ -612,9 +609,12 @@ int lttng_ust_probe_register(struct lttng_ust_probe_desc *desc);
 void lttng_ust_probe_unregister(struct lttng_ust_probe_desc *desc);
 
 /*
- * Can be used by applications that change their procname to clear the ust cached value.
+ * Applications that change their procname and need the new value to be
+ * reflected in the procname event context have to call this function to clear
+ * the internally cached value. This should not be called from a signal
+ * handler.
  */
-void lttng_context_procname_reset(void);
+void lttng_ust_context_procname_reset(void);
 
 struct lttng_transport *lttng_transport_find(const char *name);