This is a sweet spot of thread functionality for me at the moment, mixing boost and c++11, so I’m throwing it down here.\u00a0 It’s also in my Reusable code on git.<\/p>\n
\/\/ --------------------------------------------------------------------\r\n\/\/ CONCISE EXAMPLE OF THREAD WITH EXTERNALLY-ACCESSIBLE STATUS AND DATA\r\n\/\/ --------------------------------------------------------------------\r\n\/\/ We create a vector, and create a thread to start stuffing it.\r\n\/\/ Externally, we can check the status of the job, and have mutex access to the data.\r\n\/\/ The atomic job stage is SO CHEAP to change and check, do it all day long as needed.\r\n\/\/ Initially, externally, we check the job stage.\r\n\/\/ Meanwhile, we do a bunch of intense work inside the mutex.\r\n\/\/ Then we do smaller work with frequent mutexing, allowing interruption.\r\n\/\/ Great patterns, use them brother!\r\n\/\/ Hells to the yeah.\r\n\/\/ --------------------------------------------------------------------\r\nstd::atomic<int32_t> job_stage(0);\r\nstd::unordered_set<int> data;\r\nboost::shared_mutex data_guard;\r\ndata.insert(-1);\r\nstd::thread t([&job_stage,&data,&data_guard] {\r\n \/\/ stage 1 = jam in data\r\n job_stage = 1;\r\n {\r\n boost::upgrade_lock<boost::shared_mutex> lock(data_guard);\r\n boost::upgrade_to_unique_lock<boost::shared_mutex> uniqueLock(lock);\r\n for (int loop = 0; loop < 2000; ++loop)\r\n {\r\n std::this_thread::sleep_for(1ms);\r\n data.insert(loop);\r\n }\r\n }\r\n \/\/ stage 2 = mutex-jam data, allowing intervention\r\n job_stage = 2;\r\n for (int loop = 3000000; loop < 4000000 && job_stage == 2; ++loop)\r\n {\r\n boost::upgrade_lock<boost::shared_mutex> lock(data_guard);\r\n boost::upgrade_to_unique_lock<boost::shared_mutex> uniqueLock(lock);\r\n data.insert(loop);\r\n }\r\n cout << \"thread exiting...\" << endl;\r\n});\r\n\r\ncout << \"pre mutex job stage: \" << job_stage << endl;\r\n\r\nfor (int check = 0; check < 5; ++check)\r\n{\r\n std::this_thread::sleep_for(200ms);\r\n \/\/ not sure why i was getting std::hex output...\r\n cout << \"check \" << check << \" job stage: \";\r\n {\r\n boost::upgrade_lock<boost::shared_mutex> lock(data_guard);\r\n cout << dec << job_stage << \" data size \" << data.size();\r\n }\r\n cout << endl;\r\n}\r\n\r\n\/\/ We can trigger the thread to exit.\r\njob_stage = 3;\r\n\r\n\/\/ Let's see what happens if we don't join until after the thread is done.\r\nstd::this_thread::sleep_for(300ms);\r\ncout << \"done sleeping\" << endl;\r\n\r\n\/\/ NOW we will block to ensure the thread finishes.\r\ncout << \"joining\" << endl;\r\nt.join();\r\ncout << \"all done\" << endl;\r\n\/\/ --------------------------------------------------------------------<\/pre>\nOutput:<\/p>\n
pre mutex job stage: 1
\ncheck 0 job stage: 2 data size 2031
\ncheck 1 job stage: 2 data size 225848
\ncheck 2 job stage: 2 data size 456199
\ncheck 3 job stage: 2 data size 726576
\ncheck 4 job stage: 2 data size 936429
\nthread exiting...
\ncheck 5 job stage: 2 data size 1002001
\ndone sleeping
\njoining
\nall done<\/code><\/p>\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"This is a sweet spot of thread functionality for me at the moment, mixing boost and c++11, so I’m throwing it down here.\u00a0 It’s also in my Reusable code on git. \/\/ ——————————————————————– \/\/ CONCISE EXAMPLE OF THREAD WITH EXTERNALLY-ACCESSIBLE STATUS AND DATA \/\/ ——————————————————————– \/\/ We create a vector, and create a thread to […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"enabled":false},"version":2}},"categories":[22,19],"tags":[],"class_list":["post-2182","post","type-post","status-publish","format-standard","hentry","category-cpp","category-opensource"],"aioseo_notices":[],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p9M11L-zc","jetpack_likes_enabled":true,"_links":{"self":[{"href":"https:\/\/bitpost.com\/news\/wp-json\/wp\/v2\/posts\/2182","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/bitpost.com\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/bitpost.com\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/bitpost.com\/news\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/bitpost.com\/news\/wp-json\/wp\/v2\/comments?post=2182"}],"version-history":[{"count":4,"href":"https:\/\/bitpost.com\/news\/wp-json\/wp\/v2\/posts\/2182\/revisions"}],"predecessor-version":[{"id":2186,"href":"https:\/\/bitpost.com\/news\/wp-json\/wp\/v2\/posts\/2182\/revisions\/2186"}],"wp:attachment":[{"href":"https:\/\/bitpost.com\/news\/wp-json\/wp\/v2\/media?parent=2182"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/bitpost.com\/news\/wp-json\/wp\/v2\/categories?post=2182"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/bitpost.com\/news\/wp-json\/wp\/v2\/tags?post=2182"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}