summaryrefslogtreecommitdiff
path: root/libguile/numbers.c
diff options
context:
space:
mode:
authorAndy Wingo <wingo@pobox.com>2011-12-02 11:22:46 +0100
committerAndy Wingo <wingo@pobox.com>2011-12-02 11:57:25 +0100
commitb57bf2724a254cf73e255b3d2bca0a7dcad6674a (patch)
tree3cd2f3db68ebc8e81d8cbcb77cbec76abbf0253e /libguile/numbers.c
parent738c899e4c1ab9d25cfbcd1010f34e0cce400bca (diff)
downloadguile-b57bf2724a254cf73e255b3d2bca0a7dcad6674a.tar.gz
install gmp memory functions that let libgc know about allocations
* libguile/numbers.c (custom_gmp_malloc, custom_gmp_realloc, custom_gmp_free): New static functions used by GMP for allocation. These are just wrappers for scm_malloc, scm_realloc, and free. (scm_init_numbers): If scm_install_gmp_memory_functions is nonzero, use mp_set_memory_functions to configure GMP to use custom_gmp_{malloc,realloc,free} for memory allocation. (scm_bigprint): Ask gmp for the function used to deallocate the string returned by mpz_get_str. * libguile/numbers.h: Declare scm_install_gmp_memory_functions. * libguile/guile.c: When running the Guile binary, install the gmp_memory_functions. Based on a patch by Mark H Weaver <mhw@netris.org>.
Diffstat (limited to 'libguile/numbers.c')
-rw-r--r--libguile/numbers.c42
1 files changed, 40 insertions, 2 deletions
diff --git a/libguile/numbers.c b/libguile/numbers.c
index e34c60ef3..e5b4ed938 100644
--- a/libguile/numbers.c
+++ b/libguile/numbers.c
@@ -114,6 +114,10 @@ typedef scm_t_signed_bits scm_t_inum;
/* the macro above will not work as is with fractions */
+/* Default to 1, because as we used to hard-code `free' as the
+ deallocator, we know that overriding these functions with
+ instrumented `malloc' / `free' is OK. */
+int scm_install_gmp_memory_functions = 1;
static SCM flo0;
static SCM exactly_one_half;
static SCM flo_log10e;
@@ -172,6 +176,7 @@ scm_from_complex_double (complex double z)
static mpz_t z_negative_one;
+
/* Clear the `mpz_t' embedded in bignum PTR. */
static void
finalize_bignum (GC_PTR ptr, GC_PTR data)
@@ -182,6 +187,31 @@ finalize_bignum (GC_PTR ptr, GC_PTR data)
mpz_clear (SCM_I_BIG_MPZ (bignum));
}
+/* The next three functions (custom_libgmp_*) are passed to
+ mp_set_memory_functions (in GMP) so that memory used by the digits
+ themselves is known to the garbage collector. This is needed so
+ that GC will be run at appropriate times. Otherwise, a program which
+ creates many large bignums would malloc a huge amount of memory
+ before the GC runs. */
+static void *
+custom_gmp_malloc (size_t alloc_size)
+{
+ return scm_malloc (alloc_size);
+}
+
+static void *
+custom_gmp_realloc (void *old_ptr, size_t old_size, size_t new_size)
+{
+ return scm_realloc (old_ptr, new_size);
+}
+
+static void
+custom_gmp_free (void *ptr, size_t size)
+{
+ free (ptr);
+}
+
+
/* Return a new uninitialized bignum. */
static inline SCM
make_bignum (void)
@@ -5368,9 +5398,12 @@ int
scm_bigprint (SCM exp, SCM port, scm_print_state *pstate SCM_UNUSED)
{
char *str = mpz_get_str (NULL, 10, SCM_I_BIG_MPZ (exp));
+ size_t len = strlen (str);
+ void (*freefunc) (void *, size_t);
+ mp_get_memory_functions (NULL, NULL, &freefunc);
scm_remember_upto_here_1 (exp);
- scm_lfwrite (str, (size_t) strlen (str), port);
- free (str);
+ scm_lfwrite (str, len, port);
+ freefunc (str, len + 1);
return !0;
}
/*** END nums->strs ***/
@@ -9688,6 +9721,11 @@ scm_init_numbers ()
{
int i;
+ if (scm_install_gmp_memory_functions)
+ mp_set_memory_functions (custom_gmp_malloc,
+ custom_gmp_realloc,
+ custom_gmp_free);
+
mpz_init_set_si (z_negative_one, -1);
/* It may be possible to tune the performance of some algorithms by using