multi-threaded replset with durability test, requires V8 in mongo shell

1 files changed, 30 insertions, 0 deletions

diff --git a/jstests/libs/concurrent.js b/jstests/libs/concurrent.js
new file mode 100644
index 00000000000..d5db7fb94ad
--- /dev/null
+++ b/jstests/libs/concurrent.js
@@ -0,0 +1,30 @@
+/* NOTE: Request mongo shell to be built with V8 javascript engine,
+which implements concurrent threads via fork() */
+
+// Fork and start
+function fork_(thunk) {
+    thread = fork(thunk)
+    thread.start()
+    return thread
+}
+
+// In functional form, useful for high-order functions like map in fun.js
+function join_(thread) {thread.join()}
+
+// Fork a loop on each one-arg block and wait for all of them to terminate. Foreground blocks are executed n times, background blocks are executed repeatedly until all forground loops finish. If any fail, stop all loops and reraise exception in main thread
+function parallel(n, foregroundBlock1s, backgroundBlock1s) {
+    var err = null
+    var stop = false
+    function loop(m) {return function(block1) {return function() {
+        for (var i = 0; i < m; i++) {if (stop) break; block1(i)} }}}
+    function watch(block) {return function() {
+        try {block()} catch(e) {err = e; stop = true}}}
+    foreThunks = map(watch, map(loop(n), foregroundBlock1s))
+    backThunks = map(watch, map(loop(Infinity), backgroundBlock1s))
+    foreThreads = map(fork_, foreThunks)
+    backThreads = map(fork_, backThunks)
+    map(join_, foreThreads)
+    stop = true
+    map(join_, backThreads)
+    if (err != null) throw err
+}