[src/trunk]: src/usr.bin/make fix broken logic:

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/7a684ba0310e
branches:  trunk
changeset: 784706:7a684ba0310e
user:      christos <christos%NetBSD.org@localhost>
date:      Wed Feb 06 16:36:01 2013 +0000

description:
fix broken logic:
- poll can return EINTR, it is not restartable like read/write
- check poll return
- it does not make sense to check readyfd() is nready < 0
- check read return
- always call Job_CatchChildren, it is harmless
- short circuit scanning of the poll array if we got all the ready descriptors

diffstat:

 usr.bin/make/job.c |  57 +++++++++++++++++++++++++++++++++--------------------
 1 files changed, 35 insertions(+), 22 deletions(-)

diffs (104 lines):

diff -r 3371f54e1ded -r 7a684ba0310e usr.bin/make/job.c
--- a/usr.bin/make/job.c        Wed Feb 06 09:33:16 2013 +0000
+++ b/usr.bin/make/job.c        Wed Feb 06 16:36:01 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: job.c,v 1.168 2013/02/02 15:24:08 christos Exp $       */
+/*     $NetBSD: job.c,v 1.169 2013/02/06 16:36:01 christos Exp $       */
 
 /*
  * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
@@ -70,14 +70,14 @@
  */
 
 #ifndef MAKE_NATIVE
-static char rcsid[] = "$NetBSD: job.c,v 1.168 2013/02/02 15:24:08 christos Exp $";
+static char rcsid[] = "$NetBSD: job.c,v 1.169 2013/02/06 16:36:01 christos Exp $";
 #else
 #include <sys/cdefs.h>
 #ifndef lint
 #if 0
 static char sccsid[] = "@(#)job.c      8.2 (Berkeley) 3/19/94";
 #else
-__RCSID("$NetBSD: job.c,v 1.168 2013/02/02 15:24:08 christos Exp $");
+__RCSID("$NetBSD: job.c,v 1.169 2013/02/06 16:36:01 christos Exp $");
 #endif
 #endif /* not lint */
 #endif
@@ -139,6 +139,7 @@
 #include <sys/time.h>
 #include <sys/wait.h>
 
+#include <assert.h>
 #include <errno.h>
 #include <fcntl.h>
 #ifndef USE_SELECT
@@ -2040,38 +2041,50 @@
 {
     int nready;
     Job *job;
-    int i, n;
+    int i;
 
     (void)fflush(stdout);
 
     /* The first fd in the list is the job token pipe */
-    nready = poll(fds + 1 - wantToken, nfds - 1 + wantToken, POLL_MSEC);
+    do {
+       nready = poll(fds + 1 - wantToken, nfds - 1 + wantToken, POLL_MSEC);
+    } while (nready < 0 && errno == EINTR);
 
-    if (nready < 0 || readyfd(&childExitJob)) {
+    if (nready < 0)
+       Punt("poll: %s", strerror(errno));
+
+    if (nready > 0 && readyfd(&childExitJob)) {
        char token = 0;
-       nready -= 1;
-       for (n = 0; n < 5 &&
-           read(childExitJob.inPipe, &token, 1) == -1 && errno == EAGAIN; n++)
-               continue;
-       if (token == DO_JOB_RESUME[0])
-           /* Complete relay requested from our SIGCONT handler */
-           JobRestartJobs();
-       Job_CatchChildren();
+       ssize_t count;
+       count = read(childExitJob.inPipe, &token, 1);
+       switch (count) {
+       case 0:
+           Punt("unexpected eof on token pipe");
+       case -1:
+           Punt("token pipe read: %s", strerror(errno));
+       case 1:
+           if (token == DO_JOB_RESUME[0])
+               /* Complete relay requested from our SIGCONT handler */
+               JobRestartJobs();
+           break;
+       default:
+           abort();
+       }
+       --nready;
     }
 
-    if (nready <= 0)
-       return;
-
-    if (wantToken && readyfd(&tokenWaitJob))
-       nready--;
+    Job_CatchChildren();
+    if (nready == 0)
+           return;
 
     for (i = 2; i < nfds; i++) {
        if (!fds[i].revents)
            continue;
        job = jobfds[i];
-       if (job->job_state != JOB_ST_RUNNING)
-           continue;
-       JobDoOutput(job, FALSE);
+       if (job->job_state == JOB_ST_RUNNING)
+           JobDoOutput(job, FALSE);
+       if (--nready == 0)
+               return;
     }
 }