patch 8.2.5036: using two counters for timeout check in NFA engine

Problem:    Using two counters for timeout check in NFA engine.
Solution:   Use only one counter.  Tune the counts based on guessing.

diff --git a/src/regexp_nfa.c b/src/regexp_nfa.c
index 1e7cd9b4649230b6372eaf63f1d5c88ce8a59217..9c521f35d0171cda279d76401342e4ba63f2d24f 100644 (file)
--- a/src/regexp_nfa.c
+++ b/src/regexp_nfa.c
@@ -4053,7 +4053,6 @@ static int            nfa_match;
 #ifdef FEAT_RELTIME
 static proftime_T  *nfa_time_limit;
 static int        *nfa_timed_out;
-static int         nfa_time_count;
 #endif
 
 static void copy_sub(regsub_T *to, regsub_T *from);
@@ -5646,22 +5645,26 @@ find_match_text(colnr_T startcol, int regstart, char_u *match_text)
 }
 
 #ifdef FEAT_RELTIME
+/*
+ * Check if we are past the time limit, if there is one.
+ * To reduce overhead, only check one in "count" times.
+ */
     static int
-nfa_did_time_out()
+nfa_did_time_out(int count)
 {
     static int tm_count = 0;
 
-    // Check for timeout once in 800 times to avoid excessive overhead from
-    // reading the clock.  The value has been picked to check about once per
-    // msec on a modern CPU.
+    // Check for timeout once in "count" times to avoid excessive overhead from
+    // reading the clock.
     if (nfa_time_limit != NULL)
     {
-       if (tm_count == 800)
+       if (tm_count >= count)
        {
            if (profile_passed_limit(nfa_time_limit))
            {
                if (nfa_timed_out != NULL)
                    *nfa_timed_out = TRUE;
+               tm_count = 99999;
                return TRUE;
            }
            // Only reset the count when not timed out, so that when it did
@@ -5722,7 +5725,8 @@ nfa_regmatch(
     if (got_int)
        return FALSE;
 #ifdef FEAT_RELTIME
-    if (nfa_did_time_out())
+    // Check relatively often here, since this is the toplevel matching.
+    if (nfa_did_time_out(100))
        return FALSE;
 #endif
 
@@ -5876,12 +5880,9 @@ nfa_regmatch(
            if (got_int)
                break;
 #ifdef FEAT_RELTIME
-           if (nfa_time_limit != NULL && ++nfa_time_count == 20)
-           {
-               nfa_time_count = 0;
-               if (nfa_did_time_out())
-                   break;
-           }
+           // do not check very often here, since this is a loop in a loop
+           if (nfa_did_time_out(2000))
+               break;
 #endif
            t = &thislist->t[listidx];
 
@@ -7126,13 +7127,9 @@ nextchar:
        if (got_int)
            break;
 #ifdef FEAT_RELTIME
-       // Check for timeout once in a twenty times to avoid overhead.
-       if (nfa_time_limit != NULL && ++nfa_time_count == 20)
-       {
-           nfa_time_count = 0;
-           if (nfa_did_time_out())
-               break;
-       }
+       // check regularly but not too often here
+       if (nfa_did_time_out(800))
+           break;
 #endif
     }
 
@@ -7178,7 +7175,6 @@ nfa_regtry(
 #ifdef FEAT_RELTIME
     nfa_time_limit = tm;
     nfa_timed_out = timed_out;
-    nfa_time_count = 0;
 #endif
 
 #ifdef ENABLE_LOG

diff --git a/src/version.c b/src/version.c
index 0a090445ecd97ff0b04e00f41627c5718ebbe565..ff2ea1acdd2b8fa5ceb1a342f5942ef37dfb6ea3 100644 (file)
--- a/src/version.c
+++ b/src/version.c
@@ -734,6 +734,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    5036,
 /**/
     5035,
 /**/