SemaphoreCreate (Function)

ONLINE HELP
WINDEV, WEBDEV AND WINDEV MOBILE

Version:

Home | Sign in | English

Mode for sharing the semaphores

WINDEV

WEBDEV

WINDEV Mobile

Others

See also

SemaphoreCreate (Function)

In french: SémaphoreCrée

Creates a semaphore.

Reminder: Semaphores are used to define a protected code section that can only be run by a specific number of threads.

Versions 15 and later

This function is now available for Android applications.

New in version 15

This function is now available for Android applications.

Versions 18 and later

This function is now available in Windows Store apps mode.

This function is now available in Android widget mode.

New in version 18

This function is now available in Windows Store apps mode.

This function is now available in Android widget mode.

This function is now available in Windows Store apps mode.

This function is now available in Android widget mode.

Versions 19 and later

This function is now available for WEBDEV sites in Linux.

This function is now available for WINDEV applications in Linux.

This function is now available for iPhone/iPad applications.

New in version 19

This function is now available for WEBDEV sites in Linux.

This function is now available for WINDEV applications in Linux.

This function is now available for iPhone/iPad applications.

This function is now available for WEBDEV sites in Linux.

This function is now available for WINDEV applications in Linux.

This function is now available for iPhone/iPad applications.

Versions 21 and later

This function is now available in Apple Watch mode.

This function is now available in Universal Windows 10 App mode.

New in version 21

This function is now available in Apple Watch mode.

This function is now available in Universal Windows 10 App mode.

This function is now available in Apple Watch mode.

This function is now available in Universal Windows 10 App mode.

Example

// Create a semaphore
SemaphoreCreate("MySemaphore", 3)

Syntax

SemaphoreCreate(<Semaphore name> [, <Authorization> [, <Use> [, <Options>]]])

<Semaphore name>: Character string

Name of the semaphore to create. This name will be used by all the functions for semaphore management.

<Authorization>: Optional integer

Number of concurrent threads allowed in the protected section. This parameter is set to 1 by default.

<Use>: Optional integer

Number of threads found in the section when creating the semaphore (0 by default).

<Options>: Optional Integer constant

Mode for sharing the semaphore:
shareNone The semaphore is specific to the application. If SemaphoreDestroy is not called, the semaphore is destroyed at the end of the application.
The semaphores are unique for the application that created them. They cannot be shared between several applications.
shareGlobal The semaphore is shared among all the applications found on the computer.
This constant is not available.
shareUser
(default value) The semaphore is shared among all the applications of the session of the user who is running the application.
This constant is not available.

Remarks

Mode for sharing the semaphores

In shareUser mode, the semaphore is shared among all the applications of the session of the user who runs the application.

The semaphore is created the first time an application in the user's session calls SemaphoreCreate.
The following applications that call SemaphoreCreate connect to the existing semaphore.
The last application that is closed destroys the semaphore.
A semaphore with the same name cannot be used by a session of another user on the same computer: the system returns an error of access rights.

In shareGlobal mode, the semaphore is shared among all the applications found on the computer.

The semaphore is created by the first application that calls SemaphoreCreate.
The following applications that call SemaphoreCreate connect to the existing semaphore.
The last application that is closed destroys the semaphore.

Component: wd270vm.dll