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bclothierbclothier
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Refactor VBE function calls into dedicated class.
Move VBERuntime classes to VBEEditor project. Create dedicated ComMessagePumper class for pumping windows messages to handle COM objects accordingly.
1 parent 8667769 commit 4e4445d

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6 files changed

+235
-74
lines changed

6 files changed

+235
-74
lines changed

‎Rubberduck.Parsing/UIContext/UiSynchronizer.cs

Lines changed: 50 additions & 74 deletions
Original file line numberDiff line numberDiff line change
@@ -1,111 +1,87 @@
11
using System;
2-
using System.Runtime.InteropServices;
32
using System.Threading;
3+
using Rubberduck.VBEditor.ComManagement;
44

55
namespace Rubberduck.Parsing.UIContext
66
{
77
public static class UiSynchronizer
88
{
9-
private enum DllVersion
10-
{
11-
Unknown,
12-
Vbe6,
13-
Vbe7
14-
}
15-
16-
private static DllVersion _version;
17-
18-
private static SynchronizationContext UiContext { get; set; }
9+
private static readonly ReaderWriterLockSlim Sync;
10+
private const int NoTimeout = -1;
11+
private const int DefaultTimeout = NoTimeout;
1912

2013
static UiSynchronizer()
2114
{
22-
_version = DllVersion.Unknown;
15+
Sync = new ReaderWriterLockSlim(LockRecursionPolicy.SupportsRecursion);
2316
}
24-
25-
public static void Initialize()
17+
18+
public static bool RequestComAccess(Func<bool> func, int timeout = DefaultTimeout)
2619
{
27-
if (UiContext == null)
20+
if (!Sync.TryEnterReadLock(timeout))
2821
{
29-
UiContext = SynchronizationContext.Current;
22+
throw new TimeoutException("Timeout exceeded while waiting to acquire a read lock");
3023
}
31-
}
3224

33-
/// <summary>
34-
/// Used to pump any pending COM messages. This should be used only as a part of
35-
/// synchronizing or to effect a block until all other threads has finished with
36-
/// their pending COM calls. This should be used by the UI thread **ONLY**;
37-
/// otherwise execptions will be thrown.
38-
/// </summary>
39-
/// <remarks>
40-
/// Typical use would be within a event handler for an event belonging to a COM
41-
/// object which require some synchronization with COM accesses from other threads.
42-
/// Events raised by COM are on UI thread by definition so the call stack originating
43-
/// from COM objects' events can use this method.
44-
/// </remarks>
45-
/// <returns>Count of open forms which is always zero for VBA hosts but may be nonzero for VB6 projects.</returns>
46-
public static int DoEvents()
47-
{
48-
CheckContext();
49-
50-
return ExecuteDoEvents();
25+
var result = func.Invoke();
26+
Sync.ExitReadLock();
27+
return result;
5128
}
5229

53-
private static int ExecuteDoEvents()
30+
public static void RequireExclusiveComAccess(Action func, int timeout = DefaultTimeout)
5431
{
55-
switch (_version)
32+
for (var i = 0; i < timeout || timeout == NoTimeout; i++)
5633
{
57-
case DllVersion.Vbe7:
58-
return rtcDoEvents7();
59-
case DllVersion.Vbe6:
60-
return rtcDoEvents6();
61-
default:
62-
return DetermineVersionAndExecute();
63-
}
64-
}
34+
ComMessagePumper.PumpMessages();
6535

66-
private static int DetermineVersionAndExecute()
67-
{
68-
int result;
69-
try
36+
if (Sync.TryEnterWriteLock(1))
37+
{
38+
break;
39+
}
40+
}
7041

42+
if (!Sync.IsWriteLockHeld)
7143
{
72-
result = rtcDoEvents7();
73-
_version = DllVersion.Vbe7;
44+
throw new TimeoutException("Timeout exceeded while waiting to acquire a write lock");
7445
}
75-
catch
46+
47+
func.Invoke();
48+
Sync.ExitWriteLock();
49+
}
50+
51+
public static bool RequireExclusiveComAccess(Func<bool> func, int timeout = DefaultTimeout, bool DeferToParse = true)
52+
{
53+
for (var i = 0; i < timeout || timeout == NoTimeout; i++)
7654
{
77-
try
78-
{
79-
result = rtcDoEvents6();
80-
_version = DllVersion.Vbe6;
81-
}
82-
catch
55+
ComMessagePumper.PumpMessages();
56+
57+
if (Sync.TryEnterWriteLock(1))
8358
{
84-
// we shouldn't be here.... Rubberduck is a VBA add-in, so how the heck could it have loaded without a VBE dll?!?
85-
throw new InvalidOperationException("Cannot execute DoEvents; the VBE dll could not be located.");
59+
break;
8660
}
8761
}
8862

89-
return result;
90-
}
91-
92-
private static void CheckContext()
93-
{
94-
if (UiContext == null)
63+
if (!Sync.IsWriteLockHeld)
9564
{
96-
throw new InvalidOperationException("UiSynchronizer is not initialized. Invoke Initialize() from UI thread first.");
65+
throw new TimeoutException("Timeout exceeded while waiting to acquire a write lock");
9766
}
98-
99-
if (UiContext != SynchronizationContext.Current)
67+
68+
var result = func.Invoke();
69+
if (!DeferToParse)
10070
{
101-
throw new InvalidOperationException("UiSynchronizer cannot be used in other threads. Only the UI thread can call methods on the UiSynchronizer");
71+
Sync.ExitWriteLock();
10272
}
73+
return result;
10374
}
10475

105-
[DllImport("vbe6.dll", EntryPoint = "rtcDoEvents")]
106-
private static extern int rtcDoEvents6();
76+
public static bool ReleaseExclusiveComAccess()
77+
{
78+
if (Sync.IsWriteLockHeld)
79+
{
80+
Sync.ExitWriteLock();
81+
return true;
82+
}
10783

108-
[DllImport("vbe7.dll", EntryPoint = "rtcDoEvents")]
109-
private static extern int rtcDoEvents7();
84+
return false;
85+
}
11086
}
11187
}

‎Rubberduck.VBEEditor/ComManagement/ComMessagePumper.cs

Lines changed: 56 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,56 @@
1+
using System;
2+
using System.Threading;
3+
using Rubberduck.VBEditor.ComManagement.VBERuntime;
4+
5+
namespace Rubberduck.VBEditor.ComManagement
6+
{
7+
public static class ComMessagePumper
8+
{
9+
private static SynchronizationContext UiContext { get; set; }
10+
private static IVBERuntime Runtime { get; set; }
11+
12+
public static void Initialize()
13+
{
14+
if (UiContext == null)
15+
{
16+
UiContext = SynchronizationContext.Current;
17+
}
18+
19+
Runtime = new VBERuntimeAccessor();
20+
}
21+
22+
/// <summary>
23+
/// Used to pump any pending COM messages. This should be used only as a part of
24+
/// synchronizing or to effect a block until all other threads has finished with
25+
/// their pending COM calls. This should be used by the UI thread **ONLY**;
26+
/// otherwise execptions will be thrown. This is mandatory when the COM objects are
27+
/// STA which would otherwise deadlock in other threads.
28+
/// </summary>
29+
/// <remarks>
30+
/// Typical use would be within a event handler for an event belonging to a COM
31+
/// object which require some synchronization with COM accesses from other threads.
32+
/// Events raised by COM are on UI thread by definition so the call stack originating
33+
/// from COM objects' events can use this method.
34+
/// </remarks>
35+
/// <returns>Count of open forms which is always zero for VBA hosts but may be nonzero for VB6 projects.</returns>
36+
public static int PumpMessages()
37+
{
38+
CheckContext();
39+
40+
return Runtime.DoEvents();
41+
}
42+
43+
private static void CheckContext()
44+
{
45+
if (UiContext == null)
46+
{
47+
throw new InvalidOperationException("UiSynchronizer is not initialized. Invoke Initialize() from UI thread first.");
48+
}
49+
50+
if (UiContext != SynchronizationContext.Current)
51+
{
52+
throw new InvalidOperationException("UiSynchronizer cannot be used in other threads. Only the UI thread can call methods on the UiSynchronizer");
53+
}
54+
}
55+
}
56+
}

‎Rubberduck.VBEEditor/ComManagement/VBERuntime/IVBERuntime.cs

Lines changed: 8 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,8 @@
1+
namespace Rubberduck.VBEditor.ComManagement.VBERuntime
2+
{
3+
internal interface IVBERuntime
4+
{
5+
float Timer();
6+
int DoEvents();
7+
}
8+
}

‎Rubberduck.VBEEditor/ComManagement/VBERuntime/VBERuntime6.cs

Lines changed: 23 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,23 @@
1+
using System.Runtime.InteropServices;
2+
3+
namespace Rubberduck.VBEditor.ComManagement.VBERuntime
4+
{
5+
internal class VBERuntime6 : IVBERuntime
6+
{
7+
private const string DllName = "vbe6.dll";
8+
9+
[DllImport(DllName)]
10+
private static extern int rtcDoEvents();
11+
public int DoEvents()
12+
{
13+
return rtcDoEvents();
14+
}
15+
16+
[DllImport(DllName)]
17+
private static extern float rtcGetTimer();
18+
public float Timer()
19+
{
20+
return rtcGetTimer();
21+
}
22+
}
23+
}

‎Rubberduck.VBEEditor/ComManagement/VBERuntime/VBERuntime7.cs

Lines changed: 23 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,23 @@
1+
using System.Runtime.InteropServices;
2+
3+
namespace Rubberduck.VBEditor.ComManagement.VBERuntime
4+
{
5+
internal class VBERuntime7 : IVBERuntime
6+
{
7+
private const string DllName = "vbe7.dll";
8+
9+
[DllImport(DllName)]
10+
private static extern int rtcDoEvents();
11+
public int DoEvents()
12+
{
13+
return rtcDoEvents();
14+
}
15+
16+
[DllImport(DllName)]
17+
private static extern float rtcGetTimer();
18+
public float Timer()
19+
{
20+
return rtcGetTimer();
21+
}
22+
}
23+
}

‎Rubberduck.VBEEditor/ComManagement/VBERuntime/VBERuntimeAccessor.cs

Lines changed: 75 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,75 @@
1+
using System;
2+
3+
namespace Rubberduck.VBEditor.ComManagement.VBERuntime
4+
{
5+
public class VBERuntimeAccessor : IVBERuntime
6+
{
7+
private enum DllVersion
8+
{
9+
Unknown,
10+
Vbe6,
11+
Vbe7
12+
}
13+
14+
private static DllVersion _version;
15+
private readonly IVBERuntime _runtime;
16+
17+
static VBERuntimeAccessor()
18+
{
19+
_version = DllVersion.Unknown;
20+
}
21+
22+
public VBERuntimeAccessor()
23+
{
24+
switch (_version)
25+
{
26+
case DllVersion.Vbe7:
27+
_runtime = new VBERuntime7();
28+
break;
29+
case DllVersion.Vbe6:
30+
_runtime = new VBERuntime6();
31+
break;
32+
default:
33+
_runtime = DetermineVersion();
34+
break;
35+
}
36+
}
37+
38+
private IVBERuntime DetermineVersion()
39+
{
40+
IVBERuntime runtime;
41+
try
42+
{
43+
runtime = new VBERuntime7();
44+
runtime.Timer();
45+
_version = DllVersion.Vbe7;
46+
}
47+
catch
48+
{
49+
try
50+
{
51+
runtime = new VBERuntime6();
52+
runtime.Timer();
53+
_version = DllVersion.Vbe6;
54+
}
55+
catch
56+
{
57+
// we shouldn't be here.... Rubberduck is a VBA add-in, so how the heck could it have loaded without a VBE dll?!?
58+
throw new InvalidOperationException("Cannot execute DoEvents; the VBE dll could not be located.");
59+
}
60+
}
61+
62+
return _version != DllVersion.Unknown ? runtime : null;
63+
}
64+
65+
public float Timer()
66+
{
67+
return _runtime.Timer();
68+
}
69+
70+
public int DoEvents()
71+
{
72+
return _runtime.DoEvents();
73+
}
74+
}
75+
}

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