nspr-4.8.6/mozilla/nsprpub/pr/src/threads/prtpd.c - nest-learning-thermostat/5.1.3/nspr - Git at Google

 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* ***** BEGIN LICENSE BLOCK *****
  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
  *
  * The contents of this file are subject to the Mozilla Public License Version
  * 1.1 (the "License"); you may not use this file except in compliance with
  * the License. You may obtain a copy of the License at
  * http://www.mozilla.org/MPL/
  *
  * Software distributed under the License is distributed on an "AS IS" basis,
  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  * for the specific language governing rights and limitations under the
  * License.
  *
  * The Original Code is the Netscape Portable Runtime (NSPR).
  *
  * The Initial Developer of the Original Code is
  * Netscape Communications Corporation.
  * Portions created by the Initial Developer are Copyright (C) 1998-2000
  * the Initial Developer. All Rights Reserved.
  *
  * Contributor(s):
  *
  * Alternatively, the contents of this file may be used under the terms of
  * either the GNU General Public License Version 2 or later (the "GPL"), or
  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  * in which case the provisions of the GPL or the LGPL are applicable instead
  * of those above. If you wish to allow use of your version of this file only
  * under the terms of either the GPL or the LGPL, and not to allow others to
  * use your version of this file under the terms of the MPL, indicate your
  * decision by deleting the provisions above and replace them with the notice
  * and other provisions required by the GPL or the LGPL. If you do not delete
  * the provisions above, a recipient may use your version of this file under
  * the terms of any one of the MPL, the GPL or the LGPL.
  *
  * ***** END LICENSE BLOCK ***** */

 /*
 ** Thread Private Data
 **
 ** There is an aribitrary limit on the number of keys that will be allocated
 ** by the runtime. It's largish, so it is intended to be a sanity check, not
 ** an impediment.
 **
 ** There is a counter, initialized to zero and incremented every time a
 ** client asks for a new key, that holds the high water mark for keys. All
 ** threads logically have the same high water mark and are permitted to
 ** ask for TPD up to that key value.
 **
 ** The vector to hold the TPD are allocated when PR_SetThreadPrivate() is
 ** called. The size of the vector will be some value greater than or equal
 ** to the current high water mark. Each thread has its own TPD length and
 ** vector.
 **
 ** Threads that get private data for keys they have not set (or perhaps
 ** don't even exist for that thread) get a NULL return. If the key is
 ** beyond the high water mark, an error will be returned.
 */

 /*
 ** As of this time, BeOS has its own TPD implementation.  Integrating
 ** this standard one is a TODO for anyone with a bit of spare time on
 ** their hand.  For now, we just #ifdef out this whole file and use
 ** the routines in pr/src/btthreads/
 */

 #ifndef XP_BEOS

 #include "primpl.h"

 #include <string.h>

 #if defined(WIN95)
 /*
 ** Some local variables report warnings on Win95 because the code paths
 ** using them are conditioned on HAVE_CUSTOME_USER_THREADS.
 ** The pragma suppresses the warning.
 **
 */
 #pragma warning(disable : 4101)
 #endif

 #define _PR_TPD_LIMIT 128               /* arbitary limit on the TPD slots */
 static PRInt32 _pr_tpd_length = 0;      /* current length of destructor vector */
 static PRInt32 _pr_tpd_highwater = 0;   /* next TPD key to be assigned */
 static PRThreadPrivateDTOR *_pr_tpd_destructors = NULL;
                                         /* the destructors are associated with
                                             the keys, therefore asserting that
                                             the TPD key depicts the data's 'type' */

 /*
 ** Initialize the thread private data manipulation
 */
 void _PR_InitTPD(void)
 {
     _pr_tpd_destructors = (PRThreadPrivateDTOR*)
         PR_CALLOC(_PR_TPD_LIMIT * sizeof(PRThreadPrivateDTOR*));
     PR_ASSERT(NULL != _pr_tpd_destructors);
     _pr_tpd_length = _PR_TPD_LIMIT;
 }

 /*
 ** Clean up the thread private data manipulation
 */
 void _PR_CleanupTPD(void)
 {
 }  /* _PR_CleanupTPD */

 /*
 ** This routine returns a new index for per-thread-private data table.
 ** The index is visible to all threads within a process. This index can
 ** be used with the PR_SetThreadPrivate() and PR_GetThreadPrivate() routines
 ** to save and retrieve data associated with the index for a thread.
 **
 ** The index independently maintains specific values for each binding thread.
 ** A thread can only get access to its own thread-specific-data.
 **
 ** Upon a new index return the value associated with the index for all threads
 ** is NULL, and upon thread creation the value associated with all indices for
 ** that thread is NULL.
 **
 **     "dtor" is the destructor function to invoke when the private
 **       data is set or destroyed
 **
 ** Returns PR_FAILURE if the total number of indices will exceed the maximun
 ** allowed.
 */

 PR_IMPLEMENT(PRStatus) PR_NewThreadPrivateIndex(
     PRUintn *newIndex, PRThreadPrivateDTOR dtor)
 {
     PRStatus rv;
     PRInt32 index;

     if (!_pr_initialized) _PR_ImplicitInitialization();

     PR_ASSERT(NULL != newIndex);
     PR_ASSERT(NULL != _pr_tpd_destructors);

     index = PR_ATOMIC_INCREMENT(&_pr_tpd_highwater) - 1;  /* allocate index */
     if (_PR_TPD_LIMIT <= index)
     {
         PR_SetError(PR_TPD_RANGE_ERROR, 0);
         rv = PR_FAILURE;  /* that's just wrong */
     }
     else
     {
         _pr_tpd_destructors[index] = dtor;  /* record destructor @index */
         *newIndex = (PRUintn)index;  /* copy into client's location */
         rv = PR_SUCCESS;  /* that's okay */
     }

     return rv;
 }

 /*
 ** Define some per-thread-private data.
 **     "index" is an index into the per-thread private data table
 **     "priv" is the per-thread-private data
 **
 ** If the per-thread private data table has a previously registered
 ** destructor function and a non-NULL per-thread-private data value,
 ** the destructor function is invoked.
 **
 ** This can return PR_FAILURE if index is invalid (ie., beyond the current
 ** high water mark) or memory is insufficient to allocate an exanded vector.
 */

 PR_IMPLEMENT(PRStatus) PR_SetThreadPrivate(PRUintn index, void *priv)
 {
     PRThread *self = PR_GetCurrentThread();

     /*
     ** The index being set might not have a sufficient vector in this
     ** thread. But if the index has been allocated, it's okay to go
     ** ahead and extend this one now.
     */
     if ((index >= _PR_TPD_LIMIT) || (index >= _pr_tpd_highwater))
     {
         PR_SetError(PR_TPD_RANGE_ERROR, 0);
         return PR_FAILURE;
     }

     PR_ASSERT(((NULL == self->privateData) && (0 == self->tpdLength))
         || ((NULL != self->privateData) && (0 != self->tpdLength)));

     if ((NULL == self->privateData) || (self->tpdLength <= index))
     {
         void *extension = PR_CALLOC(_pr_tpd_length * sizeof(void*));
         if (NULL == extension)
         {
             PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
             return PR_FAILURE;
         }
         if (self->privateData) {
             (void)memcpy(
                 extension, self->privateData,
                 self->tpdLength * sizeof(void*));
             PR_DELETE(self->privateData);
         }
         self->tpdLength = _pr_tpd_length;
         self->privateData = (void**)extension;
     }
     /*
     ** There wasn't much chance of having to call the destructor
     ** unless the slot already existed.
     */
     else if (self->privateData[index] && _pr_tpd_destructors[index])
     {
         void *data = self->privateData[index];
         self->privateData[index] = NULL;
         (*_pr_tpd_destructors[index])(data);
     }

     PR_ASSERT(index < self->tpdLength);
     self->privateData[index] = priv;

     return PR_SUCCESS;
 }

 /*
 ** Recover the per-thread-private data for the current thread. "index" is
 ** the index into the per-thread private data table.
 **
 ** The returned value may be NULL which is indistinguishable from an error
 ** condition.
 **
 */

 PR_IMPLEMENT(void*) PR_GetThreadPrivate(PRUintn index)
 {
     PRThread *self = PR_GetCurrentThread();
     void *tpd = ((NULL == self->privateData) || (index >= self->tpdLength)) ?
         NULL : self->privateData[index];

     return tpd;
 }

 /*
 ** Destroy the thread's private data, if any exists. This is called at
 ** thread termination time only. There should be no threading issues
 ** since this is being called by the thread itself.
 */
 void _PR_DestroyThreadPrivate(PRThread* self)
 {
 #define _PR_TPD_DESTRUCTOR_ITERATIONS 4

     if (NULL != self->privateData)  /* we have some */
     {
         PRBool clean;
         PRUint32 index;
         PRInt32 passes = _PR_TPD_DESTRUCTOR_ITERATIONS;
         PR_ASSERT(0 != self->tpdLength);
         do
         {
             clean = PR_TRUE;
             for (index = 0; index < self->tpdLength; ++index)
             {
                 void *priv = self->privateData[index];  /* extract */
                 if (NULL != priv)  /* we have data at this index */
                 {
                     if (NULL != _pr_tpd_destructors[index])
                     {
                         self->privateData[index] = NULL;  /* precondition */
                         (*_pr_tpd_destructors[index])(priv);  /* destroy */
                         clean = PR_FALSE;  /* unknown side effects */
                     }
                 }
             }
         } while ((--passes > 0) && !clean);  /* limit # of passes */
         /*
         ** We give up after a fixed number of passes. Any non-NULL
         ** thread-private data value with a registered destructor
         ** function is not destroyed.
         */
         memset(self->privateData, 0, self->tpdLength * sizeof(void*));
     }
 }  /* _PR_DestroyThreadPrivate */

 #endif /* !XP_BEOS */
	/* -- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -- */
	/* *** BEGIN LICENSE BLOCK ***
	* Version: MPL 1.1/GPL 2.0/LGPL 2.1
	*
	* The contents of this file are subject to the Mozilla Public License Version
	* 1.1 (the "License"); you may not use this file except in compliance with
	* the License. You may obtain a copy of the License at
	* http://www.mozilla.org/MPL/
	*
	* Software distributed under the License is distributed on an "AS IS" basis,
	* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
	* for the specific language governing rights and limitations under the
	* License.
	*
	* The Original Code is the Netscape Portable Runtime (NSPR).
	*
	* The Initial Developer of the Original Code is
	* Netscape Communications Corporation.
	* Portions created by the Initial Developer are Copyright (C) 1998-2000
	* the Initial Developer. All Rights Reserved.
	*
	* Contributor(s):
	*
	* Alternatively, the contents of this file may be used under the terms of
	* either the GNU General Public License Version 2 or later (the "GPL"), or
	* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
	* in which case the provisions of the GPL or the LGPL are applicable instead
	* of those above. If you wish to allow use of your version of this file only
	* under the terms of either the GPL or the LGPL, and not to allow others to
	* use your version of this file under the terms of the MPL, indicate your
	* decision by deleting the provisions above and replace them with the notice
	* and other provisions required by the GPL or the LGPL. If you do not delete
	* the provisions above, a recipient may use your version of this file under
	* the terms of any one of the MPL, the GPL or the LGPL.
	*
	* *** END LICENSE BLOCK *** */

	/*
	** Thread Private Data
	**
	** There is an aribitrary limit on the number of keys that will be allocated
	** by the runtime. It's largish, so it is intended to be a sanity check, not
	** an impediment.
	**
	** There is a counter, initialized to zero and incremented every time a
	** client asks for a new key, that holds the high water mark for keys. All
	** threads logically have the same high water mark and are permitted to
	** ask for TPD up to that key value.
	**
	** The vector to hold the TPD are allocated when PR_SetThreadPrivate() is
	** called. The size of the vector will be some value greater than or equal
	** to the current high water mark. Each thread has its own TPD length and
	** vector.
	**
	** Threads that get private data for keys they have not set (or perhaps
	** don't even exist for that thread) get a NULL return. If the key is
	** beyond the high water mark, an error will be returned.
	*/

	/*
	** As of this time, BeOS has its own TPD implementation. Integrating
	** this standard one is a TODO for anyone with a bit of spare time on
	** their hand. For now, we just #ifdef out this whole file and use
	** the routines in pr/src/btthreads/
	*/

	#ifndef XP_BEOS

	#include "primpl.h"

	#include <string.h>

	#if defined(WIN95)
	/*
	** Some local variables report warnings on Win95 because the code paths
	** using them are conditioned on HAVE_CUSTOME_USER_THREADS.
	** The pragma suppresses the warning.
	**
	*/
	#pragma warning(disable : 4101)
	#endif

	#define _PR_TPD_LIMIT 128 /* arbitary limit on the TPD slots */
	static PRInt32 _pr_tpd_length = 0; /* current length of destructor vector */
	static PRInt32 _pr_tpd_highwater = 0; /* next TPD key to be assigned */
	static PRThreadPrivateDTOR *_pr_tpd_destructors = NULL;
	/* the destructors are associated with
	the keys, therefore asserting that
	the TPD key depicts the data's 'type' */

	/*
	** Initialize the thread private data manipulation
	*/
	void _PR_InitTPD(void)
	{
	_pr_tpd_destructors = (PRThreadPrivateDTOR*)
	PR_CALLOC(_PR_TPD_LIMIT * sizeof(PRThreadPrivateDTOR*));
	PR_ASSERT(NULL != _pr_tpd_destructors);
	_pr_tpd_length = _PR_TPD_LIMIT;
	}

	/*
	** Clean up the thread private data manipulation
	*/
	void _PR_CleanupTPD(void)
	{
	} /* _PR_CleanupTPD */

	/*
	** This routine returns a new index for per-thread-private data table.
	** The index is visible to all threads within a process. This index can
	** be used with the PR_SetThreadPrivate() and PR_GetThreadPrivate() routines
	** to save and retrieve data associated with the index for a thread.
	**
	** The index independently maintains specific values for each binding thread.
	** A thread can only get access to its own thread-specific-data.
	**
	** Upon a new index return the value associated with the index for all threads
	** is NULL, and upon thread creation the value associated with all indices for
	** that thread is NULL.
	**
	** "dtor" is the destructor function to invoke when the private
	** data is set or destroyed
	**
	** Returns PR_FAILURE if the total number of indices will exceed the maximun
	** allowed.
	*/

	PR_IMPLEMENT(PRStatus) PR_NewThreadPrivateIndex(
	PRUintn *newIndex, PRThreadPrivateDTOR dtor)
	{
	PRStatus rv;
	PRInt32 index;

	if (!_pr_initialized) _PR_ImplicitInitialization();

	PR_ASSERT(NULL != newIndex);
	PR_ASSERT(NULL != _pr_tpd_destructors);

	index = PR_ATOMIC_INCREMENT(&_pr_tpd_highwater) - 1; /* allocate index */
	if (_PR_TPD_LIMIT <= index)
	{
	PR_SetError(PR_TPD_RANGE_ERROR, 0);
	rv = PR_FAILURE; /* that's just wrong */
	}
	else
	{
	_pr_tpd_destructors[index] = dtor; /* record destructor @index */
	newIndex = (PRUintn)index; / copy into client's location */
	rv = PR_SUCCESS; /* that's okay */
	}

	return rv;
	}

	/*
	** Define some per-thread-private data.
	** "index" is an index into the per-thread private data table
	** "priv" is the per-thread-private data
	**
	** If the per-thread private data table has a previously registered
	** destructor function and a non-NULL per-thread-private data value,
	** the destructor function is invoked.
	**
	** This can return PR_FAILURE if index is invalid (ie., beyond the current
	** high water mark) or memory is insufficient to allocate an exanded vector.
	*/

	PR_IMPLEMENT(PRStatus) PR_SetThreadPrivate(PRUintn index, void *priv)
	{
	PRThread *self = PR_GetCurrentThread();

	/*
	** The index being set might not have a sufficient vector in this
	** thread. But if the index has been allocated, it's okay to go
	** ahead and extend this one now.
	*/
	if ((index >= _PR_TPD_LIMIT) \|\| (index >= _pr_tpd_highwater))
	{
	PR_SetError(PR_TPD_RANGE_ERROR, 0);
	return PR_FAILURE;
	}

	PR_ASSERT(((NULL == self->privateData) && (0 == self->tpdLength))
	\|\| ((NULL != self->privateData) && (0 != self->tpdLength)));

	if ((NULL == self->privateData) \|\| (self->tpdLength <= index))
	{
	void extension = PR_CALLOC(_pr_tpd_length sizeof(void*));
	if (NULL == extension)
	{
	PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
	return PR_FAILURE;
	}
	if (self->privateData) {
	(void)memcpy(
	extension, self->privateData,
	self->tpdLength * sizeof(void*));
	PR_DELETE(self->privateData);
	}
	self->tpdLength = _pr_tpd_length;
	self->privateData = (void**)extension;
	}
	/*
	** There wasn't much chance of having to call the destructor
	** unless the slot already existed.
	*/
	else if (self->privateData[index] && _pr_tpd_destructors[index])
	{
	void *data = self->privateData[index];
	self->privateData[index] = NULL;
	(*_pr_tpd_destructors[index])(data);
	}

	PR_ASSERT(index < self->tpdLength);
	self->privateData[index] = priv;

	return PR_SUCCESS;
	}

	/*
	** Recover the per-thread-private data for the current thread. "index" is
	** the index into the per-thread private data table.
	**
	** The returned value may be NULL which is indistinguishable from an error
	** condition.
	**
	*/

	PR_IMPLEMENT(void*) PR_GetThreadPrivate(PRUintn index)
	{
	PRThread *self = PR_GetCurrentThread();
	void *tpd = ((NULL == self->privateData) \|\| (index >= self->tpdLength)) ?
	NULL : self->privateData[index];

	return tpd;
	}

	/*
	** Destroy the thread's private data, if any exists. This is called at
	** thread termination time only. There should be no threading issues
	** since this is being called by the thread itself.
	*/
	void _PR_DestroyThreadPrivate(PRThread* self)
	{
	#define _PR_TPD_DESTRUCTOR_ITERATIONS 4

	if (NULL != self->privateData) /* we have some */
	{
	PRBool clean;
	PRUint32 index;
	PRInt32 passes = _PR_TPD_DESTRUCTOR_ITERATIONS;
	PR_ASSERT(0 != self->tpdLength);
	do
	{
	clean = PR_TRUE;
	for (index = 0; index < self->tpdLength; ++index)
	{
	void priv = self->privateData[index]; / extract */
	if (NULL != priv) /* we have data at this index */
	{
	if (NULL != _pr_tpd_destructors[index])
	{
	self->privateData[index] = NULL; /* precondition */
	(_pr_tpd_destructors[index])(priv); / destroy */
	clean = PR_FALSE; /* unknown side effects */
	}
	}
	}
	} while ((--passes > 0) && !clean); /* limit # of passes */
	/*
	** We give up after a fixed number of passes. Any non-NULL
	** thread-private data value with a registered destructor
	** function is not destroyed.
	*/
	memset(self->privateData, 0, self->tpdLength * sizeof(void*));
	}
	} /* _PR_DestroyThreadPrivate */

	#endif /* !XP_BEOS */