SV_CONST(name) and PL_sv_consts

SV_CONST(XXX) returns SV* that contains "XXX" string.
SVs are built on demand and stored in interp's structure
for re-use. All SVs have precomputed hash value.

Creates SVs on demand, we don't want 35 SV created during
compile time or cloned during thread creation.

1 files changed, 8 insertions, 0 deletions

diff --git a/perl.c b/perl.c
index 41b0a6403c..90b56951a2 100644
--- a/perl.c
+++ b/perl.c
@@ -308,6 +308,8 @@ perl_construct(pTHXx)
     HvSHAREKEYS_off(PL_strtab);			/* mandatory */
     hv_ksplit(PL_strtab, 512);
 
+    Zero(PL_sv_consts, SV_CONSTS_COUNT, SV*);
+
 #if defined(__DYNAMIC__) && (defined(NeXT) || defined(__NeXT__))
     _dyld_lookup_and_bind
 	("__environ", (unsigned long *) &environ_pointer, NULL);
@@ -1081,6 +1083,12 @@ perl_destruct(pTHXx)
     sys_intern_clear();
 #endif
 
+    /* constant strings */
+    for (i = 0; i < SV_CONSTS_COUNT; i++) {
+        SvREFCNT_dec(PL_sv_consts[i]);
+        PL_sv_consts[i] = NULL;
+    }
+
     /* Destruct the global string table. */
     {
 	/* Yell and reset the HeVAL() slots that are still holding refcounts,