Use more elements for tests, and run travis tests one at a time.

.travis.yml

@@ -7,7 +7,7 @@ before_script:
 script:
   - |
       travis-cargo build &&
-      travis-cargo test &&
+      RUST_TEST_THREADS=1 travis-cargo test &&
       travis-cargo bench &&
       travis-cargo doc
 after_success:

tests/for_.rs

@@ -2,12 +2,12 @@ extern crate simple_parallel;
 
 use std::sync::atomic::{AtomicUsize, ATOMIC_USIZE_INIT, Ordering};
 
+// with this many elements, its (hopefully) likely that the
+// threads won't execute sequentially.
+const N: usize = 10000;
+
 #[test]
 fn probabilistic_out_of_ordering() {
-    // with this many elements, its (hopefully) likely that the
-    // threads won't execute sequentially.
-    const N: usize = 1000;
-
     let mut index = (0..N).map(|_| 0).collect::<Vec<_>>();
 
     static ORDER: AtomicUsize = ATOMIC_USIZE_INIT;
@@ -23,9 +23,6 @@ fn probabilistic_out_of_ordering() {
 #[test]
 fn pool() {
     let mut pool = simple_parallel::Pool::new(8);
-    // with this many elements, its (hopefully) likely that the
-    // threads won't execute sequentially.
-    const N: usize = 1000;
 
     let mut index = (0..N).map(|_| 0usize).collect::<Vec<_>>();
 

tests/map.rs

@@ -1,12 +1,12 @@
 #![feature(core)]
 extern crate simple_parallel;
 
+// with this many elements, its (hopefully) likely that the
+// threads won't execute sequentially.
+const N: usize = 10000;
+
 #[test]
 fn unordered_map_probabilistic_out_of_ordering() {
-    // with this many elements, its (hopefully) likely that the
-    // threads won't execute sequentially.
-    const N: usize = 1000;
-
     let f = |_: usize| ();
     let iter = simple_parallel::unordered_map(0..N, &f);
 
@@ -18,10 +18,6 @@ fn unordered_map_probabilistic_out_of_ordering() {
 
 #[test]
 fn map_in_order() {
-    // with this many elements, its (hopefully) likely that the
-    // threads won't execute sequentially.
-    const N: usize = 1000;
-
     let f = |i: usize| i;
     let iter = simple_parallel::map(0..N, &f);
 
@@ -33,10 +29,6 @@ fn map_in_order() {
 fn pool_unordered() {
     let mut pool = simple_parallel::Pool::new(8);
 
-    // with this many elements, its (hopefully) likely that the
-    // threads won't execute sequentially.
-    const N: usize = 1000;
-
     let f = |_: usize| {};
     let iter = pool.unordered_map(0..N, &f);
 
@@ -52,10 +44,6 @@ fn pool_unordered() {
 fn pool_map_in_order() {
     let mut pool = simple_parallel::Pool::new(8);
 
-    // with this many elements, its (hopefully) likely that the
-    // threads won't execute sequentially.
-    const N: usize = 1000;
-
     let f = |i: usize| i;
     let iter = pool.map(0..N, &f);