gh-92356: Fix regression in ctypes function call overhead (#92357)

mdboom · web-flow · commit adcb6a6055c7 · 2022-05-05T20:59:45.000-07:00
38f331d introduced a delayed initialization routine to set up ctypes formattable (`_ctypes_init_fielddesc`), but inadvertently removed setting the `initialization` flag to 1 to avoid initting each time.
diff --git a/Misc/NEWS.d/next/Library/2022-05-05-19-25-09.gh-issue-92356.uvxWdu.rst b/Misc/NEWS.d/next/Library/2022-05-05-19-25-09.gh-issue-92356.uvxWdu.rst
@@ -0,0 +1 @@
+Fixed a performance regression in ctypes function calls.
diff --git a/Modules/_ctypes/cfield.c b/Modules/_ctypes/cfield.c
@@ -1602,6 +1602,7 @@ _ctypes_get_fielddesc(const char *fmt)
     struct fielddesc *table = formattable;
 
     if (!initialized) {
+        initialized = 1;
         _ctypes_init_fielddesc();
     }
 

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	`+Fixed a performance regression in ctypes function calls.`
Original file line number	Diff line number	Diff line change
`@@ -1602,6 +1602,7 @@ _ctypes_get_fielddesc(const char *fmt)`
`1602`	`1602`	`struct fielddesc *table = formattable;`
`1603`	`1603`
`1604`	`1604`	`if (!initialized) {`
	`1605`	`+ initialized = 1;`
`1605`	`1606`	`_ctypes_init_fielddesc();`
`1606`	`1607`	`}`
`1607`	`1608`