CComCriticalSection Class
This class provides methods for obtaining and releasing ownership of a critical section object.
Syntax
class CComCriticalSection
Members
Public Constructors
| Name | Description |
|---|---|
| CComCriticalSection::CComCriticalSection | The constructor. |
Public Methods
| Name | Description |
|---|---|
| CComCriticalSection::Init | Creates and initializes a critical section object. |
| CComCriticalSection::Lock | Obtains ownership of the critical section object. |
| CComCriticalSection::Term | Releases system resources used by the critical section object. |
| CComCriticalSection::Unlock | Releases ownership of the critical section object. |
Public Data Members
| Name | Description |
|---|---|
| CComCriticalSection::m_sec | A CRITICAL_SECTION object. |
Remarks
CComCriticalSection is similar to class CComAutoCriticalSection, except that you must explicitly initialize and release the critical section.
Typically, you use CComCriticalSection through the typedef name CriticalSection. This name references CComCriticalSection when CComMultiThreadModel is being used.
See CComCritSecLock Class for a safer way to use this class than calling Lock and Unlock directly.
Requirements
Header: atlcore.h
CComCriticalSection::CComCriticalSection
The constructor.
CComCriticalSection() throw();
Remarks
Sets the m_sec data member to NULL.
CComCriticalSection::Init
Calls the Win32 function InitializeCriticalSection, which initializes the critical section object contained in the m_sec data member.
HRESULT Init() throw();
Return Value
Returns S_OK on success, E_OUTOFMEMORY or E_FAIL on failure.
CComCriticalSection::Lock
Calls the Win32 function EnterCriticalSection, which waits until the thread can take ownership of the critical section object contained in the m_sec data member.
HRESULT Lock() throw();
Return Value
Returns S_OK on success, E_OUTOFMEMORY or E_FAIL on failure.
Remarks
The critical section object must first be initialized with a call to the Init method. When the protected code has finished executing, the thread must call Unlock to release ownership of the critical section.
CComCriticalSection::m_sec
Contains a critical section object that is used by all CComCriticalSection methods.
CRITICAL_SECTION m_sec;
CComCriticalSection::Term
Calls the Win32 function DeleteCriticalSection, which releases all resources used by the critical section object contained in the m_sec data member.
HRESULT Term() throw();
Return Value
Returns S_OK.
Remarks
Once Term has been called, the critical section can no longer be used for synchronization.
CComCriticalSection::Unlock
Calls the Win32 function LeaveCriticalSection, which releases ownership of the critical section object contained in the m_sec data member.
HRESULT Unlock() throw();
Return Value
Returns S_OK.
Remarks
To first obtain ownership, the thread must call the Lock method. Each call to Lock requires a corresponding call to Unlock to release ownership of the critical section.
See also
CComFakeCriticalSection Class
Class Overview
CComCritSecLock Class