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author | Andy Wingo <wingo@pobox.com> | 2011-12-02 11:22:46 +0100 |
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committer | Andy Wingo <wingo@pobox.com> | 2011-12-02 11:57:25 +0100 |
commit | b57bf2724a254cf73e255b3d2bca0a7dcad6674a (patch) | |
tree | 3cd2f3db68ebc8e81d8cbcb77cbec76abbf0253e /libguile/numbers.c | |
parent | 738c899e4c1ab9d25cfbcd1010f34e0cce400bca (diff) | |
download | guile-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.c | 42 |
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 |