the signal mask and pending signals of the calling thread. These
are stored in userland in libpthread.
There is a small race condition in this patch which could cause
problems if a signal arrives after setting the (kernel) signal
mask and before exec'ing. The thread's set of pending signals
also are not yet installed in the exec'd process. Both of these
will be corrected with the addition of a special syscall.
Reported & Tested by: Joost Bekkers <joost at jodocus dot org>
Reviewed by: julian, davidxu
a knob to force process scope threads. If the environment variable
LIBPTHREAD_PROCESS_SCOPE is set, force all threads to be process
scope threads regardless of how the application creates them. If
LIBPTHREAD_SYSTEM_SCOPE is set (forcing system scope threads), it
overrides LIBPTHREAD_PROCESS_SCOPE.
$ # To force system scope threads
$ LIBPTHREAD_SYSTEM_SCOPE=anything threaded_app
$ # To force process scope threads
$ LIBPTHREAD_PROCESS_SCOPE=anything threaded_app
LIBPTHREAD_SYSTEM_SCOPE in the environment.
You can still force libpthread to be built in strictly 1:1 by
adding -DSYSTEM_SCOPE_ONLY to CFLAGS. This is kept for archs
that don't yet support M:N mode.
Requested by: rwatson
Reviewed by: davidxu
1. Add global varible _libkse_debug, debugger uses the varible to identify
libpthread. when the varible is written to non-zero by debugger, libpthread
will take some special action at context switch time, it will check
TMDF_DOTRUNUSER flags, if a thread has the flags set by debugger, it won't
be scheduled, when a thread leaves KSE critical region, thread checks
the flag, if it was set, the thread relinquish CPU.
2. Add pq_first_debug to select a thread allowd to run by debugger.
3. Some names prefixed with _thr are renamed to _thread prefix.
which is allowed to run by debugger.
sigsuspend, thread shouldn't wait, in old code, it may be
ignored.
When a signal handler is invoked in sigsuspend, thread gets
two different signal masks, one is in thread structure,
sigprocmask() can retrieve it, another is in ucontext
which is a third parameter of signal handler, the former is
the result of sigsuspend mask ORed with sigaction's sa_mask
and current signal, the later is the mask in thread structure
before sigsuspend is called. After signal handler is called,
the mask in ucontext should be copied into thread structure,
and becomes CURRENT signal mask, then sigsuspend returns to
user code.
Reviewed by: deischen
Tested by: Sean McNeil <sean@mcneil.com>
mode (where the forked thread is the one and only thread and
is marked as system scope), set the system scope flag before
initializing the signal mask. This prevents trying to use
internal locks that haven't yet been initialized.
Reported by: Dan Nelson <dnelson at allantgroup.com>
Reviewed by: davidxu
These files had tags after the copyright notice,
inside the comment block (incorrect, removed),
and outside the comment block (correct).
Approved by: rwatson (mentor)
on a rwlock while there are writers waiting. We normally favor
writers but when a reader already has at least one other read lock,
we favor the reader. We don't track all the rwlocks owned by a
thread, nor all the threads that own a rwlock -- we just keep
a count of all the read locks owned by a thread.
PR: 24641
likely to be non-zero. When leaving the cancellation point, check
the return value against -1 to see if cancellation should be
checked. While I'm here, make the same change to connect() just
to be consisitent.
Pointed out by: davidxu
_thr_leave_cancellation_point to _thr_cancel_leave, add a parameter
to _thr_cancel_leave to indicate whether cancellation point should be
checked, this gives us an option to not check cancallation point if
a syscall successfully returns to avoid any leaks, current I have
creat(), open() and fcntl(F_DUPFD) to not check cancellation point
after they sucessfully returned.
Replace some members in structure kse with bit flags to same some
memory.
Conditionally compile THR_ASSERT to nothing if _PTHREAD_INVARIANTS is
not defined.
Inline some small functions in thr_cancel.c.
Use __predict_false in thr_kern.c for some executed only once code.
Reviewd by: deischen
through branch predict as suggested in INTEL IA32 optimization guide.
2.Allocate siginfo arrary separately to avoid pthread to be allocated at
2K boundary, which hits L1 address alias problem and causes context
switch to be slow down.
3.Simplify context switch code by removing redundant code, code size is
reduced, so it is expected to run faster.
Reviewed by: deischen
Approved by: re (scottl)
in init_main_thread. Also don't initialize lock and lockuser again for initial
thread, it is already done by _thr_alloc().
Reviewed by: deischen
Approved by: re (scottl)
signal handling mode, there is no chance to handle the signal, something
must be wrong in the library, just call kse_thr_interrupt to dump its core.
I have the code for a long time, but forgot to commit it.
