跟踪asio日志
#define BOOST_ASIO_ENABLE_HANDLER_TRACKING
#include <boost/asio.hpp>
./a.out 2>out.log
sudo apt-get install graphviz
perl handlerviz.pl < out.log | dot -Tpng > out.png
@asio|1528964168.087468|01|[email protected]_wait
@asio|1528964168.087629|02|[email protected]_waitbr/>@asio|1528964181.199519|>1|ec=system:0,signal_number=10
@asio|1528964181.199596|<1|br/>@asio|1528964181.199628|>2|ec=system:0,signal_number=10
@asio|1528964181.199671|<2|
@asio|1528964181.199717|0|[email protected]
out.log格式解释，请参考 https://www.boost.org/doc/libs/1_47_0/doc/html/boost_asio/overview/core/handler_tracking.html
摘抄过来：
Each line is of the form:
<tag>|<timestamp>|<action>|<description>
The <tag> is always @asio, and is used to identify and extract the handler tracking messages from the program output.
The <timestamp> is seconds and microseconds from 1 Jan 1970 UTC.
The <action> takes one of the following forms:
n
The program entered the handler number n. The <description> shows the arguments to the handler. <n
The program left handler number n. !n
The program left handler number n due to an exception. ~n
The handler number n was destroyed without having been invoked. This is usually the case for any unfinished asynchronous operations when the io_service is destroyed. n*m
The handler number n created a new asynchronous operation with completion handler number m. The <description> shows what asynchronous operation was started. n
The handler number n performed some other operation. The <description> shows what function was called. Currently only close() and cancel() operations are logged, as these may affect the state of pending asynchronous operations. Where the <description> shows a synchronous or asynchronous operation, the format is <object-type>@<pointer>.<operation>. For handler entry, it shows a comma-separated list of arguments and their values.
As shown above, Each handler is assigned a numeric identifier. Where the handler tracking output shows a handler number of 0, it means that the action was performed outside of any handler.