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author | 2016-10-07 14:13:19 +0200 | |
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committer | 2016-10-07 14:13:19 +0200 | |
commit | ff01b716711b97c2fcaa709ea97f7650f106aa10 (patch) | |
tree | 50dd4d687f38f50c4e136af030c02c267c769f3a /3rdparty/asio/src/examples/cpp11/spawn/parallel_grep.cpp | |
parent | 2a138159c30457aecd9e9679be5159704db0f954 (diff) |
Added ASIO networking library (nw)
Diffstat (limited to '3rdparty/asio/src/examples/cpp11/spawn/parallel_grep.cpp')
-rw-r--r-- | 3rdparty/asio/src/examples/cpp11/spawn/parallel_grep.cpp | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/3rdparty/asio/src/examples/cpp11/spawn/parallel_grep.cpp b/3rdparty/asio/src/examples/cpp11/spawn/parallel_grep.cpp new file mode 100644 index 00000000000..954d9472bbe --- /dev/null +++ b/3rdparty/asio/src/examples/cpp11/spawn/parallel_grep.cpp @@ -0,0 +1,84 @@ +// +// parallel_grep.cpp +// ~~~~~~~~~~~~~~~~~ +// +// Copyright (c) 2003-2016 Christopher M. Kohlhoff (chris at kohlhoff dot com) +// +// Distributed under the Boost Software License, Version 1.0. (See accompanying +// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) +// + +#include <asio/dispatch.hpp> +#include <asio/post.hpp> +#include <asio/spawn.hpp> +#include <asio/strand.hpp> +#include <asio/thread_pool.hpp> +#include <fstream> +#include <iostream> +#include <string> + +using asio::dispatch; +using asio::spawn; +using asio::strand; +using asio::thread_pool; +using asio::yield_context; + +int main(int argc, char* argv[]) +{ + try + { + if (argc < 2) + { + std::cerr << "Usage: parallel_grep <string> <files...>\n"; + return 1; + } + + // We use a fixed size pool of threads for reading the input files. The + // number of threads is automatically determined based on the number of + // CPUs available in the system. + thread_pool pool; + + // To prevent the output from being garbled, we use a strand to synchronise + // printing. + strand<thread_pool::executor_type> output_strand(pool.get_executor()); + + // Spawn a new coroutine for each file specified on the command line. + std::string search_string = argv[1]; + for (int argn = 2; argn < argc; ++argn) + { + std::string input_file = argv[argn]; + spawn(pool, + [=](yield_context yield) + { + std::ifstream is(input_file.c_str()); + std::string line; + std::size_t line_num = 0; + while (std::getline(is, line)) + { + // If we find a match, send a message to the output. + if (line.find(search_string) != std::string::npos) + { + dispatch(output_strand, + [=] + { + std::cout << input_file << ':' << line << std::endl; + }); + } + + // Every so often we yield control to another coroutine. + if (++line_num % 10 == 0) + post(yield); + } + }); + } + + // Join the thread pool to wait for all the spawned tasks to complete. + pool.join(); + } + catch (std::exception& e) + { + std::cerr << "Exception: " << e.what() << "\n"; + } + + return 0; +} |