LeaveCriticalSection function (synchapi.h)

Releases ownership of the specified critical section object.

Syntax

void LeaveCriticalSection(
  [in, out] LPCRITICAL_SECTION lpCriticalSection
);

Parameters

[in, out] lpCriticalSection

A pointer to the critical section object.

Return value

None

Remarks

The threads of a single process can use a critical-section object for mutual-exclusion synchronization. The process is responsible for allocating the memory used by a critical-section object, which it can do by declaring a variable of type CRITICAL_SECTION. Before using a critical section, some thread of the process must call the InitializeCriticalSection or InitializeCriticalSectionAndSpinCount function to initialize the object.

A thread uses the EnterCriticalSection or TryEnterCriticalSection function to acquire ownership of a critical section object. To release its ownership, the thread must call LeaveCriticalSection once for each time that it entered the critical section.

If a thread calls LeaveCriticalSection when it does not have ownership of the specified critical section object, an error occurs that may cause another thread using EnterCriticalSection to wait indefinitely.

LeaveCriticalSection does not access the specified CRITICAL_SECTION structure after the ownership of a critical section object is released.

Any thread of the process can use the DeleteCriticalSection function to release the system resources that were allocated when the critical section object was initialized. After this function has been called, the critical section object can no longer be used for synchronization.

Examples

For an example that uses LeaveCriticalSection, see Using Critical Section Objects.

Requirements

See also

Critical Section Objects

DeleteCriticalSection

EnterCriticalSection

InitializeCriticalSection

InitializeCriticalSectionAndSpinCount

Synchronization Functions

TryEnterCriticalSection

Vertdll APIs available in VBS enclaves