Merge branch 'mp/robustify-hipe_bifs_get_hrvtime' into dev

* mp/robustify-hipe_bifs_get_hrvtime:
  robustify hipe_bifs:get_hrvtime/0

OTP-8798

1 files changed, 31 insertions, 18 deletions

diff --git a/erts/emulator/hipe/hipe_bif1.c b/erts/emulator/hipe/hipe_bif1.c
index 5188950e17..8f43811537 100644
--- a/erts/emulator/hipe/hipe_bif1.c
+++ b/erts/emulator/hipe/hipe_bif1.c
@@ -876,22 +876,44 @@ BIF_RETTYPE hipe_bifs_misc_timer_clear_0(BIF_ALIST_0)
  * + The fallback, which is the same as {X,_} = runtime(statistics).
  */
 
+static double fallback_get_hrvtime(void)
+{
+    unsigned long ms_user;
+
+    elapsed_time_both(&ms_user, NULL, NULL, NULL);
+    return (double)ms_user;
+}
+
 #if USE_PERFCTR
 
 #include "hipe_perfctr.h"
-static int hrvtime_is_open;
-#define hrvtime_is_started()	hrvtime_is_open
+static int hrvtime_started;	/* 0: closed, +1: perfctr, -1: fallback */
+#define hrvtime_is_started()	(hrvtime_started != 0)
 
 static void start_hrvtime(void)
 {
     if (hipe_perfctr_hrvtime_open() >= 0)
-	hrvtime_is_open = 1;
+	hrvtime_started = 1;
+    else
+	hrvtime_started = -1;
 }
 
-#define get_hrvtime()		hipe_perfctr_hrvtime_get()
-#define stop_hrvtime()		hipe_perfctr_hrvtime_close()
+static void stop_hrvtime(void)
+{
+    if (hrvtime_started > 0)
+	hipe_perfctr_hrvtime_close();
+    hrvtime_started = 0;
+}
 
-#else
+static double get_hrvtime(void)
+{
+    if (hrvtime_started > 0)
+	return hipe_perfctr_hrvtime_get();
+    else
+	return fallback_get_hrvtime();
+}
+
+#else	/* !USE_PERFCTR */
 
 /*
  * Fallback, if nothing better exists.
@@ -902,15 +924,9 @@ static void start_hrvtime(void)
 #define hrvtime_is_started()	1
 #define start_hrvtime()		do{}while(0)
 #define stop_hrvtime()		do{}while(0)
+#define get_hrvtime()		fallback_get_hrvtime()
 
-static double get_hrvtime(void)
-{
-    unsigned long ms_user;
-    elapsed_time_both(&ms_user, NULL, NULL, NULL);
-    return (double)ms_user;
-}
-
-#endif	/* hrvtime support */
+#endif	/* !USE_PERFCTR */
 
 BIF_RETTYPE hipe_bifs_get_hrvtime_0(BIF_ALIST_0)
 {
@@ -918,11 +934,8 @@ BIF_RETTYPE hipe_bifs_get_hrvtime_0(BIF_ALIST_0)
     Eterm res;
     FloatDef f;
 
-    if (!hrvtime_is_started()) {
+    if (!hrvtime_is_started())
 	start_hrvtime();
-	if (!hrvtime_is_started())
-	    BIF_RET(NIL); /* arity 0 BIFs may not fail */
-    }
     f.fd = get_hrvtime();
     hp = HAlloc(BIF_P, FLOAT_SIZE_OBJECT);
     res = make_float(hp);