Issue #21116: Avoid blowing memory when allocating a multiprocessing shared
array that's larger than 50% of the available RAM.
Patch by Médéric Boquien.
diff --git a/Lib/multiprocessing/heap.py b/Lib/multiprocessing/heap.py
index 333b3ba..44d9638 100644
--- a/Lib/multiprocessing/heap.py
+++ b/Lib/multiprocessing/heap.py
@@ -71,7 +71,14 @@
os.unlink(name)
util.Finalize(self, os.close, (self.fd,))
with open(self.fd, 'wb', closefd=False) as f:
- f.write(b'\0'*size)
+ bs = 1024 * 1024
+ if size >= bs:
+ zeros = b'\0' * bs
+ for _ in range(size // bs):
+ f.write(zeros)
+ del zeros
+ f.write(b'\0' * (size % bs))
+ assert f.tell() == size
self.buffer = mmap.mmap(self.fd, self.size)
def reduce_arena(a):
diff --git a/Misc/ACKS b/Misc/ACKS
index 9a3de4e..d1074bd 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -154,6 +154,7 @@
Gawain Bolton
Forest Bond
Gregory Bond
+Médéric Boquien
Matias Bordese
Jonas Borgström
Jurjen Bos
diff --git a/Misc/NEWS b/Misc/NEWS
index 78db876..e4574a1 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -29,6 +29,9 @@
Library
-------
+- Issue #21116: Avoid blowing memory when allocating a multiprocessing shared
+ array that's larger than 50% of the available RAM. Patch by Médéric Boquien.
+
- Issue #22982: Improve BOM handling when seeking to multiple positions of
a writable text file.