MINOR: trace: implement a very basic trace() function

For now it remains quite basic. It performs a few state checks, calls
the source's sink if defined, and performs the transitions between
RUNNING, STOPPED and WAITING when the configured events match.

diff --git a/include/proto/trace.h b/include/proto/trace.h
index 24d2601559219fc14641a63f94efd9d24703db9d..6767952cd2e0fd945d352cbd2c7a12e445a54468 100644 (file)
--- a/include/proto/trace.h
+++ b/include/proto/trace.h
@@ -34,6 +34,8 @@
 extern struct list trace_sources;
 extern THREAD_LOCAL struct buffer trace_buf;
 
+void __trace(uint64_t mask, struct trace_source *src, const struct ist msg);
+
 /* return a single char to describe a trace state */
 static inline char trace_state_char(enum trace_state st)
 {
@@ -63,6 +65,13 @@ static inline void trace_register_source(struct trace_source *source)
        LIST_ADDQ(&trace_sources, &source->source_link);
 }
 
+/* sends a trace for the given source */
+static inline void trace(uint64_t mask, struct trace_source *src, const struct ist msg)
+{
+       if (unlikely(src->state != TRACE_STATE_STOPPED))
+               __trace(mask, src, msg);
+}
+
 #endif /* _PROTO_TRACE_H */
 
 /*

diff --git a/src/trace.c b/src/trace.c
index 8691b65f157cd7911ecc0614b2f288b4087253b4..4f6a913cf3dfd13d1e99b2972a46740212e2da83 100644 (file)
--- a/src/trace.c
+++ b/src/trace.c
@@ -48,6 +48,46 @@ static void free_trace_buffers_per_thread()
 REGISTER_PER_THREAD_ALLOC(alloc_trace_buffers_per_thread);
 REGISTER_PER_THREAD_FREE(free_trace_buffers_per_thread);
 
+/* write a message for the given trace source */
+void __trace(uint64_t mask, struct trace_source *src, const struct ist msg)
+{
+       if (likely(src->state == TRACE_STATE_STOPPED))
+               return;
+
+       /* check that at least one action is interested by this event */
+       if (((src->report_events | src->start_events | src->pause_events | src->stop_events) & mask) == 0)
+               return;
+
+       /* TODO: add handling of filters here, return if no match (not even update states) */
+
+       /* check if we need to start the trace now */
+       if (src->state == TRACE_STATE_WAITING) {
+               if ((src->start_events & mask) == 0)
+                       return;
+
+               /* TODO: add update of lockon+lockon_ptr here */
+               HA_ATOMIC_STORE(&src->state, TRACE_STATE_RUNNING);
+       }
+
+       /* TODO: add check of lockon+lockon_ptr here, return if no match */
+       /* here the trace is running and is tracking a desired item */
+
+       if ((src->report_events & mask) == 0)
+               goto end;
+
+       if (src->sink)
+               sink_write(src->sink, &msg, 1);
+
+ end:
+       /* check if we need to stop the trace now */
+       if ((src->stop_events & mask) != 0) {
+               HA_ATOMIC_STORE(&src->state, TRACE_STATE_STOPPED);
+       }
+       else if ((src->pause_events & mask) != 0) {
+               HA_ATOMIC_STORE(&src->state, TRACE_STATE_WAITING);
+       }
+}
+
 struct trace_source *trace_find_source(const char *name)
 {
        struct trace_source *src;