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Diffstat (limited to 'tests/test-progs/pthread/src/test_atomic.cpp')
-rw-r--r-- | tests/test-progs/pthread/src/test_atomic.cpp | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/tests/test-progs/pthread/src/test_atomic.cpp b/tests/test-progs/pthread/src/test_atomic.cpp new file mode 100644 index 000000000..edcb046ca --- /dev/null +++ b/tests/test-progs/pthread/src/test_atomic.cpp @@ -0,0 +1,117 @@ +/* + * Copyright (c) 2018, Cornell University + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or + * without modification, are permitted provided that the following + * conditions are met: + * + * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials provided + * with the distribution. + * + * Neither the name of Cornell University nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND + * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, + * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF + * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + * Authors: Tuan Ta + */ + +#include <pthread.h> + +#include <atomic> +#include <cstdlib> +#include <iostream> + +//------------------------------------------------------------------------ +// Create n threads, run them in parallel and wait for them in the master +// thread. +// Each child thread increments a shared variable m times atomically +//------------------------------------------------------------------------ + +#define MAX_N_WORKER_THREADS 10 + +typedef struct +{ + int nsteps; + std::atomic<int>* shared_var; +} ThreadArg; + +void* func( void* args ) +{ + ThreadArg* my_args = ( ThreadArg* ) args; + + int nsteps = my_args->nsteps; + std::atomic<int>* shared_var = my_args->shared_var; + + for ( int i = 0; i < nsteps; ++i ) { + std::atomic_fetch_add(shared_var, 1); + } + + return nullptr; +} + +int main( int argc, const char* argv[] ) +{ + int n_worker_threads = 0; + + // allocate all threads + pthread_t* threads = new pthread_t[MAX_N_WORKER_THREADS]; + + // variable shared among all threads + std::atomic<int> shared_var(0); + + // number of steps each thread increments the shared_var + int nsteps = 1000; + + // set up threads' arguments + ThreadArg* t_args = new ThreadArg[MAX_N_WORKER_THREADS]; + + int ret = 0; + for ( size_t tid = 0; tid < MAX_N_WORKER_THREADS; tid++ ){ + t_args[tid].nsteps = nsteps; + t_args[tid].shared_var = &shared_var; + + // spawn thread + ret = pthread_create( threads + tid, nullptr, func, &t_args[tid] ); + + if (ret != 0) { + break; + } + + n_worker_threads++; + } + + // sync up all threads + for ( int tid = 0; tid < n_worker_threads; ++tid ) { + pthread_join( threads[tid], nullptr ); + } + + // clean up + delete[] threads; + delete[] t_args; + + // verify + if ( shared_var != n_worker_threads * nsteps || n_worker_threads < 1) + return EXIT_FAILURE; + + return EXIT_SUCCESS; +} |