Change the data structures for breakpoints

Change the data structures for breakpoints to make it possible
(in a future commit) to manage breakpoints without taking down the
system to single-scheduling mode.

The current "breakpoint wheel" data structure (a circular,
double-linked list of breakpoints) was invented before the
SMP emulator. To support it in the SMP emulator, there is essentially
one breakpoint wheel per scheduler. As more breakpoint types have
been added, the implementation has become messy and hard to understand
and maintain.

Therefore, the time for a rewrite has come. Use one struct to hold
all breakpoint data for a breakpoint in a function. Use a flag field
to indicate what different type of break actions that are enabled.

1 files changed, 8 insertions, 174 deletions

diff --git a/erts/emulator/beam/beam_emu.c b/erts/emulator/beam/beam_emu.c
index 15a937289d..b5282830af 100644
--- a/erts/emulator/beam/beam_emu.c
+++ b/erts/emulator/beam/beam_emu.c
@@ -4643,80 +4643,22 @@ void process_main(void)
      Goto(*I);
  }
 
- OpCase(i_count_breakpoint): {
+ OpCase(i_generic_breakpoint): {
      BeamInstr real_I;
-     
-     ErtsCountBreak(c_p, (BeamInstr *) I, &real_I);
+     ASSERT(I[-5] == (BeamInstr) BeamOp(op_i_func_info_IaaI));
+     SWAPOUT;
+     reg[0] = r(0);
+     real_I = erts_generic_breakpoint(c_p, I, reg);
+     r(0) = reg[0];
+     SWAPIN;
      ASSERT(VALID_INSTR(real_I));
      Goto(real_I);
  }
 
- /* need to send mfa instead of bdt pointer
-  * the pointer might be deallocated.
-  */
-
- OpCase(i_time_breakpoint): {
-     BeamInstr real_I;
-     BpData **bds = (BpData **) (I)[-4];
-     BpDataTime *bdt = NULL;
-     Uint ix = 0;
-#ifdef ERTS_SMP
-     ix = c_p->scheduler_data->no - 1;
-#else
-     ix = 0;
-#endif
-     bdt = (BpDataTime *)bds[ix];
-
-     ASSERT((I)[-5] == (BeamInstr) BeamOp(op_i_func_info_IaaI));
-     ASSERT(bdt);
-     bdt = (BpDataTime *) bdt->next;
-     ASSERT(bdt);
-     bds[ix] = (BpData *) bdt;
-     real_I = bdt->orig_instr;
-     ASSERT(VALID_INSTR(real_I));
-
-     if (IS_TRACED_FL(c_p, F_TRACE_CALLS) && !(bdt->pause)) {
-	 if (	(*(c_p->cp) == (BeamInstr) OpCode(i_return_time_trace)) ||
-		(*(c_p->cp) == (BeamInstr) OpCode(return_trace)) ||
-		(*(c_p->cp) == (BeamInstr) OpCode(i_return_to_trace))) {
-	     /* This _IS_ a tail recursive call */
-	     SWAPOUT;
-	     erts_trace_time_break(c_p, I, bdt, ERTS_BP_CALL_TIME_TAIL_CALL);
-	     SWAPIN;
-	 } else {
-	     SWAPOUT;
-	     erts_trace_time_break(c_p, I, bdt, ERTS_BP_CALL_TIME_CALL);
-
-	     /* r register needs to be copied to the array
-	      * for the garbage collector
-	      */
-	     ASSERT(c_p->htop <= E && E <= c_p->hend);
-	     if (E - 2 < HTOP) {
-		 reg[0] = r(0);
-		 PROCESS_MAIN_CHK_LOCKS(c_p);
-		 FCALLS -= erts_garbage_collect(c_p, 2, reg, I[-1]);
-		 ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
-		 PROCESS_MAIN_CHK_LOCKS(c_p);
-		 r(0) = reg[0];
-	     }
-	     SWAPIN;
-
-	     ASSERT(c_p->htop <= E && E <= c_p->hend);
-
-	     E -= 2;
-	     E[0] = make_cp(I);
-	     E[1] = make_cp(c_p->cp);     /* original return address */
-	     c_p->cp = beam_return_time_trace;
-	 }
-     }
-
-     Goto(real_I);
- }
-
  OpCase(i_return_time_trace): {
      BeamInstr *pc = (BeamInstr *) (UWord) E[0];
      SWAPOUT;
-     erts_trace_time_break(c_p, pc, NULL, ERTS_BP_CALL_TIME_RETURN);
+     erts_trace_time_return(c_p, pc);
      SWAPIN;
      c_p->cp = NULL;
      SET_I((BeamInstr *) cp_val(E[1]));
@@ -4724,114 +4666,6 @@ void process_main(void)
      Goto(*I);
  }
 
- OpCase(i_trace_breakpoint):
-     if (! IS_TRACED_FL(c_p, F_TRACE_CALLS)) {
-	 BeamInstr real_I;
-	 
-	 ErtsBreakSkip(c_p, (BeamInstr *) I, &real_I);
-	 Goto(real_I);
-     }
- /* Fall through to next case */
- OpCase(i_mtrace_breakpoint): {
-     BeamInstr real_I;
-     Uint32 flags;
-     Eterm tracer_pid;
-     Uint* cpp;
-     int return_to_trace = 0, need = 0;
-     flags = 0;
-     SWAPOUT;
-     reg[0] = r(0);
-
-     if (*(c_p->cp) == (BeamInstr) OpCode(return_trace)) {
-	 cpp = &E[2];
-     } else if (*(c_p->cp) == (BeamInstr) OpCode(i_return_to_trace)) {
-	 return_to_trace = !0;
-	 cpp = &E[0];
-     } else if (*(c_p->cp) == (BeamInstr) OpCode(i_return_time_trace)) {
-	 return_to_trace = !0;
-	 cpp = &E[0];
-     } else {
-	 cpp = NULL;
-     }
-     if (cpp) {
-	 /* This _IS_ a tail recursive call, if there are
-	  * return_trace and/or i_return_to_trace stackframes
-	  * on the stack, they are not intermixed with y registers
-	  */
-	 BeamInstr *cp_save = c_p->cp;
-	 for (;;) {
-	     ASSERT(is_CP(*cpp));
-	     if (*cp_val(*cpp) == (BeamInstr) OpCode(return_trace)) {
-		 cpp += 3;
-	     } else if (*cp_val(*cpp) == (BeamInstr) OpCode(i_return_to_trace)) {
-		 return_to_trace = !0;
-		 cpp += 1;
-	     } else if (*cp_val(*cpp) == (BeamInstr) OpCode(i_return_time_trace)) {
-		 cpp += 2;
-	     } else
-		 break;
-	 }
-	 c_p->cp = (BeamInstr *) cp_val(*cpp);
-	 ASSERT(is_CP(*cpp));
-	 ERTS_SMP_UNREQ_PROC_MAIN_LOCK(c_p);
-	 real_I = erts_trace_break(c_p, I, reg, &flags, &tracer_pid);
-	 ERTS_SMP_REQ_PROC_MAIN_LOCK(c_p);
-	 SWAPIN;		/* Needed by shared heap. */
-	 c_p->cp = cp_save;
-     } else {
-	 ERTS_SMP_UNREQ_PROC_MAIN_LOCK(c_p);
-	 real_I = erts_trace_break(c_p, I, reg, &flags, &tracer_pid);
-	 ERTS_SMP_REQ_PROC_MAIN_LOCK(c_p);
-	 SWAPIN;		/* Needed by shared heap. */
-     }
-
-     ASSERT(!ERTS_PROC_IS_EXITING(c_p));
-
-     if ((flags & MATCH_SET_RETURN_TO_TRACE) && !return_to_trace) {
-	 need += 1;
-     }
-     if (flags & MATCH_SET_RX_TRACE) {
-	 need += 3;
-     }
-     if (need) {
-	 ASSERT(c_p->htop <= E && E <= c_p->hend);
-	 if (E - need < HTOP) {
-	     /* SWAPOUT was done and r(0) was saved above */
-	     PROCESS_MAIN_CHK_LOCKS(c_p);
-	     FCALLS -= erts_garbage_collect(c_p, need, reg, I[-1]);
-	     ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
-	     PROCESS_MAIN_CHK_LOCKS(c_p);
-	     r(0) = reg[0];
-	     SWAPIN;
-	 }
-     }
-     if ((flags & MATCH_SET_RETURN_TO_TRACE) && !return_to_trace) {
-	 E -= 1;
-	 ASSERT(c_p->htop <= E && E <= c_p->hend);
-	 E[0] = make_cp(c_p->cp);
-	 c_p->cp = (BeamInstr *) beam_return_to_trace;
-     }
-     if (flags & MATCH_SET_RX_TRACE) {
-	 E -= 3;
-	 ASSERT(c_p->htop <= E && E <= c_p->hend);
-	 ASSERT(is_CP((Eterm) (UWord) (I - 3)));
-	 ASSERT(am_true == tracer_pid || 
-		is_internal_pid(tracer_pid) || is_internal_port(tracer_pid));
-	 E[2] = make_cp(c_p->cp);
-	 E[1] = tracer_pid;
-	 E[0] = make_cp(I - 3); /* We ARE at the beginning of an 
-				   instruction,
-				   the funcinfo is above i. */
-	 c_p->cp =
-	     (flags & MATCH_SET_EXCEPTION_TRACE)
-		     ? beam_exception_trace : beam_return_trace;
-	 erts_smp_proc_lock(c_p, ERTS_PROC_LOCKS_ALL_MINOR);
-	 c_p->trace_flags |= F_EXCEPTION_TRACE;
-	 erts_smp_proc_unlock(c_p, ERTS_PROC_LOCKS_ALL_MINOR);
-     }
-     Goto(real_I);
- }
- 
  OpCase(i_return_to_trace): {
      if (IS_TRACED_FL(c_p, F_TRACE_RETURN_TO)) {
 	 Uint *cpp = (Uint*) E;