On 08/07/2014 09:54 PM, bbxiong wrote:

Hello, all,

If i write some code like this:
boost::asio::async_read(socket_, bosot::asio::buffer(buffer1_.data(), len1, handler1);
boost::asio::async_read(socket_, boost::asio::buffer(buffer2_.data(), len2, handler2);

Will asio guarantee len1 bytes received by the first async_read, then schedule async_read2?

or the result is undefined(like several bytes filled into buffer1, then next several bytes into buffer, then next several bytes into buffer1)?

I don't believe you're guaranteed that you will get `len1` bytes from the first read; it could be shorter. If you want to ensure that you get exactly that size in the first read, you should use the `transfer_exactly` completion condition:

http://www.boost.org/doc/libs/1_56_0/doc/html/boost_asio/reference/transfer_exactly.html

Jason

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