Monkey-patch default(parisize) and default(parisizemax)

Author: jdemeyer

cypari2/handle_error.pyx

@@ -221,6 +221,12 @@ cdef void _pari_err_recover(long errnum):
     """
     reset_avma()
 
+    # Special case errnum == -1 corresponds to a reallocation of the
+    # PARI stack. This is not an error, so just proceed as if nothing
+    # happened.
+    if errnum < 0:
+        return
+
     # An exception was raised.  Jump to the signal-handling code
     # which will cause sig_on() to see the exception.
     sig_error()

cypari2/pari_instance.pyx

@@ -254,6 +254,17 @@ PARI stack size set to 8000000 bytes, maximum size set to ...
 ...         pari.binomial(2**100, 2**22)
 ...     except AlarmInterrupt:
 ...         pass
+
+Test that changing the stack size using ``default`` works properly:
+
+>>> pari.default("parisizemax", 2**23)
+>>> pari = cypari2.Pari()  # clear stack
+>>> a = pari(1)
+>>> pari.default("parisizemax", 2**29)
+>>> a + a
+2
+>>> pari.default("parisizemax")
+536870912
 """
 
 #*****************************************************************************
@@ -270,7 +281,7 @@ import sys
 from libc.stdio cimport *
 cimport cython
 
-from cysignals.signals cimport sig_check, sig_on, sig_off
+from cysignals.signals cimport sig_check, sig_on, sig_off, sig_error
 
 from .string_utils cimport to_string, to_bytes
 from .paridecl cimport *
@@ -522,6 +533,14 @@ cdef class Pari(Pari_auto):
         global factor_proven
         factor_proven = 1
 
+        # Monkey-patch default(parisize) and default(parisizemax)
+        ep = pari_is_default("parisize")
+        if ep:
+            ep.value = <void*>patched_parisize
+        ep = pari_is_default("parisizemax")
+        if ep:
+            ep.value = <void*>patched_parisizemax
+
     def __init__(self, size_t size=8000000, size_t sizemax=0, unsigned long maxprime=500000):
         """
         (Re)-Initialize the PARI system.
@@ -1385,6 +1404,25 @@ cdef long get_var(v) except -2:
     return varno
 
 
+# Monkey-patched versions of default(parisize) and default(parisizemax).
+# We need to call move_gens_to_heap(-1) before reallocating the PARI
+# stack. The monkey-patching is set up in PariInstance.__cinit__
+cdef GEN patched_parisize(const char* v, long flag):
+    try:
+        move_gens_to_heap(-1)
+    except:
+        sig_error()
+    return sd_parisize(v, flag)
+
+
+cdef GEN patched_parisizemax(const char* v, long flag):
+    try:
+        move_gens_to_heap(-1)
+    except:
+        sig_error()
+    return sd_parisizemax(v, flag)
+
+
 IF HAVE_PLOT_SVG:
     cdef void get_plot_ipython(PARI_plot* T):
         # Values copied from src/graph/plotsvg.c in PARI sources

cypari2/types.pxd

@@ -95,6 +95,18 @@ cdef extern from "pari/pari.h":
         long fheight
         void (*draw)(PARI_plot *T, GEN w, GEN x, GEN y)
 
+    ctypedef struct entree:
+        const char *name
+        ulong valence
+        void *value
+        long menu
+        const char *code
+        const char *help
+        void *pvalue
+        long arity
+        ulong hash
+        entree *next
+
     # Various structures that we don't interface but which need to be
     # declared, such that Cython understands the declarations of
     # functions using these types.
@@ -108,7 +120,6 @@ cdef extern from "pari/pari.h":
     struct forpart_t
     struct forprime_t
     struct forvec_t
-    struct entree
     struct gp_context
     struct nfbasic_t
     struct pariFILE