On Monday, 22 February 2021 at 02:39:58 UTC, Steven Schveighoffer
wrote:
On 2/21/21 9:29 PM, Preetpal wrote:
I want to restrict a D application to a single instance. Is
there a way to do this using the D standard library?
When you say "application", you mean a class or type?
I decided to implement what I meant (single application
(executable) instance restriction) using the Windows API (since
my application only runs on Windows currently anyways):
// Ensures only one instance of application can run at one
time
HANDLE globalMutexHandle = CreateMutex(NULL, true,
"multi-monitor-window-maximization");
if (globalMutexHandle == NULL) {
return -1;
}
DWORD lastErrorAfterMutexCreationAttempt = GetLastError();
if (lastErrorAfterMutexCreationAttempt ==
ERROR_ALREADY_EXISTS) {
return -2;
} if (lastErrorAfterMutexCreationAttempt ==
ERROR_INVALID_HANDLE) {
return -3;
}
scope(exit) {
ReleaseMutex(globalMutexHandle);
CloseHandle(globalMutexHandle);
}
This prevents someone from opening my particular application
twice (so there cannot be two processes running of the same
application/executable). I also updated by Github GIST code with
the update.
