summaryrefslogtreecommitdiff
path: root/source/modules/asura-utils/threading/semaphore.cpp
blob: 7e5ccf5f5d9f641d8aa50ce1cb70bf39aad6769c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
#include "../exceptions/exception.h"
#include "../type.h"

#include "mutex.h"
#include "semaphore.h"

namespace AsuraEngine
{
	namespace Threading
	{

#define try_create_semaphore(impl) \
		if (!m_Impl)												\
		{																	\
			try															\
			{																\
			 m_Impl = new impl(init_count);	\
			}																\
			catch (Exception& e)						\
			{																\
			 m_Impl = nullptr;							\
			}																\
		}

		Semaphore::Semaphore(unsigned int init_count)
			: m_Impl(nullptr)
		{
#ifdef ASURA_THREAD_WIN32 
			try_create_semaphore(SemaphoreWin32);
#endif
			//ASSERT(m_Impl);
		}

		Semaphore::~Semaphore()
		{
			if (m_Impl) delete m_Impl;
		}

		void Semaphore::Signal()
		{
			ASSERT(m_Impl);
		 m_Impl->Signal();
		}

		bool Semaphore::Wait(int timeout /*= ASURA_MUTEX_MAXWAIT*/)
		{
			ASSERT(m_Impl);
			return m_Impl->Wait(timeout);
		}

#if ASURA_THREAD_WIN32 

		SemaphoreWin32::SemaphoreWin32(unsigned int init_value)
			: SemaphoreImpl(init_value)
		{
			// UINT_MAX get error.
		 m_Sem = CreateSemaphore(NULL, init_value, INT_MAX, NULL);
			if (!m_Sem)
			{
				int errorCode = GetLastError();
				throw Exception("Cant use win32 semaphore. Error code: %d.", errorCode);
			}
		}

		SemaphoreWin32::~SemaphoreWin32()
		{
			CloseHandle(m_Sem);
		}

		void SemaphoreWin32::Signal()
		{
			InterlockedIncrement(&m_Count);
			if (ReleaseSemaphore(m_Sem, 1, NULL) == FALSE)
				InterlockedDecrement(&m_Count);
		}

		bool SemaphoreWin32::Wait(int timeout)
		{
			int result;
			result = WaitForSingleObject(m_Sem, timeout);
			if (result == WAIT_OBJECT_0)
			{
				InterlockedDecrement(&m_Count);
				return true;
			}
			else if(result == WAIT_TIMEOUT)
			{
				// ��ʱ
				return false;
			}
			else
			{
				// δ֪����
				throw Exception("WaitForSingleObject() failed");
			}
		}

#endif // ASURA_THREAD_WIN32 

	}
}