287 lines
11 KiB
C
287 lines
11 KiB
C
|
/* -*- 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 ***** */
|
||
|
|
|
||
|
|
#ifndef prthread_h___
|
||
|
|
#define prthread_h___
|
||
|
|
|
||
|
|
/*
|
||
|
|
** API for NSPR threads. On some architectures (MAC and WIN16
|
||
|
|
** notably) pre-emptibility is not guaranteed. Hard priority scheduling
|
||
|
|
** is not guaranteed, so programming using priority based synchronization
|
||
|
|
** is a no-no.
|
||
|
|
**
|
||
|
|
** NSPR threads are scheduled based loosely on their client set priority.
|
||
|
|
** In general, a thread of a higher priority has a statistically better
|
||
|
|
** chance of running relative to threads of lower priority. However,
|
||
|
|
** NSPR uses multiple strategies to provide execution vehicles for thread
|
||
|
|
** abstraction of various host platforms. As it turns out, there is little
|
||
|
|
** NSPR can do to affect the scheduling attributes of "GLOBAL" threads.
|
||
|
|
** However, a semblance of GLOBAL threads is used to implement "LOCAL"
|
||
|
|
** threads. An arbitrary number of such LOCAL threads can be assigned to
|
||
|
|
** a single GLOBAL thread.
|
||
|
|
**
|
||
|
|
** For scheduling, NSPR will attempt to run the highest priority LOCAL
|
||
|
|
** thread associated with a given GLOBAL thread. It is further assumed
|
||
|
|
** that the host OS will apply some form of "fair" scheduling on the
|
||
|
|
** GLOBAL threads.
|
||
|
|
**
|
||
|
|
** Threads have a "system flag" which when set indicates the thread
|
||
|
|
** doesn't count for determining when the process should exit (the
|
||
|
|
** process exits when the last user thread exits).
|
||
|
|
**
|
||
|
|
** Threads also have a "scope flag" which controls whether the threads
|
||
|
|
** are scheduled in the local scope or scheduled by the OS globally. This
|
||
|
|
** indicates whether a thread is permanently bound to a native OS thread.
|
||
|
|
** An unbound thread competes for scheduling resources in the same process.
|
||
|
|
**
|
||
|
|
** Another flag is "state flag" which control whether the thread is joinable.
|
||
|
|
** It allows other threads to wait for the created thread to reach completion.
|
||
|
|
**
|
||
|
|
** Threads can have "per-thread-data" attached to them. Each thread has a
|
||
|
|
** per-thread error number and error string which are updated when NSPR
|
||
|
|
** operations fail.
|
||
|
|
*/
|
||
|
|
#include "prtypes.h"
|
||
|
|
#include "prinrval.h"
|
||
|
|
|
||
|
|
PR_BEGIN_EXTERN_C
|
||
|
|
|
||
|
|
typedef struct PRThread PRThread;
|
||
|
|
typedef struct PRThreadStack PRThreadStack;
|
||
|
|
|
||
|
|
typedef enum PRThreadType {
|
||
|
|
PR_USER_THREAD,
|
||
|
|
PR_SYSTEM_THREAD
|
||
|
|
} PRThreadType;
|
||
|
|
|
||
|
|
typedef enum PRThreadScope {
|
||
|
|
PR_LOCAL_THREAD,
|
||
|
|
PR_GLOBAL_THREAD,
|
||
|
|
PR_GLOBAL_BOUND_THREAD
|
||
|
|
} PRThreadScope;
|
||
|
|
|
||
|
|
typedef enum PRThreadState {
|
||
|
|
PR_JOINABLE_THREAD,
|
||
|
|
PR_UNJOINABLE_THREAD
|
||
|
|
} PRThreadState;
|
||
|
|
|
||
|
|
typedef enum PRThreadPriority
|
||
|
|
{
|
||
|
|
PR_PRIORITY_FIRST = 0, /* just a placeholder */
|
||
|
|
PR_PRIORITY_LOW = 0, /* the lowest possible priority */
|
||
|
|
PR_PRIORITY_NORMAL = 1, /* most common expected priority */
|
||
|
|
PR_PRIORITY_HIGH = 2, /* slightly more aggressive scheduling */
|
||
|
|
PR_PRIORITY_URGENT = 3, /* it does little good to have more than one */
|
||
|
|
PR_PRIORITY_LAST = 3 /* this is just a placeholder */
|
||
|
|
} PRThreadPriority;
|
||
|
|
|
||
|
|
/*
|
||
|
|
** Create a new thread:
|
||
|
|
** "type" is the type of thread to create
|
||
|
|
** "start(arg)" will be invoked as the threads "main"
|
||
|
|
** "priority" will be created thread's priority
|
||
|
|
** "scope" will specify whether the thread is local or global
|
||
|
|
** "state" will specify whether the thread is joinable or not
|
||
|
|
** "stackSize" the size of the stack, in bytes. The value can be zero
|
||
|
|
** and then a machine specific stack size will be chosen.
|
||
|
|
**
|
||
|
|
** This can return NULL if some kind of error occurs, such as if memory is
|
||
|
|
** tight.
|
||
|
|
**
|
||
|
|
** If you want the thread to start up waiting for the creator to do
|
||
|
|
** something, enter a lock before creating the thread and then have the
|
||
|
|
** threads start routine enter and exit the same lock. When you are ready
|
||
|
|
** for the thread to run, exit the lock.
|
||
|
|
**
|
||
|
|
** If you want to detect the completion of the created thread, the thread
|
||
|
|
** should be created joinable. Then, use PR_JoinThread to synchrnoize the
|
||
|
|
** termination of another thread.
|
||
|
|
**
|
||
|
|
** When the start function returns the thread exits. If it is the last
|
||
|
|
** PR_USER_THREAD to exit then the process exits.
|
||
|
|
*/
|
||
|
|
NSPR_API(PRThread*) PR_CreateThread(PRThreadType type,
|
||
|
|
void (PR_CALLBACK *start)(void *arg),
|
||
|
|
void *arg,
|
||
|
|
PRThreadPriority priority,
|
||
|
|
PRThreadScope scope,
|
||
|
|
PRThreadState state,
|
||
|
|
PRUint32 stackSize);
|
||
|
|
|
||
|
|
/*
|
||
|
|
** Wait for thread termination:
|
||
|
|
** "thread" is the target thread
|
||
|
|
**
|
||
|
|
** This can return PR_FAILURE if no joinable thread could be found
|
||
|
|
** corresponding to the specified target thread.
|
||
|
|
**
|
||
|
|
** The calling thread is blocked until the target thread completes.
|
||
|
|
** Several threads cannot wait for the same thread to complete; one thread
|
||
|
|
** will operate successfully and others will terminate with an error PR_FAILURE.
|
||
|
|
** The calling thread will not be blocked if the target thread has already
|
||
|
|
** terminated.
|
||
|
|
*/
|
||
|
|
NSPR_API(PRStatus) PR_JoinThread(PRThread *thread);
|
||
|
|
|
||
|
|
/*
|
||
|
|
** Return the current thread object for the currently running code.
|
||
|
|
** Never returns NULL.
|
||
|
|
*/
|
||
|
|
NSPR_API(PRThread*) PR_GetCurrentThread(void);
|
||
|
|
#ifndef NO_NSPR_10_SUPPORT
|
||
|
|
#define PR_CurrentThread() PR_GetCurrentThread() /* for nspr1.0 compat. */
|
||
|
|
#endif /* NO_NSPR_10_SUPPORT */
|
||
|
|
|
||
|
|
/*
|
||
|
|
** Get the priority of "thread".
|
||
|
|
*/
|
||
|
|
NSPR_API(PRThreadPriority) PR_GetThreadPriority(const PRThread *thread);
|
||
|
|
|
||
|
|
/*
|
||
|
|
** Change the priority of the "thread" to "priority".
|
||
|
|
*/
|
||
|
|
NSPR_API(void) PR_SetThreadPriority(PRThread *thread, PRThreadPriority priority);
|
||
|
|
|
||
|
|
/*
|
||
|
|
** 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.
|
||
|
|
**
|
||
|
|
** Each index is associationed with a destructor function ('dtor'). The function
|
||
|
|
** may be specified as NULL when the index is created. If it is not NULL, the
|
||
|
|
** function will be called when:
|
||
|
|
** - the thread exits and the private data for the associated index
|
||
|
|
** is not NULL,
|
||
|
|
** - new thread private data is set and the current private data is
|
||
|
|
** not NULL.
|
||
|
|
**
|
||
|
|
** 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.
|
||
|
|
**
|
||
|
|
** Returns PR_FAILURE if the total number of indices will exceed the maximun
|
||
|
|
** allowed.
|
||
|
|
*/
|
||
|
|
typedef void (PR_CALLBACK *PRThreadPrivateDTOR)(void *priv);
|
||
|
|
|
||
|
|
NSPR_API(PRStatus) PR_NewThreadPrivateIndex(
|
||
|
|
PRUintn *newIndex, PRThreadPrivateDTOR destructor);
|
||
|
|
|
||
|
|
/*
|
||
|
|
** Define some per-thread-private data.
|
||
|
|
** "tpdIndex" 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 the index is invalid.
|
||
|
|
*/
|
||
|
|
NSPR_API(PRStatus) PR_SetThreadPrivate(PRUintn tpdIndex, void *priv);
|
||
|
|
|
||
|
|
/*
|
||
|
|
** Recover the per-thread-private data for the current thread. "tpdIndex" is
|
||
|
|
** the index into the per-thread private data table.
|
||
|
|
**
|
||
|
|
** The returned value may be NULL which is indistinguishable from an error
|
||
|
|
** condition.
|
||
|
|
**
|
||
|
|
** A thread can only get access to its own thread-specific-data.
|
||
|
|
*/
|
||
|
|
NSPR_API(void*) PR_GetThreadPrivate(PRUintn tpdIndex);
|
||
|
|
|
||
|
|
/*
|
||
|
|
** This routine sets the interrupt request for a target thread. The interrupt
|
||
|
|
** request remains in the thread's state until it is delivered exactly once
|
||
|
|
** or explicitly canceled.
|
||
|
|
**
|
||
|
|
** A thread that has been interrupted will fail all NSPR blocking operations
|
||
|
|
** that return a PRStatus (I/O, waiting on a condition, etc).
|
||
|
|
**
|
||
|
|
** PR_Interrupt may itself fail if the target thread is invalid.
|
||
|
|
*/
|
||
|
|
NSPR_API(PRStatus) PR_Interrupt(PRThread *thread);
|
||
|
|
|
||
|
|
/*
|
||
|
|
** Clear the interrupt request for the calling thread. If no such request
|
||
|
|
** is pending, this operation is a noop.
|
||
|
|
*/
|
||
|
|
NSPR_API(void) PR_ClearInterrupt(void);
|
||
|
|
|
||
|
|
/*
|
||
|
|
** Block the interrupt for the calling thread.
|
||
|
|
*/
|
||
|
|
NSPR_API(void) PR_BlockInterrupt(void);
|
||
|
|
|
||
|
|
/*
|
||
|
|
** Unblock the interrupt for the calling thread.
|
||
|
|
*/
|
||
|
|
NSPR_API(void) PR_UnblockInterrupt(void);
|
||
|
|
|
||
|
|
/*
|
||
|
|
** Make the current thread sleep until "ticks" time amount of time
|
||
|
|
** has expired. If "ticks" is PR_INTERVAL_NO_WAIT then the call is
|
||
|
|
** equivalent to calling PR_Yield. Calling PR_Sleep with an argument
|
||
|
|
** equivalent to PR_INTERVAL_NO_TIMEOUT is an error and will result
|
||
|
|
** in a PR_FAILURE error return.
|
||
|
|
*/
|
||
|
|
NSPR_API(PRStatus) PR_Sleep(PRIntervalTime ticks);
|
||
|
|
|
||
|
|
/*
|
||
|
|
** Get the scoping of this thread.
|
||
|
|
*/
|
||
|
|
NSPR_API(PRThreadScope) PR_GetThreadScope(const PRThread *thread);
|
||
|
|
|
||
|
|
/*
|
||
|
|
** Get the type of this thread.
|
||
|
|
*/
|
||
|
|
NSPR_API(PRThreadType) PR_GetThreadType(const PRThread *thread);
|
||
|
|
|
||
|
|
/*
|
||
|
|
** Get the join state of this thread.
|
||
|
|
*/
|
||
|
|
NSPR_API(PRThreadState) PR_GetThreadState(const PRThread *thread);
|
||
|
|
|
||
|
|
PR_END_EXTERN_C
|
||
|
|
|
||
|
|
#endif /* prthread_h___ */
|