From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Fri, 3 Oct 2014 20:43:39 +0000 (+0100)
Subject: poll: Avoid duplicate array index counting
X-Git-Tag: proposed.polypath.v4~55
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=secnet.git;a=commitdiff_plain;h=d613fd78298a9911b7917c06f3ea11de45462e76

poll: Avoid duplicate array index counting

Calculate remain from idx at the top of the loop.  This avoids having
to keep both remain and idx in step.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---

diff --git a/secnet.c b/secnet.c
index 7a9d3f0..6d08323 100644
--- a/secnet.c
+++ b/secnet.c
@@ -291,7 +291,7 @@ uint64_t now_global;
 static void run(void)
 {
     struct poll_interest *i;
-    int rv, nfds, remain, idx;
+    int rv, nfds, idx;
     int timeout;
     struct pollfd *fds=0;
     int allocdfds=0, shortfall=0;
@@ -320,11 +320,11 @@ static void run(void)
 	    allocdfds += shortfall;
 	    fds=safe_realloc_ary(fds,sizeof(*fds),allocdfds, "run");
 	}
-	remain=allocdfds;
 	shortfall=0;
 	idx=0;
 	timeout=-1;
 	LIST_FOREACH(i, &reg, entry) {
+	    int remain=allocdfds-idx;
 	    nfds=remain;
 	    rv=i->before(i->state, fds+idx, &nfds, &timeout);
 	    if (rv!=0) {
@@ -340,7 +340,6 @@ static void run(void)
 		      i->desc,timeout);
 	    }
 	    idx+=nfds;
-	    remain-=nfds;
 	    i->nfds=nfds;
 	}
 	do {