\(\newcommand{\W}[1]{ \; #1 \; }\) \(\newcommand{\R}[1]{ {\rm #1} }\) \(\newcommand{\B}[1]{ {\bf #1} }\) \(\newcommand{\D}[2]{ \frac{\partial #1}{\partial #2} }\) \(\newcommand{\DD}[3]{ \frac{\partial^2 #1}{\partial #2 \partial #3} }\) \(\newcommand{\Dpow}[2]{ \frac{\partial^{#1}}{\partial {#2}^{#1}} }\) \(\newcommand{\dpow}[2]{ \frac{ {\rm d}^{#1}}{{\rm d}\, {#2}^{#1}} }\)
harmonic_common¶
View page sourceCommon Variables Used by Multi-threading Sum of 1/i¶
Purpose¶
This source code defines the common include files, defines, and variables that are used by the summation that defines the harmonic series
\[1 + 1/2 + 1/3 + ... + 1/n\]
Source¶
# include <cppad/cppad.hpp>
# include "harmonic.hpp"
# include "team_thread.hpp"
# define MAX_NUMBER_THREADS 48
namespace {
using CppAD::thread_alloc; // fast multi-threadeding memory allocator
// Number of threads, set by previous call to harmonic_time
// (zero means one thread with no multi-threading setup)
size_t num_threads_ = 0;
// value of mega_sum, set by previous call to harmonic_time.
size_t mega_sum_;
// structure with information for one thread
typedef struct {
// index to start summation at (worker input)
// set by previous call to harmonic_setup
size_t start;
// index to end summation at (worker input)
// set by previous call to harmonic_setup
size_t stop;
// summation for this thread
// set by worker
double sum;
// false if an error occurs, true otherwise
// set by worker
bool ok;
} work_one_t;
// vector with information for all threads
// (use pointers instead of values to avoid false sharing)
work_one_t* work_all_[MAX_NUMBER_THREADS];
}