”people have more trouble writing correct multithreaded routines using message passing”
The paper makes that claim for blocking bugs, but it also says ”Message passing causes less non-blocking bugs than shared memory synchronization”
Also, having more blocking bugs in message passing could be explained by users using message passing only for the harder cases. I don’t see that discussed in the paper, but ”Message passing […] was even used to fix bugs that are caused by wrong shared memory synchronization.” might hint at it.
Finally, programmers having less familiarity with message passing code might explain the difference in number of blocking bugs, rather than writing message passing code being more difficult.
The paper makes that claim for blocking bugs, but it also says ”Message passing causes less non-blocking bugs than shared memory synchronization”
Also, having more blocking bugs in message passing could be explained by users using message passing only for the harder cases. I don’t see that discussed in the paper, but ”Message passing […] was even used to fix bugs that are caused by wrong shared memory synchronization.” might hint at it.
Finally, programmers having less familiarity with message passing code might explain the difference in number of blocking bugs, rather than writing message passing code being more difficult.