Return and exception trace for nif-export scheduled BIFs

The support is somewhat primitive, since it is determined at
call time if trace on return or exception should be sent.

8 files changed, 133 insertions, 13 deletions

diff --git a/erts/emulator/beam/beam_bp.c b/erts/emulator/beam/beam_bp.c
index 455362f5ae..27329a339e 100644
--- a/erts/emulator/beam/beam_bp.c
+++ b/erts/emulator/beam/beam_bp.c
@@ -32,6 +32,7 @@
 #include "erl_binary.h"
 #include "beam_bp.h"
 #include "erl_term.h"
+#include "erl_nfunc_sched.h"
 
 /* *************************************************************************
 ** Macros
@@ -805,6 +806,30 @@ erts_bif_trace(int bif_index, Process* p, Eterm* args, BeamInstr* I)
 
     result = func(p, args, I);
 
+    if (erts_nif_export_check_save_trace(p, result,
+					 applying, ep,
+					 cp, flags,
+					 flags_meta, I,
+					 meta_tracer)) {
+	/*
+	 * erts_bif_trace_epilogue() will be called
+	 * later when appropriate via the NIF export
+	 * scheduling functionality...
+	 */
+	return result;
+    }
+
+    return erts_bif_trace_epilogue(p, result, applying, ep, cp,
+				   flags, flags_meta, I,
+				   meta_tracer);
+}
+
+Eterm
+erts_bif_trace_epilogue(Process *p, Eterm result, int applying,
+			Export* ep, BeamInstr *cp, Uint32 flags,
+			Uint32 flags_meta, BeamInstr* I,
+			ErtsTracer meta_tracer)
+{
     if (applying && (flags & MATCH_SET_RETURN_TO_TRACE)) {
 	BeamInstr i_return_trace      = beam_return_trace[0];
 	BeamInstr i_return_to_trace   = beam_return_to_trace[0];
diff --git a/erts/emulator/beam/bif.c b/erts/emulator/beam/bif.c
index 5f0564474f..cae346267c 100644
--- a/erts/emulator/beam/bif.c
+++ b/erts/emulator/beam/bif.c
@@ -5047,7 +5047,7 @@ schedule(Process *c_p, Process *dirty_shadow_proc,
 static BIF_RETTYPE dirty_bif_result(BIF_ALIST_1)
 {
     NifExport *nep = (NifExport *) ERTS_PROC_GET_NIF_TRAP_EXPORT(BIF_P);
-    erts_nif_export_restore(BIF_P, nep);
+    erts_nif_export_restore(BIF_P, nep, BIF_ARG_1);
     BIF_RET(BIF_ARG_1);
 }
 
@@ -5062,7 +5062,7 @@ static BIF_RETTYPE dirty_bif_trap(BIF_ALIST)
 
     ASSERT(BIF_P->arity == nep->exp.info.mfa.arity);
 
-    erts_nif_export_restore(BIF_P, nep);
+    erts_nif_export_restore(BIF_P, nep, THE_NON_VALUE);
 
     BIF_P->i = (BeamInstr *) nep->func;
     BIF_P->freason = TRAP;
@@ -5216,12 +5216,12 @@ call_bif(Process *c_p, Eterm *reg, BeamInstr *I)
     ret = (*bif)(c_p, reg, I);
 
     if (is_value(ret))
-	erts_nif_export_restore(c_p, nep);
+	erts_nif_export_restore(c_p, nep, ret);
     else if (c_p->freason != TRAP)
 	c_p->freason |= EXF_RESTORE_NIF; /* restore in handle_error() */
     else if (nep->func == ERTS_SCHED_BIF_TRAP_MARKER) {
 	/* BIF did an ordinary trap... */
-	erts_nif_export_restore(c_p, nep);
+	erts_nif_export_restore(c_p, nep, ret);
     }
     /* else:
      *   BIF rescheduled itself using erts_schedule_bif().
diff --git a/erts/emulator/beam/erl_alloc.c b/erts/emulator/beam/erl_alloc.c
index 40a45c961f..4d990a9c56 100644
--- a/erts/emulator/beam/erl_alloc.c
+++ b/erts/emulator/beam/erl_alloc.c
@@ -44,6 +44,7 @@
 #include "erl_hl_timer.h"
 #include "erl_cpu_topology.h"
 #include "erl_thr_queue.h"
+#include "erl_nfunc_sched.h"
 #if defined(ERTS_ALC_T_DRV_SEL_D_STATE) || defined(ERTS_ALC_T_DRV_EV_D_STATE)
 #include "erl_check_io.h"
 #endif
@@ -679,6 +680,8 @@ erts_alloc_init(int *argc, char **argv, ErtsAllocInitOpts *eaiop)
     fix_type_sizes[ERTS_ALC_FIX_TYPE_IX(ERTS_ALC_T_ABIF_TIMER)]
 	= erts_timer_type_size(ERTS_ALC_T_ABIF_TIMER);
 #endif
+    fix_type_sizes[ERTS_ALC_FIX_TYPE_IX(ERTS_ALC_T_NIF_EXP_TRACE)]
+	= sizeof(NifExportTrace);
 
 #ifdef HARD_DEBUG
     hdbg_init();
@@ -2437,6 +2440,10 @@ erts_memory(fmtfn_t *print_to_p, void *print_to_arg, void *proc, Eterm earg)
 		       fi,
 		       ERTS_ALC_T_ABIF_TIMER);
 #endif
+	add_fix_values(&size.processes,
+		       &size.processes_used,
+		       fi,
+		       ERTS_ALC_T_NIF_EXP_TRACE);
     }
 
     if (want.atom || want.atom_used) {
diff --git a/erts/emulator/beam/erl_alloc.types b/erts/emulator/beam/erl_alloc.types
index 6e8710eb8a..70eca5b49c 100644
--- a/erts/emulator/beam/erl_alloc.types
+++ b/erts/emulator/beam/erl_alloc.types
@@ -376,7 +376,8 @@ type	DB_MS_PSDO_PROC	LONG_LIVED	ETS		db_match_pseudo_proc
 type	SCHDLR_DATA	LONG_LIVED	SYSTEM		scheduler_data
 type  	LL_TEMP_TERM 	LONG_LIVED	SYSTEM		ll_temp_term
 
-type	NIF_TRAP_EXPORT	STANDARD	CODE		nif_trap_export_entry
+type	NIF_TRAP_EXPORT	STANDARD	PROCESSES	nif_trap_export_entry
+type	NIF_EXP_TRACE	FIXED_SIZE	PROCESSES	nif_export_trace
 type	EXPORT		LONG_LIVED	CODE		export_entry
 type	MONITOR_SH	FIXED_SIZE	PROCESSES	monitor_sh
 type	NLINK_SH	FIXED_SIZE	PROCESSES	nlink_sh
diff --git a/erts/emulator/beam/erl_nfunc_sched.c b/erts/emulator/beam/erl_nfunc_sched.c
index bc3fd83d7a..1bebc1eda4 100644
--- a/erts/emulator/beam/erl_nfunc_sched.c
+++ b/erts/emulator/beam/erl_nfunc_sched.c
@@ -28,6 +28,7 @@
 #include "erl_process.h"
 #include "bif.h"
 #include "erl_nfunc_sched.h"
+#include "erl_trace.h"
 
 NifExport *
 erts_new_proc_nif_export(Process *c_p, int argc)
@@ -44,9 +45,12 @@ erts_new_proc_nif_export(Process *c_p, int argc)
 
     nep->argc = -1; /* unused marker */
     nep->argv_size = argc;
+    nep->trace = NULL;
     old_nep = ERTS_PROC_SET_NIF_TRAP_EXPORT(c_p, nep);
-    if (old_nep)
+    if (old_nep) {
+	ASSERT(!nep->trace);
 	erts_free(ERTS_ALC_T_NIF_TRAP_EXPORT, old_nep);
+    }
     return nep;
 }
 
@@ -61,6 +65,40 @@ erts_destroy_nif_export(Process *p)
     }
 }
 
+void
+erts_nif_export_save_trace(Process *c_p, NifExport *nep, int applying,
+			   Export* ep, BeamInstr *cp, Uint32 flags,
+			   Uint32 flags_meta, BeamInstr* I,
+			   ErtsTracer meta_tracer)
+{
+    NifExportTrace *netp;
+    ASSERT(nep && nep->argc >= 0);
+    ASSERT(!nep->trace);
+    netp = erts_alloc(ERTS_ALC_T_NIF_EXP_TRACE,
+		      sizeof(NifExportTrace));
+    netp->applying = applying;
+    netp->ep = ep;
+    netp->cp = cp;
+    netp->flags = flags;
+    netp->flags_meta = flags_meta;
+    netp->I = I;
+    netp->meta_tracer = NIL;
+    erts_tracer_update(&netp->meta_tracer, meta_tracer);
+    nep->trace = netp;
+}
+
+void
+erts_nif_export_restore_trace(Process *c_p, Eterm result, NifExport *nep)
+{
+    NifExportTrace *netp = nep->trace;
+    nep->trace = NULL;
+    erts_bif_trace_epilogue(c_p, result, netp->applying, netp->ep,
+			    netp->cp, netp->flags, netp->flags_meta,
+			    netp->I, netp->meta_tracer);
+    erts_tracer_update(&netp->meta_tracer, NIL);
+    erts_free(ERTS_ALC_T_NIF_EXP_TRACE, netp);
+}
+
 NifExport *
 erts_nif_export_schedule(Process *c_p, Process *dirty_shadow_proc,
 			 ErtsCodeMFA *mfa, BeamInstr *pc,
diff --git a/erts/emulator/beam/erl_nfunc_sched.h b/erts/emulator/beam/erl_nfunc_sched.h
index d7eccb28ba..5c98957cb7 100644
--- a/erts/emulator/beam/erl_nfunc_sched.h
+++ b/erts/emulator/beam/erl_nfunc_sched.h
@@ -23,6 +23,17 @@
 
 #include "erl_process.h"
 #include "bif.h"
+#include "error.h"
+
+typedef struct {
+    int applying;
+    Export* ep;
+    BeamInstr *cp;
+    Uint32 flags;
+    Uint32 flags_meta;
+    BeamInstr* I;
+    ErtsTracer meta_tracer;
+} NifExportTrace;
 
 /*
  * NIF exports need a few more items than the Export struct provides,
@@ -39,6 +50,7 @@ typedef struct {
     struct erl_module_nif* m; /* NIF module, or NULL if BIF */
     void *func;		/* Indirect NIF or BIF to execute (may be unused) */
     ErtsCodeMFA *current;/* Current as set when originally called */
+    NifExportTrace *trace;
     /* --- The following is only used on error --- */
     BeamInstr *pc;	/* Program counter */
     BeamInstr *cp;	/* Continuation pointer */
@@ -50,6 +62,11 @@ typedef struct {
 } NifExport;
 
 NifExport *erts_new_proc_nif_export(Process *c_p, int argc);
+void erts_nif_export_save_trace(Process *c_p, NifExport *nep, int applying,
+				Export* ep, BeamInstr *cp, Uint32 flags,
+				Uint32 flags_meta, BeamInstr* I,
+				ErtsTracer meta_tracer);
+void erts_nif_export_restore_trace(Process *c_p, Eterm result, NifExport *nep);
 void erts_destroy_nif_export(Process *p);
 NifExport *erts_nif_export_schedule(Process *c_p, Process *dirty_shadow_proc,
 				    ErtsCodeMFA *mfa, BeamInstr *pc,
@@ -63,9 +80,15 @@ ERTS_GLB_INLINE int erts_setup_nif_export_rootset(Process* proc, Eterm** objv,
 						  Uint* nobj);
 ERTS_GLB_INLINE int erts_check_nif_export_in_area(Process *p,
 						  char *start, Uint size);
-ERTS_GLB_INLINE void erts_nif_export_restore(Process *c_p, NifExport *ep);
+ERTS_GLB_INLINE void erts_nif_export_restore(Process *c_p, NifExport *ep,
+					     Eterm result);
 ERTS_GLB_INLINE void erts_nif_export_restore_error(Process* c_p, BeamInstr **pc,
 						   Eterm *reg, ErtsCodeMFA **nif_mfa);
+ERTS_GLB_INLINE int erts_nif_export_check_save_trace(Process *c_p, Eterm result,
+						     int applying, Export* ep,
+						     BeamInstr *cp, Uint32 flags,
+						     Uint32 flags_meta, BeamInstr* I,
+						     ErtsTracer meta_tracer);
 ERTS_GLB_INLINE Process *erts_proc_shadow2real(Process *c_p);
 
 #if ERTS_GLB_INLINE_INCL_FUNC_DEF
@@ -119,7 +142,7 @@ erts_check_nif_export_in_area(Process *p, char *start, Uint size)
 }
 
 ERTS_GLB_INLINE void
-erts_nif_export_restore(Process *c_p, NifExport *ep)
+erts_nif_export_restore(Process *c_p, NifExport *ep, Eterm result)
 {
     ASSERT(!ERTS_SCHEDULER_IS_DIRTY(erts_get_scheduler_data()));
     ERTS_SMP_LC_ASSERT(!(c_p->static_flags
@@ -129,6 +152,8 @@ erts_nif_export_restore(Process *c_p, NifExport *ep)
 
     c_p->current = ep->current;
     ep->argc = -1; /* Unused nif-export marker... */
+    if (ep->trace)
+	erts_nif_export_restore_trace(c_p, result, ep);
 }
 
 ERTS_GLB_INLINE void
@@ -144,7 +169,26 @@ erts_nif_export_restore_error(Process* c_p, BeamInstr **pc,
     *nif_mfa = nep->mfa;
     for (ix = 0; ix < nep->argc; ix++)
 	reg[ix] = nep->argv[ix];
-    erts_nif_export_restore(c_p, nep);
+    erts_nif_export_restore(c_p, nep, THE_NON_VALUE);
+}
+
+ERTS_GLB_INLINE int
+erts_nif_export_check_save_trace(Process *c_p, Eterm result,
+				 int applying, Export* ep,
+				 BeamInstr *cp, Uint32 flags,
+				 Uint32 flags_meta, BeamInstr* I,
+				 ErtsTracer meta_tracer)
+{
+    if (is_non_value(result) && c_p->freason == TRAP) {
+	NifExport *nep = ERTS_PROC_GET_NIF_TRAP_EXPORT(c_p);
+	if (nep && nep->argc >= 0) {
+	    erts_nif_export_save_trace(c_p, nep, applying, ep,
+				       cp, flags, flags_meta,
+				       I, meta_tracer);
+	    return 1;
+	}
+    }
+    return 0;
 }
 
 ERTS_GLB_INLINE Process *
diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c
index fd756692f9..d946844f15 100644
--- a/erts/emulator/beam/erl_nif.c
+++ b/erts/emulator/beam/erl_nif.c
@@ -2290,9 +2290,9 @@ erts_nif_export_cleanup_nif_mod(NifExport *ep)
 }
 
 static ERTS_INLINE void
-nif_export_restore(Process *c_p, NifExport *ep)
+nif_export_restore(Process *c_p, NifExport *ep, Eterm res)
 {
-    erts_nif_export_restore(c_p, ep);
+    erts_nif_export_restore(c_p, ep, res);
     ASSERT(ep->m);
     nif_export_cleanup_nif_mod(ep);
 }
@@ -2320,7 +2320,7 @@ dirty_nif_finalizer(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
     ASSERT(!ERTS_SCHEDULER_IS_DIRTY(erts_proc_sched_data(proc)));
     ep = (NifExport*) ERTS_PROC_GET_NIF_TRAP_EXPORT(proc);
     ASSERT(ep);
-    nif_export_restore(proc, ep);
+    nif_export_restore(proc, ep, argv[0]);
     return argv[0];
 }
 
@@ -2462,7 +2462,7 @@ execute_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 	/* Done (not rescheduled)... */
 	ASSERT(ep->func == ERTS_DBG_NIF_NOT_SCHED_MARKER);
 	if (!env->exception_thrown)
-	    nif_export_restore(proc, ep);
+	    nif_export_restore(proc, ep, result);
 	else {
 	    nif_export_cleanup_nif_mod(ep);
 	    /*
diff --git a/erts/emulator/beam/erl_trace.h b/erts/emulator/beam/erl_trace.h
index 378b6de49c..01fe1e5e23 100644
--- a/erts/emulator/beam/erl_trace.h
+++ b/erts/emulator/beam/erl_trace.h
@@ -143,6 +143,11 @@ Uint erts_trace_flag2bit(Eterm flag);
 int erts_trace_flags(Eterm List, 
 		 Uint *pMask, ErtsTracer *pTracer, int *pCpuTimestamp);
 Eterm erts_bif_trace(int bif_index, Process* p, Eterm* args, BeamInstr *I);
+Eterm
+erts_bif_trace_epilogue(Process *p, Eterm result, int applying,
+			Export* ep, BeamInstr *cp, Uint32 flags,
+			Uint32 flags_meta, BeamInstr* I,
+			ErtsTracer meta_tracer);
 
 #ifdef ERTS_SMP
 void erts_send_pending_trace_msgs(ErtsSchedulerData *esdp);