Commit Graph
88 Commits
Author SHA1 Message Date
Ingo Weinhold 5662ae4585 Changed the team shutdown process a bit:
* The threads beside the main thread are killed earlier now (in the new
  team_shutdown_team()), before removing the team from the team hash and from
  its process group. This fixes #5296.
* Use a condition variable instead of a semaphore to wait for the non-main
  threads to die. We notify the condition right after a thread has left the
  team. The semaphore was released by the undertaker.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35196 a95241bf-73f2-0310-859d-f6bbb57e9c96
2010-01-20 09:34:53 +00:00
Ingo Weinhold 0338371f26 * 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
2009-12-13 21:18:27 +00:00
Axel Dörfler a195cce7b5 * Added a bit more missing info about user_threads.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34647 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-12-12 19:08:04 +00:00
Ingo Weinhold b4be7c9021 * Added cpu_ent::running_thread which is maintained by the schedulers.
* simple_smp scheduler: Rewrote the interesting part of
  enqueue_in_run_queue(). It always selects a target CPU for the inserted
  thread, now. If no CPU is idle, the CPU running the thread with the lowest
  priority is chosen. If the thread running on the target CPU has a lower
  priority than the inserted one, it will be asked to reschedule. If that's
  the current CPU, we'll return the correct value (wasn't done before at
  all).
  These changes help reducing latencies. On my machine in an idle system
  playing music DebugAnalyzer shows maximum latencies of about 1 us. I still
  find that a bit much, but it's several orders of magnitude better than
  before. The -j8 Haiku image build time dropped about 10%.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34635 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-12-11 19:06:57 +00:00
Ingo Weinhold 3533b6597d * Reintroduced the SMP_MSG_RESCHEDULE_IF_IDLE ICI message. This time
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
2009-12-10 11:54:38 +00:00
Ingo Weinhold e50cf8765b * 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
2009-12-02 18:05:10 +00:00
Ingo Weinhold 90d870c155 * Moved VMAddressSpace definition to vm_address_space.h.
* "Classified" VMAddressSpace, i.e. turned the vm_address_space_*() functions
  into methods, made all attributes (but "areas") private, and added
  accessors.
* Also turned the vm.cpp functions vm_area_lookup() and
  remove_area_from_address_space() into VMAddressSpace methods. The rest of
  the area management functionality will follow soon.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34447 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-12-02 16:12:15 +00:00
Michael Lotz 8665c30ace That was not such a good destruction order in the error case. As the scheduler
accesses the scheduler data inside the thread structure, freeing it first lead
to a crash when a thread couldn't be created.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@33940 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-11-07 16:33:29 +00:00
Axel Dörfler 6390c0ca80 * _get_next_thread_info() should be a bit more picky about its team needs.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@33741 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-10-23 01:15:55 +00:00
Axel Dörfler 3530c3eb6b * Reimplemented the insane _get_next_thread_info() which previously just
iterated over all known thread *IDs* with interrupts disabled.
  Now it iterates over the team's thread list (going from back to front, since
  new threads are added at the front of the singly linked queue).
* Alexandre restarted Tracker quite a lot, and let the shell script run to
  reproduce a certain bug - and then wondered why ProcessController would
  take several seconds to open its windows until it passed through more than
  8 million IDs... :-)


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@33737 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-10-23 00:09:45 +00:00
Axel Dörfler 68d9d8809b * Just use the heap instead of cbuf for send_data().
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@33722 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-10-22 11:42:51 +00:00
Axel Dörfler ea95b4d03e * Cleanup, no functional change.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@33580 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-10-14 07:50:53 +00:00
Rene Gollent 009ccc2962 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
2009-08-21 04:11:40 +00:00
Ingo Weinhold d3b44ccb14 Added explicit physical address parameter to vm_create_anonymous_area() and
create_area_etc(). 0 for the default behavior.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31941 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-07-29 21:30:35 +00:00
Ingo Weinhold ba391bcc56 Added team_debug_info::debugger_changed_condition to serialize changes to the
installed team debugger and adjusted the code accordingly. It's not needed yet,
but I intend to add support for software breakpoints and those require a bit of
uninitialization that needs to be synchronized with debugger changes and can't
be done with interrupts disabled.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31194 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-06-23 01:39:51 +00:00
Ingo Weinhold 6ad4a777b6 Also set user_thread to NULL. It shouldn't make a difference, though.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31040 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-06-14 10:58:54 +00:00
Jérôme Duval 591bc3f2d9 * various fixes identified by gcc4, provided by Joe Prostko
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30902 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-05-28 20:36:22 +00:00
Ingo Weinhold efd536ff89 * Cleared up a misconception in the notification mechanism. We already had
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
2009-04-11 21:45:25 +00:00
Ingo Weinhold ec29f0842c bonefish + mmlr:
Don't really resume the undertaker thread after creating it, since at that
point the scheduler has not been started yet. Didn't do any harm, since it was
only the second thread anyway and the idle thread was rescheduled almost
immediately.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29908 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-04-04 21:59:37 +00:00
Rene Gollent 0296b82ae6 Add several extra scheduler hook functions to allow the scheduler(s) to maintain private housekeeping data on the thread structs. These hooks are called on thread creation/destruction and when prepping a thread for use. Review welcome.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29721 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-03-26 00:58:20 +00:00
Ingo Weinhold 4c35c6b5e1 * _user_unblock_thread[s]() also set the user thread's wait_status, now. This
makes them more convenient to use, since the caller doesn't need to know the
  target threads' user thread structure.
* Adjusted the pthread rwlock implementation accordingly.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29578 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-03-18 01:53:06 +00:00
Michael Lotz c33667d400 Fixing warnings under GCC4 in preparation to enable -Werror there as well:
* Replaced the use of offsetof() for structs that aren't PODs. Add a
  offset_of_member() macro to util/khash.h because that's what it's used for
  in our cases.
* Change the signature of add_debugger_command()/remove_debugger_command() on
  GCC > 2 to avoid the depricated conversion from string constants to char *.
* Adding some "suggested" parenthesis. I know that not everyone likes that, but
  it pointed out at least one bug that is fixed here as well.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29113 a95241bf-73f2-0310-859d-f6bbb57e9c96
2009-02-01 20:48:02 +00:00
Axel Dörfler 2c1e463c7e * Removed B_{MIN|MAX}_PRIORITY from OS.h - they were never really intended
as public defines. They are now called THREAD_{MIN|MAX}_SET_PRIORITY to
  better reflect what they are for. Minimum priority is now 1, ie. you no
  longer can set another thread to the idle priority. This fixes part of
  ticket #2959.
* set_thread_priority() will no longer allow to change the priority of the
  idle thread to something else. This fixes the rest of ticket #2959.
* Automatic whitespace cleanup in OS.h.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28521 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-11-05 18:11:58 +00:00
Ingo Weinhold 53892c92a0 * Replaced scheduler_remove_from_run_queue() by
scheduler_set_thread_priority(). Setting the thread priority was the
  only situation in which it was used.
* Renamed scheduler.cpp to scheduler_simple.cpp.
* The scheduler functions are no longer called directly. Instead there's
  an operation vector now, which is initialized at kernel init time.
  This allows for picking the most suitable scheduler for the machine
  (e.g. a non-SMP scheduler on a non-SMP machine).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28262 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-10-21 12:37:13 +00:00
Ingo Weinhold 808de9c700 * The undertaker was not locking when enqueuing the thread structure in
the free queue.
* "thread" also prints the thread's I/O priority.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28218 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-10-17 16:28:02 +00:00
François Revol 1e2bc11e99 bonefish+mmu_man: fix cbuf_user_memcpy_from_chain() returning an error when the source buffer was NULL despite being asked for 0 bytes, while the counterpart was actually not creating a buffer for 0 bytes to send... Also don't bother calling it from receive_data() in that case anyway.
This fixes a deadlock in SoundPlay that made it freeze when trying to play the 2nd sound.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28179 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-10-16 19:48:28 +00:00
Ingo Weinhold 6503e5d9c6 Added functions to pin a thread to the current CPU (i.e. it will only be
scheduled on that CPU) and to avoid unscheduling it.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27974 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-10-11 18:11:12 +00:00
Ingo Weinhold 74785e79db * Added "from" address space parameter to vm_swap_address_space()/
arch_vm_aspace_swap().
* The x86 implementation does now maintain a bit mask per
  vm_translation_map_arch_info indicating on which CPUs the address
  space is active. This allows flush_tmap() to avoid ICI for user
  address spaces when the team isn't currently running on any other CPU.
  In this context ICI is relatively expensive, particularly since we map
  most pages via vm_map_page() and therefore invoke flush_tmap() pretty
  much for every single page.
  This optimization speeds up a "hello world" compilation about 20% on
  my machine (KDEBUG turned off, freshly booted), but interestingly it
  has virtually no effect on the "-j2" haiku build time.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27912 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-10-07 21:39:19 +00:00
Ingo Weinhold 032ff97fbd When a thread times out on a locking primitive, reschedule only, if the
timed out thread has a higher priority than the currently running one.
Maybe we should even restrict this behavior to realtime threads.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27897 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-10-06 23:00:17 +00:00
Ingo Weinhold 23884ae025 Introduced a callback field in the thread structure. It can be set in an
interrupt handler and will be executed right before returning from the
interrupt.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27648 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-09-20 12:38:27 +00:00
Ingo Weinhold cbcebd3330 * Extended the debugger API by sampling-based profiling support. This is
still pretty much work in progress.
* Introduced init_thread_debug_info() which is used instead of
  clear_thread_debug_info() when the thread is created. The latter
  requires former initialization.
* user_debug_thread_deleted() is now already invoked in thread_exit(),
  not in the undertaker.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27531 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-09-15 13:36:31 +00:00
Ryan Leavengood c2a59f2305 Remove the null check as per Axel's advice: valid arguments within the range
are never null.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27450 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-09-12 13:44:00 +00:00
Ryan Leavengood d1363991a8 Fixed CID 1299: the char* name was used in a call to strtoul on line 1220
before being NULL checked on line 1234. I moved the null check to be after name
is initialized and removed it from line 1234.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27428 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-09-12 04:28:09 +00:00
Karsten Heimrich 89cfd54279 * revert r27322 and apply the patch provided by Salvatore
Thanks you!  :)



git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27323 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-09-04 17:00:01 +00:00
Ingo Weinhold 3b3e3805f8 Added thread::io_priority field and functions to get/set it.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27247 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-08-31 00:37:02 +00:00
Ingo Weinhold 07569b03c9 * Added kernel private thread_state_to_text() which just calls
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
2008-08-22 23:51:22 +00:00
Ingo Weinhold 16cfc87748 * Added option "-s" to the "thread" command, which prints the info in
short form (like "threads").
* "thread" allows to specify more than one thread now.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27152 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-08-22 14:29:00 +00:00
Ingo Weinhold 1e90630527 * Added a "flags" parameter to vm_create_anonymous_area() and
create_area_etc().
* When the new flag CREATE_AREA_DONT_WAIT is specified, the functions
  don't wait for memory or pages to become available. They fail
  immediately instead.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27117 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-08-21 22:50:11 +00:00
Ingo Weinhold 3b99126c1e Fixed table columns alignment in the "threads" command.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26948 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-08-12 17:03:43 +00:00
Ingo Weinhold 57f2b5a013 * Changed the meaning of the {KERNEL,USER}_STACK_SIZE macros to not
include the guard pages. Adjusted the kernel and boot loader code
  accordingly -- the guard pages size is added/not removed respectively.
  The stack size passed to _kern_spawn_thread() is now the actually usable
  size, and it is no longer possible to specify a size smaller than or
  equal to the guard pages size.
* vm_create_anonymous_area(): Precommit two pages maximum -- a stack with
  only one page usable size obviously doesn't need two pages.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26819 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-08-05 17:19:46 +00:00
Ingo Weinhold a9d458d8db Also init kernel_stack_top for the idle threads. It was NULL before,
which caused stack traces in those threads to crash.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26746 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-08-02 23:50:14 +00:00
Axel Dörfler 15374c5dbd * 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
2008-08-02 14:55:53 +00:00
Ingo Weinhold 12c9f1761f * Added thread block type constant for rw_locks, so that they are listed
correctly by the "thread" and "threads" debugger commands.
* Added "rwlock" debugger command.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26703 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-07-31 20:43:40 +00:00
Axel Dörfler 736352dcf5 * Added [un]lock_memory_etc() versions that accept a team_id as first argument.
This allows drivers to lock the memory outside of the original team context.
* create_area_etc() got a struct team as first argument, but that should have
  been a team_id.
* Removed delete_area_etc() - there is already vm_delete_area() doing the same
  thing.
* Renamed vm_get_address_space_by_id() to vm_get_address_space(), as there is
  no other method of getting an address space.
* Removed erroneous white space.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26455 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-07-16 22:55:17 +00:00
Ingo Weinhold dc27129332 stippi + bonefish:
* Missing backslash in UPDATE_THREAD_KERNEL_TIME() macro. Caused the
  thread's kernel time never to be updated when the thread left the
  kernel. The time would be added to the user time instead.
* Changed semantics of thread_at_kernel_exit(). It leaves interrupts
  disabled when returning, now. All code using it would disable
  interrupts afterwards anyway, and inbetween the thread could be
  interrupted causing two more time updates (or actually not causing
  them erroneously).
* The code in x86's interrupt handler entry (int_bottom) also checks
  thread::in_kernel now, to determine whether the thread was already
  considered to be in userland. This is necessary since the sysexit
  instruction doesn't reenable interrupts, so that we have to do that
  with the preceeding instruction. Hence an interrupt can occur
  inbetween, which would incorrectly add the interrupt's kernel time
  to the thread's user time.
* For userland threads team_create_thread_start() didn't invoke
  thread_at_kernel_exit() or any equivalent. We do that in 
  arch_thread_enter_userspace() now.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26240 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-07-03 20:37:08 +00:00
Ingo Weinhold 0cb2617fa5 Before starting to wait the undertaker does now check whether there's
already a dead thread available. Fixes a race condition.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25754 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-06-02 04:34:09 +00:00
Ingo Weinhold 1c8de8581b * 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
2008-06-02 02:04:12 +00:00
Ingo Weinhold 9101535322 Added new kernel thread "undertaker" which gets rid of dead thread
remains. This replaces the previous mechanism of switching the thread to
a dedicated death stack. We might consider moving more cleanup work to
the undertaker, but that seems a little more involved.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25704 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-05-29 14:28:31 +00:00
Ingo Weinhold b5e3c0a1ea Added new syscalls _kern_block_thread()/_kern_unblock_thread[s]().
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25469 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-05-12 13:53:56 +00:00
Ingo Weinhold d648afb8d7 * For each userland team the kernel creates an area in the userland
address space that is fully locked and marked B_KERNEL_AREA. It can
  thus be accessed by the kernel without additional checks.
* For each userland thread we do create a user_thread structure in that
  area. The structure is accessible from userland via TLS, using the
  private get_user_thread() function.
* Introduced private userland functions [un]defer_signals(). They can be
  used to cheaply disable/re-enable signal delivery. They use the
  user_thread::defer_signals/pending_signals fields which are
  checked/updated by the kernel.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25451 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-05-11 16:25:35 +00:00