1 files changed, 61 insertions, 0 deletions
diff --git a/examples/parallel_bars.py b/examples/parallel_bars.py
new file mode 100644
index 0000000..498fd61
--- /dev/null
+++ b/examples/parallel_bars.py
@@ -0,0 +1,61 @@
+from __future__ import print_function
+
+import sys
+from concurrent.futures import ThreadPoolExecutor
+from functools import partial
+from multiprocessing import Pool, RLock, freeze_support
+from random import random
+from threading import RLock as TRLock
+from time import sleep
+
+from tqdm.auto import tqdm, trange
+from tqdm.contrib.concurrent import process_map, thread_map
+
+NUM_SUBITERS = 9
+PY2 = sys.version_info[:1] <= (2,)
+
+
+def progresser(n, auto_position=True, write_safe=False, blocking=True, progress=False):
+    interval = random() * 0.002 / (NUM_SUBITERS - n + 2)  # nosec
+    total = 5000
+    text = "#{0}, est. {1:<04.2}s".format(n, interval * total)
+    for _ in trange(total, desc=text, disable=not progress,
+                    lock_args=None if blocking else (False,),
+                    position=None if auto_position else n):
+        sleep(interval)
+    # NB: may not clear instances with higher `position` upon completion
+    # since this worker may not know about other bars #796
+    if write_safe:
+        # we think we know about other bars (currently only py3 threading)
+        if n == 6:
+            tqdm.write("n == 6 completed")
+    return n + 1
+
+
+if __name__ == '__main__':
+    freeze_support()  # for Windows support
+    L = list(range(NUM_SUBITERS))[::-1]
+
+    print("Simple thread mapping")
+    thread_map(partial(progresser, write_safe=not PY2), L, max_workers=4)
+
+    print("Simple process mapping")
+    process_map(partial(progresser), L, max_workers=4)
+
+    print("Manual nesting")
+    for i in trange(16, desc="1"):
+        for _ in trange(16, desc="2 @ %d" % i, leave=i % 2):
+            sleep(0.01)
+
+    print("Multi-processing")
+    tqdm.set_lock(RLock())
+    p = Pool(initializer=tqdm.set_lock, initargs=(tqdm.get_lock(),))
+    p.map(partial(progresser, progress=True), L)
+
+    print("Multi-threading")
+    tqdm.set_lock(TRLock())
+    pool_args = {}
+    if not PY2:
+        pool_args.update(initializer=tqdm.set_lock, initargs=(tqdm.get_lock(),))
+    with ThreadPoolExecutor(**pool_args) as p:
+        p.map(partial(progresser, progress=True, write_safe=not PY2, blocking=False), L)