Refactor the irs_context API to use ISC_THREAD_LOCAL

Previously, the irs_context API used isc_thread_key API for TLS, which is
fairly complicated and requires initialization of memory contexts, etc.
This part of code was refactored to use a ISC_THREAD_LOCAL pointer which
greatly simplifies the whole code related to storing TLS variables.

diff --git a/lib/irs/context.c b/lib/irs/context.c
index d1b71c420412546120115c40243eac47b38f9b4d..de2796b4a6d7cb9ae213e82efe9fe1e26a8832df 100644 (file)
--- a/lib/irs/context.c
+++ b/lib/irs/context.c
@@ -42,11 +42,7 @@
 #define DNS_CONF "/etc/dns.conf"
 #endif
 
-static bool thread_key_initialized = false;
-static isc_mutex_t thread_key_mutex;
-static isc_thread_key_t irs_context_key;
-static isc_once_t once = ISC_ONCE_INIT;
-
+ISC_THREAD_LOCAL irs_context_t *irs_context = NULL;
 
 struct irs_context {
        /*
@@ -119,68 +115,20 @@ ctxs_init(isc_mem_t **mctxp, isc_appctx_t **actxp,
        return (result);
 }
 
-static void
-free_specific_context(void *arg) {
-       irs_context_t *context = arg;
-
-       irs_context_destroy(&context);
-
-       isc_thread_key_setspecific(irs_context_key, NULL);
-}
-
-static void
-thread_key_mutex_init(void) {
-       isc_mutex_init(&thread_key_mutex);
-}
-
-static isc_result_t
-thread_key_init(void) {
-       isc_result_t result;
-
-       result = isc_once_do(&once, thread_key_mutex_init);
-       if (result != ISC_R_SUCCESS)
-               return (result);
-
-       if (!thread_key_initialized) {
-               LOCK(&thread_key_mutex);
-
-               if (!thread_key_initialized &&
-                   isc_thread_key_create(&irs_context_key,
-                                         free_specific_context) != 0) {
-                       result = ISC_R_FAILURE;
-               } else
-                       thread_key_initialized = true;
-
-               UNLOCK(&thread_key_mutex);
-       }
-
-       return (result);
-}
-
 isc_result_t
 irs_context_get(irs_context_t **contextp) {
-       irs_context_t *context;
        isc_result_t result;
 
        REQUIRE(contextp != NULL && *contextp == NULL);
 
-       result = thread_key_init();
-       if (result != ISC_R_SUCCESS)
-               return (result);
-
-       context = isc_thread_key_getspecific(irs_context_key);
-       if (context == NULL) {
-               result = irs_context_create(&context);
-               if (result != ISC_R_SUCCESS)
-                       return (result);
-               result = isc_thread_key_setspecific(irs_context_key, context);
+       if (irs_context == NULL) {
+               result = irs_context_create(&irs_context);
                if (result != ISC_R_SUCCESS) {
-                       irs_context_destroy(&context);
                        return (result);
                }
        }
 
-       *contextp = context;
+       *contextp = irs_context;
 
        return (ISC_R_SUCCESS);
 }
@@ -289,6 +237,7 @@ irs_context_destroy(irs_context_t **contextp) {
        REQUIRE(contextp != NULL);
        context = *contextp;
        REQUIRE(IRS_CONTEXT_VALID(context));
+       *contextp = irs_context = NULL;
 
        isc_task_detach(&context->task);
        irs_dnsconf_destroy(&context->dnsconf);
@@ -302,9 +251,6 @@ irs_context_destroy(irs_context_t **contextp) {
 
        isc_mem_putanddetach(&context->mctx, context, sizeof(*context));
 
-       *contextp = NULL;
-
-       (void)isc_thread_key_setspecific(irs_context_key, NULL);
 }
 
 isc_mem_t *