critical_section Class
A non-reentrant mutex which is explicitly aware of the Concurrency Runtime.
Syntax
class critical_section;
Members
Public Typedefs
| Name | Description |
|---|---|
native_handle_type |
A reference to a critical_section object. |
Public Classes
| Name | Description |
|---|---|
| critical_section::scoped_lock Class | An exception safe RAII wrapper for a critical_section object. |
Public Constructors
| Name | Description |
|---|---|
| critical_section | Constructs a new critical section. |
| ~critical_section Destructor | Destroys a critical section. |
Public Methods
| Name | Description |
|---|---|
| lock | Acquires this critical section. |
| native_handle | Returns a platform specific native handle, if one exists. |
| try_lock | Tries to acquire the lock without blocking. |
| try_lock_for | Tries to acquire the lock without blocking for a specific number of milliseconds. |
| unlock | Unlocks the critical section. |
Remarks
For more information, see Synchronization Data Structures.
Inheritance Hierarchy
critical_section
Requirements
Header: concrt.h
Namespace: concurrency
critical_section
Constructs a new critical section.
critical_section();
~critical_section
Destroys a critical section.
~critical_section();
Remarks
It is expected that the lock is no longer held when the destructor runs. Allowing the critical section to destruct with the lock still held results in undefined behavior.
lock
Acquires this critical section.
void lock();
Remarks
It is often safer to utilize the scoped_lock construct to acquire and release a critical_section object in an exception safe way.
If the lock is already held by the calling context, an improper_lock exception will be thrown.
native_handle
Returns a platform specific native handle, if one exists.
native_handle_type native_handle();
Return Value
A reference to the critical section.
Remarks
A critical_section object is not associated with a platform specific native handle for the Windows operating system. The method simply returns a reference to the object itself.
critical_section::scoped_lock Class
An exception safe RAII wrapper for a critical_section object.
class scoped_lock;
scoped_lock::scoped_lock
Constructs a scoped_lock object and acquires the critical_section object passed in the _Critical_section parameter. If the critical section is held by another thread, this call will block.
explicit _CRTIMP scoped_lock(critical_section& _Critical_section);
Parameters
_Critical_section
The critical section to lock.
scoped_lock::~scoped_lock
Destroys a scoped_lock object and releases the critical section supplied in its constructor.
~scoped_lock();
try_lock
Tries to acquire the lock without blocking.
bool try_lock();
Return Value
If the lock was acquired, the value true; otherwise, the value false.
try_lock_for
Tries to acquire the lock without blocking for a specific number of milliseconds.
bool try_lock_for(unsigned int _Timeout);
Parameters
_Timeout
The number of milliseconds to wait before timing out.
Return Value
If the lock was acquired, the value true; otherwise, the value false.
unlock
Unlocks the critical section.
void unlock();