- Patch from Neel Goyal: Add an API call to set an event base on an

  existing ub_ctx.  This basically just destroys the current worker and
  sets the event base to the current.  And fix a deadlock in
  ub_resolve_event – the cfglock is held when libworker_create is
  called.  This ends up trying to acquire the lock again in
  context_obtain_alloc in the call chain.

git-svn-id: file:///svn/unbound/trunk@2992 be551aaa-1e26-0410-a405-d3ace91eadb9

diff --git a/doc/Changelog b/doc/Changelog
index 523f0973a2e0eb80aacef30486b4f950a768e758..ff0f765e434259e6299fa35a74dfe5e9504b3048 100644 (file)
--- a/doc/Changelog
+++ b/doc/Changelog
@@ -1,3 +1,11 @@
+22 Oct 2013: Wouter
+       - Patch from Neel Goyal: Add an API call to set an event base on an
+         existing ub_ctx.  This basically just destroys the current worker and
+         sets the event base to the current.  And fix a deadlock in
+         ub_resolve_event – the cfglock is held when libworker_create is
+         called.  This ends up trying to acquire the lock again in
+         context_obtain_alloc in the call chain.
+
 26 Sep 2013: Wouter
        - unbound-event.h is installed if configured --with-libevent.  It
          contains low-level library calls, that use libevent's event_base

diff --git a/libunbound/libunbound.c b/libunbound/libunbound.c
index 847ac1a54079ac297812cc1843d95aae2a48a2f4..870e37699b1793f2b5899fe01f46a1da357ef448 100644 (file)
--- a/libunbound/libunbound.c
+++ b/libunbound/libunbound.c
@@ -656,15 +656,14 @@ ub_resolve_event(struct ub_ctx* ctx, const char* name, int rrtype,
                        return r;
                }
        }
+       lock_basic_unlock(&ctx->cfglock);
        if(!ctx->event_worker) {
                ctx->event_worker = libworker_create_event(ctx,
                        ctx->event_base);
                if(!ctx->event_worker) {
-                       lock_basic_unlock(&ctx->cfglock);
                        return UB_INITFAIL;
                }
        }
-       lock_basic_unlock(&ctx->cfglock);
 
        /* create new ctx_query and attempt to add to the list */
        q = context_new(ctx, name, rrtype, rrclass, (ub_callback_t)callback,
@@ -1212,3 +1211,24 @@ const char* ub_version(void)
 {
        return PACKAGE_VERSION;
 }
+
+int 
+ub_ctx_set_event(struct ub_ctx* ctx, struct event_base* base) {
+       if (!ctx || !ctx->event_base || !base) {
+               return UB_INITFAIL;
+       }
+       if (ctx->event_base == base) {
+               /* already set */
+               return UB_NOERROR;
+       }
+       
+       lock_basic_lock(&ctx->cfglock);
+       /* destroy the current worker - safe to pass in NULL */
+       libworker_delete_event(ctx->event_worker);
+       ctx->event_worker = NULL;
+       ctx->event_base = base; 
+       ctx->created_bg = 0;
+       ctx->dothread = 1;
+       lock_basic_unlock(&ctx->cfglock);
+       return UB_NOERROR;
+}

diff --git a/libunbound/ubsyms.def b/libunbound/ubsyms.def
index 26040921b8b2a3641396755ec4d8c3b27c66978d..866c1764cf7a5f1f9197d1353d814bcf96bc9aae 100644 (file)
--- a/libunbound/ubsyms.def
+++ b/libunbound/ubsyms.def
@@ -29,3 +29,4 @@ ub_ctx_zone_remove
 ub_ctx_data_add
 ub_ctx_data_remove
 ub_version
+ub_ctx_set_event

diff --git a/libunbound/unbound-event.h b/libunbound/unbound-event.h
index 519e4e0de18f1bf2c1cf3807b0f70c452be58ce8..c49005eec8142f424fb3e6f0c8473914af437a1b 100644 (file)
--- a/libunbound/unbound-event.h
+++ b/libunbound/unbound-event.h
@@ -63,9 +63,9 @@ extern "C" {
 struct ub_ctx;
 struct ub_result;
 struct event_base;
-struct ldns_buffer;
+struct ldns_struct_buffer;
 
-typedef void (*ub_event_callback_t)(void*, int, struct ldns_buffer*, int, char*);
+typedef void (*ub_event_callback_t)(void*, int, struct ldns_struct_buffer*, int, char*);
 
 /**
  * Create a resolving and validation context.
@@ -81,6 +81,15 @@ typedef void (*ub_event_callback_t)(void*, int, struct ldns_buffer*, int, char*)
  */
 struct ub_ctx* ub_ctx_create_event(struct event_base* base);
 
+/**
+ * Set a new event_base on a context created with ub_ctx_create_event.
+ * Any outbound queries will be canceled.
+ * @param ctx the ub_ctx to update.  Must have been created with ub_ctx_create_event
+ * @param base the new event_base to attach to the ctx
+ * @return 0 if OK, else error
+ */
+int ub_ctx_set_event(struct ub_ctx* ctx, struct event_base* base); 
+
 /**
  * Perform resolution and validation of the target name.
  * Asynchronous, after a while, the callback will be called with your