OSX/utilities/sec_action.c

   1 /*
   2  * Copyright (c) 2017 Apple Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 #include <stdlib.h>
  25 #include <Block.h>
  26 #include <dispatch/dispatch.h>
  27
  28 #include "sec_action.h"
  29
  30 struct sec_action_context_s {
  31         dispatch_queue_t queue;
  32         dispatch_source_t source;
  33         dispatch_block_t handler;
  34         uint64_t interval;
  35 };
  36
  37 static void _sec_action_event(void *ctx);
  38 static void _sec_action_finalize(void *ctx);
  39
  40 #pragma mark -
  41
  42 sec_action_t
  43 sec_action_create_with_queue(dispatch_queue_t queue, const char *label, uint64_t interval)
  44 {
  45         dispatch_source_t source;
  46         struct sec_action_context_s *context;
  47         if (queue) {
  48                 dispatch_retain(queue);
  49         } else {
  50                 queue = dispatch_queue_create(label, DISPATCH_QUEUE_SERIAL);
  51         }
  52         source = dispatch_source_create(DISPATCH_SOURCE_TYPE_DATA_ADD, 0, 0, queue);
  53
  54         context = malloc(sizeof(*context));
  55         context->queue = queue;
  56         context->source = source;
  57         context->handler = NULL;
  58         context->interval = interval;
  59         dispatch_set_context(source, context);
  60
  61         dispatch_source_set_event_handler_f(source, _sec_action_event);
  62         dispatch_set_finalizer_f(source, _sec_action_finalize);
  63
  64         return source;
  65 }
  66
  67 sec_action_t
  68 sec_action_create(const char *label, uint64_t interval)
  69 {
  70         return sec_action_create_with_queue(NULL, label, interval);
  71 }
  72
  73 void
  74 sec_action_set_handler(sec_action_t source, dispatch_block_t handler)
  75 {
  76         struct sec_action_context_s *context;
  77
  78         context = dispatch_get_context(source);
  79         context->handler = Block_copy(handler);
  80
  81         dispatch_activate(source);
  82 }
  83
  84 void
  85 sec_action_perform(sec_action_t source)
  86 {
  87         dispatch_source_merge_data(source, 1);
  88 }
  89
  90 #pragma mark -
  91
  92 static void
  93 _sec_action_event(void *ctx)
  94 {
  95         struct sec_action_context_s *context = (struct sec_action_context_s *)ctx;
  96
  97         if (context->handler != NULL) {
  98                 context->handler();
  99         }
 100
 101         // Suspend the source; resume after specified interval.
 102         dispatch_suspend(context->source);
 103         dispatch_after_f(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(context->interval * NSEC_PER_SEC)), context->queue, context->source, (dispatch_function_t)dispatch_resume);
 104 }
 105
 106 static void
 107 _sec_action_finalize(void *ctx)
 108 {
 109         struct sec_action_context_s *context = (struct sec_action_context_s *)ctx;
 110
 111         dispatch_release(context->queue);
 112         if (context->handler != NULL) {
 113                 Block_release(context->handler);
 114         }
 115         free(context);
 116 }