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authorRickard Green <[email protected]>2016-04-27 10:36:10 +0200
committerRickard Green <[email protected]>2016-05-04 14:41:03 +0200
commit19932cade31a7973120eba8db9a3b57b925f674a (patch)
tree0a8e6a26ddce7800ab77f3c7f631a0cf16c3b8a6 /erts/emulator/hipe/hipe_mode_switch.c
parent1d51d64979116d14258555c0c61e2a911110424b (diff)
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Ensure correct reduction counting
Diffstat (limited to 'erts/emulator/hipe/hipe_mode_switch.c')
-rw-r--r--erts/emulator/hipe/hipe_mode_switch.c102
1 files changed, 76 insertions, 26 deletions
diff --git a/erts/emulator/hipe/hipe_mode_switch.c b/erts/emulator/hipe/hipe_mode_switch.c
index 43144e75ec..9ad44b25ac 100644
--- a/erts/emulator/hipe/hipe_mode_switch.c
+++ b/erts/emulator/hipe/hipe_mode_switch.c
@@ -218,15 +218,37 @@ static __inline__ void hipe_pop_beam_trap_frame(Process *p)
Process *hipe_mode_switch(Process *p, unsigned cmd, Eterm reg[])
{
unsigned result;
-#if NR_ARG_REGS > 5
- /* When NR_ARG_REGS > 5, we need to protect the process' input
- reduction count (which BEAM stores in def_arg_reg[5]) from
- being clobbered by the arch glue code. */
Eterm reds_in = p->def_arg_reg[5];
-#endif
-#if NR_ARG_REGS > 4
- Eterm o_reds = p->def_arg_reg[4];
-#endif
+ /*
+ * Process is in the normal case scheduled out when reduction
+ * count reach zero. When "save calls" is enabled reduction
+ * count is subtracted with CONTEXT_REDS, i.e. initial reduction
+ * count will be zero or less and process is scheduled out
+ * when -CONTEXT_REDS is reached.
+ *
+ * HiPE does not support the "save calls" feature, so we switch
+ * to using a positive reduction counter when executing in
+ * hipe mode, but need to restore the "save calls" when
+ * returning to beam. We also need to hide the save calls buffer
+ * from BIFs. We do that by moving the saved calls buf to
+ * suspended saved calls buf.
+ *
+ * Beam has initial reduction count in stored in p->def_arg_reg[5].
+ *
+ * Beam expects -neg_o_reds to be found in p->def_arg_reg[4]
+ * on return to beam.
+ */
+
+ {
+ struct saved_calls *scb = ERTS_PROC_SET_SAVED_CALLS_BUF(p, NULL);
+ if (scb) {
+ reds_in += CONTEXT_REDS;
+ p->fcalls += CONTEXT_REDS;
+ ERTS_PROC_SET_SUSPENDED_SAVED_CALLS_BUF(p, scb);
+ }
+ }
+
+ p->flags |= F_HIPE_MODE; /* inform bifs where we are comming from... */
p->i = NULL;
/* Set current_function to undefined. stdlib hibernate tests rely on it. */
@@ -481,12 +503,21 @@ Process *hipe_mode_switch(Process *p, unsigned cmd, Eterm reg[])
erts_smp_proc_unlock(p, ERTS_PROC_LOCKS_MSG_RECEIVE);
do_schedule:
{
-#if !(NR_ARG_REGS > 5)
- int reds_in = p->def_arg_reg[5];
+ struct saved_calls *scb;
+
+ scb = ERTS_PROC_SET_SUSPENDED_SAVED_CALLS_BUF(p, NULL);
+ if (scb)
+ ERTS_PROC_SET_SAVED_CALLS_BUF(p, scb);
+
+#ifdef DEBUG
+ ASSERT(p->debug_reds_in == reds_in);
#endif
+ p->flags &= ~F_HIPE_MODE;
+
ERTS_SMP_UNREQ_PROC_MAIN_LOCK(p);
p = schedule(p, reds_in - p->fcalls);
ERTS_SMP_REQ_PROC_MAIN_LOCK(p);
+ ASSERT(!(p->flags & F_HIPE_MODE));
#ifdef ERTS_SMP
p->hipe_smp.have_receive_locks = 0;
reg = p->scheduler_data->x_reg_array;
@@ -501,28 +532,32 @@ Process *hipe_mode_switch(Process *p, unsigned cmd, Eterm reg[])
reg[i] = argp[i];
}
{
-#if !(NR_ARG_REGS > 5)
- Eterm reds_in;
-#endif
-#if !(NR_ARG_REGS > 4)
- Eterm o_reds;
-#endif
+ struct saved_calls *scb;
reds_in = p->fcalls;
- o_reds = 0;
- if (ERTS_PROC_GET_SAVED_CALLS_BUF(p)) {
- o_reds = reds_in;
- reds_in = 0;
- p->fcalls = 0;
- }
- p->def_arg_reg[4] = o_reds;
p->def_arg_reg[5] = reds_in;
+#ifdef DEBUG
+ p->debug_reds_in = reds_in;
+#endif
if (p->i == hipe_beam_pc_resume) {
+ p->flags |= F_HIPE_MODE; /* inform bifs where we are comming from... */
+ scb = ERTS_PROC_SET_SAVED_CALLS_BUF(p, NULL);
+ if (scb)
+ ERTS_PROC_SET_SUSPENDED_SAVED_CALLS_BUF(p, scb);
p->i = NULL;
p->arity = 0;
goto do_resume;
}
+
+ scb = ERTS_PROC_GET_SAVED_CALLS_BUF(p);
+ if (!scb)
+ p->def_arg_reg[4] = 0;
+ else {
+ p->def_arg_reg[4] = CONTEXT_REDS;
+ p->fcalls = -CONTEXT_REDS + reds_in;
+ }
}
+
HIPE_CHECK_PCB(p);
result = HIPE_MODE_SWITCH_RES_CALL_BEAM;
p->def_arg_reg[3] = result;
@@ -562,14 +597,29 @@ Process *hipe_mode_switch(Process *p, unsigned cmd, Eterm reg[])
default:
erts_exit(ERTS_ERROR_EXIT, "hipe_mode_switch: result %#x\r\n", result);
}
+
+ {
+ struct saved_calls *scb = ERTS_PROC_SET_SUSPENDED_SAVED_CALLS_BUF(p, NULL);
+ if (!scb)
+ p->def_arg_reg[4] = 0;
+ else {
+ p->def_arg_reg[4] = CONTEXT_REDS;
+ p->fcalls -= CONTEXT_REDS;
+ ERTS_PROC_SET_SAVED_CALLS_BUF(p, scb);
+ }
+ }
+
HIPE_CHECK_PCB(p);
p->def_arg_reg[3] = result;
-#if NR_ARG_REGS > 4
- p->def_arg_reg[4] = o_reds;
-#endif
#if NR_ARG_REGS > 5
+ /*
+ * When NR_ARG_REGS > 5, we need to protect the process' input
+ * reduction count (which BEAM stores in def_arg_reg[5]) from
+ * being clobbered by the arch glue code.
+ */
p->def_arg_reg[5] = reds_in;
#endif
+ p->flags &= ~F_HIPE_MODE;
return p;
}