This patch adds pthread compatibility by using libmthread.
To use this with a program using pthreads, you have to replace
#include <pthread>
with
#define _MTHREADIFY_PTHREADS
#include <minix/mthreads>
This also changes the initialization function to be a constructor, which
is implicitly called before the call to main. This allows for
conformance with pthreads, while not paying a high price by checking on
each mthread_* call whether the library has been initialized or not.
As mthread_init is now a constructor, it also has been set as static, and
relevent calls removed from programs using it.
Change-Id: I2aa375db557958d2bee9a70d285aabb990c88f00
This can be turned back on when the library is compiled with
-DMTHREAD_STRICT (which enables more sanity checks). However,
always performing this check shows up in system profiling results.
Add guard pages to the top of the stack to catch overflow errors.
Moreover, fix a bug where libmthread would keep using a stack that was
just deallocated; a detached thread would deallocate its own stack after
it was finished running).
- Remove sanity checks for initialized mutexes and condition variables. This
significantly boosts performance. The checks can be turned back on by
compiling libmthread with MTHREAD_STRICT. According to POSIX operations on
uninitialized variables are a MAY fail if, therefore allowing this
optimization.
- Test59 has to be accommodated to the lack of sanity checks on uninitialized
variables in the library. It specifically tests for them and will run into
segfaults when the checks are absent in the library.
- Fix a few bugs related to the scheduler
- Do some general code cleanups
Before, the 'main thread' of a process was never taken into account anywhere in
the library, causing mutexes not to work properly (and consequently, neither
did the condition variables). For example, if the 'main thread' (that is, the
thread which is started at the beginning of a process; not a spawned thread by
the library) would lock a mutex, it wasn't actually locked.
