Make lib/isc/app.c opaque and thread-safe

This work cleans up the API which includes couple of things:

1. Make the isc_appctx_t type fully opaque

2. Protect all access to the isc_app_t members via stdatomics

3. sigwait() is part of POSIX.1, remove dead non-sigwait code

4. Remove unused code: isc_appctx_set{taskmgr,sockmgr,timermgr}

lib/isc/include/isc/app.h

@@ -103,14 +103,7 @@ typedef isc_event_t isc_appevent_t;
  * of the isc_app_ routines to work.  app implementations must maintain
  * all app context invariants.
  */
-struct isc_appctx {
-	unsigned int		impmagic;
-	unsigned int		magic;
-};
-
-#define ISCAPI_APPCTX_MAGIC		ISC_MAGIC('A','a','p','c')
-#define ISCAPI_APPCTX_VALID(c)		((c) != NULL && \
-					 (c)->magic == ISCAPI_APPCTX_MAGIC)
+struct isc_appctx;
 
 ISC_LANG_BEGINDECLS
 
@@ -184,10 +177,10 @@ isc_app_isrunning(void);
  *\li	false   App is not running.
  */
 
-isc_result_t
+void
 isc_app_ctxshutdown(isc_appctx_t *ctx);
 
-isc_result_t
+void
 isc_app_shutdown(void);
 /*!<
  * \brief Request application shutdown.
@@ -205,13 +198,13 @@ isc_app_shutdown(void);
  *\li	ISC_R_UNEXPECTED
  */
 
-isc_result_t
+void
 isc_app_ctxsuspend(isc_appctx_t *ctx);
 /*!<
  * \brief This has the same behavior as isc_app_ctxsuspend().
  */
 
-isc_result_t
+void
 isc_app_reload(void);
 /*!<
  * \brief Request application reload.
@@ -295,44 +288,6 @@ isc_appctx_destroy(isc_appctx_t **ctxp);
  *\li	*ctxp == NULL.
  */
 
-void
-isc_appctx_settaskmgr(isc_appctx_t *ctx, isc_taskmgr_t *taskmgr);
-/*!<
- * \brief Associate a task manager with an application context.
- *
- * This must be done before running tasks within the application context.
- *
- * Requires:
- *\li	'ctx' is a valid application context.
- *\li	'taskmgr' is a valid task manager.
- */
-
-void
-isc_appctx_setsocketmgr(isc_appctx_t *ctx, isc_socketmgr_t *socketmgr);
-/*!<
- * \brief Associate a socket manager with an application context.
- *
- * This must be done before handling socket events within the application
- * context.
- *
- * Requires:
- *\li	'ctx' is a valid application context.
- *\li	'socketmgr' is a valid socket manager.
- */
-
-void
-isc_appctx_settimermgr(isc_appctx_t *ctx, isc_timermgr_t *timermgr);
-/*!<
- * \brief Associate a socket timer with an application context.
- *
- * This must be done before handling timer events within the application
- * context.
- *
- * Requires:
- *\li	'ctx' is a valid application context.
- *\li	'timermgr' is a valid timer manager.
- */
-
 ISC_LANG_ENDDECLS
 
 #endif /* ISC_APP_H */

lib/isc/include/isc/socket.h

@@ -805,8 +805,7 @@ isc_socket_sendto2(isc_socket_t *sock, isc_region_t *region,
 /*@}*/
 
 isc_result_t
-isc_socketmgr_createinctx(isc_mem_t *mctx, isc_appctx_t *actx,
-			  isc_socketmgr_t **managerp);
+isc_socketmgr_createinctx(isc_mem_t *mctx, isc_socketmgr_t **managerp);
 
 isc_result_t
 isc_socketmgr_create(isc_mem_t *mctx, isc_socketmgr_t **managerp);

lib/isc/include/isc/task.h

@@ -630,7 +630,7 @@ isc_task_privilege(isc_task_t *task);
  *****/
 
 isc_result_t
-isc_taskmgr_createinctx(isc_mem_t *mctx, isc_appctx_t *actx,
+isc_taskmgr_createinctx(isc_mem_t *mctx,
 			unsigned int workers, unsigned int default_quantum,
 			isc_taskmgr_t **managerp);
 isc_result_t

lib/isc/include/isc/timer.h

@@ -316,8 +316,7 @@ isc_timer_gettype(isc_timer_t *timer);
  */
 
 isc_result_t
-isc_timermgr_createinctx(isc_mem_t *mctx, isc_appctx_t *actx,
-			 isc_timermgr_t **managerp);
+isc_timermgr_createinctx(isc_mem_t *mctx, isc_timermgr_t **managerp);
 
 isc_result_t
 isc_timermgr_create(isc_mem_t *mctx, isc_timermgr_t **managerp);