一直不清楚异步与多线程的区别,不知道回调函数是在新线程还是原线程执行。
上网没查找到,自已研究。





































上面的结果是每输出5个 endwrite_i 输出一个 main_i ,说明异步也是在不同线程中运行,和多线程没什么不同。
但是MSDN和网上的代码上很多代码都是在回调函数中再次调用异步函数,这样岂不是会产生很多进程?不过MSDN中都这样写也许不是这样,再次测试。







































输出结果:
main_0
main_1
endwrite_2264
main_2
endwrite_2264
main_3
endwrite_2264
main_4
endwrite_2264
main_5
endwrite_2356
main_6
endwrite_2356
main_7
endwrite_2356
main_8
endwrite_2356
main_9
endwrite_2264
endwrite_2356
endwrite_2264
main_1
endwrite_2264
main_2
endwrite_2264
main_3
endwrite_2264
main_4
endwrite_2264
main_5
endwrite_2356
main_6
endwrite_2356
main_7
endwrite_2356
main_8
endwrite_2356
main_9
endwrite_2264
endwrite_2356
endwrite_2264
可以看到产生线程的ID多是相同的,是使用了同一个线程还是线程结束后,新线程ID号相同?再次测试。








































main_98
endwrite_2204
endwrite_3884
endwrite_2280
endwrite_2216
endwrite_1632
endwrite_740
endwrite_3760
endwrite_4016
endwrite_1220
endwrite_1784
endwrite_4088
endwrite_3964
endwrite_2160
endwrite_2360
endwrite_2352
endwrite_912
endwrite_2376
endwrite_4048
endwrite_2364
endwrite_4076
endwrite_4008
endwrite_992
main_99
endwrite_2204
endwrite_3884
endwrite_2280
endwrite_2216
endwrite_1632
endwrite_740
endwrite_3760
endwrite_4016
endwrite_1220
endwrite_1784
endwrite_4088
endwrite_3964
endwrite_2160
endwrite_2360
endwrite_2352
endwrite_912
endwrite_2376
endwrite_4048
endwrite_2364
endwrite_4076
endwrite_4008
endwrite_992
endwrite_2204
endwrite_3884
endwrite_2280
endwrite_2216
endwrite_1632
endwrite_740
endwrite_3760
endwrite_4016
endwrite_1220
endwrite_1784
endwrite_4088
endwrite_3964
endwrite_2160
endwrite_2360
endwrite_2352
endwrite_912
endwrite_2376
endwrite_4048
endwrite_2364
endwrite_4076
endwrite_4008
endwrite_992
main_99
endwrite_2204
endwrite_3884
endwrite_2280
endwrite_2216
endwrite_1632
endwrite_740
endwrite_3760
endwrite_4016
endwrite_1220
endwrite_1784
endwrite_4088
endwrite_3964
endwrite_2160
endwrite_2360
endwrite_2352
endwrite_912
endwrite_2376
endwrite_4048
endwrite_2364
endwrite_4076
endwrite_4008
endwrite_992
结论:异步和多线程没有区别,有可能是经过优化后的多线程
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