fbeb36e4bf
thread switches should be on par with that under scheduler
activations.
o Timing is achieved through the use of a fixed interval
timer (ITIMER_PROF) to count scheduling ticks instead
of retrieving the time-of-day upon every thread switch
and calculating elapsed real time.
o Polling for I/O readiness is performed once for each
scheduling tick instead of every thread switch.
o The non-signal saving/restoring versions of setjmp/longjmp
are used to save and restore thread contexts. This may
allow the removal of _THREAD_SAFE macros from setjmp()
and longjmp() - needs more investigation.
Change signal handling so that signals are handled in the
context of the thread that is receiving the signal. When
signals are dispatched to a thread, a special signal handling
frame is created on top of the target threads stack. The
frame contains the threads saved state information and a new
context in which the thread can run. The applications signal
handler is invoked through a wrapper routine that knows how
to restore the threads saved state and unwind to previous
frames.
Fix interruption of threads due to signals. Some states
were being improperly interrupted while other states were
not being interrupted. This should fix several PRs.
Signal handlers, which are invoked as a result of a process
signal (not by pthread_kill()), are now called with the
code (or siginfo_t if SA_SIGINFO was set in sa_flags) and
sigcontext_t as received from the process signal handler.
Modify the search for a thread to which a signal is delivered.
The search algorithm is now:
o First thread found in sigwait() with signal in wait mask.
o First thread found sigsuspend()'d on the signal.
o Current thread if signal is unmasked.
o First thread found with signal unmasked.
Collapse machine dependent support into macros defined in
pthread_private.h. These should probably eventually be moved
into separate MD files.
Change the range of settable priorities to be compliant with
POSIX (0-31). The threads library uses higher priorities
internally for real-time threads (not yet implemented) and
threads executing signal handlers. Real-time threads and
threads running signal handlers add 64 and 32, respectively,
to a threads base priority.
Some other small changes and cleanups.
PR: 17757 18559 21943
Reviewed by: jasone
203 lines
6.8 KiB
C
203 lines
6.8 KiB
C
/*
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* Copyright (C) 2000 Jason Evans <jasone@freebsd.org>.
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* All rights reserved.
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* Copyright (C) 2000 Daniel M. Eischen <eischen@vigrid.com>.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice(s), this list of conditions and the following disclaimer as
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* the first lines of this file unmodified other than the possible
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* addition of one or more copyright notices.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice(s), this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
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* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
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* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
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* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
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* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#include <unistd.h>
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#include <setjmp.h>
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#include <sys/param.h>
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#include <sys/user.h>
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#ifdef _THREAD_SAFE
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#include <machine/reg.h>
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#include <pthread.h>
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#include "pthread_private.h"
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void
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siglongjmp(sigjmp_buf env, int savemask)
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{
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void *jmp_stackp;
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void *stack_begin, *stack_end;
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int frame, dst_frame;
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if ((frame = _thread_run->sigframe_count) == 0)
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__siglongjmp(env, savemask);
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/* Get the stack pointer from the jump buffer. */
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jmp_stackp = (void *) GET_STACK_SJB(env);
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/* Get the bounds of the current threads stack. */
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PTHREAD_ASSERT(_thread_run->stack != NULL,
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"Thread stack pointer is null");
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stack_begin = _thread_run->stack;
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stack_end = stack_begin + _thread_run->attr.stacksize_attr;
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/*
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* Make sure we aren't jumping to a different stack. Make sure
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* jmp_stackp is between stack_begin and stack end, to correctly detect
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* this condition regardless of whether the stack grows up or down.
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*/
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if (((jmp_stackp < stack_begin) && (jmp_stackp < stack_end)) ||
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((jmp_stackp > stack_begin) && (jmp_stackp > stack_end)))
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PANIC("siglongjmp()ing between thread contexts is undefined by "
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"POSIX 1003.1");
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if ((dst_frame = _thread_sigframe_find(_thread_run, jmp_stackp)) < 0)
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/*
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* The stack pointer was verified above, so this
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* shouldn't happen. Let's be anal anyways.
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*/
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PANIC("Error locating signal frame");
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else if (dst_frame == frame) {
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/*
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* The stack pointer is somewhere within the current
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* frame. Jump to the users context.
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*/
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__siglongjmp(env, savemask);
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}
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/*
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* Copy the users context to the return context of the
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* destination frame.
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*/
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memcpy(&_thread_run->sigframes[dst_frame]->ctx.sigjb, env, sizeof(*env));
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_thread_run->sigframes[dst_frame]->ctxtype = CTX_SJB;
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_thread_run->sigframes[dst_frame]->longjmp_val = savemask;
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_thread_run->curframe->dst_frame = dst_frame;
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___longjmp(*_thread_run->curframe->sig_jb, 1);
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}
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void
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longjmp(jmp_buf env, int val)
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{
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void *jmp_stackp;
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void *stack_begin, *stack_end;
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int frame, dst_frame;
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if ((frame = _thread_run->sigframe_count) == 0)
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__longjmp(env, val);
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/* Get the stack pointer from the jump buffer. */
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jmp_stackp = (void *) GET_STACK_JB(env);
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/* Get the bounds of the current threads stack. */
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PTHREAD_ASSERT(_thread_run->stack != NULL,
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"Thread stack pointer is null");
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stack_begin = _thread_run->stack;
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stack_end = stack_begin + _thread_run->attr.stacksize_attr;
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/*
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* Make sure we aren't jumping to a different stack. Make sure
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* jmp_stackp is between stack_begin and stack end, to correctly detect
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* this condition regardless of whether the stack grows up or down.
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*/
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if (((jmp_stackp < stack_begin) && (jmp_stackp < stack_end)) ||
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((jmp_stackp > stack_begin) && (jmp_stackp > stack_end)))
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PANIC("longjmp()ing between thread contexts is undefined by "
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"POSIX 1003.1");
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if ((dst_frame = _thread_sigframe_find(_thread_run, jmp_stackp)) < 0)
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/*
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* The stack pointer was verified above, so this
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* shouldn't happen. Let's be anal anyways.
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*/
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PANIC("Error locating signal frame");
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else if (dst_frame == frame) {
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/*
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* The stack pointer is somewhere within the current
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* frame. Jump to the users context.
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*/
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__longjmp(env, val);
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}
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/*
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* Copy the users context to the return context of the
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* destination frame.
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*/
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memcpy(&_thread_run->sigframes[dst_frame]->ctx.jb, env, sizeof(*env));
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_thread_run->sigframes[dst_frame]->ctxtype = CTX_JB;
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_thread_run->sigframes[dst_frame]->longjmp_val = val;
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_thread_run->curframe->dst_frame = dst_frame;
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___longjmp(*_thread_run->curframe->sig_jb, 1);
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}
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void
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_longjmp(jmp_buf env, int val)
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{
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void *jmp_stackp;
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void *stack_begin, *stack_end;
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int frame, dst_frame;
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if ((frame = _thread_run->sigframe_count) == 0)
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___longjmp(env, val);
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/* Get the stack pointer from the jump buffer. */
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jmp_stackp = (void *) GET_STACK_JB(env);
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/* Get the bounds of the current threads stack. */
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PTHREAD_ASSERT(_thread_run->stack != NULL,
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"Thread stack pointer is null");
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stack_begin = _thread_run->stack;
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stack_end = stack_begin + _thread_run->attr.stacksize_attr;
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/*
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* Make sure we aren't jumping to a different stack. Make sure
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* jmp_stackp is between stack_begin and stack end, to correctly detect
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* this condition regardless of whether the stack grows up or down.
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*/
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if (((jmp_stackp < stack_begin) && (jmp_stackp < stack_end)) ||
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((jmp_stackp > stack_begin) && (jmp_stackp > stack_end)))
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PANIC("_longjmp()ing between thread contexts is undefined by "
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"POSIX 1003.1");
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if ((dst_frame = _thread_sigframe_find(_thread_run, jmp_stackp)) < 0)
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/*
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* The stack pointer was verified above, so this
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* shouldn't happen. Let's be anal anyways.
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*/
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PANIC("Error locating signal frame");
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else if (dst_frame == frame) {
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/*
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* The stack pointer is somewhere within the current
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* frame. Jump to the users context.
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*/
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___longjmp(env, val);
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}
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/*
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* Copy the users context to the return context of the
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* destination frame.
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*/
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memcpy(&_thread_run->sigframes[dst_frame]->ctx.jb, env, sizeof(*env));
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_thread_run->sigframes[dst_frame]->ctxtype = CTX_JB_NOSIG;
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_thread_run->sigframes[dst_frame]->longjmp_val = val;
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_thread_run->curframe->dst_frame = dst_frame;
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___longjmp(*_thread_run->curframe->sig_jb, 1);
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}
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#endif
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