From 618d56c7ac8bd8cd701344a0eaca8373a78dea95 Mon Sep 17 00:00:00 2001

From: Martin Wilck <mwilck@suse.com>

Date: Mon, 23 Apr 2018 21:59:05 +0200

Subject: [PATCH] test/udev-test.pl: allow concurrent additions and removals

Allow testing cases where multiple devices are added and removed

simultaneously. Tests are started as synchronously as possible using a

semaphore, in order to test possible race conditions. If this isn't desired,

the test parameter "sleep_us" can be set to the number of microseconds to wait

between udev invocations.

(cherry picked from commit 09a4062d70b3a10d022e40066e2adf09df05bbbc)

Related: #1642728

---

 test/udev-test.pl | 90 +++++++++++++++++++++++++++++++++++++----------

 1 file changed, 72 insertions(+), 18 deletions(-)

diff --git a/test/udev-test.pl b/test/udev-test.pl

index 8b5a97ad61..db25ef13c1 100755

--- a/test/udev-test.pl

+++ b/test/udev-test.pl

@@ -18,6 +18,10 @@

 use warnings;

 use strict;

+use POSIX qw(WIFEXITED WEXITSTATUS);

+use IPC::SysV qw(IPC_PRIVATE S_IRUSR S_IWUSR IPC_CREAT);

+use IPC::Semaphore;

+use Time::HiRes qw(usleep);

 my $udev_bin            = "./test-udev";

 my $valgrind            = 0;

@@ -2210,6 +2214,8 @@ sub check_add {

                         sleep(1);

                 }

         }

+

+        print "device \'$device->{devpath}\' expecting node/link \'$device->{exp_name}\'\n";

         if ((-e "$udev_dev/$device->{exp_name}") ||

             (-l "$udev_dev/$device->{exp_name}")) {

@@ -2257,21 +2263,72 @@ sub check_remove {

         }

 }

+sub run_udev {

+        my ($action, $dev, $sleep_us, $sema) = @_;

+

+        # Notify main process that this worker has started

+        $sema->op(0, 1, 0);

+

+        # Wait for start

+        $sema->op(0, 0, 0);

+        usleep($sleep_us) if defined ($sleep_us);

+        my $rc = udev($action, $dev->{devpath});

+        exit $rc;

+}

+

+sub fork_and_run_udev {

+        my ($action, $rules, $sema) = @_;

+        my @devices = @{$rules->{devices}};

+        my $dev;

+        my $k = 0;

+

+        $sema->setval(0, 1);

+        foreach $dev (@devices) {

+                my $pid = fork();

+

+                if (!$pid) {

+                        run_udev($action, $dev,

+                                 defined($rules->{sleep_us}) ? $k * $rules->{sleep_us} : undef,

+                                 $sema);

+                } else {

+                        $dev->{pid} = $pid;

+                }

+                $k++;

+        }

+

+        # This operation waits for all workers to become ready, and

+        # starts them off when that's the case.

+        $sema->op(0, -($#devices + 2), 0);

+

+        foreach $dev (@devices) {

+                my $rc;

+                my $pid;

+

+                $pid = waitpid($dev->{pid}, 0);

+                if ($pid == -1) {

+                        print "error waiting for pid dev->{pid}\n";

+                        $error += 1;

+                }

+                if (WIFEXITED($?)) {

+                        $rc = WEXITSTATUS($?);

+

+                        if ($rc) {

+                                print "$udev_bin $action for $dev->{devpath} failed with code $rc\n";

+                                $error += 1;

+                        }

+                }

+        }

+}

+

 sub run_test {

-        my ($rules, $number) = @_;

+        my ($rules, $number, $sema) = @_;

         my $rc;

         my @devices = @{$rules->{devices}};

         print "TEST $number: $rules->{desc}\n";

         create_rules(\$rules->{rules});

-        foreach my $dev (@devices) {

-                print "device \'$dev->{devpath}\' expecting node/link \'$dev->{exp_name}\'\n";

-                $rc = udev("add", $dev->{devpath});

-                if ($rc != 0) {

-                        print "$udev_bin add failed with code $rc\n";

-                        $error++;

-                }

-        }

+

+        fork_and_run_udev("add", $rules, $sema);

         foreach my $dev (@devices) {

                 check_add($dev);

@@ -2282,13 +2339,8 @@ sub run_test {

                 return;

         }

-        foreach my $dev (@devices) {

-                $rc = udev("remove", $dev->{devpath});

-                if ($rc != 0) {

-                        print "$udev_bin remove failed with code $rc\n";

-                        $error++;

-                }

-        }

+        fork_and_run_udev("remove", $rules, $sema);

+

         foreach my $dev (@devices) {

                 check_remove($dev);

         }

@@ -2350,12 +2402,13 @@ foreach my $arg (@ARGV) {

                 push(@list, $arg);

         }

 }

+my $sema = IPC::Semaphore->new(IPC_PRIVATE, 1, S_IRUSR | S_IWUSR | IPC_CREAT);

 if ($list[0]) {

         foreach my $arg (@list) {

                 if (defined($tests[$arg-1]->{desc})) {

                         print "udev-test will run test number $arg:\n\n";

-                        run_test($tests[$arg-1], $arg);

+                        run_test($tests[$arg-1], $arg, $sema);

                 } else {

                         print "test does not exist.\n";

                 }

@@ -2365,11 +2418,12 @@ if ($list[0]) {

         print "\nudev-test will run ".($#tests + 1)." tests:\n\n";

         foreach my $rules (@tests) {

-                run_test($rules, $test_num);

+                run_test($rules, $test_num, $sema);

                 $test_num++;

         }

 }

+$sema->remove;

 print "$error errors occurred\n\n";

 cleanup();