我正在尝试在异步环境中模拟同步控制流。
目的是在没有回调或请求阻塞的情况下支持数据库请求。
我正在尝试使用 Coro
模块,但我想我没有完全理解它。
代码片段如下:
sub execute {
my ($sth, @vars) = @_;
my $res = $sth->SUPER::execute(@vars);
my $dbh = $sth->{Database};
my $async = new Coro::State;
my $new;
$new = new Coro::State sub {
my $w;
while (!$dbh->pg_ready) {
$w = AnyEvent->io(
fh => $dbh->{pg_socket},
poll => 'r',
cb => sub {
if($dbh->pg_ready) {
$w = undef;
$new->transfer($async);
}
}
) if not $w;
print "run once before statement: $sth->{Statement}\n";
EV::run EV::RUN_ONCE;
}
};
$async->transfer($new);
$res = $dbh->pg_result;
$res;
}
测试代码如下:
my $cv = AE::cv;
ok(my $dbh = db_connect(), 'connected');
ok(my $sth = $dbh->prepare('select pg_sleep(2)'), 'prepared');
my $start_time = time;
ok($sth->execute(), 'executed');
my $duration = time - $start_time;
ok(($duration > 1 && $duration < 3), 'slept');
is(ref($dbh), 'DBIx::PgCoroAnyEvent::db', 'dbh class');
is(ref($sth), 'DBIx::PgCoroAnyEvent::st', 'sth class');
my $status = 0;
my $finished = 0;
for my $t (1 .. 10) {
$finished += 1 << $t;
}
for my $t (1 .. 10) {
my $timer;
$timer = AE::timer 0.01 + $t/100, 0, sub {
ok(my $dbh = db_connect(), "connected $t");
ok(my $sth = $dbh->prepare('select pg_sleep(' . $t . ')'), "prepared $t");
my $start_time = time;
ok($sth->execute(), "executed $t");
my $duration = time - $start_time;
ok(($duration > $t - 1 && $duration < $t + 1), "slept $t");
print "duration: $t: $duration\n";
$status += 1 << $t;
if ($status == $finished) {
$cv->send;
}
undef $timer;
};
}
$cv->recv;
完整的模块和测试脚本在这里 DBIx::PgCoroAnyEvent
在这里 01_sleeps.t
谁能帮我看看哪里出了问题?
最佳答案
eval+die 是 Perl 中的典型方法。
eval { some_function( @args ); };
if( $@ ){
# caught longjmp
}
...
sub some_function {
...
if( some_condition ){
die "throw longjmp"
}
...
}
关于perl - 是否有可能在 EV 回调中使用 Perl 进行 longjump 之类的操作?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/38028943/