From 47a6797e30861e0b59f6badcfb5ef7a1a020befa Mon Sep 17 00:00:00 2001
From: ian <ian>
Date: Wed, 9 Aug 2006 11:16:59 +0000
Subject: [PATCH] +  Improvements for multithreaded programs:

@@ -1,3 +1,14 @@
+adns (1.3.0.99.1); urgency=low
+
+  Improvements for multithreaded programs:
+  * New documentation comment in adns.h explaining thread guarantees
+    (or lack of them), replaces `single-threaded' note at the top.
+  * Fix string conversion of adns_r_addr not to use a static buffer
+    (function csp_addr) so as to make thread promise true.
+  * Make an internal variable const-correct (expectdomain in pa_ptr).
+
+ --
+
 adns (1.3); urgency=low

   Portability fixes:
---
 changelog   | 11 +++++++++++
 src/adns.h  | 14 +++++++++++++-
 src/types.c |  4 ++--
 3 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/changelog b/changelog
index 693120e..751f0ed 100644
--- a/changelog
+++ b/changelog
@@ -1,3 +1,14 @@
+adns (1.3.0.99.1); urgency=low
+
+  Improvements for multithreaded programs:
+  * New documentation comment in adns.h explaining thread guarantees
+    (or lack of them), replaces `single-threaded' note at the top.
+  * Fix string conversion of adns_r_addr not to use a static buffer
+    (function csp_addr) so as to make thread promise true.
+  * Make an internal variable const-correct (expectdomain in pa_ptr).
+
+ --
+
 adns (1.3); urgency=low
 
   Portability fixes:
diff --git a/src/adns.h b/src/adns.h
index befa0b3..a903934 100644
--- a/src/adns.h
+++ b/src/adns.h
@@ -1,6 +1,6 @@
 /*
  * adns.h
- * - adns user-visible API (single-threaded, without any locking)
+ * - adns user-visible API
  */
 /*
  *
@@ -401,6 +401,18 @@ typedef struct {
  *  requested.
  */
 
+/* Threads:
+ *  adns does not use any static modifiable state, so it
+ *   is safe to call adns_init several times and then use the
+ *   resulting adns_states concurrently.
+ *  However, it is NOT safe to make simultaneous calls into
+ *   adns using the same adns_state; a single adns_state must be used
+ *   only by one thread at a time.  You can solve this problem by
+ *   having one adns_state per thread, or if that isn't feasible, you
+ *   could maintain a pool of adns_states.  Unfortunately neither of
+ *   these approaches has optimal performance.
+ */
+
 int adns_init(adns_state *newstate_r, adns_initflags flags,
 	      FILE *diagfile /*0=>stderr*/);
 
diff --git a/src/types.c b/src/types.c
index b369322..36ff879 100644
--- a/src/types.c
+++ b/src/types.c
@@ -320,7 +320,7 @@ static int div_addr(void *context, const void *datap_a, const void *datap_b) {
 
 static adns_status csp_addr(vbuf *vb, const adns_rr_addr *rrp) {
   const char *ia;
-  static char buf[30];
+  char buf[30];
 
   switch (rrp->addr.inet.sin_family) {
   case AF_INET:
@@ -736,7 +736,7 @@ static void icb_ptr(adns_query parent, adns_query child) {
 
 static adns_status pa_ptr(const parseinfo *pai, int dmstart,
 			  int max, void *datap) {
-  static const char *(expectdomain[])= { DNS_INADDR_ARPA };
+  static const char *const (expectdomain[])= { DNS_INADDR_ARPA };
   
   char **rrp= datap;
   adns_status st;
-- 
2.30.2