erts: Implement tracer modules

Add the possibility to use modules as trace data receivers. The functions
in the module have to be nifs as otherwise complex trace probes will be
very hard to handle (complex means trace probes for ports for example).

This commit changes the way that the ptab->tracer field works from always
being an immediate, to now be NIL if no tracer is present or else be
the tuple {TracerModule, TracerState} where TracerModule is an atom that
is later used to lookup the appropriate tracer callbacks to call and
TracerState is just passed to the tracer callback. The default process and
port tracers have been rewritten to use the new API.

This commit also changes the order which trace messages are delivered to the
potential tracer process. Any enif_send done in a tracer module may be delayed
indefinitely because of lock order issues. If a message is delayed any other
trace message send from that process is also delayed so that order is preserved
for each traced entity. This means that for some trace events (i.e. send/receive)
the events may come in an unintuitive order (receive before send) to the
trace receiver. Timestamps are taken when the trace message is generated so
trace messages from differented processes may arrive with the timestamp
out of order.

Both the erlang:trace and seq_trace:set_system_tracer accept the new tracer
module tracers and also the backwards compatible arguments.

OTP-10267

1 files changed, 8 insertions, 8 deletions

diff --git a/erts/emulator/beam/beam_bp.h b/erts/emulator/beam/beam_bp.h
index f9eca94e2a..bb171be8a6 100644
--- a/erts/emulator/beam/beam_bp.h
+++ b/erts/emulator/beam/beam_bp.h
@@ -55,15 +55,15 @@ typedef struct {
 } BpCount;
 
 typedef struct {
-    erts_smp_atomic_t pid;
+    erts_smp_atomic_t tracer;
     erts_refc_t refc;
-} BpMetaPid;
+} BpMetaTracer;
 
 typedef struct generic_bp_data {
     Uint flags;
     Binary* local_ms;		/* Match spec for local call trace */
     Binary* meta_ms;		/* Match spec for meta trace */
-    BpMetaPid* meta_pid;	/* Meta trace pid */
+    BpMetaTracer* meta_tracer;	/* Meta tracer */
     BpCount* count;		/* For call count */
     BpDataTime* time;		/* For time trace */
 } GenericBpData;
@@ -132,10 +132,10 @@ void erts_set_call_trace_bif(BeamInstr *pc, Binary *match_spec, int local);
 void erts_clear_call_trace_bif(BeamInstr *pc, int local);
 
 void erts_set_mtrace_break(BpFunctions *f, Binary *match_spec,
-			  Eterm tracer_pid);
+			  ErtsTracer tracer);
 void erts_clear_mtrace_break(BpFunctions *f);
 void erts_set_mtrace_bif(BeamInstr *pc, Binary *match_spec,
-			 Eterm tracer_pid);
+			 ErtsTracer tracer);
 void erts_clear_mtrace_bif(BeamInstr *pc);
 
 void erts_set_debug_break(BpFunctions *f);
@@ -150,13 +150,13 @@ void erts_clear_export_break(Module *modp, BeamInstr* pc);
 
 BeamInstr erts_generic_breakpoint(Process* c_p, BeamInstr* I, Eterm* reg);
 BeamInstr erts_trace_break(Process *p, BeamInstr *pc, Eterm *args,
-		      Uint32 *ret_flags, Eterm *tracer_pid);
+                           Uint32 *ret_flags, ErtsTracer *tracer);
 
 int erts_is_trace_break(BeamInstr *pc, Binary **match_spec_ret, int local);
 int erts_is_mtrace_break(BeamInstr *pc, Binary **match_spec_ret,
-			 Eterm *tracer_pid_rte);
+			 ErtsTracer *tracer_ret);
 int erts_is_mtrace_bif(BeamInstr *pc, Binary **match_spec_ret,
-		       Eterm *tracer_pid_ret);
+		       ErtsTracer *tracer_ret);
 int erts_is_native_break(BeamInstr *pc);
 int erts_is_count_break(BeamInstr *pc, Uint *count_ret);
 int erts_is_time_break(Process *p, BeamInstr *pc, Eterm *call_time);