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 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */

 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 #include <kernel/OS.h>

 #include <support/TLS.h>

 #include "prlog.h"

 #include "primpl.h"

 #include "prcvar.h"

 #include "prpdce.h"

 #include <stdlib.h>

 #include <string.h>

 #include <signal.h>

 /* values for PRThread.state */

 #define BT_THREAD_PRIMORD   0x01    /* this is the primordial thread */

 #define BT_THREAD_SYSTEM    0x02    /* this is a system thread */

 #define BT_THREAD_JOINABLE  0x04	/* this is a joinable thread */

 struct _BT_Bookeeping

 {

     PRLock *ml;                 /* a lock to protect ourselves */

 	sem_id cleanUpSem;		/* the primoridal thread will block on this

 							   sem while waiting for the user threads */

     PRInt32 threadCount;	/* user thred count */

 } bt_book = { NULL, B_ERROR, 0 };

 #define BT_TPD_LIMIT 128	/* number of TPD slots we'll provide (arbitrary) */

 /* these will be used to map an index returned by PR_NewThreadPrivateIndex()

    to the corresponding beos native TLS slot number, and to the destructor

    for that slot - note that, because it is allocated globally, this data

    will be automatically zeroed for us when the program begins */

 static int32 tpd_beosTLSSlots[BT_TPD_LIMIT];

 static PRThreadPrivateDTOR tpd_dtors[BT_TPD_LIMIT];

 static vint32 tpd_slotsUsed=0;	/* number of currently-allocated TPD slots */

 static int32 tls_prThreadSlot;	/* TLS slot in which PRThread will be stored */

 /* this mutex will be used to synchronize access to every

    PRThread.md.joinSem and PRThread.md.is_joining (we could

    actually allocate one per thread, but that seems a bit excessive,

    especially considering that there will probably be little

    contention, PR_JoinThread() is allowed to block anyway, and the code

    protected by the mutex is short/fast) */

 static PRLock *joinSemLock;

 static PRUint32 _bt_MapNSPRToNativePriority( PRThreadPriority priority );

 static PRThreadPriority _bt_MapNativeToNSPRPriority( PRUint32 priority );

 static void _bt_CleanupThread(void *arg);

 static PRThread *_bt_AttachThread();

 void

 _PR_InitThreads (PRThreadType type, PRThreadPriority priority,

                  PRUintn maxPTDs)

 {

     PRThread *primordialThread;

     PRUint32  beThreadPriority;

 	/* allocate joinSem mutex */

 	joinSemLock = PR_NewLock();

 	if (joinSemLock == NULL)

 	{

 		PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);

 		return;

     }

     /*

     ** Create and initialize NSPR structure for our primordial thread.

     */

     primordialThread = PR_NEWZAP(PRThread);

     if( NULL == primordialThread )

     {

         PR_SetError( PR_OUT_OF_MEMORY_ERROR, 0 );

         return;

     }

 	primordialThread->md.joinSem = B_ERROR;

     /*

     ** Set the priority to the desired level.

     */

     beThreadPriority = _bt_MapNSPRToNativePriority( priority );

     set_thread_priority( find_thread( NULL ), beThreadPriority );

     primordialThread->priority = priority;

 	/* set the thread's state - note that the thread is not joinable */

     primordialThread->state |= BT_THREAD_PRIMORD;

 	if (type == PR_SYSTEM_THREAD)

 		primordialThread->state |= BT_THREAD_SYSTEM;

     /*

     ** Allocate a TLS slot for the PRThread structure (just using

     ** native TLS, as opposed to NSPR TPD, will make PR_GetCurrentThread()

     ** somewhat faster, and will leave one more TPD slot for our client)

     */

 	tls_prThreadSlot = tls_allocate();

     /*

     ** Stuff our new PRThread structure into our thread specific

     ** slot.

     */

 	tls_set(tls_prThreadSlot, primordialThread);

 	/* allocate lock for bt_book */

     bt_book.ml = PR_NewLock();

     if( NULL == bt_book.ml )

     {

     	PR_SetError( PR_OUT_OF_MEMORY_ERROR, 0 );

 	return;

     }

 }

 PRUint32

 _bt_MapNSPRToNativePriority( PRThreadPriority priority )

     {

     switch( priority )

     {

     	case PR_PRIORITY_LOW:	 return( B_LOW_PRIORITY );

 	case PR_PRIORITY_NORMAL: return( B_NORMAL_PRIORITY );

 	case PR_PRIORITY_HIGH:	 return( B_DISPLAY_PRIORITY );

 	case PR_PRIORITY_URGENT: return( B_URGENT_DISPLAY_PRIORITY );

 	default:		 return( B_NORMAL_PRIORITY );

     }

 }

 PRThreadPriority

 _bt_MapNativeToNSPRPriority(PRUint32 priority)

     {

 	if (priority < B_NORMAL_PRIORITY)

 		return PR_PRIORITY_LOW;

 	if (priority < B_DISPLAY_PRIORITY)

 		return PR_PRIORITY_NORMAL;

 	if (priority < B_URGENT_DISPLAY_PRIORITY)

 		return PR_PRIORITY_HIGH;

 	return PR_PRIORITY_URGENT;

 }

 PRUint32

 _bt_mapNativeToNSPRPriority( int32 priority )

 {

     switch( priority )

     {

     	case PR_PRIORITY_LOW:	 return( B_LOW_PRIORITY );

 	case PR_PRIORITY_NORMAL: return( B_NORMAL_PRIORITY );

 	case PR_PRIORITY_HIGH:	 return( B_DISPLAY_PRIORITY );

 	case PR_PRIORITY_URGENT: return( B_URGENT_DISPLAY_PRIORITY );

 	default:		 return( B_NORMAL_PRIORITY );

     }

 }

 /* This method is called by all NSPR threads as they exit */

 void _bt_CleanupThread(void *arg)

 {

 	PRThread *me = PR_GetCurrentThread();

 	int32 i;

 	/* first, clean up all thread-private data */

 	for (i = 0; i < tpd_slotsUsed; i++)

 	{

 		void *oldValue = tls_get(tpd_beosTLSSlots[i]);

 		if ( oldValue != NULL && tpd_dtors[i] != NULL )

 			(*tpd_dtors[i])(oldValue);

 	}

 	/* if this thread is joinable, wait for someone to join it */

 	if (me->state & BT_THREAD_JOINABLE)

 	{

 		/* protect access to our joinSem */

 		PR_Lock(joinSemLock);

 		if (me->md.is_joining)

 		{

 			/* someone is already waiting to join us (they've

 			   allocated a joinSem for us) - let them know we're

 			   ready */

 			delete_sem(me->md.joinSem);

 			PR_Unlock(joinSemLock);

 		}

 		else

     {

 			/* noone is currently waiting for our demise - it

 			   is our responsibility to allocate the joinSem

 			   and block on it */

 			me->md.joinSem = create_sem(0, "join sem");

 			/* we're done accessing our joinSem */

 			PR_Unlock(joinSemLock);

 			/* wait for someone to join us */

 			while (acquire_sem(me->md.joinSem) == B_INTERRUPTED);

 	    }

 	}

 	/* if this is a user thread, we must update our books */

 	if ((me->state & BT_THREAD_SYSTEM) == 0)

 	{

 		/* synchronize access to bt_book */

     PR_Lock( bt_book.ml );

 		/* decrement the number of currently-alive user threads */

 	bt_book.threadCount--;

 		if (bt_book.threadCount == 0 && bt_book.cleanUpSem != B_ERROR) {

 			/* we are the last user thread, and the primordial thread is

 			   blocked in PR_Cleanup() waiting for us to finish - notify

 			   it */

 			delete_sem(bt_book.cleanUpSem);

 	}

     PR_Unlock( bt_book.ml );

 	}

 	/* finally, delete this thread's PRThread */

 	PR_DELETE(me);

 }

 /**

  * This is a wrapper that all threads invoke that allows us to set some

  * things up prior to a thread's invocation and clean up after a thread has

  * exited.

  */

 static void*

 _bt_root (void* arg)

 	{

     PRThread *thred = (PRThread*)arg;

     PRIntn rv;

     void *privData;

     status_t result;

     int i;

 	/* save our PRThread object into our TLS */

 	tls_set(tls_prThreadSlot, thred);

     thred->startFunc(thred->arg);  /* run the dang thing */

 	/* clean up */

 	_bt_CleanupThread(NULL);

 	return 0;

 }

 PR_IMPLEMENT(PRThread*)

     PR_CreateThread (PRThreadType type, void (*start)(void* arg), void* arg,

                      PRThreadPriority priority, PRThreadScope scope,

                      PRThreadState state, PRUint32 stackSize)

 {

     PRUint32 bePriority;

     PRThread* thred;

     if (!_pr_initialized) _PR_ImplicitInitialization();

 	thred = PR_NEWZAP(PRThread);

  	if (thred == NULL)

 	{

         PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);

         return NULL;

     }

     thred->md.joinSem = B_ERROR;

         thred->arg = arg;

         thred->startFunc = start;

         thred->priority = priority;

 	if( state == PR_JOINABLE_THREAD )

 	{

 	    thred->state |= BT_THREAD_JOINABLE;

 	}

         /* keep some books */

 	PR_Lock( bt_book.ml );

 	if (type == PR_USER_THREAD)

 	{

 	    bt_book.threadCount++;

         }

 	PR_Unlock( bt_book.ml );

 	bePriority = _bt_MapNSPRToNativePriority( priority );

         thred->md.tid = spawn_thread((thread_func)_bt_root, "moz-thread",

                                      bePriority, thred);

         if (thred->md.tid < B_OK) {

             PR_SetError(PR_UNKNOWN_ERROR, thred->md.tid);

             PR_DELETE(thred);

 			return NULL;

         }

         if (resume_thread(thred->md.tid) < B_OK) {

             PR_SetError(PR_UNKNOWN_ERROR, 0);

             PR_DELETE(thred);

 			return NULL;

         }

     return thred;

     }

 PR_IMPLEMENT(PRThread*)

 	PR_AttachThread(PRThreadType type, PRThreadPriority priority,

 					PRThreadStack *stack)

 {

 	/* PR_GetCurrentThread() will attach a thread if necessary */

 	return PR_GetCurrentThread();

 }

 PR_IMPLEMENT(void)

 	PR_DetachThread()

 {

 	/* we don't support detaching */

 }

 PR_IMPLEMENT(PRStatus)

     PR_JoinThread (PRThread* thred)

 {

     status_t eval, status;

     PR_ASSERT(thred != NULL);

 	if ((thred->state & BT_THREAD_JOINABLE) == 0)

     {

 	PR_SetError( PR_INVALID_ARGUMENT_ERROR, 0 );

 	return( PR_FAILURE );

     }

 	/* synchronize access to the thread's joinSem */

 	PR_Lock(joinSemLock);

 	if (thred->md.is_joining)

 	{

 		/* another thread is already waiting to join the specified

 		   thread - we must fail */

 		PR_Unlock(joinSemLock);

 		return PR_FAILURE;

 	}

 	/* let others know we are waiting to join */

 	thred->md.is_joining = PR_TRUE;

 	if (thred->md.joinSem == B_ERROR)

 	{

 		/* the thread hasn't finished yet - it is our responsibility to

 		   allocate a joinSem and wait on it */

 		thred->md.joinSem = create_sem(0, "join sem");

 		/* we're done changing the joinSem now */

 		PR_Unlock(joinSemLock);

 		/* wait for the thread to finish */

 		while (acquire_sem(thred->md.joinSem) == B_INTERRUPTED);

 	}

 	else

 	{

 		/* the thread has already finished, and has allocated the

 		   joinSem itself - let it know it can finally die */

 		delete_sem(thred->md.joinSem);

 		PR_Unlock(joinSemLock);

     }

 	/* make sure the thread is dead */

     wait_for_thread(thred->md.tid, &eval);

     return PR_SUCCESS;

 }

 PR_IMPLEMENT(PRThread*)

     PR_GetCurrentThread ()

 {

     PRThread* thred;

     if (!_pr_initialized) _PR_ImplicitInitialization();

     thred = (PRThread *)tls_get( tls_prThreadSlot);

 	if (thred == NULL)

 	{

 		/* this thread doesn't have a PRThread structure (it must be

 		   a native thread not created by the NSPR) - assimilate it */

 		thred = _bt_AttachThread();

 	}

     PR_ASSERT(NULL != thred);

     return thred;

 }

 PR_IMPLEMENT(PRThreadScope)

     PR_GetThreadScope (const PRThread* thred)

 {

     PR_ASSERT(thred != NULL);

     return PR_GLOBAL_THREAD;

 }

 PR_IMPLEMENT(PRThreadType)

     PR_GetThreadType (const PRThread* thred)

 {

     PR_ASSERT(thred != NULL);

     return (thred->state & BT_THREAD_SYSTEM) ?

         PR_SYSTEM_THREAD : PR_USER_THREAD;

 }

 PR_IMPLEMENT(PRThreadState)

     PR_GetThreadState (const PRThread* thred)

 {

     PR_ASSERT(thred != NULL);

     return (thred->state & BT_THREAD_JOINABLE)?

     					PR_JOINABLE_THREAD: PR_UNJOINABLE_THREAD;

 }

 PR_IMPLEMENT(PRThreadPriority)

     PR_GetThreadPriority (const PRThread* thred)

 {

     PR_ASSERT(thred != NULL);

     return thred->priority;

 }  /* PR_GetThreadPriority */

 PR_IMPLEMENT(void) PR_SetThreadPriority(PRThread *thred,

                                         PRThreadPriority newPri)

 {

     PRUint32 bePriority;

     PR_ASSERT( thred != NULL );

     thred->priority = newPri;

     bePriority = _bt_MapNSPRToNativePriority( newPri );

     set_thread_priority( thred->md.tid, bePriority );

 }

 PR_IMPLEMENT(PRStatus)

     PR_NewThreadPrivateIndex (PRUintn* newIndex,

                               PRThreadPrivateDTOR destructor)

 {

 	int32    index;

     if (!_pr_initialized) _PR_ImplicitInitialization();

 	/* reserve the next available tpd slot */

 	index = atomic_add( &tpd_slotsUsed, 1 );

 	if (index >= BT_TPD_LIMIT)

 	{

 		/* no slots left - decrement value, then fail */

 		atomic_add( &tpd_slotsUsed, -1 );

 		PR_SetError( PR_TPD_RANGE_ERROR, 0 );

 	    return( PR_FAILURE );

 	}

 	/* allocate a beos-native TLS slot for this index (the new slot

 	   automatically contains NULL) */

 	tpd_beosTLSSlots[index] = tls_allocate();

 	/* remember the destructor */

 	tpd_dtors[index] = destructor;

     *newIndex = (PRUintn)index;

     return( PR_SUCCESS );

 }

 PR_IMPLEMENT(PRStatus)

     PR_SetThreadPrivate (PRUintn index, void* priv)

 {

 	void *oldValue;

     /*

     ** Sanity checking

     */

     if(index < 0 || index >= tpd_slotsUsed || index >= BT_TPD_LIMIT)

     {

 		PR_SetError( PR_TPD_RANGE_ERROR, 0 );

 	return( PR_FAILURE );

     }

 	/* if the old value isn't NULL, and the dtor for this slot isn't

 	   NULL, we must destroy the data */

 	oldValue = tls_get(tpd_beosTLSSlots[index]);

 	if (oldValue != NULL && tpd_dtors[index] != NULL)

 		(*tpd_dtors[index])(oldValue);

 	/* save new value */

 	tls_set(tpd_beosTLSSlots[index], priv);

 	    return( PR_SUCCESS );

 	}

 PR_IMPLEMENT(void*)

     PR_GetThreadPrivate (PRUintn index)

 {

 	/* make sure the index is valid */

 	if (index < 0 || index >= tpd_slotsUsed || index >= BT_TPD_LIMIT)

     {   

 		PR_SetError( PR_TPD_RANGE_ERROR, 0 );

 		return NULL;

     }

 	/* return the value */

 	return tls_get( tpd_beosTLSSlots[index] );

 	}

 PR_IMPLEMENT(PRStatus)

     PR_Interrupt (PRThread* thred)

 {

     PRIntn rv;

     PR_ASSERT(thred != NULL);

     /*

     ** there seems to be a bug in beos R5 in which calling

     ** resume_thread() on a blocked thread returns B_OK instead

     ** of B_BAD_THREAD_STATE (beos bug #20000422-19095).  as such,

     ** to interrupt a thread, we will simply suspend then resume it

     ** (no longer call resume_thread(), check for B_BAD_THREAD_STATE,

     ** the suspend/resume to wake up a blocked thread).  this wakes

     ** up blocked threads properly, and doesn't hurt unblocked threads

     ** (they simply get stopped then re-started immediately)

     */

     rv = suspend_thread( thred->md.tid );

     if( rv != B_NO_ERROR )

     {

         /* this doesn't appear to be a valid thread_id */

         PR_SetError( PR_UNKNOWN_ERROR, rv );

         return PR_FAILURE;

     }

     rv = resume_thread( thred->md.tid );

     if( rv != B_NO_ERROR )

     {

         PR_SetError( PR_UNKNOWN_ERROR, rv );

         return PR_FAILURE;

     }

     return PR_SUCCESS;

 }

 PR_IMPLEMENT(void)

     PR_ClearInterrupt ()

 {

 }

 PR_IMPLEMENT(PRStatus)

     PR_Yield ()

 {

     /* we just sleep for long enough to cause a reschedule (100

        microseconds) */

     snooze(100);

 }

 #define BT_MILLION 1000000UL

 PR_IMPLEMENT(PRStatus)

     PR_Sleep (PRIntervalTime ticks)

 {

     bigtime_t tps;

     status_t status;

     if (!_pr_initialized) _PR_ImplicitInitialization();

     tps = PR_IntervalToMicroseconds( ticks );

     status = snooze(tps);

     if (status == B_NO_ERROR) return PR_SUCCESS;

     PR_SetError(PR_NOT_IMPLEMENTED_ERROR, status);

     return PR_FAILURE;

 }

 PR_IMPLEMENT(PRStatus)

     PR_Cleanup ()

 {

     PRThread *me = PR_GetCurrentThread();

     PR_ASSERT(me->state & BT_THREAD_PRIMORD);

     if ((me->state & BT_THREAD_PRIMORD) == 0) {

         return PR_FAILURE;

     }

     PR_Lock( bt_book.ml );

 	if (bt_book.threadCount != 0)

     {

 		/* we'll have to wait for some threads to finish - create a

 		   sem to block on */

 		bt_book.cleanUpSem = create_sem(0, "cleanup sem");

     }

     PR_Unlock( bt_book.ml );

 	/* note that, if all the user threads were already dead, we

 	   wouldn't have created a sem above, so this acquire_sem()

 	   will fail immediately */

 	while (acquire_sem(bt_book.cleanUpSem) == B_INTERRUPTED);

     return PR_SUCCESS;

 }

 PR_IMPLEMENT(void)

     PR_ProcessExit (PRIntn status)

 {

     exit(status);

 }

 PRThread *_bt_AttachThread()

 {

 	PRThread *thread;

 	thread_info tInfo;

 	/* make sure this thread doesn't already have a PRThread structure */

 	PR_ASSERT(tls_get(tls_prThreadSlot) == NULL);

 	/* allocate a PRThread structure for this thread */

 	thread = PR_NEWZAP(PRThread);

 	if (thread == NULL)

 	{

 		PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);

 		return NULL;

 	}

 	/* get the native thread's current state */

 	get_thread_info(find_thread(NULL), &tInfo);

 	/* initialize new PRThread */

 	thread->md.tid = tInfo.thread;

 	thread->md.joinSem = B_ERROR;

 	thread->priority = _bt_MapNativeToNSPRPriority(tInfo.priority);

 	/* attached threads are always non-joinable user threads */

 	thread->state = 0;

 	/* increment user thread count */

 	PR_Lock(bt_book.ml);

 	bt_book.threadCount++;

 	PR_Unlock(bt_book.ml);

 	/* store this thread's PRThread */

 	tls_set(tls_prThreadSlot, thread);

 	/* the thread must call _bt_CleanupThread() before it dies, in order

 	   to clean up its PRThread, synchronize with the primordial thread,

 	   etc. */

 	on_exit_thread(_bt_CleanupThread, NULL);

 	return thread;

 }