InterprocessLockGetNamedSemaphore(Boolean, Int32, Int32) Method

public static NamedSemaphore GetNamedSemaphore(
	bool perUser,
	int maximumCount = 10,
	int initialCount = -1
)

Public Shared Function GetNamedSemaphore ( 
	perUser As Boolean,
	Optional maximumCount As Integer = 10,
	Optional initialCount As Integer = -1
) As NamedSemaphore

public:
static NamedSemaphore^ GetNamedSemaphore(
	bool perUser, 
	int maximumCount = 10, 
	int initialCount = -1
)

Gemstone.Threading.InterprocessLock.GetNamedSemaphore = function(perUser, maximumCount, initialCount);

Parameters

perUser  Boolean

Indicates whether to generate a different name for the NamedSemaphore dependent upon the user running the application.

maximumCount  Int32  (Optional)

The maximum number of requests for the semaphore that can be granted concurrently.

initialCount  Int32  (Optional)

The initial number of requests for the semaphore that can be granted concurrently, or -1 to default to maximumCount.

Return Value

This function uses a hash of the assembly's GUID when creating the NamedSemaphore, if it is available. If it is not available, it uses a hash of the simple name of the assembly. Although the name is hashed to help guarantee uniqueness, it is still entirely possible that another application may use that name with the same hashing algorithm to generate its NamedSemaphore name. Therefore, it is best to ensure that the GuidAttribute is defined in the AssemblyInfo of your application.

On POSIX systems, the NamedSemaphore exhibits kernel persistence, meaning instances will remain active beyond the lifespan of the creating process. Named semaphores must be explicitly removed by invoking Unlink when they are no longer needed. Kernel persistence necessitates careful design consideration regarding the responsibility for invoking Unlink. Since the common use case for named semaphores is across multiple applications, it is advisable for the last exiting process to handle the cleanup. In cases where an application may crash before calling Unlink, the semaphore persists in the system, potentially leading to resource leakage. Implementations should include strategies to address and mitigate this risk.

Reference