After load_image() the child thread is suspended and the parent is
expected to resume it later. However, it is possible that the parent
attempts to resume its child after it has been notified that the image
had been loaded but before the child managed to suspend itself. In such
case the child would suspends itself after that wake up attempt and,
consequently will not be ever resumed.
To mitigate that problem flag Thread::going_to_suspend has been added
which helps synchronizing thread suspension and continuation in a similar
way that "traditional" thread blocking is performed. This means that
the child should behave in a following manner: set its going_to_suspend flag,
notify the parent (i.e. any thread that may want to resume it), acquire
its scheduler_lock and suspend itself if the going_to_suspend flag is set.
The parent should follow pattern: clear going_to_suspend flag of the thread
that is about to be resumed, acquire that thread scheduler_lock and enqueue
it in a run queue if it is suspended.
Thanks Oliver for reporting the bug and identifying what causes it.
* 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.
Kernel support for yielding to all (including lower priority) threads
has been removed. POSIX sched_yield() remains unchanged.
If a thread really needs to yield to everyone it can reduce its priority
to the lowest possible and then yield (it will then need to manually
return to its prvious priority upon continuing).
* 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
* 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
- 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
implemented by means of an additional member in cpu_ent.
* Removed thread::keep_scheduled and the related functions. The feature
wasn't used yet and wouldn't have worked as implemented anyway.
* Resurrected an older, SMP aware version of our simple scheduler and made it
the default instead of the affine scheduler. The latter is in no state to
be used yet. It causes enormous latencies (I've seen up to 0.1s) even when
six or seven CPUs were idle at the same time, totally killing parallelism.
That's also the reason why a -j8 build was slower than a -j2. This is no
longer the case. On my machine the -j2 build takes about 10% less time now
and the -j8 build saves another 20%. The latter is not particularly
impressive (compared with Linux), but that seems to be due to lock
contention.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34615 a95241bf-73f2-0310-859d-f6bbb57e9c96
* 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
methods that used an "event mask" field. There was no need to introduce
a "flags" field for the same purpose.
* Renamed protected DefaultNotificationService methods (removed "_" prefix).
* Adjusted the code providing a notification service accordingly.
* Changed the event message several notification services generated by renaming
the "opcode" field to "event".
* Implemented the TEAM_ADDED event and also added a TEAM_EXEC event.
* Added notifications for threads and images.
* Added visitor-like iteration functions for teams, threads, and images.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30126 a95241bf-73f2-0310-859d-f6bbb57e9c96
state_to_text().
* state_to_text() can now deal with a NULL thread argument.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27163 a95241bf-73f2-0310-859d-f6bbb57e9c96
to contain headers shared by kernel and userland (mainly libroot).
* Moved quite a few private kernel headers to the new location. Split
several kernel headers into a shared part and one that is still kernel
private. Adjusted all affected Jamfiles and source in the standard x86
build accordingly. The build for other architectures and for test code
may be broken.
* Quite a bit of userland code still includes private kernel headers.
Mostly those are <util/*> headers. The ones that aren't strictly
kernel-only should be moved to some other place (maybe
headers/private/shared/util).
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25486 a95241bf-73f2-0310-859d-f6bbb57e9c96
arguments they get a single thread_creation_attributes structure now.
* Added stack_address and stack_size to thread_creation_attributes,
which allow to specify the stack size or the stack to be used for the
new user thread.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25389 a95241bf-73f2-0310-859d-f6bbb57e9c96
* Made the object pointer passed to thread_prepare_to_block() const, so
that strings can be passed without casting. Passing a string could
maybe be made a convention for THREAD_BLOCK_TYPE_OTHER.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25109 a95241bf-73f2-0310-859d-f6bbb57e9c96
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
function has the old behavior. When false, it just calls the scheduler
without any priority adjustment or other stuff.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23906 a95241bf-73f2-0310-859d-f6bbb57e9c96
23139 into trunk, with roughly the following changes (for details svn
log the branch):
* The int 99 syscall handler is now fully in assembly.
* Added a sysenter/sysexit handler and use it on Pentiums that support
it (via commpage).
* Got rid of i386_handle_trap(). A bit of functionality was moved into
the assembly handler which now uses a jump table to call C functions
handling the respective interrupt.
* Some optimizations to get user debugger support code out of the
interrupt handling path.
* Introduced a thread::flags fields which allows to skip handling of
rare events (signals, user debug enabling/disabling) on the
common interrupt handling path.
* Got rid of the explicit iframe stack. The iframes can still be
retrieved by iterating through the stack frames.
* Made the commpage an architecture independent feature. It's used for
the real time data stuff (instead of creating a separate area).
* The x86 CPU modules can now provide processor optimized versions for
common functions (currently memcpy() only). They are used in the
kernel and are provided to the userland via commpage entries.
* Introduced build system feature allowing easy use of C structure
member offsets in assembly code.
Changes after merging:
* Fixed merge conflict in src/system/kernel/arch/x86/arch_debug.cpp
(caused by refactoring and introduction of "call" debugger command).
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23370 a95241bf-73f2-0310-859d-f6bbb57e9c96
vfs_select.h, respectively moved most of it into the new kernel
private header wait_for_objects.h.
* Added new experimental API functions wait_for_objects[_etc](). They
work pretty much like poll(), but also for semaphores, ports, and
threads.
* Removed the "ref" parameter from notify_select_events() and the
select_sync_pool functions as well as from fd_ops::fd_[de]select(). It
is no longer needed. The FS interface select() hook still has it,
though -- the VFS will always pass 0.
* de]select_fd() take a select_info* instead of a select_sync* + ref
pair, now. Added respective functions for semaphores, ports, and
threads.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@22416 a95241bf-73f2-0310-859d-f6bbb57e9c96
* On exec() the new function thread_reset_for_exec() is called which clears the signals
and cancels an eventually set alarm. Both things weren't done before...
* Some minor cleanups.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@21989 a95241bf-73f2-0310-859d-f6bbb57e9c96
the new cpuid stuff was apparently exacerbating an existing problem where various bits of low level
cpu code (specifically get_current_cpu) weren't really initialized before being used. Changed the
order to set up a fake set of threads to point each cpu at really early in boot to make sure that at
all points in code it can get the current 'thread' and thus the current cpu.
A probably better solution would be to have dr3 point to the current cpu which would then point to the
current thread, but that has a race condition that would require an int disable, etc.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@20160 a95241bf-73f2-0310-859d-f6bbb57e9c96
and a timeout.
* _user_wait_for_thread() was not interruptible before, ie. Control-C wouldn't
work.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@16654 a95241bf-73f2-0310-859d-f6bbb57e9c96
time of the idle thread as a measure, we now compute the CPU activity on
each thread switch - the time the CPU worked is the total of user and kernel
time a thread spent during its quantum.
Unlike before, this mechanism works correctly on SMP machines. I hope this
works as expected :)
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@16193 a95241bf-73f2-0310-859d-f6bbb57e9c96
The test application lets run a thread at the highest priority that calls
yield all the time - the system stays responsible when it runs, so it seems
to work fine :)
Changed the malloc implementation to use _kern_thread_yield() instead of
snoozing.
We should think about making this call public, too.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@16166 a95241bf-73f2-0310-859d-f6bbb57e9c96
Extracted scheduler_init() from start_scheduler() (which is now called scheduler_start()).
Moved scheduler related function prototypes from thread.h to the new scheduler.h.
Cleanup.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@14518 a95241bf-73f2-0310-859d-f6bbb57e9c96
time of the idle thread. IOW Pulse now works :-)
Renamed the idle thread/stack to start with 1 instead of 0 (first idle thread will
be called "idle thread 1").
Minor cleanup.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@13373 a95241bf-73f2-0310-859d-f6bbb57e9c96
threadID parameter to spawn_kernel_thread_etc(). It's now possible to
set the ID of a new thread. Used in team.c to make team ID and the ID of
the main thread equal.
Fascinatingly the two added functions prompt my compiler to issue
`missing prototype' warnings, although those are obviously there. It would
be nice if someone could solve that riddle.
git-svn-id: file:///srv/svn/repos/haiku/trunk/current@11621 a95241bf-73f2-0310-859d-f6bbb57e9c96
and thread_at_kernel_exit() are always called for userland threads at the appropriate
situation (note, I've renamed those from *_atkernel_*).
The timing should be more accurate this way, and the thread::last_time_type field
is no longer needed: all interrupts are now added to the kernel time (where the
time is actually spent).
git-svn-id: file:///srv/svn/repos/haiku/trunk/current@11331 a95241bf-73f2-0310-859d-f6bbb57e9c96
a new thread_entry_func typedef in the kernel only. Unlike thread_func, it accepts
two arguments - that functionality is not exported to the user, though.
git-svn-id: file:///srv/svn/repos/haiku/trunk/current@8777 a95241bf-73f2-0310-859d-f6bbb57e9c96
Renamed the thread/team syscalls to the new naming scheme.
Some other minor cleanups.
git-svn-id: file:///srv/svn/repos/haiku/trunk/current@6867 a95241bf-73f2-0310-859d-f6bbb57e9c96
