Refactor the code for managing breakpoints

To allow us to manage breakpoints without going to single-scheduler
mode, we will need to update the breakpoints in several stages with
memory barriers in between each stage. Prepare for that by splitting
up the breakpoint setting and clearing functions into several smaller
functions.

1 files changed, 58 insertions, 16 deletions

diff --git a/erts/emulator/beam/beam_bp.h b/erts/emulator/beam/beam_bp.h
index 38b5536b9d..e854df2e19 100644
--- a/erts/emulator/beam/beam_bp.h
+++ b/erts/emulator/beam/beam_bp.h
@@ -56,18 +56,25 @@ typedef struct {
     erts_refc_t refc;
 } BpCount;
 
+typedef struct {
+    erts_smp_atomic_t pid;
+    erts_refc_t refc;
+} BpMetaPid;
+
 typedef struct generic_bp_data {
     Uint flags;
     Binary* local_ms;		/* Match spec for local call trace */
     Binary* meta_ms;		/* Match spec for meta trace */
-    erts_smp_atomic_t tracer_pid; /* For meta trace */
-    BpCount* count;		  /* For call count */
-    BpDataTime* time;		  /* For time trace */
+    BpMetaPid* meta_pid;	/* Meta trace pid */
+    BpCount* count;		/* For call count */
+    BpDataTime* time;		/* For time trace */
 } GenericBpData;
 
+#define ERTS_NUM_BP_IX 2
+
 typedef struct generic_bp {
     BeamInstr orig_instr;
-    GenericBpData data[1];
+    GenericBpData data[ERTS_NUM_BP_IX];
 } GenericBp;
 
 #define ERTS_BP_CALL_TIME_SCHEDULE_IN      (0)
@@ -87,7 +94,17 @@ enum erts_break_op{
     erts_break_stop
 };
 
+typedef Uint32 ErtsBpIndex;
 
+typedef struct {
+    BeamInstr* pc;
+    Module* mod;
+} BpFunction;
+
+typedef struct {
+    Uint matched;		/* Number matched */
+    BpFunction* matching;	/* Matching functions */
+} BpFunctions;
 
 /*
 ** Function interface exported from beam_bp.c
@@ -95,23 +112,35 @@ enum erts_break_op{
 
 void erts_bp_init(void);
 
-int erts_set_trace_break(Eterm mfa[3], int specified, Binary *match_spec);
-int erts_clear_trace_break(Eterm mfa[3], int specified);
-int erts_set_mtrace_break(Eterm mfa[3], int specified, Binary *match_spec,
+void erts_prepare_bp_staging(void);
+void erts_commit_staged_bp(void);
+
+ERTS_GLB_INLINE ErtsBpIndex erts_active_bp_ix(void);
+ERTS_GLB_INLINE ErtsBpIndex erts_staging_bp_ix(void);
+
+void erts_bp_match_functions(BpFunctions* f, Eterm mfa[3], int specified);
+void erts_bp_free_matched_functions(BpFunctions* f);
+
+void erts_install_breakpoints(BpFunctions* f);
+void erts_uninstall_breakpoints(BpFunctions* f);
+void erts_consolidate_bp_data(BpFunctions* f);
+
+void erts_set_trace_break(BpFunctions *f, Binary *match_spec);
+void erts_clear_trace_break(BpFunctions *f);
+void erts_set_mtrace_break(BpFunctions *f, Binary *match_spec,
 			  Eterm tracer_pid);
-int erts_clear_mtrace_break(Eterm mfa[3], int specified);
+void erts_clear_mtrace_break(BpFunctions *f);
 void erts_set_mtrace_bif(BeamInstr *pc, Binary *match_spec,
 			 Eterm tracer_pid);
 void erts_clear_mtrace_bif(BeamInstr *pc);
-int erts_set_debug_break(Eterm mfa[3], int specified);
-int erts_clear_debug_break(Eterm mfa[3], int specified);
-int erts_set_count_break(Eterm mfa[3], int specified, enum erts_break_op);
-int erts_clear_count_break(Eterm mfa[3], int specified);
+void erts_set_debug_break(BpFunctions *f);
+void erts_clear_debug_break(BpFunctions *f);
+void erts_set_count_break(BpFunctions *f, enum erts_break_op);
+void erts_clear_count_break(BpFunctions *f);
 
 
-int erts_clear_break(Eterm mfa[3], int specified);
+void erts_clear_all_breaks(BpFunctions* f);
 int erts_clear_module_break(Module *modp);
-int erts_clear_function_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,
@@ -131,8 +160,8 @@ int erts_is_time_break(Process *p, BeamInstr *pc, Eterm *call_time);
 void erts_trace_time_call(Process* c_p, BeamInstr* pc, BpDataTime* bdt);
 void erts_trace_time_return(Process* c_p, BeamInstr* pc);
 void erts_schedule_time_break(Process *p, Uint out);
-int erts_set_time_break(Eterm mfa[3], int specified, enum erts_break_op);
-int erts_clear_time_break(Eterm mfa[3], int specified);
+void erts_set_time_break(BpFunctions *f, enum erts_break_op);
+void erts_clear_time_break(BpFunctions *f);
 
 int erts_is_time_trace_bif(Process *p, BeamInstr *pc, Eterm *call_time);
 void erts_set_time_trace_bif(BeamInstr *pc, enum erts_break_op);
@@ -154,6 +183,19 @@ ERTS_GLB_INLINE Uint erts_bp_sched2ix(void)
     return 0;
 #endif
 }
+
+extern erts_smp_atomic32_t erts_active_bp_index;
+extern erts_smp_atomic32_t erts_staging_bp_index;
+
+ERTS_GLB_INLINE ErtsBpIndex erts_active_bp_ix(void)
+{
+    return erts_smp_atomic32_read_nob(&erts_active_bp_index);
+}
+
+ERTS_GLB_INLINE ErtsBpIndex erts_staging_bp_ix(void)
+{
+    return erts_smp_atomic32_read_nob(&erts_staging_bp_index);
+}
 #endif
 
 #endif /* _BEAM_BP_H */