ompOptions

Sets various OpenMP options.

Synopsis with Optional Arguments

ompOptions ()

Return Value

The return value for this function is void.

Optional Arguments

setFunctionsThreadSafe, int (Input)

If nonzero, user supplied functions are assumed to be thread-safe. This allows user functions to be evaluated in parallel with different arguments.

Default: User supplied functions are not assumed to be thread-safe and are not evaluated in parallel by PyIMSL functions.

getFunctionsThreadSafe (Output)

Retrieves the current thread-safe setting for user functions. If user functions are not thread-safe, then a value of zero is returned; otherwise a value of one is returned.

Description

The performance of some PyIMSL functions can be improved if they evaluate user supplied functions in parallel. Unfortunately, incorrect results can occur if the user supplied functions are not thread-safe. By default, the PyIMSL functions assumes user supplied functions are not thread-safe and thus will not evaluate them in parallel. To change this assumption, use the optional argument setFunctionsThreadSafe with its argument equal to one.

This function can be used multiple times in an application to change the thread-safe assumption.

Example

This example computes the integral \(\int_{0}^{2} x e^x dx\). A call to the function ompOptions is used to indicate that function fcn is thread-safe and so can be safely evaluated by multiple, simultaneous threads.

from __future__ import print_function
from pyimsl.math.ompOptions import ompOptions
from pyimsl.math.intFcn import intFcn
from math import exp


def fcn(x):
    return x * (exp(x))


ompOptions(setFunctionsThreadSafe=1)
# Evaluate the integral and print result */
q = intFcn(fcn, 0.0, 2.0)
exact = exp(2.0) + 1.0
print("integral = %10.3f\nexact    = %10.3f\n" % (q, exact))
a = []
ompOptions(getFunctionsThreadSafe=a)
print("getFunctionThreadSafe =", a[0])

Output

integral =      8.389
exact    =      8.389

getFunctionThreadSafe = 1