provide locked access to string table for USE_THREADS

p4raw-id: //depot/perl@1863

6 files changed, 34 insertions, 6 deletions

diff --git a/embedvar.h b/embedvar.h
index 8c1b786b97..be36de0430 100644
--- a/embedvar.h
+++ b/embedvar.h
@@ -252,6 +252,7 @@
 #define PL_stdingv		(PL_curinterp->Istdingv)
 #define PL_strchop		(PL_curinterp->Istrchop)
 #define PL_strtab		(PL_curinterp->Istrtab)
+#define PL_strtab_mutex		(PL_curinterp->Istrtab_mutex)
 #define PL_sub_generation	(PL_curinterp->Isub_generation)
 #define PL_sublex_info		(PL_curinterp->Isublex_info)
 #define PL_sv_arenaroot		(PL_curinterp->Isv_arenaroot)
@@ -386,6 +387,7 @@
 #define PL_Istdingv		PL_stdingv
 #define PL_Istrchop		PL_strchop
 #define PL_Istrtab		PL_strtab
+#define PL_Istrtab_mutex	PL_strtab_mutex
 #define PL_Isub_generation	PL_sub_generation
 #define PL_Isublex_info		PL_sublex_info
 #define PL_Isv_arenaroot	PL_sv_arenaroot
diff --git a/hv.c b/hv.c
index 40bb9b8e73..2416831256 100644
--- a/hv.c
+++ b/hv.c
@@ -1149,6 +1149,7 @@ unsharepvn(char *str, I32 len, U32 hash)
     } */
     xhv = (XPVHV*)SvANY(PL_strtab);
     /* assert(xhv_array != 0) */
+    LOCK_STRTAB_MUTEX;
     oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
     for (entry = *oentry; entry; i=0, oentry = &HeNEXT(entry), entry = *oentry) {
 	if (HeHASH(entry) != hash)		/* strings can't be equal */
@@ -1166,6 +1167,7 @@ unsharepvn(char *str, I32 len, U32 hash)
 	    del_he(entry);
 	    --xhv->xhv_keys;
 	}
+	UNLOCK_STRTAB_MUTEX;
 	break;
     }
     
@@ -1193,6 +1195,7 @@ share_hek(char *str, I32 len, register U32 hash)
     */
     xhv = (XPVHV*)SvANY(PL_strtab);
     /* assert(xhv_array != 0) */
+    LOCK_STRTAB_MUTEX;
     oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
     for (entry = *oentry; entry; i=0, entry = HeNEXT(entry)) {
 	if (HeHASH(entry) != hash)		/* strings can't be equal */
@@ -1219,6 +1222,7 @@ share_hek(char *str, I32 len, register U32 hash)
     }
 
     ++HeVAL(entry);				/* use value slot as REFCNT */
+    UNLOCK_STRTAB_MUTEX;
     return HeKEY_hek(entry);
 }
 
diff --git a/intrpvar.h b/intrpvar.h
index dfdcca8e1c..1f6244d557 100644
--- a/intrpvar.h
+++ b/intrpvar.h
@@ -199,6 +199,7 @@ PERLVAR(Isublex_info,	SUBLEXINFO)	/* from toke.c */
 #ifdef USE_THREADS
 PERLVAR(Ithrsv,		SV *)		/* struct perl_thread for main thread */
 PERLVARI(Ithreadnum,	U32,	0)	/* incremented each thread creation */
+PERLVAR(Istrtab_mutex,	perl_mutex)	/* Mutex for string table access */
 #endif /* USE_THREADS */
 
 PERLVARI(Ibytecode_iv_overflows,int,	0)	/* from bytecode.h */
diff --git a/objXSUB.h b/objXSUB.h
index 2c43839370..116075b93b 100644
--- a/objXSUB.h
+++ b/objXSUB.h
@@ -447,6 +447,8 @@
 #define PL_strchop				pPerl->PL_strchop		
 #undef  PL_strtab		
 #define PL_strtab				pPerl->PL_strtab		
+#undef  PL_strtab_mutex
+#define PL_strtab_mutex				pPerl->PL_strtab_mutex
 #undef  PL_sub_generation	
 #define PL_sub_generation		pPerl->PL_sub_generation	
 #undef  PL_sublex_info		
diff --git a/perl.c b/perl.c
index 79fab4a4ef..a5bb53649a 100644
--- a/perl.c
+++ b/perl.c
@@ -553,6 +553,7 @@ perl_destruct(register PerlInterpreter *sv_interp)
     
     DEBUG_P(debprofdump());
 #ifdef USE_THREADS
+    MUTEX_DESTROY(&PL_strtab_mutex);
     MUTEX_DESTROY(&PL_sv_mutex);
     MUTEX_DESTROY(&PL_eval_mutex);
     COND_DESTROY(&PL_eval_cond);
@@ -1905,6 +1906,9 @@ init_main_stash(void)
        about not iterating on it, and not adding tie magic to it.
        It is properly deallocated in perl_destruct() */
     PL_strtab = newHV();
+#ifdef USE_THREADS
+    MUTEX_INIT(&PL_strtab_mutex);
+#endif
     HvSHAREKEYS_off(PL_strtab);			/* mandatory */
     hv_ksplit(PL_strtab, 512);
     
diff --git a/thread.h b/thread.h
index 3eb061a22a..035c5caec9 100644
--- a/thread.h
+++ b/thread.h
@@ -161,16 +161,29 @@ struct perl_thread *getTHR _((void));
  * Systems with very fast mutexes (and/or slow conditionals) may wish to
  * remove the "if (threadnum) ..." test.
  */
-#define LOCK_SV_MUTEX			\
-    STMT_START {			\
+#define LOCK_SV_MUTEX				\
+    STMT_START {				\
+	if (PL_threadnum)			\
+	    MUTEX_LOCK(&PL_sv_mutex);		\
+    } STMT_END
+
+#define UNLOCK_SV_MUTEX				\
+    STMT_START {				\
 	if (PL_threadnum)			\
-	    MUTEX_LOCK(&PL_sv_mutex);	\
+	    MUTEX_UNLOCK(&PL_sv_mutex);		\
     } STMT_END
 
-#define UNLOCK_SV_MUTEX			\
-    STMT_START {			\
+/* Likewise for strtab_mutex */
+#define LOCK_STRTAB_MUTEX			\
+    STMT_START {				\
+	if (PL_threadnum)			\
+	    MUTEX_LOCK(&PL_strtab_mutex);	\
+    } STMT_END
+
+#define UNLOCK_STRTAB_MUTEX			\
+    STMT_START {				\
 	if (PL_threadnum)			\
-	    MUTEX_UNLOCK(&PL_sv_mutex);	\
+	    MUTEX_UNLOCK(&PL_strtab_mutex);	\
     } STMT_END
 
 #ifndef THREAD_RET_TYPE
@@ -223,6 +236,8 @@ typedef struct condpair {
 #define COND_DESTROY(c)
 #define LOCK_SV_MUTEX
 #define UNLOCK_SV_MUTEX
+#define LOCK_STRTAB_MUTEX
+#define UNLOCK_STRTAB_MUTEX
 
 #define THR
 /* Rats: if dTHR is just blank then the subsequent ";" throws an error */