28 lines
535 B
Perl
28 lines
535 B
Perl
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use Thread;
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$level = 0;
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sub worker
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{
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my $num = shift;
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my $i;
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print "thread $num starting\n";
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for ($i = 1; $i <= 20; $i++) {
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print "thread $num iteration $i\n";
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select(undef, undef, undef, rand(10)/100);
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{
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lock($lock);
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warn "thread $num saw non-zero level = $level\n" if $level;
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$level++;
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print "thread $num has lock\n";
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select(undef, undef, undef, rand(10)/100);
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$level--;
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}
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print "thread $num released lock\n";
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}
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}
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for ($t = 1; $t <= 5; $t++) {
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new Thread \&worker, $t;
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}
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