History log of /haiku/src/system/kernel/sem.cpp
Revision Date Author Comments
# daf1dd9c 28-Nov-2023 Augustin Cavalier <waddlesplash@gmail.com>

kernel/sem: Use "count" as thread_unblock status in B_RELEASE_ALL.

Previously, "count" did nothing for B_RELEASE_ALL. Now, if it is
< 0, it will be the error code returned by acquire_sem() of any
waiting threads.

As B_RELEASE_ALL is a Haiku extension, this change should not
cause any compatibility problems that we cannot fix.

This will be useful in implementing some features of TUN/TAP
with network FIFOs.

Change-Id: I2dbccedefac2024fe740b87543ff3b80f5257e20
Reviewed-on: https://review.haiku-os.org/c/haiku/+/7163
Reviewed-by: waddlesplash <waddlesplash@gmail.com>


# 87bdc2b0 05-Aug-2019 Adrien Destugues <pulkomandy@pulkomandy.tk>

fix dumping semaphores by name

There was no check for strtoul success or failure (it returns 0 on
failure but that is also a valid conversion result). Detect if endptr
has been advanced instead (meaning there were some parsed characters in
strtoul so the argument at least starts with a number)

Change-Id: Ieefbd57a250ddcdb9362094389151c2a432e4c73
Reviewed-on: https://review.haiku-os.org/c/1683
Reviewed-by: Rene Gollent <rene@gollent.com>


# 698c471f 22-Jul-2019 waddlesplash <waddlesplash@gmail.com>

kernel/sem: Restore interrupts-unlock before free().


# 0a564c2c 20-Jul-2019 Augustin Cavalier <waddlesplash@gmail.com>

kernel/sem: Drop GRAB macros in favor of SpinLockers.

No functional change intended.

Change-Id: I24f6f8c55b18f8d031d0b5a87672cc969e141577
Reviewed-on: https://review.haiku-os.org/c/1636
Reviewed-by: waddlesplash <waddlesplash@gmail.com>


# 1eededf1 17-Feb-2019 Augustin Cavalier <waddlesplash@gmail.com>

kernel: Only sanity-check interrupts in switch_sem_etc under KDEBUG.

"are_interrupts_enabled()" is a "relatively" expensive function, so avoiding
it makes sense. This is the same way it's done elsewhere in sem.cpp, as well
as for mutexes and condition variables also.


# f8ea9ed5 15-Jan-2019 Augustin Cavalier <waddlesplash@gmail.com>

kernel/sem: Fix -Wformat.


# 2e33d79d 07-Jan-2019 Augustin Cavalier <waddlesplash@gmail.com>

kernel: Panic on attempting to release a semaphore with interrupts disabled...

... and B_DO_NOT_RESCHEDULE unset. We already have equivalent panics
for mutexes and condition variables, so it seems to make sense to
check for this too.

There have been some bug reports recently about hard deadlocks with
symptoms (i.e. kernel debugger can't even be summoned) that match
"interrupt handler thread was context-switched while holding interrupt
lock," and this is the only major remaining path to that without
such a check.

This would have also helped me with recent FreeBSD driver porting;
I forgot to pass the flag once and deadlocked my system in precisely
this manner.


# 03fb2d88 07-Nov-2013 Pawel Dziepak <pdziepak@quarnos.org>

kernel: Remove gSchedulerLock

* Thread::scheduler_lock protects thread state, priority, etc.
* sThreadCreationLock protects thread creation and removal and list of
threads in team.
* Team::signal_lock and Team::time_lock protect list of threads in team
as well.
* Scheduler uses its own internal locking.


# 11cacd0c 04-Nov-2013 Pawel Dziepak <pdziepak@quarnos.org>

kernel: Remove thread_block_with_timeout_locked()


# c8dd9f77 29-Oct-2013 Pawel Dziepak <pdziepak@quarnos.org>

kernel: Add thread_unblock() and use it where possible


# d1f280c8 01-Apr-2012 Hamish Morrison <hamishm53@gmail.com>

Add support for pthread_attr_get/setguardsize()

* Added the aforementioned functions.
* create_area_etc() now takes a guard size parameter.
* The thread_info::stack_base/end range now refers to the usable range
only.


# b7b5d763 17-Dec-2012 Sergei Reznikov <diver@gelios.net>

64-bit fixes for kernel with KDEBUG_LEVEL = 0

Signed-off-by: Alex Smith <alex@alex-smith.me.uk>


# c3f0fd28 12-Jul-2012 Alex Smith <alex@alex-smith.me.uk>

Fixed formatting of output in some debugger commands.

Currently all debugger commands assume 32-bit pointers when formatting their
output. This means that on x86_64 the output is incorrectly formatted. Fixed
this by adding a B_PRINTF_POINTER_WIDTH definition (16 on 64-bit, 8 on
32-bit), and using this to correctly format the output. Not all commands have
been fixed yet, but all VM, slab, VFS, team, thread and image commands should
be correct.


# 0e88a887 13-Jun-2012 Alex Smith <alex@alex-smith.me.uk>

First round of 64-bit safety fixes in the kernel.

* Most of this is incorrect printf format strings. Changed all strings
causing errors to use the B_PRI* format string definitions, which
means the strings should be correct across all platforms.
* Some other fixes for errors, casts required, etc.


# c83bde41 05-Apr-2012 Ingo Weinhold <ingo_weinhold@gmx.de>

switch_sem_etc(): Unbreak the actual switch case

The scheduler lock was still being held when release_sem_etc() was
called. The bug was introduced in
24df65921befcd0ad0c5c7866118f922da61cb96. Fixes #8448.


# 24df6592 11-Jun-2011 Ingo Weinhold <ingo_weinhold@gmx.de>

Merged signals-merge branch into trunk with the following changes:
* Reorganized the kernel locking related to threads and teams.
* We now discriminate correctly between process and thread signals. Signal
handlers have been moved to teams. Fixes #5679.
* Implemented real-time signal support, including signal queuing, SA_SIGINFO
support, sigqueue(), sigwaitinfo(), sigtimedwait(), waitid(), and the addition
of the real-time signal range. Closes #1935 and #2695.
* Gave SIGBUS a separate signal number. Fixes #6704.
* Implemented <time.h> clock and timer support, and fixed/completed alarm() and
[set]itimer(). Closes #5682.
* Implemented support for thread cancellation. Closes #5686.
* Moved send_signal() from <signal.h> to <OS.h>. Fixes #7554.
* Lots over smaller more or less related changes.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@42116 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 4535495d 10-Jan-2011 Ingo Weinhold <ingo_weinhold@gmx.de>

Merged the signals branch into trunk, with these changes:
* The team and thread kernel structures have been renamed to Team and Thread
respectively and moved into the new BKernel namespace.
* Several (kernel add-on) sources have been converted from C to C++ since
private kernel headers are included that are no longer C compatible.

Changes after merging:
* Fixed gcc 2 build (warnings mainly in the scary firewire bus manager).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@40196 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 5e2ed2f3 07-Aug-2010 Stefano Ceccherini <stefano.ceccherini@gmail.com>

tempName was leaked in case team was NULL. CID 1702


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37970 a95241bf-73f2-0310-859d-f6bbb57e9c96


# a8ad734f 14-Jun-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

* Introduced structures {virtual,physical}_address_restrictions, which specify
restrictions for virtual/physical addresses.
* vm_page_allocate_page_run():
- Fixed conversion of base/limit to array indexes. sPhysicalPageOffset was not
taken into account.
- Takes a physical_address_restrictions instead of base/limit and also
supports alignment and boundary restrictions, now.
* map_backing_store(), VM[User,Kernel]AddressSpace::InsertArea()/
ReserveAddressRange() take a virtual_address_restrictions parameter, now. They
also support an alignment independent from the range size.
* create_area_etc(), vm_create_anonymous_area(): Take
{virtual,physical}_address_restrictions parameters, now.
* Removed no longer needed B_PHYSICAL_BASE_ADDRESS.
* DMAResources:
- Fixed potential overflows of uint32 when initializing from device node
attributes.
- Fixed bounce buffer creation TODOs: By using create_area_etc() with the
new restrictions parameters we can directly support physical high address,
boundary, and alignment.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37131 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 7198f765 05-May-2010 Axel Dörfler <axeld@pinc-software.de>

* During early kernel startup, we must not create areas without the
CREATE_AREA_DONT_WAIT flag; waiting at this point is not allowed.
* I hope I found all occurences, but there might be some areas left (note,
only those that don't use B_ALREADY_WIRED are problematic).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@36624 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 0338371f 13-Dec-2009 Ingo Weinhold <ingo_weinhold@gmx.de>

* All scheduler implementations:
- enqueue_in_run_queue() no longer returns whether rescheduling is supposed
to happen. Instead is sets cpu_ent::invoke_scheduler on the current CPU.
- reschedule() does now handle cpu_ent::invoke_scheduler_if_idle(). No need
to let all callers do that.
* thread_unblock[_locked]() no longer return whether rescheduling is supposed
to happen.
* Got rid of the B_INVOKE_SCHEDULER handling. The interrupt hooks really
can't know, when it makes sense to reschedule or not.
* Introduced scheduler_reschedule_if_necessary[_locked]() functions for
checking+invoking the scheduler.
* Some semaphore functions (e.g. delete_sem()) invoke the scheduler now, if
they wake up anything with greater priority.
I've also tried to add scheduler invocations in the condition variable and
mutex/rw_lock code, but that actually has a negative impact on performance,
probably because it causes too much ping-ponging between threads when
multiple locking primitives are involved.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34657 a95241bf-73f2-0310-859d-f6bbb57e9c96


# e50cf876 02-Dec-2009 Ingo Weinhold <ingo_weinhold@gmx.de>

* Moved the VM headers into subdirectory vm/.
* Renamed vm_cache.h/vm_address_space.h to VMCache.h/VMAddressSpace.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34449 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 07d45563 16-Nov-2009 Axel Dörfler <axeld@pinc-software.de>

* Change get_next_sem_info() to be index based, not ID based - the semaphore IDs
aren't monotonically increasing which this code was assuming. This fixes bug
#4917.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34074 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 0087f940 26-Oct-2009 Axel Dörfler <axeld@pinc-software.de>

* sem_entry no contains a pointer to the owning team, instead of only its
ID.
* Accidently, this should also fix bug #4839.
* Optimized _get_next_sem_info() a whole lot by iterating over the team's
semaphore list.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@33773 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 07e9fd1d 26-Oct-2009 Axel Dörfler <axeld@pinc-software.de>

* sem_delete_owned_sems() now grabs the team lock for a very short time, and
once only.
* Improved missing team warning.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@33770 a95241bf-73f2-0310-859d-f6bbb57e9c96


# ddbe1200 22-Oct-2009 Axel Dörfler <axeld@pinc-software.de>

* Semaphores are now put into the team struct in a doubly linked list.
* This makes sem_delete_owned_sems() a lot more efficient; before it would need
to scan the entire semaphore table.
* This speeds up the test build of the kernel by another 2 seconds (with
KDEBUG=2) on my laptop.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@33743 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 009ccc29 20-Aug-2009 Rene Gollent <anevilyak@gmail.com>

anevilyak+mmlr:
* scheduler_enqueue_in_runqueue() now allows the scheduler to return a hint as to whether a reschedule is desirable or not. This is used in a few other places in order to relegate scheduling decisions entirely to the scheduler rather than the priority hacks previously used. There are probably other places in the kernel that could now make use of that information to more intelligently call reschedule() though.
* Switch over the default scheduler to scheduler_affine().



git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@32554 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 227fe7d3 23-Apr-2009 Ingo Weinhold <ingo_weinhold@gmx.de>

* Scheduler/wait object listener:
- Moved scheduler listening interface to <listeners.h> and added more
convenient to use templatized notification functions.
- Added a listener mechanism for the wait objects (semaphores, condition
variables, mutex, rw_lock).
* system profiler:
- Hopefully fixed locking issues related to notifying the profiler thread
for good. We still had an inconsistent locking order, since the scheduler
notification callbacks are invoked with the thread lock held and have to
acquire the object lock then, while the other callbacks acquired the object
lock first and as a side effect of ConditionVariable::NotifyOne() acquired
the thread lock. Now we make sure the object lock is the innermost lock.
- Track the number of dropped events due to a full buffer.
_user_system_profiler_next_buffer() returns this count now.
- When scheduling profiling events are requested also listen to wait objects
and generate the respective profiling events. We send those events lazily
and cache the infos to avoid resending an event for the same wait object.
- When starting profiling we do now generate "thread scheduled" events for
the already running threads.
- _user_system_profiler_start(): Check whether the parameters pointer is a
userland address at all.
- The system_profiler_team_added event does now also contain the team's name.
* Added a sem_get_name_unsafe() returning a semaphore's name. It is "unsafe",
since the caller has to ensure that the semaphore exists and continues to
exist as long as the returned name is used.
* Adjusted the "profile" and "scheduling_recorder" according to the system
profiling changes. The latter prints the number of dropped events, now.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30345 a95241bf-73f2-0310-859d-f6bbb57e9c96


# c8b762e4 20-Mar-2009 Axel Dörfler <axeld@pinc-software.de>

* Userland applications can no longer delete kernel semaphores. However, they
are still allowed to delete semaphores of other teams...
* Anyway, this fixes bug #3585.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29621 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 209c0f49 23-Oct-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

0 is a valid semaphore ID.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28292 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 59dbd26f 20-Oct-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

* Moved more debug macros to kernel_debug_config.h.
* Turned the checks for all those macros to "#if"s instead of "#ifdef"s.
* Introduced macro KDEBUG_LEVEL which serves as a master setting.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28248 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 537d0818 03-Sep-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

release_sem_etc(): Reschedule only when a thread with a priority greater
than that of the current thread has been woken up. I didn't see the
reason why the thread should otherwise relinquish the rest of its
quantum. I noticed for instance that client and app server window
threads were ping-ponging more than seemed necessary. In most cases
when the client sent a port message it would be unscheduled although it
had run only for a few microseconds and had still stuff to do.
I measured a relatively Terminal-heavy "find /boot" (second run), which
does now take 5-10% less time.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27314 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 020ac568 03-Sep-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

* Fixed bug in the "scheduler" command: The check when a thread was
unscheduled was incorrect.
* Introduced _kern_analyze_scheduling() syscall. It requires scheduler
kernel tracing to be enabled. It uses the tracing entries for a given
period of time to do a similar analysis the "scheduler" debugger
command does (i.e. number of runs, run time, latencies, preemption
times) for each thread. Additionally the analysis includes for each
thread how long the thread waited on each locking primitive in total.
* Added kernel tracing for the creation of semaphores and initialization
of condition variables, mutexes, and rw locks. The enabling macro is
SCHEDULING_ANALYSIS_TRACING. The only purpose is to provide
_kern_analyze_scheduling() with more info on the locking primitives
(the name in particular).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27304 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 6bf26da2 02-Aug-2008 Axel Dörfler <axeld@pinc-software.de>

* Renamed sem_spinlock to sSemsSpinlock.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26732 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 27245755 02-Aug-2008 Axel Dörfler <axeld@pinc-software.de>

* Renamed kernel_startup to gKernelStartup.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26731 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 15374c5d 02-Aug-2008 Axel Dörfler <axeld@pinc-software.de>

* Renamed thread_spinlock and team_spinlock to gThreadSpinlock and
gTeamSpinlock.
* Renamed the static global variables in smp.c to match our style guide.
* Minor other cleanup.
* Removed superfluous white space.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26730 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 5c99d639 22-Jul-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

Merged branch haiku/branches/developer/bonefish/vm into trunk. This
introduces the following relevant changes:
* VMCache:
- Renamed vm_cache to VMCache, merged it with vm_store and made it a
C++ class with virtual methods (replacing the store operations).
Turned the different store implementations into subclasses.
- Introduced MergeStore() callback, changed semantics of Commit().
- Changed locking and referencing semantics. A reference can only be
acquired/released with the cache locked. An unreferenced cache is
deleted and a mergeable cache merged when it is unlocked. This
removes the "busy" state of a cache and simplifies the page fault
code.
* Added VMAnonymousCache, which will implement swap support (work by
Zhao Shuai). It is not integrated and used yet, though.
* Enabled the mutex/recursive lock holder asserts.
* Fixed DoublyLinkedList::Swap().
* Generalized the low memory handler to a low resource handler. And made
semaphores and reserved memory handled resources. Made
vm_try_resource_memory() optionally wait (with timeout), and used that
feature to reserve memory for areas.
...


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26572 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 1c8de858 01-Jun-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

* Added optional spinlock contention measurement feature. Enabled when
B_DEBUG_SPINLOCK_CONTENTION is defined to 1. It typedefs spinlock to a
structure (thus breaking BeOS binary compatibility), containing a
counter which is incremented whenever a thread has to wait for the
spinlock.
* Added macros for spinlock initialization and access and changed
code using spinlocks accordingly. This breaks compilation for BeOS --
the macros should be defined in the respective compatibility wrappers.
* Added generic syscall to get the spinlock counters for the thread and
the team spinlocks.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25752 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 5142c2ac 05-May-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

Added support for POSIX semaphores (the ones from the XSI extension
Realtime option group). The implementation should be complete, but is
totally untested yet.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25326 a95241bf-73f2-0310-859d-f6bbb57e9c96


# e225a906 24-Apr-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

With my recent changes release_sem_etc() accidentally lost the
cleverness to reschedule only, if it actually unblocked another thread.
Should have been the reason for #2152 (overall slowdown).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25131 a95241bf-73f2-0310-859d-f6bbb57e9c96


# b95f6d47 22-Apr-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

* Introduced a set of functions (thread_prepare_to_block(),
thread_block(), thread_unblock(),...) that allow a thread to wait for
something without needing a semaphore or condition variable. It can
simply block and another thread can unblock it. Supports timeouts and
interrupting. Both semaphores and condition variables use this
common mechanism, now.
* Semaphores:
- Some simplifications due to the thread blocking mechanism.
- Changed locking order to sem -> thread. It was the other way around
before and when introducing the wait_for_objects() support I had
also introduced a situation where the locking was reverse, which
could potentially cause a dead lock on SMP systems.
- Instead of queueing thread structures, a semaphore queues
queued_thread entries now, which are created on the stack. The
thread::sem structure could thus be removed.
- Added sem_entry::net_count, which is sem_entry::count plus the
acquisition count of all waiting threads. This number is needed in
remove_thread_from_sem() and instead of computing it there we
maintain it.
- Fixed remove_thread_from_sem(). It would not unblock threads, if
the sem count was <= 0.
- Made sem::last_acquirer unconditional. It is actually needed for
sem_info::latest_holder. Fixed fill_sem_info() accordingly.
- Added some optional tracing output, though only via ktrace_printf().
* Condition variables:
- Could be simplified significantly through the use of the thread
blocking mechanism. Removed a good deal of unnecessary code.
- Moved the ConditionVariableEntry "flags" parameter from Wait() to
Add(), and adjusted all places where condition variables are used
accordingly.
* snooze() uses thread_block_with_timeout() instead of a semaphore.
* Simplified thread interrupting in the signal and user debugger code.
Instead of separate functions for threads waiting on a semaphore or
condititon variable, we only have a single thread_interrupt(), now.



git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25099 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 037f7094 09-Apr-2008 Axel Dörfler <axeld@pinc-software.de>

* Cleaned up KernelExport.h completely, removed deprecated and non implemented
API, uses the _PRINTFLIKE macro where appropriate.
* Got rid of the "qent" structure, struct timer now contains everything we
need. This makes the affected code in sem.cpp, signal.cpp, and timer.c much
cleaner, and resolves a few TODOs.
* Minor cleanup in vfs.cpp.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@24871 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 20e4f92c 23-Feb-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

switch_sem_etc() doesn't check the return value of add_timer(), hence we
need to make sure that we never get that far with a negative timeout or
we'll wait forever.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@24083 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 4048494c 17-Feb-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

axeld + bonefish:
* Implemented automatic syscall restarts:
- A syscall can indicate that it has been interrupted and can be
restarted by setting a respective bit in thread::flags. It can
store parameters it wants to be preserved for the restart in
thread::syscall_restart::parameters. Another thread::flags bit
indicates whether it has been restarted.
- handle_signals() clears the restart flag, if the handled signal
has a handler function installed and SA_RESTART is not set. Another
thread flag (THREAD_FLAGS_DONT_RESTART_SYSCALL) can prevent syscalls
from being restarted, even if they could be (not used yet, but we
might want to use it in resume_thread(), so that we stay
behaviorally compatible with BeOS).
- The architecture specific syscall handler restarts the syscall, if
the restart flag is set. Implemented for x86 only.
- Added some support functions in the private <syscall_restart.h> to
simplify the syscall restart code in the syscalls.
- Adjusted all syscalls that can potentially be restarted accordingly.
- _user_ioctl() sets new thread flag THREAD_FLAGS_IOCTL_SYSCALL while
calling the underlying FS's/driver's hook, so that syscall restarts
can also be supported there.
* thread_at_kernel_exit() invokes handle_signals() in a loop now, as
long as the latter indicates that the thread shall be suspended, so
that after waking up signals received in the meantime will be handled
before the thread returns to userland. Adjusted handle_signals()
accordingly -- when encountering a suspending signal we don't check
for further signals.
* Fixed sigsuspend(): Suspending the thread and rescheduling doesn't
result in the correct behavior. Instead we employ a temporary
condition variable and interruptably wait on it. The POSIX test
suite test passes, now.
* Made the switch_sem[_etc]() behavior on interruption consistent.
Depending on when the signal arrived (before the call or when already
waiting) the first semaphore would or wouldn't be released. Now we
consistently release it.
* Refactored _user_{read,write}[v]() syscalls. Use a common function for
either pair. The iovec version doesn't fail anymore, if anything could
be read/written at all. It also checks whether a complete vector
could be read/written, so that we won't skip data, if the underlying
FS/driver couldn't read/write more ATM.
* Some refactoring in the x86 syscall handler: The int 99 and sysenter
handlers use a common subroutine to avoid code duplication.



git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23983 a95241bf-73f2-0310-859d-f6bbb57e9c96


# c486dde9 28-Jan-2008 Marcus Overhagen <marcusoverhagen@gmail.com>

cosmetic


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23778 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 36b55f46 26-Jan-2008 Michael Lotz <mmlr@mlotz.ch>

Don't panic in case a thread is not in the wait queue of a sem anymore. On SMP
systems it can easily happen that the thread gets removed from the queue (when
it times out for example) during the time we don't hold the sem lock.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23749 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 1b0e74fc 26-Jan-2008 Michael Lotz <mmlr@mlotz.ch>

Don't clobber the thread variable as we use it again. Since it always is NULL
at the end of that loop we guaranteed a crash when this special handling was
triggered.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23748 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 7e80cf00 25-Jan-2008 Michael Lotz <mmlr@mlotz.ch>

Missed this setting of thread state which is now unnecessary. Otherwise nothing in the kernel seems to mess with the state outside of the scheduler so checking for B_THREAD_RUNNING there should be fine.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23740 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 6761f5a6 25-Jan-2008 Michael Lotz <mmlr@mlotz.ch>

Move the handling of still running threads into scheduler_enqueue_in_run_queue().
This should be in line with all uses of scheduler_enqueue_in_run_queue() and
simplifies a few places where it is used.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23738 a95241bf-73f2-0310-859d-f6bbb57e9c96


# d9256509 25-Jan-2008 Michael Lotz <mmlr@mlotz.ch>

Apply the same logic as in r23731 to all other places in the semaphore code
where threads are enqueued into the run queue.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23733 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 2f3f3d79 25-Jan-2008 Michael Lotz <mmlr@mlotz.ch>

Fix the underlying problem that caused the issue of running threads being
enqueued into the run_queue again. Modified the workaround to a panic in the
scheduler so we notice when something else does the same.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23731 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 5aee691e 17-Jan-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

The "sem" and "port" debugger commands set some temporary variables,
now.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23595 a95241bf-73f2-0310-859d-f6bbb57e9c96


# ce637fda 17-Jan-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

Added usage (respectively more detailed usage) messages for "sem",
"sems", "port", and "ports" debugger commands.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23586 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 224aee3f 17-Jan-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

sem.c -> sem.cpp, port.c -> port.cpp


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23585 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 03fb2d886830e4dd4b344c56725db59f96733216 07-Nov-2013 Pawel Dziepak <pdziepak@quarnos.org>

kernel: Remove gSchedulerLock

* Thread::scheduler_lock protects thread state, priority, etc.
* sThreadCreationLock protects thread creation and removal and list of
threads in team.
* Team::signal_lock and Team::time_lock protect list of threads in team
as well.
* Scheduler uses its own internal locking.


# 11cacd0c1345cd3296f12e07d18996a2c7572a64 04-Nov-2013 Pawel Dziepak <pdziepak@quarnos.org>

kernel: Remove thread_block_with_timeout_locked()


# c8dd9f7780c426e592a3ccb231e6bfab51f15eb9 29-Oct-2013 Pawel Dziepak <pdziepak@quarnos.org>

kernel: Add thread_unblock() and use it where possible


# d1f280c80529d5f0bc55030c2934f9255bc7f6a2 01-Apr-2012 Hamish Morrison <hamishm53@gmail.com>

Add support for pthread_attr_get/setguardsize()

* Added the aforementioned functions.
* create_area_etc() now takes a guard size parameter.
* The thread_info::stack_base/end range now refers to the usable range
only.


# b7b5d7636b96de53bb4327684cc1843e56f62320 17-Dec-2012 Sergei Reznikov <diver@gelios.net>

64-bit fixes for kernel with KDEBUG_LEVEL = 0

Signed-off-by: Alex Smith <alex@alex-smith.me.uk>


# c3f0fd28cda13d70a8c092003609442e4e29cf78 12-Jul-2012 Alex Smith <alex@alex-smith.me.uk>

Fixed formatting of output in some debugger commands.

Currently all debugger commands assume 32-bit pointers when formatting their
output. This means that on x86_64 the output is incorrectly formatted. Fixed
this by adding a B_PRINTF_POINTER_WIDTH definition (16 on 64-bit, 8 on
32-bit), and using this to correctly format the output. Not all commands have
been fixed yet, but all VM, slab, VFS, team, thread and image commands should
be correct.


# 0e88a887b4a9ecaaf1062078d9ca9bfca78fcf3a 13-Jun-2012 Alex Smith <alex@alex-smith.me.uk>

First round of 64-bit safety fixes in the kernel.

* Most of this is incorrect printf format strings. Changed all strings
causing errors to use the B_PRI* format string definitions, which
means the strings should be correct across all platforms.
* Some other fixes for errors, casts required, etc.


# c83bde410aa07480175ab2b0743c35da9a0572bb 05-Apr-2012 Ingo Weinhold <ingo_weinhold@gmx.de>

switch_sem_etc(): Unbreak the actual switch case

The scheduler lock was still being held when release_sem_etc() was
called. The bug was introduced in
24df65921befcd0ad0c5c7866118f922da61cb96. Fixes #8448.


# 24df65921befcd0ad0c5c7866118f922da61cb96 11-Jun-2011 Ingo Weinhold <ingo_weinhold@gmx.de>

Merged signals-merge branch into trunk with the following changes:
* Reorganized the kernel locking related to threads and teams.
* We now discriminate correctly between process and thread signals. Signal
handlers have been moved to teams. Fixes #5679.
* Implemented real-time signal support, including signal queuing, SA_SIGINFO
support, sigqueue(), sigwaitinfo(), sigtimedwait(), waitid(), and the addition
of the real-time signal range. Closes #1935 and #2695.
* Gave SIGBUS a separate signal number. Fixes #6704.
* Implemented <time.h> clock and timer support, and fixed/completed alarm() and
[set]itimer(). Closes #5682.
* Implemented support for thread cancellation. Closes #5686.
* Moved send_signal() from <signal.h> to <OS.h>. Fixes #7554.
* Lots over smaller more or less related changes.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@42116 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 4535495d80c86e19e2610e7444a4fcefe3e0f8e6 10-Jan-2011 Ingo Weinhold <ingo_weinhold@gmx.de>

Merged the signals branch into trunk, with these changes:
* The team and thread kernel structures have been renamed to Team and Thread
respectively and moved into the new BKernel namespace.
* Several (kernel add-on) sources have been converted from C to C++ since
private kernel headers are included that are no longer C compatible.

Changes after merging:
* Fixed gcc 2 build (warnings mainly in the scary firewire bus manager).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@40196 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 5e2ed2f356cdf9ddb7d76be1392b7f88b7a6f072 07-Aug-2010 Stefano Ceccherini <stefano.ceccherini@gmail.com>

tempName was leaked in case team was NULL. CID 1702


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37970 a95241bf-73f2-0310-859d-f6bbb57e9c96


# a8ad734f1c698917badb15e1641e0f38b3e9a013 14-Jun-2010 Ingo Weinhold <ingo_weinhold@gmx.de>

* Introduced structures {virtual,physical}_address_restrictions, which specify
restrictions for virtual/physical addresses.
* vm_page_allocate_page_run():
- Fixed conversion of base/limit to array indexes. sPhysicalPageOffset was not
taken into account.
- Takes a physical_address_restrictions instead of base/limit and also
supports alignment and boundary restrictions, now.
* map_backing_store(), VM[User,Kernel]AddressSpace::InsertArea()/
ReserveAddressRange() take a virtual_address_restrictions parameter, now. They
also support an alignment independent from the range size.
* create_area_etc(), vm_create_anonymous_area(): Take
{virtual,physical}_address_restrictions parameters, now.
* Removed no longer needed B_PHYSICAL_BASE_ADDRESS.
* DMAResources:
- Fixed potential overflows of uint32 when initializing from device node
attributes.
- Fixed bounce buffer creation TODOs: By using create_area_etc() with the
new restrictions parameters we can directly support physical high address,
boundary, and alignment.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37131 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 7198f76564e4b062401bb95f6ddf540bbf9e8625 05-May-2010 Axel Dörfler <axeld@pinc-software.de>

* During early kernel startup, we must not create areas without the
CREATE_AREA_DONT_WAIT flag; waiting at this point is not allowed.
* I hope I found all occurences, but there might be some areas left (note,
only those that don't use B_ALREADY_WIRED are problematic).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@36624 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 0338371f26864c2a248b1ea53b9fe78c884af7f2 13-Dec-2009 Ingo Weinhold <ingo_weinhold@gmx.de>

* All scheduler implementations:
- enqueue_in_run_queue() no longer returns whether rescheduling is supposed
to happen. Instead is sets cpu_ent::invoke_scheduler on the current CPU.
- reschedule() does now handle cpu_ent::invoke_scheduler_if_idle(). No need
to let all callers do that.
* thread_unblock[_locked]() no longer return whether rescheduling is supposed
to happen.
* Got rid of the B_INVOKE_SCHEDULER handling. The interrupt hooks really
can't know, when it makes sense to reschedule or not.
* Introduced scheduler_reschedule_if_necessary[_locked]() functions for
checking+invoking the scheduler.
* Some semaphore functions (e.g. delete_sem()) invoke the scheduler now, if
they wake up anything with greater priority.
I've also tried to add scheduler invocations in the condition variable and
mutex/rw_lock code, but that actually has a negative impact on performance,
probably because it causes too much ping-ponging between threads when
multiple locking primitives are involved.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34657 a95241bf-73f2-0310-859d-f6bbb57e9c96


# e50cf8765be50a7454c9488db38b638cf90805af 02-Dec-2009 Ingo Weinhold <ingo_weinhold@gmx.de>

* Moved the VM headers into subdirectory vm/.
* Renamed vm_cache.h/vm_address_space.h to VMCache.h/VMAddressSpace.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34449 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 07d455634689a48ad5e3c1289dd6773a274e58bd 16-Nov-2009 Axel Dörfler <axeld@pinc-software.de>

* Change get_next_sem_info() to be index based, not ID based - the semaphore IDs
aren't monotonically increasing which this code was assuming. This fixes bug
#4917.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34074 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 0087f9409bdd85d996c69c0a0cdb9a35b478abef 26-Oct-2009 Axel Dörfler <axeld@pinc-software.de>

* sem_entry no contains a pointer to the owning team, instead of only its
ID.
* Accidently, this should also fix bug #4839.
* Optimized _get_next_sem_info() a whole lot by iterating over the team's
semaphore list.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@33773 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 07e9fd1d8427a325a8637e3108633023b56b41cc 26-Oct-2009 Axel Dörfler <axeld@pinc-software.de>

* sem_delete_owned_sems() now grabs the team lock for a very short time, and
once only.
* Improved missing team warning.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@33770 a95241bf-73f2-0310-859d-f6bbb57e9c96


# ddbe12007a455315c7904deeea339dc8827c66ad 22-Oct-2009 Axel Dörfler <axeld@pinc-software.de>

* Semaphores are now put into the team struct in a doubly linked list.
* This makes sem_delete_owned_sems() a lot more efficient; before it would need
to scan the entire semaphore table.
* This speeds up the test build of the kernel by another 2 seconds (with
KDEBUG=2) on my laptop.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@33743 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 009ccc29623e2b54f3e881739754c5cea121e7d6 20-Aug-2009 Rene Gollent <anevilyak@gmail.com>

anevilyak+mmlr:
* scheduler_enqueue_in_runqueue() now allows the scheduler to return a hint as to whether a reschedule is desirable or not. This is used in a few other places in order to relegate scheduling decisions entirely to the scheduler rather than the priority hacks previously used. There are probably other places in the kernel that could now make use of that information to more intelligently call reschedule() though.
* Switch over the default scheduler to scheduler_affine().



git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@32554 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 227fe7d34aeed45d0727a0abde2ea2309352983b 23-Apr-2009 Ingo Weinhold <ingo_weinhold@gmx.de>

* Scheduler/wait object listener:
- Moved scheduler listening interface to <listeners.h> and added more
convenient to use templatized notification functions.
- Added a listener mechanism for the wait objects (semaphores, condition
variables, mutex, rw_lock).
* system profiler:
- Hopefully fixed locking issues related to notifying the profiler thread
for good. We still had an inconsistent locking order, since the scheduler
notification callbacks are invoked with the thread lock held and have to
acquire the object lock then, while the other callbacks acquired the object
lock first and as a side effect of ConditionVariable::NotifyOne() acquired
the thread lock. Now we make sure the object lock is the innermost lock.
- Track the number of dropped events due to a full buffer.
_user_system_profiler_next_buffer() returns this count now.
- When scheduling profiling events are requested also listen to wait objects
and generate the respective profiling events. We send those events lazily
and cache the infos to avoid resending an event for the same wait object.
- When starting profiling we do now generate "thread scheduled" events for
the already running threads.
- _user_system_profiler_start(): Check whether the parameters pointer is a
userland address at all.
- The system_profiler_team_added event does now also contain the team's name.
* Added a sem_get_name_unsafe() returning a semaphore's name. It is "unsafe",
since the caller has to ensure that the semaphore exists and continues to
exist as long as the returned name is used.
* Adjusted the "profile" and "scheduling_recorder" according to the system
profiling changes. The latter prints the number of dropped events, now.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30345 a95241bf-73f2-0310-859d-f6bbb57e9c96


# c8b762e456822d2840626b29b80640b95f349a36 20-Mar-2009 Axel Dörfler <axeld@pinc-software.de>

* Userland applications can no longer delete kernel semaphores. However, they
are still allowed to delete semaphores of other teams...
* Anyway, this fixes bug #3585.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29621 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 209c0f495ecf4a9040fdd517840012f01f486030 23-Oct-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

0 is a valid semaphore ID.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28292 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 59dbd26f5f41a6c1272f6cac9c8cda4b19b79097 20-Oct-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

* Moved more debug macros to kernel_debug_config.h.
* Turned the checks for all those macros to "#if"s instead of "#ifdef"s.
* Introduced macro KDEBUG_LEVEL which serves as a master setting.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28248 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 537d0818170525281422c4a5c31ef7ae887eb377 03-Sep-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

release_sem_etc(): Reschedule only when a thread with a priority greater
than that of the current thread has been woken up. I didn't see the
reason why the thread should otherwise relinquish the rest of its
quantum. I noticed for instance that client and app server window
threads were ping-ponging more than seemed necessary. In most cases
when the client sent a port message it would be unscheduled although it
had run only for a few microseconds and had still stuff to do.
I measured a relatively Terminal-heavy "find /boot" (second run), which
does now take 5-10% less time.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27314 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 020ac568404b8ab78825622d8815be48e987f649 03-Sep-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

* Fixed bug in the "scheduler" command: The check when a thread was
unscheduled was incorrect.
* Introduced _kern_analyze_scheduling() syscall. It requires scheduler
kernel tracing to be enabled. It uses the tracing entries for a given
period of time to do a similar analysis the "scheduler" debugger
command does (i.e. number of runs, run time, latencies, preemption
times) for each thread. Additionally the analysis includes for each
thread how long the thread waited on each locking primitive in total.
* Added kernel tracing for the creation of semaphores and initialization
of condition variables, mutexes, and rw locks. The enabling macro is
SCHEDULING_ANALYSIS_TRACING. The only purpose is to provide
_kern_analyze_scheduling() with more info on the locking primitives
(the name in particular).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27304 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 6bf26da22824059d3ce1fde70188fea1d6ce2082 02-Aug-2008 Axel Dörfler <axeld@pinc-software.de>

* Renamed sem_spinlock to sSemsSpinlock.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26732 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 272457553e0ff0860cf931c1d193c2c6020a7da8 02-Aug-2008 Axel Dörfler <axeld@pinc-software.de>

* Renamed kernel_startup to gKernelStartup.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26731 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 15374c5dbdb2c6b700bb2191887cadad7ef9eb73 02-Aug-2008 Axel Dörfler <axeld@pinc-software.de>

* Renamed thread_spinlock and team_spinlock to gThreadSpinlock and
gTeamSpinlock.
* Renamed the static global variables in smp.c to match our style guide.
* Minor other cleanup.
* Removed superfluous white space.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26730 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 5c99d639708df9b4e2cc847b38d510149d19ec78 22-Jul-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

Merged branch haiku/branches/developer/bonefish/vm into trunk. This
introduces the following relevant changes:
* VMCache:
- Renamed vm_cache to VMCache, merged it with vm_store and made it a
C++ class with virtual methods (replacing the store operations).
Turned the different store implementations into subclasses.
- Introduced MergeStore() callback, changed semantics of Commit().
- Changed locking and referencing semantics. A reference can only be
acquired/released with the cache locked. An unreferenced cache is
deleted and a mergeable cache merged when it is unlocked. This
removes the "busy" state of a cache and simplifies the page fault
code.
* Added VMAnonymousCache, which will implement swap support (work by
Zhao Shuai). It is not integrated and used yet, though.
* Enabled the mutex/recursive lock holder asserts.
* Fixed DoublyLinkedList::Swap().
* Generalized the low memory handler to a low resource handler. And made
semaphores and reserved memory handled resources. Made
vm_try_resource_memory() optionally wait (with timeout), and used that
feature to reserve memory for areas.
...


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26572 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 1c8de8581b66c14ea94bccd7ddcea99291955796 01-Jun-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

* Added optional spinlock contention measurement feature. Enabled when
B_DEBUG_SPINLOCK_CONTENTION is defined to 1. It typedefs spinlock to a
structure (thus breaking BeOS binary compatibility), containing a
counter which is incremented whenever a thread has to wait for the
spinlock.
* Added macros for spinlock initialization and access and changed
code using spinlocks accordingly. This breaks compilation for BeOS --
the macros should be defined in the respective compatibility wrappers.
* Added generic syscall to get the spinlock counters for the thread and
the team spinlocks.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25752 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 5142c2ac86c0f020ffa3fc31cea9f1f2f1b6ef91 05-May-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

Added support for POSIX semaphores (the ones from the XSI extension
Realtime option group). The implementation should be complete, but is
totally untested yet.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25326 a95241bf-73f2-0310-859d-f6bbb57e9c96


# e225a906d2ac4e4f4a22d3787265c5124ed8e2b4 24-Apr-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

With my recent changes release_sem_etc() accidentally lost the
cleverness to reschedule only, if it actually unblocked another thread.
Should have been the reason for #2152 (overall slowdown).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25131 a95241bf-73f2-0310-859d-f6bbb57e9c96


# b95f6d4710855a27bec41b6fae2b064347780173 22-Apr-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

* Introduced a set of functions (thread_prepare_to_block(),
thread_block(), thread_unblock(),...) that allow a thread to wait for
something without needing a semaphore or condition variable. It can
simply block and another thread can unblock it. Supports timeouts and
interrupting. Both semaphores and condition variables use this
common mechanism, now.
* Semaphores:
- Some simplifications due to the thread blocking mechanism.
- Changed locking order to sem -> thread. It was the other way around
before and when introducing the wait_for_objects() support I had
also introduced a situation where the locking was reverse, which
could potentially cause a dead lock on SMP systems.
- Instead of queueing thread structures, a semaphore queues
queued_thread entries now, which are created on the stack. The
thread::sem structure could thus be removed.
- Added sem_entry::net_count, which is sem_entry::count plus the
acquisition count of all waiting threads. This number is needed in
remove_thread_from_sem() and instead of computing it there we
maintain it.
- Fixed remove_thread_from_sem(). It would not unblock threads, if
the sem count was <= 0.
- Made sem::last_acquirer unconditional. It is actually needed for
sem_info::latest_holder. Fixed fill_sem_info() accordingly.
- Added some optional tracing output, though only via ktrace_printf().
* Condition variables:
- Could be simplified significantly through the use of the thread
blocking mechanism. Removed a good deal of unnecessary code.
- Moved the ConditionVariableEntry "flags" parameter from Wait() to
Add(), and adjusted all places where condition variables are used
accordingly.
* snooze() uses thread_block_with_timeout() instead of a semaphore.
* Simplified thread interrupting in the signal and user debugger code.
Instead of separate functions for threads waiting on a semaphore or
condititon variable, we only have a single thread_interrupt(), now.



git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25099 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 037f70947f14b7e7d452543ad645f38d7c96f6eb 09-Apr-2008 Axel Dörfler <axeld@pinc-software.de>

* Cleaned up KernelExport.h completely, removed deprecated and non implemented
API, uses the _PRINTFLIKE macro where appropriate.
* Got rid of the "qent" structure, struct timer now contains everything we
need. This makes the affected code in sem.cpp, signal.cpp, and timer.c much
cleaner, and resolves a few TODOs.
* Minor cleanup in vfs.cpp.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@24871 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 20e4f92cf540b33a55c36a414b63057b948417dc 23-Feb-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

switch_sem_etc() doesn't check the return value of add_timer(), hence we
need to make sure that we never get that far with a negative timeout or
we'll wait forever.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@24083 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 4048494ce44a925d3d1e40e4ffb9abe670b4b827 17-Feb-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

axeld + bonefish:
* Implemented automatic syscall restarts:
- A syscall can indicate that it has been interrupted and can be
restarted by setting a respective bit in thread::flags. It can
store parameters it wants to be preserved for the restart in
thread::syscall_restart::parameters. Another thread::flags bit
indicates whether it has been restarted.
- handle_signals() clears the restart flag, if the handled signal
has a handler function installed and SA_RESTART is not set. Another
thread flag (THREAD_FLAGS_DONT_RESTART_SYSCALL) can prevent syscalls
from being restarted, even if they could be (not used yet, but we
might want to use it in resume_thread(), so that we stay
behaviorally compatible with BeOS).
- The architecture specific syscall handler restarts the syscall, if
the restart flag is set. Implemented for x86 only.
- Added some support functions in the private <syscall_restart.h> to
simplify the syscall restart code in the syscalls.
- Adjusted all syscalls that can potentially be restarted accordingly.
- _user_ioctl() sets new thread flag THREAD_FLAGS_IOCTL_SYSCALL while
calling the underlying FS's/driver's hook, so that syscall restarts
can also be supported there.
* thread_at_kernel_exit() invokes handle_signals() in a loop now, as
long as the latter indicates that the thread shall be suspended, so
that after waking up signals received in the meantime will be handled
before the thread returns to userland. Adjusted handle_signals()
accordingly -- when encountering a suspending signal we don't check
for further signals.
* Fixed sigsuspend(): Suspending the thread and rescheduling doesn't
result in the correct behavior. Instead we employ a temporary
condition variable and interruptably wait on it. The POSIX test
suite test passes, now.
* Made the switch_sem[_etc]() behavior on interruption consistent.
Depending on when the signal arrived (before the call or when already
waiting) the first semaphore would or wouldn't be released. Now we
consistently release it.
* Refactored _user_{read,write}[v]() syscalls. Use a common function for
either pair. The iovec version doesn't fail anymore, if anything could
be read/written at all. It also checks whether a complete vector
could be read/written, so that we won't skip data, if the underlying
FS/driver couldn't read/write more ATM.
* Some refactoring in the x86 syscall handler: The int 99 and sysenter
handlers use a common subroutine to avoid code duplication.



git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23983 a95241bf-73f2-0310-859d-f6bbb57e9c96


# c486dde9d67280f29dd0f24a34aae6fc71926c13 28-Jan-2008 Marcus Overhagen <marcusoverhagen@gmail.com>

cosmetic


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23778 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 36b55f46942a4cb38e23b1130885b5f82e4d6772 26-Jan-2008 Michael Lotz <mmlr@mlotz.ch>

Don't panic in case a thread is not in the wait queue of a sem anymore. On SMP
systems it can easily happen that the thread gets removed from the queue (when
it times out for example) during the time we don't hold the sem lock.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23749 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 1b0e74fc1884bb49d4aed74395abc120d98f89fc 26-Jan-2008 Michael Lotz <mmlr@mlotz.ch>

Don't clobber the thread variable as we use it again. Since it always is NULL
at the end of that loop we guaranteed a crash when this special handling was
triggered.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23748 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 7e80cf009622e5ade1f87703c0ad3e9a17cd4a80 25-Jan-2008 Michael Lotz <mmlr@mlotz.ch>

Missed this setting of thread state which is now unnecessary. Otherwise nothing in the kernel seems to mess with the state outside of the scheduler so checking for B_THREAD_RUNNING there should be fine.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23740 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 6761f5a660bcba247e0967e09ac58f2f4488bd55 25-Jan-2008 Michael Lotz <mmlr@mlotz.ch>

Move the handling of still running threads into scheduler_enqueue_in_run_queue().
This should be in line with all uses of scheduler_enqueue_in_run_queue() and
simplifies a few places where it is used.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23738 a95241bf-73f2-0310-859d-f6bbb57e9c96


# d92565096840c6248cc435ebfc662432a3b5c252 25-Jan-2008 Michael Lotz <mmlr@mlotz.ch>

Apply the same logic as in r23731 to all other places in the semaphore code
where threads are enqueued into the run queue.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23733 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 2f3f3d79b5dff34f0ca64bf38db332bf2d8caa09 25-Jan-2008 Michael Lotz <mmlr@mlotz.ch>

Fix the underlying problem that caused the issue of running threads being
enqueued into the run_queue again. Modified the workaround to a panic in the
scheduler so we notice when something else does the same.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23731 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 5aee691ed843815dab1736dc5eb77d9cd20ea1ef 17-Jan-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

The "sem" and "port" debugger commands set some temporary variables,
now.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23595 a95241bf-73f2-0310-859d-f6bbb57e9c96


# ce637fda24b5c07f99236db30b2f9086d77317bb 17-Jan-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

Added usage (respectively more detailed usage) messages for "sem",
"sems", "port", and "ports" debugger commands.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23586 a95241bf-73f2-0310-859d-f6bbb57e9c96


# 224aee3ffc83a306629696fe4cf45cad9efa4349 17-Jan-2008 Ingo Weinhold <ingo_weinhold@gmx.de>

sem.c -> sem.cpp, port.c -> port.cpp


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23585 a95241bf-73f2-0310-859d-f6bbb57e9c96