ae.sys.memory source code

1 /**
2  * Memory and GC stuff.
3  *
4  * License:
5  *   This Source Code Form is subject to the terms of
6  *   the Mozilla Public License, v. 2.0. If a copy of
7  *   the MPL was not distributed with this file, You
8  *   can obtain one at http://mozilla.org/MPL/2.0/.
9  *
10  * Authors:
11  *   Vladimir Panteleev <vladimir@thecybershadow.net>
12  */
13 
14 module ae.sys.memory;
15 
16 /// Did the GC run since this function's last call on this thread?
17 /// Not 100% reliable (due to false pointers).
18 bool gcRan()
19 {
20 	static bool initialized = false;
21 	static bool destroyed = false;
22 
23 	static class Beacon
24 	{
25 		~this()
26 		{
27 			destroyed = true;
28 		}
29 	}
30 
31 	if (!initialized)
32 	{
33 		destroyed = false;
34 		new Beacon();
35 		initialized = true;
36 	}
37 
38 	bool result = destroyed;
39 	if (destroyed)
40 	{
41 		destroyed = false;
42 		new Beacon();
43 	}
44 
45 	return result;
46 }
47 
48 import core.thread;
49 
50 /// Is the given pointer located on the stack of the current thread?
51 /// Useful to assert on before taking the address of e.g. a struct member.
52 bool onStack(const(void)* p)
53 {
54 	auto p0 = thread_stackTop();
55 	auto p1 = thread_stackBottom();
56 	return p0 <= p && p <= p1;
57 }
58 
59 unittest
60 {
61 	/* .......... */ int l; auto pl = &l;
62 	static /* ... */ int s; auto ps = &s;
63 	static __gshared int g; auto pg = &g;
64 	/* ................. */ auto ph = new int;
65 	assert( pl.onStack());
66 	assert(!ps.onStack());
67 	assert(!pg.onStack());
68 	assert(!ph.onStack());
69 }