Function GMP::Solver::GetAsynchronousSessionsLimit(solver, cores, GMP)

GMP::Solver::GetAsynchronousSessionsLimit

The function GMP::Solver::GetAsynchronousSessionsLimit returns the maximum number of asynchronous solver sessions that can run simultaneous for a certain solver. This number depends on the AIMMS license.

GMP::Solver::GetAsynchronousSessionsLimit(
     solver,     ! (input) a solver
     [cores],    ! (input, optional) a binary scalar value
     [GMP]       ! (input, optional) a generated mathematical program
     )

Arguments

solver

An element in the set AllSolvers.

cores

A binary scalar indicating whether the this function should take into account the number of cores on the machine. The default is 0 (cores are not used).

GMP

An element in AllGeneratedMathematicalPrograms. By default this argument is empty.

Return Value

The maximal number of asynchronous solver sessions that can run simultaneous using solver, or any other version of the same solver.

If the cores argument equals 1 then this function returns the number of cores on the machine if that number is smaller than the maximal number of asynchronous solver sessions.

If the GMP argument is used then this function will return 0 if the specified generated mathematical program cannot be used for asynchronous executing (e.g., if it contains a constraint with a nonlinear expression referencing an external function).

Note

• The function returns 0 if the solver cannot be found or is not licensed. It also returns 0 if the solver cannot be used to do an asynchronous solve (e.g., BARON, CBC, ODH-CPLEX).

• The function returns 1 if the solver is not thread-safe (e.g., IPOPT, SNOPT).

• The number of asynchronous solver sessions running in parallel using a certain solver should not exceed the limit on asynchronous solver sessions, as returned by this function. To count the number of asynchronous solver sessions currently running with a solver, AIMMS checks all solver versions available. For example, if one asynchronous solver session is running with CPLEX 22.1 and another simultaneous with CPLEX 20.1 then solver CPLEX is running two asynchronous solver sessions. The value returned by this function limits all solver versions together (even though the argument passed to the function refers to a particular solver version).

Example

Assume that ‘MaxSes’ is a parameter then the following statement returns the maximal number of asynchronous solver sessions for CPLEX:

MaxSes := GMP::Solver::GetAsynchronousSessionsLimit( 'CPLEX 22.1' );

The value MaxSes is the limit on asynchronous solver sessions that can run at the same time with CPLEX 22.1 plus CPLEX 20.1 plus CPLEX 12.10, etc.

See also

The routine GMP::SolverSession::AsynchronousExecute.