[3.9] bpo-44145: Release the GIL around HMAC_Update. (GH-26157) (GH-26188)

miss-islington · web-flow · commit 2057ce87498f · 2021-05-17T01:07:49.000-07:00
It was always meant to be released for parallelization. This now matches the other similar code in the module. Thanks michaelforney for noticing! (cherry picked from commit c10392e) Co-authored-by: Gregory P. Smith <greg@krypto.org> Automerge-Triggered-By: GH:gpshead
diff --git a/Misc/NEWS.d/next/Library/2021-05-16-00-00-38.bpo-44145.ko5SJ7.rst b/Misc/NEWS.d/next/Library/2021-05-16-00-00-38.bpo-44145.ko5SJ7.rst
@@ -0,0 +1,3 @@
+:mod:`hmac` computations were not releasing the GIL while calling the
+OpenSSL ``HMAC_Update`` C API (a new feature in 3.9).  This unintentionally
+prevented parallel computation as other :mod:`hashlib` algorithms support.
diff --git a/Modules/_hashopenssl.c b/Modules/_hashopenssl.c
@@ -1496,9 +1496,11 @@ _hmac_update(HMACobject *self, PyObject *obj)
     }
 
     if (self->lock != NULL) {
-        ENTER_HASHLIB(self);
+        Py_BEGIN_ALLOW_THREADS
+        PyThread_acquire_lock(self->lock, 1);
         r = HMAC_Update(self->ctx, (const unsigned char*)view.buf, view.len);
-        LEAVE_HASHLIB(self);
+        PyThread_release_lock(self->lock);
+        Py_END_ALLOW_THREADS
     } else {
         r = HMAC_Update(self->ctx, (const unsigned char*)view.buf, view.len);
     }

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	+:mod:`hmac` computations were not releasing the GIL while calling the
	`2`	+OpenSSL ``HMAC_Update`` C API (a new feature in 3.9). This unintentionally
	`3`	+prevented parallel computation as other :mod:`hashlib` algorithms support.
Original file line number	Diff line number	Diff line change
`@@ -1496,9 +1496,11 @@ _hmac_update(HMACobject self, PyObject obj)`
`1496`	`1496`	`}`
`1497`	`1497`
`1498`	`1498`	`if (self->lock != NULL) {`
`1499`		`- ENTER_HASHLIB(self);`
	`1499`	`+ Py_BEGIN_ALLOW_THREADS`
	`1500`	`+ PyThread_acquire_lock(self->lock, 1);`
`1500`	`1501`	`r = HMAC_Update(self->ctx, (const unsigned char*)view.buf, view.len);`
`1501`		`- LEAVE_HASHLIB(self);`
	`1502`	`+ PyThread_release_lock(self->lock);`
	`1503`	`+ Py_END_ALLOW_THREADS`
`1502`	`1504`	`} else {`
`1503`	`1505`	`r = HMAC_Update(self->ctx, (const unsigned char*)view.buf, view.len);`
`1504`	`1506`	`}`