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tdegraphics/kviewshell/plugins/djvu/libdjvu/GThreads.cpp

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//C- -------------------------------------------------------------------
//C- DjVuLibre-3.5
//C- Copyright (c) 2002 Leon Bottou and Yann Le Cun.
//C- Copyright (c) 2001 AT&T
//C-
//C- This software is subject to, and may be distributed under, the
//C- GNU General Public License, Version 2. The license should have
//C- accompanied the software or you may obtain a copy of the license
//C- from the Free Software Foundation at http://www.fsf.org .
//C-
//C- This program is distributed in the hope that it will be useful,
//C- but WITHOUT ANY WARRANTY; without even the implied warranty of
//C- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
//C- GNU General Public License for more details.
//C-
//C- DjVuLibre-3.5 is derived from the DjVu(r) Reference Library
//C- distributed by Lizardtech Software. On July 19th 2002, Lizardtech
//C- Software authorized us to replace the original DjVu(r) Reference
//C- Library notice by the following text (see doc/lizard2002.djvu):
//C-
//C- ------------------------------------------------------------------
//C- | DjVu (r) Reference Library (v. 3.5)
//C- | Copyright (c) 1999-2001 LizardTech, Inc. All Rights Reserved.
//C- | The DjVu Reference Library is protected by U.S. Pat. No.
//C- | 6,058,214 and patents pending.
//C- |
//C- | This software is subject to, and may be distributed under, the
//C- | GNU General Public License, Version 2. The license should have
//C- | accompanied the software or you may obtain a copy of the license
//C- | from the Free Software Foundation at http://www.fsf.org .
//C- |
//C- | The computer code originally released by LizardTech under this
//C- | license and unmodified by other parties is deemed "the LIZARDTECH
//C- | ORIGINAL CODE." Subject to any third party intellectual property
//C- | claims, LizardTech grants recipient a worldwide, royalty-free,
//C- | non-exclusive license to make, use, sell, or otherwise dispose of
//C- | the LIZARDTECH ORIGINAL CODE or of programs derived from the
//C- | LIZARDTECH ORIGINAL CODE in compliance with the terms of the GNU
//C- | General Public License. This grant only confers the right to
//C- | infringe patent claims underlying the LIZARDTECH ORIGINAL CODE to
//C- | the extent such infringement is reasonably necessary to enable
//C- | recipient to make, have made, practice, sell, or otherwise dispose
//C- | of the LIZARDTECH ORIGINAL CODE (or portions thereof) and not to
//C- | any greater extent that may be necessary to utilize further
//C- | modifications or combinations.
//C- |
//C- | The LIZARDTECH ORIGINAL CODE is provided "AS IS" WITHOUT WARRANTY
//C- | OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
//C- | TO ANY WARRANTY OF NON-INFRINGEMENT, OR ANY IMPLIED WARRANTY OF
//C- | MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
//C- +------------------------------------------------------------------
//
// $Id: GThreads.cpp,v 1.15 2004/04/21 14:54:43 leonb Exp $
// $Name: release_3_5_15 $
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#if NEED_GNUG_PRAGMAS
# pragma implementation
#endif
// This file defines machine independent classes
// for running and synchronizing threads.
// - Author: Leon Bottou, 01/1998
// From: Leon Bottou, 1/31/2002
// Almost unchanged by Lizardtech.
// GSafeFlags should go because it not as safe as it claims.
#include "GThreads.h"
#include "GException.h"
#include "DjVuMessageLite.h"
#include <stdlib.h>
#include <stdio.h>
// ----------------------------------------
// Consistency check
#if THREADMODEL!=NOTHREADS
#ifdef USE_EXCEPTION_EMULATION
#warning "Compiler must support thread safe exceptions"
#endif //USE_EXCEPTION_EMULATION
#if defined(__GNUC__)
#if (__GNUC__<2) || ((__GNUC__==2) && (__GNUC_MINOR__<=8))
#warning "GCC 2.8 exceptions are not thread safe."
#warning "Use properly configured EGCS-1.1 or greater."
#endif // (__GNUC__<2 ...
#endif // defined(__GNUC__)
#endif // THREADMODEL!=NOTHREADS
#ifndef _DEBUG
#if defined(DEBUG)
#define _DEBUG /* */
#elif DEBUGLVL >= 1
#define _DEBUG /* */
#endif
#endif
#if THREADMODEL==WINTHREADS
# include <process.h>
#endif
#if THREADMODEL==COTHREADS
# include <setjmp.h>
# include <string.h>
# include <unistd.h>
# include <sys/types.h>
# include <sys/time.h>
#endif
#ifdef HAVE_NAMESPACES
namespace DJVU {
# ifdef NOT_DEFINED // Just to fool emacs c++ mode
}
#endif
#endif
// ----------------------------------------
// NOTHREADS
// ----------------------------------------
#if THREADMODEL==NOTHREADS
int
GThread::create( void (*entry)(void*), void *arg)
{
(*entry)(arg);
return 0;
}
#endif
// ----------------------------------------
// WIN32 IMPLEMENTATION
// ----------------------------------------
#if THREADMODEL==WINTHREADS
static unsigned __stdcall
start(void *arg)
{
GThread *gt = (GThread*)arg;
try
{
G_TRY
{
gt->xentry( gt->xarg );
}
G_CATCH(ex)
{
ex.perror();
DjVuMessageLite::perror( ERR_MSG("GThreads.uncaught") );
#ifdef _DEBUG
abort();
#endif
}
G_ENDCATCH;
}
catch(...)
{
DjVuMessageLite::perror( ERR_MSG("GThreads.unrecognized") );
#ifdef _DEBUG
abort();
#endif
}
return 0;
}
GThread::GThread(int stacksize)
: hthr(0), thrid(0), xentry(0), xarg(0)
{
}
GThread::~GThread()
{
if (hthr)
CloseHandle(hthr);
hthr = 0;
thrid = 0;
}
int
GThread::create(void (*entry)(void*), void *arg)
{
if (hthr)
return -1;
xentry = entry;
xarg = arg;
unsigned uthread = 0;
hthr = (HANDLE)_beginthreadex(NULL, 0, start, (void*)this, 0, &uthread);
thrid = (DWORD) uthread;
if (hthr)
return 0;
return -1;
}
void
GThread::terminate()
{
OutputDebugString("Terminating thread.\n");
if (hthr)
TerminateThread(hthr,0);
}
int
GThread::yield()
{
Sleep(0);
return 0;
}
void *
GThread::current()
{
return (void*) GetCurrentThreadId();
}
struct thr_waiting {
struct thr_waiting *next;
struct thr_waiting *prev;
BOOL waiting;
HANDLE gwait;
};
GMonitor::GMonitor()
: ok(0), count(1), head(0), tail(0)
{
InitializeCriticalSection(&cs);
locker = GetCurrentThreadId();
ok = 1;
}
GMonitor::~GMonitor()
{
ok = 0;
EnterCriticalSection(&cs);
for (struct thr_waiting *w=head; w; w=w->next)
SetEvent(w->gwait);
LeaveCriticalSection(&cs);
DeleteCriticalSection(&cs);
}
void
GMonitor::enter()
{
DWORD self = GetCurrentThreadId();
if (count>0 || self!=locker)
{
if (ok)
EnterCriticalSection(&cs);
locker = self;
count = 1;
}
count -= 1;
}
void
GMonitor::leave()
{
DWORD self = GetCurrentThreadId();
if (ok && (count>0 || self!=locker))
G_THROW( ERR_MSG("GThreads.not_acq_broad") );
count += 1;
if (count > 0)
{
count = 1;
if (ok)
LeaveCriticalSection(&cs);
}
}
void
GMonitor::signal()
{
if (ok)
{
DWORD self = GetCurrentThreadId();
if (count>0 || self!=locker)
G_THROW( ERR_MSG("GThreads.not_acq_signal") );
for (struct thr_waiting *w=head; w; w=w->next)
if (w->waiting)
{
SetEvent(w->gwait);
w->waiting = FALSE;
break; // Only one thread is allowed to run!
}
}
}
void
GMonitor::broadcast()
{
if (ok)
{
DWORD self = GetCurrentThreadId();
if (count>0 || self!=locker)
G_THROW( ERR_MSG("GThreads.not_acq_broad") );
for (struct thr_waiting *w=head; w; w=w->next)
if (w->waiting)
{
SetEvent(w->gwait);
w->waiting = FALSE;
}
}
}
void
GMonitor::wait()
{
// Check state
DWORD self = GetCurrentThreadId();
if (count>0 || self!=locker)
G_THROW( ERR_MSG("GThreads.not_acq_wait") );
// Wait
if (ok)
{
// Prepare wait record
struct thr_waiting waitrec;
waitrec.waiting = TRUE;
waitrec.gwait = CreateEvent(NULL,FALSE,FALSE,NULL);
waitrec.next = 0;
waitrec.prev = tail;
// Link wait record (protected by critical section)
*(waitrec.next ? &waitrec.next->prev : &tail) = &waitrec;
*(waitrec.prev ? &waitrec.prev->next : &head) = &waitrec;
// Start wait
int sav_count = count;
count = 1;
LeaveCriticalSection(&cs);
WaitForSingleObject(waitrec.gwait,INFINITE);
// Re-acquire
EnterCriticalSection(&cs);
count = sav_count;
locker = self;
// Unlink wait record
*(waitrec.next ? &waitrec.next->prev : &tail) = waitrec.prev;
*(waitrec.prev ? &waitrec.prev->next : &head) = waitrec.next;
CloseHandle(waitrec.gwait);
}
}
void
GMonitor::wait(unsigned long timeout)
{
// Check state
DWORD self = GetCurrentThreadId();
if (count>0 || self!=locker)
G_THROW( ERR_MSG("GThreads.not_acq_wait") );
// Wait
if (ok)
{
// Prepare wait record
struct thr_waiting waitrec;
waitrec.waiting = TRUE;
waitrec.gwait = CreateEvent(NULL,FALSE,FALSE,NULL);
waitrec.next = 0;
waitrec.prev = tail;
// Link wait record (protected by critical section)
*(waitrec.prev ? &waitrec.prev->next : &head) = &waitrec;
*(waitrec.next ? &waitrec.next->prev : &tail) = &waitrec;
// Start wait
int sav_count = count;
count = 1;
LeaveCriticalSection(&cs);
WaitForSingleObject(waitrec.gwait,timeout);
// Re-acquire
EnterCriticalSection(&cs);
count = sav_count;
locker = self;
// Unlink wait record
*(waitrec.next ? &waitrec.next->prev : &tail) = waitrec.prev;
*(waitrec.prev ? &waitrec.prev->next : &head) = waitrec.next;
CloseHandle(waitrec.gwait);
}
}
#endif
// ----------------------------------------
// MACTHREADS IMPLEMENTATION (from Praveen)
// ----------------------------------------
#if THREADMODEL==MACTHREADS
// Doubly linked list of waiting threads
struct thr_waiting {
struct thr_waiting *next; // ptr to next waiting thread record
struct thr_waiting *prev; // ptr to ptr to this waiting thread
unsigned long thid; // id of waiting thread
int *wchan; // cause of the wait
};
static struct thr_waiting *first_waiting_thr = 0;
static struct thr_waiting *last_waiting_thr = 0;
// Stops current thread.
// Argument ``self'' must be current thread id.
// Assumes ``ThreadBeginCritical'' has been called before.
static void
macthread_wait(ThreadID self, int *wchan)
{
// Prepare and link wait record
struct thr_waiting wait; // no need to malloc :-)
wait.thid = self;
wait.wchan = wchan;
wait.next = 0;
wait.prev = last_waiting_thr;
*(wait.prev ? &wait.prev->next : &first_waiting_thr ) = &wait;
*(wait.next ? &wait.next->prev : &last_waiting_thr ) = &wait;
// Leave critical section and start waiting.
(*wchan)++;
SetThreadStateEndCritical(self, kStoppedThreadState, kNoThreadID);
// The Apple documentation says that the above call reschedules a new
// thread. Therefore it will only return when the thread wakes up.
ThreadBeginCritical();
(*wchan)--;
// Unlink wait record
*(wait.prev ? &wait.prev->next : &first_waiting_thr ) = wait.next;
*(wait.next ? &wait.next->prev : &last_waiting_thr ) = wait.prev;
// Returns from the wait.
}
// Wakeup one thread or all threads waiting on cause wchan
static void
macthread_wakeup(int *wchan, int onlyone)
{
if (*wchan == 0)
return;
for (struct thr_waiting *q=first_waiting_thr; q; q=q->next)
if (q->wchan == wchan) {
// Found a waiting thread
q->wchan = 0;
SetThreadState(q->thid, kReadyThreadState, kNoThreadID);
if (onlyone)
return;
}
}
GThread::GThread(int stacksize)
: thid(kNoThreadID), xentry(0), xarg(0)
{
}
GThread::~GThread(void)
{
thid = kNoThreadID;
}
pascal void *
GThread::start(void *arg)
{
GThread *gt = (GThread*)arg;
try
{
G_TRY
{
(gt->xentry)(gt->xarg);
}
G_CATCH(ex)
{
ex.perror();
DjVuMessageLite::perror( ERR_MSG("GThreads.uncaught") );
#ifdef _DEBUG
abort();
#endif
}
G_ENDCATCH;
}
catch(...)
{
DjVuMessageLite::perror( ERR_MSG("GThreads.unrecognized") );
#ifdef _DEBUG
abort();
#endif
}
return 0;
}
int
GThread::create(void (*entry)(void*), void *arg)
{
if (xentry || thid!=kNoThreadID)
return -1;
xentry = entry;
xarg = arg;
int err = NewThread( kCooperativeThread, GThread::start , this, 0,
kCreateIfNeeded, (void**)nil, &thid );
if( err != noErr )
return err;
return 0;
}
void
GThread::terminate()
{
if (thid != kNoThreadID) {
DisposeThread( thid, NULL, false );
thid = kNoThreadID;
}
}
int
GThread::yield()
{
YieldToAnyThread();
return 0;
}
void*
GThread::current()
{
unsigned long thid = kNoThreadID;
GetCurrentThread(&thid);
return (void*) thid;
}
// GMonitor implementation
GMonitor::GMonitor()
: ok(0), count(1), locker(0), wlock(0), wsig(0)
{
locker = kNoThreadID;
ok = 1;
}
GMonitor::~GMonitor()
{
ok = 0;
ThreadBeginCritical();
macthread_wakeup(&wsig, 0);
macthread_wakeup(&wlock, 0);
ThreadEndCritical();
YieldToAnyThread();
}
void
GMonitor::enter()
{
ThreadID self;
GetCurrentThread(&self);
ThreadBeginCritical();
if (count>0 || self!=locker)
{
while (ok && count<=0)
macthread_wait(self, &wlock);
count = 1;
locker = self;
}
count -= 1;
ThreadEndCritical();
}
void
GMonitor::leave()
{
ThreadID self;
GetCurrentThread(&self);
if (ok && (count>0 || self!=locker))
G_THROW( ERR_MSG("GThreads.not_acq_leave") );
ThreadBeginCritical();
if (++count > 0)
macthread_wakeup(&wlock, 1);
ThreadEndCritical();
}
void
GMonitor::signal()
{
ThreadID self;
GetCurrentThread(&self);
if (count>0 || self!=locker)
G_THROW( ERR_MSG("GThreads.not_acq_signal") );
ThreadBeginCritical();
macthread_wakeup(&wsig, 1);
ThreadEndCritical();
}
void
GMonitor::broadcast()
{
ThreadID self;
GetCurrentThread(&self);
if (count>0 || self!=locker)
G_THROW( ERR_MSG("GThreads.not_acq_broad") );
ThreadBeginCritical();
macthread_wakeup(&wsig, 0);
ThreadEndCritical();
}
void
GMonitor::wait()
{
// Check state
ThreadID self;
GetCurrentThread(&self);
if (count>0 || locker!=self)
G_THROW( ERR_MSG("GThreads.not_acq_wait") );
// Wait
if (ok)
{
// Atomically release monitor and wait
ThreadBeginCritical();
int sav_count = count;
count = 1;
macthread_wakeup(&wlock, 1);
macthread_wait(self, &wsig);
// Re-acquire
while (ok && count<=0)
macthread_wait(self, &wlock);
count = sav_count;
locker = self;
ThreadEndCritical();
}
}
void
GMonitor::wait(unsigned long timeout)
{
// Timeouts are not used for anything important.
// Just ignore the timeout and wait the regular way.
wait();
}
#endif
// ----------------------------------------
// POSIXTHREADS IMPLEMENTATION
// ----------------------------------------
#if THREADMODEL==POSIXTHREADS
#if defined(CMA_INCLUDE)
#define DCETHREADS
#define pthread_key_create pthread_keycreate
#else
#define pthread_mutexattr_default NULL
#define pthread_condattr_default NULL
#endif
void *
GThread::start(void *arg)
{
GThread *gt = (GThread*)arg;
#ifdef DCETHREADS
#ifdef CANCEL_ON
pthread_setcancel(CANCEL_ON);
pthread_setasynccancel(CANCEL_ON);
#endif
#else // !DCETHREADS
#ifdef PTHREAD_CANCEL_ENABLE
pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, 0);
#endif
#ifdef PTHREAD_CANCEL_ASYNCHRONOUS
pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, 0);
#endif
#endif
// Catch exceptions
#ifdef __EXCEPTIONS
try
{
#endif
G_TRY
{
(gt->xentry)(gt->xarg);
}
G_CATCH(ex)
{
ex.perror();
DjVuMessageLite::perror( ERR_MSG("GThreads.uncaught") );
#ifdef _DEBUG
abort();
#endif
}
G_ENDCATCH;
#ifdef __EXCEPTIONS
}
catch(...)
{
DjVuMessageLite::perror( ERR_MSG("GThreads.unrecognized") );
#ifdef _DEBUG
abort();
#endif
}
#endif
return 0;
}
// GThread
GThread::GThread(int stacksize) :
hthr(0), xentry(0), xarg(0)
{
}
GThread::~GThread()
{
hthr = 0;
}
int
GThread::create(void (*entry)(void*), void *arg)
{
if (xentry || xarg)
return -1;
xentry = entry;
xarg = arg;
#ifdef DCETHREADS
int ret = pthread_create(&hthr, pthread_attr_default, GThread::start, (void*)this);
if (ret >= 0)
pthread_detach(hthr);
#else
pthread_attr_t attr;
pthread_attr_init(&attr);
pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
int ret = pthread_create(&hthr, &attr, start, (void*)this);
pthread_attr_destroy(&attr);
#endif
return ret;
}
void
GThread::terminate()
{
if (xentry || xarg)
pthread_cancel(hthr);
}
int
GThread::yield()
{
#ifdef DCETHREADS
pthread_yield();
#else
// should use sched_yield() when available.
static struct timeval timeout = { 0, 0 };
::select(0, 0,0,0, &timeout);
#endif
return 0;
}
void*
GThread::current()
{
pthread_t self = pthread_self();
#if defined(pthread_getunique_np)
return (void*) pthread_getunique_np( & self );
#elif defined(cma_thread_get_unique)
return (void*) cma_thread_get_unique( & self );
#else
return (void*) self;
#endif
}
// -- GMonitor
GMonitor::GMonitor()
: ok(0), count(1), locker(0)
{
// none of this should be necessary ... in theory.
#ifdef PTHREAD_MUTEX_INITIALIZER
static pthread_mutex_t tmutex=PTHREAD_MUTEX_INITIALIZER;
memcpy(&mutex,&tmutex,sizeof(mutex));
#endif
#ifdef PTHREAD_COND_INITIALIZER
static pthread_cond_t tcond=PTHREAD_COND_INITIALIZER;
memcpy(&cond,&tcond,sizeof(cond));
#endif
// standard
pthread_mutex_init(&mutex, pthread_mutexattr_default);
pthread_cond_init(&cond, pthread_condattr_default);
locker = pthread_self();
ok = 1;
}
GMonitor::~GMonitor()
{
ok = 0;
pthread_cond_destroy(&cond);
pthread_mutex_destroy(&mutex);
}
void
GMonitor::enter()
{
pthread_t self = pthread_self();
if (count>0 || !pthread_equal(locker, self))
{
if (ok)
pthread_mutex_lock(&mutex);
locker = self;
count = 1;
}
count -= 1;
}
void
GMonitor::leave()
{
pthread_t self = pthread_self();
if (ok && (count>0 || !pthread_equal(locker, self)))
G_THROW( ERR_MSG("GThreads.not_acq_broad") );
count += 1;
if (count > 0)
{
count = 1;
if (ok)
pthread_mutex_unlock(&mutex);
}
}
void
GMonitor::signal()
{
if (ok)
{
pthread_t self = pthread_self();
if (count>0 || !pthread_equal(locker, self))
G_THROW( ERR_MSG("GThreads.not_acq_signal") );
pthread_cond_signal(&cond);
}
}
void
GMonitor::broadcast()
{
if (ok)
{
pthread_t self = pthread_self();
if (count>0 || !pthread_equal(locker, self))
G_THROW( ERR_MSG("GThreads.not_acq_broad") );
pthread_cond_broadcast(&cond);
}
}
void
GMonitor::wait()
{
// Check
pthread_t self = pthread_self();
if (count>0 || !pthread_equal(locker, self))
G_THROW( ERR_MSG("GThreads.not_acq_wait") );
// Wait
if (ok)
{
// Release
int sav_count = count;
count = 1;
// Wait
pthread_cond_wait(&cond, &mutex);
// Re-acquire
count = sav_count;
locker = self;
}
}
void
GMonitor::wait(unsigned long timeout)
{
// Check
pthread_t self = pthread_self();
if (count>0 || !pthread_equal(locker, self))
G_THROW( ERR_MSG("GThreads.not_acq_wait") );
// Wait
if (ok)
{
// Release
int sav_count = count;
count = 1;
// Wait
struct timeval abstv;
struct timespec absts;
gettimeofday(&abstv, NULL); // grrr
absts.tv_sec = abstv.tv_sec + timeout/1000;
absts.tv_nsec = abstv.tv_usec*1000 + (timeout%1000)*1000000;
if (absts.tv_nsec > 1000000000) {
absts.tv_nsec -= 1000000000;
absts.tv_sec += 1;
}
pthread_cond_timedwait(&cond, &mutex, &absts);
// Re-acquire
count = sav_count;
locker = self;
}
}
#endif
// ----------------------------------------
// CUSTOM COOPERATIVE THREADS
// ----------------------------------------
#if THREADMODEL==COTHREADS
#ifndef __GNUG__
#error "COTHREADS require G++"
#endif
#if (__GNUC__<2) || ((__GNUC__==2) && (__GNUC_MINOR__<=90))
#warning "COTHREADS require EGCS-1.1.1 with Leon's libgcc patch."
#warning "You may have trouble with thread-unsafe exceptions..."
#define NO_LIBGCC_HOOKS
#endif
// -------------------------------------- constants
// Minimal stack size
#define MINSTACK (32*1024)
// Default stack size
#define DEFSTACK (127*1024)
// Maxtime between checking fdesc (ms)
#define MAXFDWAIT (200)
// Maximum time to wait in any case
#define MAXWAIT (60*60*1000)
// Maximum penalty for hog task (ms)
#define MAXPENALTY (1000)
// Trace task switches
#undef COTHREAD_TRACE
#undef COTHREAD_TRACE_VERBOSE
// -------------------------------------- context switch code
struct mach_state {
jmp_buf buf;
};
static void
mach_switch(mach_state *st1, mach_state *st2)
{
#if #cpu(sparc)
asm("ta 3"); // save register windows
#endif
if (! setjmp(st1->buf))
longjmp(st2->buf, 1);
}
static void
mach_start(mach_state *st1, void *pc, char *stacklo, char *stackhi)
{
#if #cpu(sparc)
asm("ta 3"); // save register windows
#endif
if (! setjmp(st1->buf))
{
// The following code must perform two tasks:
// -- set stack pointer to a proper value between #stacklo# and #stackhi#.
// -- branch to or call the function at address #pc#.
// This function never returns ... so there is no need to save anything
#if #cpu(mips)
char *sp = (char*)(((unsigned long)stackhi-16) & ~0xff);
asm volatile ("move $sp,%0\n\t" // set new stack pointer
"move $25,%1\n\t" // call subroutine via $25
"jal $25\n\t" // call subroutine via $25
"nop" // delay slot
: : "r" (sp), "r" (pc) );
#elif #cpu(i386)
char *sp = (char*)(((unsigned long)stackhi-16) & ~0xff);
asm volatile ("movl %0,%%esp\n\t" // set new stack pointer
"call *%1" // call function
: : "r" (sp), "r" (pc) );
#elif #cpu(sparc)
char *sp = (char*)(((unsigned long)stackhi-16) & ~0xff);
asm volatile ("ta 3\n\t" // saving the register windows will not hurt.
"mov %0,%%sp\n\t" // set new stack pointer
"call %1,0\n\t" // call function
"nop" // delay slot
: : "r" (sp), "r" (pc) );
#elif #cpu(hppa)
char *sp = (char*)(((unsigned long)stacklo+128+255) & ~0xff);
asm volatile("copy %0,%%sp\n\t" // set stack pointer
"copy %1,%%r22\n\t" // set call address
".CALL\n\t" // call pseudo instr (why?)
"bl $$dyncall,%%r31\n\t" // call
"copy %%r31,%%r2" // delay slot ???
: : "r" (sp), "r" (pc) );
#elif #cpu(alpha)
char *sp = (char*)(((unsigned long)stackhi-16) & ~0xff);
asm volatile ("bis $31,%0,$30\n\t" // set new stack pointer
"bis $31,%1,$27\n\t" // load function pointer
"jsr $26,($27),0" // call function
: : "r" (sp), "r" (pc) );
#elif #cpu(powerpc)
char *sp = (char*)(((unsigned long)stackhi-16) & ~0xff);
asm volatile ("mr 1,%0\n\t" // set new stack pointer
"mr 0,%1\n\t" // load func pointer into r0
"mtlr 0\n\t" // load link register with r0
"blrl" // branch
: : "r" (sp), "r" (pc) );
#elif #cpu(m68k) && defined(COTHREAD_UNTESTED)
char *sp = (char*)(((unsigned long)stackhi-16) & ~0xff);
asm volatile ("move%.l %0,%Rsp\n\t" // set new stack pointer
"jmp %a1" // branch to address %1
: : "r" (sp), "a" (pc) );
#elif #cpu(arm) && defined(COTHREAD_UNTESTED)
char *sp = (char*)(((unsigned long)stackhi-16) & ~0xff);
asm volatile ("mov%?\t%|sp, %0\n\t" // set new stack pointer
"mov%?\t%|pc, %1" // branch to address %1
: : "r" (sp), "r" (pc) );
#else
#error "COTHREADS not supported on this machine."
#error "Try -DTHREADMODEL=NOTHREADS."
#endif
// We should never reach this point
abort();
// Note that this call to abort() makes sure
// that function mach_start() is compiled as a non-leaf
// function. It is indeed a non-leaf function since the
// piece of assembly code calls a function, but the compiler
// would not know without the call to abort() ...
}
}
#ifdef CHECK
// This code can be used to verify that task switching works.
char stack[16384];
mach_state st1, st2;
void th2() {
puts("2b"); mach_switch(&st2, &st1);
puts("4b"); mach_switch(&st2, &st1);
puts("6b"); mach_switch(&st2, &st1);
}
void th2relay() {
th2(); puts("ooops\n");
}
void th1() {
mach_start(&st1, (void*)th2relay, stack, stack+sizeof(stack));
puts("3a"); mach_switch(&st1, &st2);
puts("5a"); mach_switch(&st1, &st2);
}
int main() {
puts("1a"); th1(); puts("6a");
}
#endif
// -------------------------------------- select
struct coselect {
int nfds;
fd_set rset;
fd_set wset;
fd_set eset;
};
static void
coselect_merge(coselect *dest, coselect *from)
{
int i;
int nfds = from->nfds;
if (nfds > dest->nfds)
dest->nfds = nfds;
for (i=0; i<nfds; i++) if (FD_ISSET(i, &from->rset)) FD_SET(i, &dest->rset);
for (i=0; i<nfds; i++) if (FD_ISSET(i, &from->wset)) FD_SET(i, &dest->wset);
for (i=0; i<nfds; i++) if (FD_ISSET(i, &from->eset)) FD_SET(i, &dest->eset);
}
static int
coselect_test(coselect *c)
{
static timeval tmzero = {0,0};
fd_set copyr = c->rset;
fd_set copyw = c->wset;
fd_set copye = c->eset;
return select(c->nfds, &copyr, &copyw, &copye, &tmzero);
}
// -------------------------------------- cotask
class GThread::cotask {
public:
#ifndef NO_LIBGCC_HOOKS
cotask(const int xstacksize,void *);
#else
cotask(const int xstacksize);
#endif
~cotask();
class GThread::cotask *next;
class GThread::cotask *prev;
// context
mach_state regs;
// stack information
char *stack;
GPBuffer<char> gstack;
int stacksize;
// timing information
unsigned long over;
// waiting information
void *wchan;
coselect *wselect;
unsigned long *maxwait;
// delete after termination
bool autodelete;
// egcs exception support
#ifndef NO_LIBGCC_HOOKS
void *ehctx;
#endif
};
#ifndef NO_LIBGCC_HOOKS
GThread::cotask::cotask(const int xstacksize, void *xehctx)
#else
GThread::cotask::cotask(const int xstacksize)
#endif
: next(0), prev(0), gstack(stack,xstacksize), stacksize(xstacksize),
over(0), wchan(0), wselect(0), maxwait(0), autodelete(false)
#ifndef NO_LIBGCC_HOOKS
,ehctx(xehctx)
#endif
{
memset(&regs,0,sizeof(regs));
}
static GThread::cotask *maintask = 0;
static GThread::cotask *curtask = 0;
static GThread::cotask *autodeletetask = 0;
static unsigned long globalmaxwait = 0;
static void (*scheduling_callback)(int) = 0;
static timeval time_base;
GThread::cotask::~cotask()
{
gstack.resize(0);
#ifndef NO_LIBGCC_HOOKS
if (ehctx)
free(ehctx);
ehctx = 0;
#endif
}
static void
cotask_free(GThread::cotask *task)
{
#ifdef COTHREAD_TRACE
DjVuPrintErrorUTF8("cothreads: freeing task %p with autodelete=%d\n",
task,task->autodelete);
#endif
if (task!=maintask)
{
delete task;
}
}
// -------------------------------------- time
static unsigned long
time_elapsed(int reset=1)
{
timeval tm;
gettimeofday(&tm, NULL);
long msec = (tm.tv_usec-time_base.tv_usec)/1000;
unsigned long elapsed = (long)(tm.tv_sec-time_base.tv_sec)*1000 + msec;
if (reset && elapsed>0)
{
#ifdef COTHREAD_TRACE
#ifdef COTHREAD_TRACE_VERBOSE
DjVuPrintErrorUTF8("cothreads: %4ld ms in task %p\n", elapsed, curtask);
#endif
#endif
time_base.tv_sec = tm.tv_sec;
time_base.tv_usec += msec*1000;
}
return elapsed;
}
// -------------------------------------- scheduler
static int
cotask_yield()
{
// ok
if (! maintask)
return 0;
// get elapsed time and return immediately when it is too small
unsigned long elapsed = time_elapsed();
if (elapsed==0 && curtask->wchan==0 && curtask->prev && curtask->next)
return 0;
// adjust task running time
curtask->over += elapsed;
if (curtask->over > MAXPENALTY)
curtask->over = MAXPENALTY;
// start scheduling
reschedule:
// try unblocking tasks
GThread::cotask *n = curtask->next;
GThread::cotask *q = n;
do
{
if (q->wchan)
{
if (q->maxwait && *q->maxwait<=elapsed)
{
*q->maxwait = 0;
q->wchan=0;
q->maxwait=0;
q->wselect=0;
}
else if (q->wselect && globalmaxwait<=elapsed && coselect_test(q->wselect))
{
q->wchan=0;
if (q->maxwait)
*q->maxwait -= elapsed;
q->maxwait = 0;
q->wselect=0;
}
if (q->maxwait)
*q->maxwait -= elapsed;
}
q = q->next;
}
while (q!=n);
// adjust globalmaxwait
if (globalmaxwait < elapsed)
globalmaxwait = MAXFDWAIT;
else
globalmaxwait -= elapsed;
// find best candidate
static int count;
unsigned long best = MAXPENALTY + 1;
GThread::cotask *r = 0;
count = 0;
q = n;
do
{
if (! q->wchan)
{
count += 1;
if (best > q->over)
{
r = q;
best = r->over;
}
}
q = q->next;
}
while (q != n);
// found
if (count > 0)
{
// adjust over
q = n;
do
{
q->over = (q->over>best ? q->over-best : 0);
q = q->next;
}
while (q != n);
// Switch
if (r != curtask)
{
#ifdef COTHREAD_TRACE
DjVuPrintErrorUTF8("cothreads: ----- switch to %p [%ld]\n", r, best);
#endif
GThread::cotask *old = curtask;
curtask = r;
mach_switch(&old->regs, &curtask->regs);
}
// handle autodelete
if (autodeletetask && autodeletetask->autodelete)
cotask_free(autodeletetask);
autodeletetask = 0;
// return
if (count == 1)
return 1;
return 0;
}
// No task ready
count = 0;
unsigned long minwait = MAXWAIT;
coselect allfds;
allfds.nfds = 1;
FD_ZERO(&allfds.rset);
FD_ZERO(&allfds.wset);
FD_ZERO(&allfds.eset);
q = n;
do
{
if (q->maxwait || q->wselect)
count += 1;
if (q->maxwait && *q->maxwait<minwait)
minwait = *q->maxwait;
if (q->wselect)
coselect_merge(&allfds, q->wselect);
q = q->next;
}
while (q != n);
// abort on deadlock
if (count == 0) {
DjVuMessageLite::perror( ERR_MSG("GThreads.panic") );
abort();
}
// select
timeval tm;
tm.tv_sec = minwait/1000;
tm.tv_usec = 1000*(minwait-1000*tm.tv_sec);
select(allfds.nfds,&allfds.rset, &allfds.wset, &allfds.eset, &tm);
// reschedule
globalmaxwait = 0;
elapsed = time_elapsed();
goto reschedule;
}
static void
cotask_terminate(GThread::cotask *task)
{
#ifdef COTHREAD_TRACE
DjVuPrintErrorUTF8("cothreads: terminating task %p\n", task);
#endif
if (task && task!=maintask)
{
if (task->prev && task->next)
{
if (scheduling_callback)
(*scheduling_callback)(GThread::CallbackTerminate);
task->prev->next = task->next;
task->next->prev = task->prev;
// mark task as terminated
task->prev = 0;
// self termination
if (task == curtask)
{
if (task->autodelete)
autodeletetask = task;
cotask_yield();
}
}
}
}
static void
cotask_wakeup(void *wchan, int onlyone)
{
if (maintask && curtask)
{
GThread::cotask *n = curtask->next;
GThread::cotask *q = n;
do
{
if (q->wchan == wchan)
{
q->wchan=0;
q->maxwait=0;
q->wselect=0;
q->over = 0;
if (onlyone)
return;
}
q = q->next;
}
while (q!=n);
}
}
// -------------------------------------- select / get_select
static int
cotask_select(int nfds,
fd_set *rfds, fd_set *wfds, fd_set *efds,
struct timeval *tm)
{
// bypass
if (maintask==0 || (tm && tm->tv_sec==0 && tm->tv_usec<1000))
return select(nfds, rfds, wfds, efds, tm);
// copy parameters
unsigned long maxwait = 0;
coselect parm;
// set waiting info
curtask->wchan = (void*)&parm;
if (rfds || wfds || efds)
{
parm.nfds = nfds;
if (rfds) { parm.rset=*rfds; } else { FD_ZERO(&parm.rset); }
if (wfds) { parm.wset=*wfds; } else { FD_ZERO(&parm.wset); }
if (efds) { parm.eset=*efds; } else { FD_ZERO(&parm.eset); }
curtask->wselect = &parm;
}
if (tm)
{
maxwait = time_elapsed(0) + tm->tv_sec*1000 + tm->tv_usec/1000;
curtask->maxwait = &maxwait;
}
// reschedule
cotask_yield();
// call select to update masks
if (tm)
{
tm->tv_sec = maxwait/1000;
tm->tv_usec = 1000*(maxwait-1000*tm->tv_sec);
}
static timeval tmzero = {0,0};
return select(nfds, rfds, wfds, efds, &tmzero);
}
static void
cotask_get_select(int &nfds, fd_set *rfds, fd_set *wfds, fd_set *efds,
unsigned long &timeout)
{
int ready = 1;
unsigned long minwait = MAXWAIT;
unsigned long elapsed = time_elapsed(0);
coselect allfds;
allfds.nfds=0;
FD_ZERO(&allfds.rset);
FD_ZERO(&allfds.wset);
FD_ZERO(&allfds.eset);
if (curtask)
{
GThread::cotask *q=curtask->next;
while (q != curtask)
{
ready++;
if (q->wchan)
{
if (q->wselect)
coselect_merge(&allfds, q->wselect);
if (q->maxwait && *q->maxwait<minwait)
minwait = *q->maxwait;
ready--;
}
q = q->next;
}
}
timeout = 0;
nfds=allfds.nfds;
*rfds=allfds.rset;
*wfds=allfds.wset;
*efds=allfds.eset;
if (ready==1 && minwait>elapsed)
timeout = minwait-elapsed;
}
// -------------------------------------- libgcc hook
#ifndef NO_LIBGCC_HOOKS
// These are exported by Leon's patched version of libgcc.a
// Let's hope that the egcs people will include the patch in
// the distributions.
extern "C"
{
extern void* (*__get_eh_context_ptr)(void);
extern void* __new_eh_context(void);
}
// This function is called via the pointer __get_eh_context_ptr
// by the internal mechanisms of egcs. It must return the
// per-thread event handler context. This is necessary to
// implement thread safe exceptions on some machine and/or
// when flag -fsjlj-exception is set.
static void *
cotask_get_eh_context()
{
if (curtask)
return curtask->ehctx;
else if (maintask)
return maintask->ehctx;
DjVuMessageLite::perror( ERR_MSG("GThreads.co_panic") );
abort();
}
#endif
// -------------------------------------- GThread
void
GThread::set_scheduling_callback(void (*call)(int))
{
if (scheduling_callback)
G_THROW( ERR_MSG("GThreads.dupl_callback") );
scheduling_callback = call;
}
GThread::GThread(int stacksize)
: task(0), xentry(0), xarg(0)
{
// check argument
if (stacksize < 0)
stacksize = DEFSTACK;
if (stacksize < MINSTACK)
stacksize = MINSTACK;
// initialization
if (! maintask)
{
#ifndef NO_LIBGCC_HOOKS
static GThread::cotask comaintask(0,(*__get_eh_context_ptr)());
__get_eh_context_ptr = cotask_get_eh_context;
#else
static GThread::cotask comaintask(0);
#endif
maintask = &comaintask;
// memset(maintask, 0, sizeof(GThread::cotask));
maintask->next = maintask;
maintask->prev = maintask;
gettimeofday(&time_base,NULL);
curtask = maintask;
}
// allocation
#ifndef NO_LIBGCC_HOOKS
task = new GThread::cotask(stacksize,__new_eh_context());
#else
task = new GThread::cotask(stacksize);
#endif
}
GThread::~GThread()
{
if (task && task!=maintask)
{
if (task->prev) // running
task->autodelete = true;
else
cotask_free(task);
task = 0;
}
}
#if __GNUC__ >= 3
# if __GNUC_MINOR__ >= 4
# define noinline __attribute__((noinline,used))
# elif __GNUC_MINOR >= 2
# define noinline __attribute__((noinline))
# endif
#endif
#ifndef noinline
# define noinline /**/
#endif
static noinline void startone(void);
static noinline void starttwo(GThread *thr);
static GThread * volatile starter;
static void
startone(void)
{
GThread *thr = starter;
mach_switch(&thr->task->regs, &curtask->regs);
// Registers may still contain an improper pointer
// to the exception context. We should neither
// register cleanups nor register handlers.
starttwo(thr);
abort();
}
static void
starttwo(GThread *thr)
{
// Hopefully this function reacquires
// an exception context pointer. Therefore
// we can register the exception handlers.
// It is placed after ``startone'' to avoid inlining.
#ifdef __EXCEPTIONS
try
{
#endif
G_TRY
{
thr->xentry( thr->xarg );
}
G_CATCH(ex)
{
ex.perror();
DjVuMessageLite::perror( ERR_MSG("GThreads.uncaught") );
#ifdef _DEBUG
abort();
#endif
}
G_ENDCATCH;
#ifdef __EXCEPTIONS
}
catch(...)
{
DjVuMessageLite::perror( ERR_MSG("GThreads.unrecognized") );
#ifdef _DEBUG
abort();
#endif
}
#endif
cotask_terminate(curtask);
GThread::yield();
// Do not add anything below this line!
// Nothing should reach it anyway.
abort();
}
int
GThread::create(void (*entry)(void*), void *arg)
{
if (task->next || task->prev)
return -1;
xentry = entry;
xarg = arg;
task->wchan = 0;
task->next = curtask;
task->prev = curtask->prev;
task->next->prev = task;
task->prev->next = task;
GThread::cotask *old = curtask;
starter = this;
mach_start(&old->regs, (void*)startone,
task->stack, task->stack+task->stacksize);
if (scheduling_callback)
(*scheduling_callback)(CallbackCreate);
return 0;
}
void
GThread::terminate()
{
if (task && task!=maintask)
cotask_terminate(task);
}
int
GThread::yield()
{
return cotask_yield();
}
int
GThread::select(int nfds,
fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
struct timeval *timeout)
{
return cotask_select(nfds, readfds, writefds, exceptfds, timeout);
}
void
GThread::get_select(int &nfds, fd_set *rfds, fd_set *wfds, fd_set *efds,
unsigned long &timeout)
{
cotask_get_select(nfds, rfds, wfds, efds, timeout);
}
inline void *
GThread::current()
{
if (curtask && curtask!=maintask)
return (void*)curtask;
return (void*)0;
}
// -------------------------------------- GMonitor
GMonitor::GMonitor()
: count(1), locker(0), wlock(0), wsig(0)
{
locker = 0;
ok = 1;
}
GMonitor::~GMonitor()
{
ok = 0;
cotask_wakeup((void*)&wsig, 0);
cotask_wakeup((void*)&wlock, 0);
cotask_yield();
// Because we know how the scheduler works, we know that this single call to
// yield will run all unblocked tasks and given them the chance to leave the
// scope of the monitor object.
}
void
GMonitor::enter()
{
void *self = GThread::current();
if (count>0 || self!=locker)
{
while (ok && count<=0)
{
curtask->wchan = (void*)&wlock;
wlock++;
cotask_yield();
wlock--;
}
count = 1;
locker = self;
}
count -= 1;
}
void
GMonitor::leave()
{
void *self = GThread::current();
if (ok && (count>0 || self!=locker))
G_THROW( ERR_MSG("GThreads.not_acq_leave") );
if (++count > 0 && wlock > 0)
cotask_wakeup((void*)&wlock, 1);
}
void
GMonitor::signal()
{
void *self = GThread::current();
if (count>0 || self!=locker)
G_THROW( ERR_MSG("GThreads.not_acq_signal") );
if (wsig > 0)
{
cotask_wakeup((void*)&wsig, 1);
if (scheduling_callback)
(*scheduling_callback)(GThread::CallbackUnblock);
}
}
void
GMonitor::broadcast()
{
void *self = GThread::current();
if (count>0 || self!=locker)
G_THROW( ERR_MSG("GThreads.not_acq_broad") );
if (wsig > 0)
{
cotask_wakeup((void*)&wsig, 0);
if (scheduling_callback)
(*scheduling_callback)(GThread::CallbackUnblock);
}
}
void
GMonitor::wait()
{
// Check state
void *self = GThread::current();
if (count>0 || locker!=self)
G_THROW( ERR_MSG("GThreads.not_acq_wait") );
// Wait
if (ok)
{
// Atomically release monitor and wait
int sav_count = count;
count = 1;
curtask->wchan = (void*)&wsig;
cotask_wakeup((void*)&wlock, 1);
wsig++;
cotask_yield();
wsig--;
// Re-acquire
while (ok && count <= 0)
{
curtask->wchan = (void*)&wlock;
wlock++;
cotask_yield();
wlock--;
}
count = sav_count;
locker = self;
}
}
void
GMonitor::wait(unsigned long timeout)
{
// Check state
void *self = GThread::current();
if (count>0 || locker!=self)
G_THROW( ERR_MSG("GThreads.not_acq_wait") );
// Wait
if (ok)
{
// Atomically release monitor and wait
int sav_count = count;
count = 1;
unsigned long maxwait = time_elapsed(0) + timeout;
curtask->maxwait = &maxwait;
curtask->wchan = (void*)&wsig;
cotask_wakeup((void*)&wlock, 1);
wsig++;
cotask_yield();
wsig--;
// Re-acquire
while (ok && count<=0)
{
curtask->wchan = (void*)&wlock;
wlock++;
cotask_yield();
wlock--;
}
count = sav_count;
locker = self;
}
}
#endif
// ----------------------------------------
// GSAFEFLAGS
// ----------------------------------------
GSafeFlags &
GSafeFlags::operator=(long xflags)
{
enter();
if (flags!=xflags)
{
flags=xflags;
broadcast();
}
leave();
return *this;
}
GSafeFlags::operator long(void) const
{
long f;
((GSafeFlags *) this)->enter();
f=flags;
((GSafeFlags *) this)->leave();
return f;
}
bool
GSafeFlags::test_and_modify(long set_mask, long clr_mask,
long set_mask1, long clr_mask1)
{
enter();
if ((flags & set_mask)==set_mask &&
(~flags & clr_mask)==clr_mask)
{
long new_flags=flags;
new_flags|=set_mask1;
new_flags&=~clr_mask1;
if (new_flags!=flags)
{
flags=new_flags;
broadcast();
}
leave();
return true;
}
leave();
return false;
}
void
GSafeFlags::wait_and_modify(long set_mask, long clr_mask,
long set_mask1, long clr_mask1)
{
enter();
while((flags & set_mask)!=set_mask ||
(~flags & clr_mask)!=clr_mask) wait();
long new_flags=flags;
new_flags|=set_mask1;
new_flags&=~clr_mask1;
if (flags!=new_flags)
{
flags=new_flags;
broadcast();
}
leave();
}
#ifdef HAVE_NAMESPACES
}
# ifndef NOT_USING_DJVU_NAMESPACE
using namespace DJVU;
# endif
#endif
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