Move the Bigint freelist to _PyRuntimeState.

ericsnowcurrently · Nov 15, 2022 · Nov 14, 2022 · Nov 14, 2022 · Nov 14, 2022 · Nov 14, 2022
commit c7e4333177e9a2fd1d08c6990a9da23124b655a9
diff --git a/Include/internal/pycore_dtoa.h b/Include/internal/pycore_dtoa.h
@@ -1,3 +1,5 @@
+#ifndef Py_INTERNAL_DTOA_H
+#define Py_INTERNAL_DTOA_H
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -11,6 +13,21 @@ extern "C" {
 
 #if _PY_SHORT_FLOAT_REPR == 1
 
+typedef uint32_t ULong;
+
+struct
+Bigint {
+    struct Bigint *next;
+    int k, maxwds, sign, wds;
+    ULong x[1];
+};
+
+#ifndef Py_USING_MEMORY_DEBUGGER
+/* The size of the Bigint freelist */
+# define Bigint_Kmax 7
+#endif
+
+
 /* These functions are used by modules compiled as C extension like math:
    they must be exported. */
 
@@ -26,3 +43,4 @@ PyAPI_FUNC(double) _Py_dg_infinity(int sign);
 #ifdef __cplusplus
 }
 #endif
+#endif /* !Py_INTERNAL_DTOA_H */
@@ -9,6 +9,7 @@ extern "C" {
 #endif
 
 #include "pycore_atomic.h"          /* _Py_atomic_address */
+#include "pycore_dtoa.h"            // struct Bigint
 #include "pycore_gil.h"             // struct _gil_runtime_state
 #include "pycore_global_objects.h"  // struct _Py_global_objects
 #include "pycore_import.h"          // struct _import_runtime_state
@@ -128,6 +129,11 @@ typedef struct pyruntimestate {
     struct {
         struct _PyTraceMalloc_Config config;
     } tracemalloc;
+    struct {
+#ifndef Py_USING_MEMORY_DEBUGGER
+        struct Bigint *freelist[Bigint_Kmax+1];
+#endif
+    } dtoa;
 
     PyPreConfig preconfig;
 

diff --git a/Python/dtoa.c b/Python/dtoa.c
@@ -119,6 +119,7 @@
 
 #include "Python.h"
 #include "pycore_dtoa.h"          // _PY_SHORT_FLOAT_REPR
+#include "pycore_runtime.h"       // _PyRuntime
 #include <stdlib.h>               // exit()
 
 /* if _PY_SHORT_FLOAT_REPR == 0, then don't even try to compile
@@ -156,7 +157,7 @@
 #endif
 
 
-typedef uint32_t ULong;
+// ULong is defined in pycore_dtoa.h.
 typedef int32_t Long;
 typedef uint64_t ULLong;
 
@@ -298,8 +299,6 @@ BCinfo {
 
 #define FFFFFFFF 0xffffffffUL
 
-#define Kmax 7
-
 /* struct Bigint is used to represent arbitrary-precision integers.  These
    integers are stored in sign-magnitude format, with the magnitude stored as
    an array of base 2**32 digits.  Bigints are always normalized: if x is a
@@ -322,13 +321,7 @@ BCinfo {
        significant (x[0]) to most significant (x[wds-1]).
 */
 
-struct
-Bigint {
-    struct Bigint *next;
-    int k, maxwds, sign, wds;
-    ULong x[1];
-};
-
+// struct Bigint is defined in pycore_dtoa.h.
 typedef struct Bigint Bigint;
 
 #ifndef Py_USING_MEMORY_DEBUGGER
@@ -352,7 +345,7 @@ typedef struct Bigint Bigint;
    Bfree to PyMem_Free.  Investigate whether this has any significant
    performance on impact. */
 
-static Bigint *freelist[Kmax+1];
+#define freelist _PyRuntime.dtoa.freelist
 
 /* Allocate space for a Bigint with up to 1<<k digits */
 
@@ -363,13 +356,15 @@ Balloc(int k)
     Bigint *rv;
     unsigned int len;
 
-    if (k <= Kmax && (rv = freelist[k]))
+    if (k <= Bigint_Kmax && (rv = freelist[k]))
         freelist[k] = rv->next;
     else {
         x = 1 << k;
         len = (sizeof(Bigint) + (x-1)*sizeof(ULong) + sizeof(double) - 1)
             /sizeof(double);
-        if (k <= Kmax && pmem_next - private_mem + len <= (Py_ssize_t)PRIVATE_mem) {
+        if (k <= Bigint_Kmax &&
+            pmem_next - private_mem + len <= (Py_ssize_t)PRIVATE_mem
+        ) {
             rv = (Bigint*)pmem_next;
             pmem_next += len;
         }
@@ -391,7 +386,7 @@ static void
 Bfree(Bigint *v)
 {
     if (v) {
-        if (v->k > Kmax)
+        if (v->k > Bigint_Kmax)
             FREE((void*)v);
         else {
             v->next = freelist[v->k];
@@ -400,6 +395,8 @@ Bfree(Bigint *v)
     }
 }
 
+#undef freelist
+
 #else
 
 /* Alternative versions of Balloc and Bfree that use PyMem_Malloc and

@@ -325,7 +325,6 @@ Objects/unicodeobject.c	-	ucnhash_capi	-
 # state
 
 # pre-allocated memory
-Python/dtoa.c	-	freelist	-
 Python/dtoa.c	-	private_mem	-
 
 # local buffer