diff --git a/setup/parallel_build.py b/setup/parallel_build.py
index 69140492a9..9c1a0bbaa9 100644
--- a/setup/parallel_build.py
+++ b/setup/parallel_build.py
@@ -6,20 +6,22 @@ __license__ = 'GPL v3'
 __copyright__ = '2014, Kovid Goyal <kovid at kovidgoyal.net>'
 
 import subprocess, os, itertools, json, sys
-from multiprocessing.dummy import Pool
+from multiprocessing.pool import ThreadPool as Pool
+from collections import namedtuple
 from threading import Thread
 from functools import partial
 from contextlib import closing
 
 from polyglot.builtins import unicode_type, as_bytes
+Job = namedtuple('Job', 'cmd human_text cwd')
 
 cpu_count = min(16, max(1, os.cpu_count()))
 
 
 def run_worker(job, decorate=True):
-    cmd, human_text = job
+    cmd, human_text = job.cmd, job.human_text
     human_text = human_text or ' '.join(cmd)
-    cwd = None
+    cwd = job.cwd
     if cmd[0].lower().endswith('cl.exe'):
         cwd = os.environ.get('COMPILER_CWD')
     try:
@@ -37,7 +39,7 @@ def run_worker(job, decorate=True):
     return ok, stdout, (stderr or '')
 
 
-def create_job(cmd, human_text=None):
+def create_job(cmd, human_text=None, cwd=None):
     return (cmd, human_text)
 
 
@@ -54,6 +56,18 @@ def parallel_build(jobs, log, verbose=True):
         return True
 
 
+def parallel_build_silent(jobs):
+    p = Pool(cpu_count)
+    results = []
+    failed = False
+    with closing(p):
+        for (ok, stdout, stderr), job in zip(p.imap(partial(run_worker, decorate=False), jobs), jobs):
+            results.append((ok, job.cmd, job.human_text, stdout, stderr))
+            if not ok:
+                failed = True
+    return failed, results
+
+
 def parallel_check_output(jobs, log):
     p = Pool(cpu_count)
     with closing(p):
@@ -67,7 +81,11 @@ def parallel_check_output(jobs, log):
             yield stdout
 
 
-def get_tasks(it, size):
+def get_tasks(it):
+    it = tuple(it)
+    size, extra = divmod(len(it), cpu_count)
+    if extra:
+        size += 1
     it = iter(it)
     while 1:
         x = tuple(itertools.islice(it, size))
@@ -77,15 +95,12 @@ def get_tasks(it, size):
 
 
 def batched_parallel_jobs(cmd, jobs, cwd=None):
-    chunksize, extra = divmod(len(jobs), cpu_count)
-    if extra:
-        chunksize += 1
     workers = []
 
     def get_output(p):
         p.output = p.communicate(as_bytes(json.dumps(p.jobs_batch)))
 
-    for batch in get_tasks(jobs, chunksize):
+    for batch in get_tasks(jobs):
         p = subprocess.Popen(cmd, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, cwd=cwd)
         p.jobs_batch = batch
         p.output_thread = t = Thread(target=get_output, args=(p,))
@@ -106,3 +121,13 @@ def batched_parallel_jobs(cmd, jobs, cwd=None):
     if failed:
         raise SystemExit('Worker process failed')
     return ans
+
+
+def threaded_func_jobs(func, jobs_args):
+
+    def f(args):
+        return func(*args)
+
+    p = Pool(cpu_count)
+    with closing(p):
+        return p.map(f, jobs_args)