fMemWait (Function)

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Functions for managing processes

Functions for managing shared memory zones

fMemWait

Presentation

Example

Mechanism for automatic notification of modifications

See also

fMemWait (Function)

In french: fMemAttend

Waits for the end of process about the notifications of modification of a shared memory zone. This process is performed by the other applications that use the memory zone and that have asked to be notified.

Example

// Opens the shared memory zone
ZoneNum is int
ZoneNum = fMemOpen("DialogZone", 1024, shareGlobal)

// Writes an information
fWriteLine(ZoneNum, "IDAPP=" + ExeInfo(exeName))

// Waits for the other applications to process the writing notification
fMemWait(ZoneNum)

Syntax

<Result> = fMemWait(<Identifier of shared memory zone> [, <Timeout>])

<Result>: Optional boolean

True if all applications that received a notification have processed it,
False if the timeout was exceeded.

<Identifier of shared memory zone>: Integer

Identifier of shared memory zone to use, defined by fMemOpen.

<Timeout>: Optional integer

Maximum timeout (in milliseconds). This parameter can correspond to:
an integer corresponding to the number of milliseconds,
a Duration variable,
Versions 23 and later
the direct indication of duration ('1s' or '10ms' for example).
New in version 23
the direct indication of duration ('1s' or '10ms' for example).
the direct indication of duration ('1s' or '10ms' for example).
There is no timeout if this parameter is not specified.

Remarks

Mechanism for automatic notification of modifications

A procedure for processing the notifications of modifications can be passed in parameter to fMemOpen. If this procedure was specified, it will be automatically called whenever the content of the shared memory zone is modified.

By using fMemWait, an application that writes into a shared memory zone can be sure that its modification was processed by the other applications that use the memory zone.

Remark: The mechanism for automatic notification only operates between WLanguage applications.

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