The current isc_hp API uses internal tid_v variable that gets
incremented for each new thread using hazard pointers. This tid_v
variable is then used as a index to global shared table with hazard
pointers state. Since the tid_v is only incremented and never
decremented the table could overflow very quickly if we create set of
threads for short period of time, they finish the work and cease to
exist. Then we create identical set of threads and so on and so on.
This is not a problem for a normal `named` operation as the set of
threads is stable, but the problematic place are the unit tests where we
test network manager or other APIs (task, timer) that create threads.
This commits adds a thin wrapper around any function called from
isc_thread_create() that adds unique-but-reusable small digit thread id
that can be used as index to f.e. hazard pointer tables. The trampoline
wrapper ensures that the thread ids will be reused, so the highest
thread_id number doesn't grow indefinitely when threads are created and
destroyed and then created again. This fixes the hazard pointer table
overflow on machines with many cores. [GL #2396]
Previously isc_thread_join() would return ISC_R_UNEXPECTED on a failure to
create new thread. All such occurences were caught and wrapped into assert
function at higher level. The function was simplified to assert directly in the
isc_thread_join() function and all caller level assertions were removed.
Previously isc_thread_create() would return ISC_R_UNEXPECTED on a failure to
create new thread. All such occurences were caught and wrapped into assert
function at higher level. The function was simplified to assert directly in the
isc_thread_create() function and all caller level assertions were removed.
Cleanup of redundant/useless header file inclusion.
ISC style lint, primarily for function declarations and standalone
comments -- ie, those that appear on a line without any code, which
should be written as follows:
/*
* This is a comment.
*/
Ondřej Surý
Mark AndrewsandMatthijs Mekking
Evan Hunt
Håvard EidnesandOndřej Surý
Tinderbox User
Automatic Updater
Rob Austein
Michael Graff