dxx.app.job source code

1 /**
2 Copyright: 2018 Mark Fisher
3 
4 License:
5 Permission is hereby granted, free of charge, to any person obtaining a copy of
6 this software and associated documentation files (the "Software"), to deal in
7 the Software without restriction, including without limitation the rights to
8 use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
9 of the Software, and to permit persons to whom the Software is furnished to do
10 so, subject to the following conditions:
11 
12 The above copyright notice and this permission notice shall be included in all
13 copies or substantial portions of the Software.
14 
15 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21 SOFTWARE.
22 **/
23 module dxx.app.job;
24 
25 private import std.exception;
26 
27 private import core.thread;
28 
29 private import dxx.util;
30 private import dxx.app;
31 
32 /++
33 Represents a task to run once in a single thread.
34 Notifications are sent when the job state changes.
35 ++/
36 interface Job : NotificationSource {
37     enum Status {
38         NOT_STARTED,
39         STARTED,
40         SUSPENDED,
41         TERMINATED,
42         THROWN_EXCEPTION
43     }
44     struct JobStatusEvent {
45       shared(Job) job;
46       Status status;
47     }
48 
49     @property pure @safe nothrow @nogc shared
50     const(Status) status() const;
51 
52     @property pure @safe nothrow @nogc shared
53     bool terminated() const;
54 
55     @property pure @safe nothrow @nogc shared
56     ref inout(shared(Exception))
57     thrownException() inout;
58 
59     nothrow shared
60     void execute();
61 
62 }
63 
64 /++
65 A simple default class for clients to use.
66 The method `process` should be overriden.
67 ++/
68 abstract class JobBase : SyncNotificationSource, Job {
69     Status _status = Status.NOT_STARTED;
70     shared(Exception) _thrownException;
71 
72     @property pure @safe nothrow @nogc shared
73     const(Status) status() const {
74         return _status;
75     }
76     @property nothrow shared
77     void status(Status s) {
78       _status = s;
79       auto e = JobStatusEvent(this,s);
80       (cast(shared)this).send!JobStatusEvent(&e);
81     }
82     @property pure @safe nothrow @nogc shared
83     bool terminated() const {
84         return (status == Status.TERMINATED) || (status == Status.THROWN_EXCEPTION);
85     }
86     @property @safe nothrow shared
87     ref inout(shared(Exception)) thrownException() inout {
88         return _thrownException;
89     }
90 
91     nothrow
92     void execute() shared {
93         try {
94             enforce(_status == Status.NOT_STARTED);
95             setup;
96             status(Status.STARTED);
97             process;
98             status = Status.TERMINATED;
99         } catch(Exception e) {
100             MsgLog.error(e.file,":",e.line,"-",e.message);
101             _thrownException = cast(shared(Exception))e;
102             status = Status.THROWN_EXCEPTION;
103             version(Posix) {
104               import backtrace;
105               import std.stdio;
106               try {
107                 printPrettyTrace(stderr);
108               } catch(Throwable t) {
109               }
110             } else {
111               MsgLog.info("[Exception]",e.info);
112             }
113         } finally {
114             terminate;
115         }
116     }
117 
118     static void join(shared(Job) j) {
119         while(!j.terminated) {
120             Thread.sleep( dur!("msecs")( 10 ) );
121         }
122     }
123 
124     void setup() shared {}
125 
126     abstract void process() shared;
127 
128     nothrow void terminate() shared {}
129 
130 }
131 
132 class JobDelegate(alias F) : JobBase {
133     override void process() {
134         F();
135     }
136 }