libcore: Use 4x the number of scheduler threads for testing

An arbitrary number. I've done no measurements but it's intended to overcome
the effects of tasks randomly being scheduled to threads and no work stealing.

If scheduler threads == 1 then we just use a single test task.

1 files changed, 5 insertions, 1 deletions

diff --git a/src/libstd/test.rs b/src/libstd/test.rs
index 88601ebb19e..7fc63c015ee 100644
--- a/src/libstd/test.rs
+++ b/src/libstd/test.rs
@@ -227,7 +227,11 @@ fn run_tests(opts: test_opts, tests: [test_desc],
     }
 }
 
-fn get_concurrency() -> uint { rustrt::sched_threads() }
+fn get_concurrency() -> uint {
+    let threads = rustrt::sched_threads();
+    if threads == 1u { 1u }
+    else { threads * 4u }
+}
 
 fn filter_tests(opts: test_opts,
                 tests: [test_desc]) -> [test_desc] {