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// SPDX-License-Identifier: EPL-2.0 OR GPL-2.0-or-later
// SPDX-FileCopyrightText: Bradley M. Bell <bradbell@seanet.com>
// SPDX-FileContributor: 2003-22 Bradley M. Bell
// ----------------------------------------------------------------------------
/*
{xrst_begin capacity_order.cpp}
Controlling Taylor Coefficient Memory Allocation: Example and Test
##################################################################
{xrst_literal
// BEGIN C++
// END C++
}
{xrst_end capacity_order.cpp}
*/
// BEGIN C++
# include <cppad/cppad.hpp>
namespace {
bool test(void)
{ bool ok = true;
using CppAD::AD;
using CppAD::NearEqual;
using CppAD::thread_alloc;
// domain space vector
size_t n(1), m(1);
CPPAD_TESTVECTOR(AD<double>) ax(n), ay(n);
// declare independent variables and start tape recording
ax[0] = 1.0;
CppAD::Independent(ax);
// Set y = x^3, use enough variables so more that the minimal amount
// of memory is allocated for Taylor coefficients
ay[0] = 0.;
for( size_t i = 0; i < 10; i++)
ay[0] += ax[0] * ax[0] * ax[0];
ay[0] = ay[0] / 10.;
// create f: x -> y and stop tape recording
// (without running zero order forward mode).
CppAD::ADFun<double> f;
f.Dependent(ax, ay);
// check that this is master thread
size_t thread = thread_alloc::thread_num();
ok &= thread == 0; // this should be master thread
// The highest order forward mode calculation below is first order.
// This corresponds to two Taylor coefficient per variable,direction
// (orders zero and one). Preallocate memory for speed.
size_t inuse = thread_alloc::inuse(thread);
f.capacity_order(2);
ok &= thread_alloc::inuse(thread) > inuse;
// zero order forward mode
CPPAD_TESTVECTOR(double) x(n), y(m);
x[0] = 0.5;
y = f.Forward(0, x);
double eps = 10. * CppAD::numeric_limits<double>::epsilon();
ok &= NearEqual(y[0], x[0] * x[0] * x[0], eps, eps);
// forward computation of partials w.r.t. x
CPPAD_TESTVECTOR(double) dx(n), dy(m);
dx[0] = 1.;
dy = f.Forward(1, dx);
ok &= NearEqual(dy[0], 3. * x[0] * x[0], eps, eps);
// Suppose we no longer need the first order Taylor coefficients.
inuse = thread_alloc::inuse(thread);
f.capacity_order(1); // just keep zero order coefficients
ok &= thread_alloc::inuse(thread) < inuse;
// Suppose we no longer need the zero order Taylor coefficients
// (could have done this first and not used f.capacity_order(1)).
inuse = thread_alloc::inuse(thread);
f.capacity_order(0);
ok &= thread_alloc::inuse(thread) < inuse;
// turn off memory holding
thread_alloc::hold_memory(false);
return ok;
}
}
bool capacity_order(void)
{ bool ok = true;
using CppAD::thread_alloc;
// original amount of memory inuse
size_t thread = thread_alloc::thread_num();
ok &= thread == 0; // this should be master thread
size_t inuse = thread_alloc::inuse(thread);
// do test in separate routine so all objects are destroyed
ok &= test();
// check that the amount of memroy inuse has not changed
ok &= thread_alloc::inuse(thread) == inuse;
// Test above uses hold_memory, so return available memory
thread_alloc::free_available(thread);
return ok;
}
// END C++
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