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Diffstat (limited to 'pr/src/threads/combined/prucpu.c')
| -rw-r--r-- | pr/src/threads/combined/prucpu.c | 437 |
1 files changed, 437 insertions, 0 deletions
diff --git a/pr/src/threads/combined/prucpu.c b/pr/src/threads/combined/prucpu.c new file mode 100644 index 0000000..599925d --- /dev/null +++ b/pr/src/threads/combined/prucpu.c @@ -0,0 +1,437 @@ +/* -*- 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 ***** */ + +#include "primpl.h" + +_PRCPU *_pr_primordialCPU = NULL; + +PRInt32 _pr_md_idle_cpus; /* number of idle cpus */ +/* + * The idle threads in MxN models increment/decrement _pr_md_idle_cpus. + * If _PR_HAVE_ATOMIC_OPS is not defined, they can't use the atomic + * increment/decrement routines (which are based on PR_Lock/PR_Unlock), + * because PR_Lock asserts that the calling thread is not an idle thread. + * So we use a _MDLock to protect _pr_md_idle_cpus. + */ +#if !defined(_PR_LOCAL_THREADS_ONLY) && !defined(_PR_GLOBAL_THREADS_ONLY) +#ifndef _PR_HAVE_ATOMIC_OPS +static _MDLock _pr_md_idle_cpus_lock; +#endif +#endif +PRUintn _pr_numCPU; +PRInt32 _pr_cpus_exit; +PRUint32 _pr_cpu_affinity_mask = 0; + +#if !defined (_PR_GLOBAL_THREADS_ONLY) + +static PRUintn _pr_cpuID; + +static void PR_CALLBACK _PR_CPU_Idle(void *); + +static _PRCPU *_PR_CreateCPU(void); +static PRStatus _PR_StartCPU(_PRCPU *cpu, PRThread *thread); + +#if !defined(_PR_LOCAL_THREADS_ONLY) +static void _PR_RunCPU(void *arg); +#endif + +void _PR_InitCPUs() +{ + PRThread *me = _PR_MD_CURRENT_THREAD(); + + if (_native_threads_only) + return; + + _pr_cpuID = 0; + _MD_NEW_LOCK( &_pr_cpuLock); +#if !defined(_PR_LOCAL_THREADS_ONLY) && !defined(_PR_GLOBAL_THREADS_ONLY) +#ifndef _PR_HAVE_ATOMIC_OPS + _MD_NEW_LOCK(&_pr_md_idle_cpus_lock); +#endif +#endif + +#ifdef _PR_LOCAL_THREADS_ONLY + +#ifdef HAVE_CUSTOM_USER_THREADS + _PR_MD_CREATE_PRIMORDIAL_USER_THREAD(me); +#endif + + /* Now start the first CPU. */ + _pr_primordialCPU = _PR_CreateCPU(); + _pr_numCPU = 1; + _PR_StartCPU(_pr_primordialCPU, me); + + _PR_MD_SET_CURRENT_CPU(_pr_primordialCPU); + + /* Initialize cpu for current thread (could be different from me) */ + _PR_MD_CURRENT_THREAD()->cpu = _pr_primordialCPU; + + _PR_MD_SET_LAST_THREAD(me); + +#else /* Combined MxN model */ + + _pr_primordialCPU = _PR_CreateCPU(); + _pr_numCPU = 1; + _PR_CreateThread(PR_SYSTEM_THREAD, + _PR_RunCPU, + _pr_primordialCPU, + PR_PRIORITY_NORMAL, + PR_GLOBAL_THREAD, + PR_UNJOINABLE_THREAD, + 0, + _PR_IDLE_THREAD); + +#endif /* _PR_LOCAL_THREADS_ONLY */ + + _PR_MD_INIT_CPUS(); +} + +#ifdef WINNT +/* + * Right now this function merely stops the CPUs and does + * not do any other cleanup. + * + * It is only implemented for WINNT because bug 161998 only + * affects the WINNT version of NSPR, but it would be nice + * to implement this function for other platforms too. + */ +void _PR_CleanupCPUs(void) +{ + PRUintn i; + PRCList *qp; + _PRCPU *cpu; + + _pr_cpus_exit = 1; + for (i = 0; i < _pr_numCPU; i++) { + _PR_MD_WAKEUP_WAITER(NULL); + } + for (qp = _PR_CPUQ().next; qp != &_PR_CPUQ(); qp = qp->next) { + cpu = _PR_CPU_PTR(qp); + _PR_MD_JOIN_THREAD(&cpu->thread->md); + } +} +#endif + +static _PRCPUQueue *_PR_CreateCPUQueue(void) +{ + PRInt32 index; + _PRCPUQueue *cpuQueue; + cpuQueue = PR_NEWZAP(_PRCPUQueue); + + _MD_NEW_LOCK( &cpuQueue->runQLock ); + _MD_NEW_LOCK( &cpuQueue->sleepQLock ); + _MD_NEW_LOCK( &cpuQueue->miscQLock ); + + for (index = 0; index < PR_PRIORITY_LAST + 1; index++) + PR_INIT_CLIST( &(cpuQueue->runQ[index]) ); + PR_INIT_CLIST( &(cpuQueue->sleepQ) ); + PR_INIT_CLIST( &(cpuQueue->pauseQ) ); + PR_INIT_CLIST( &(cpuQueue->suspendQ) ); + PR_INIT_CLIST( &(cpuQueue->waitingToJoinQ) ); + + cpuQueue->numCPUs = 1; + + return cpuQueue; +} + +/* + * Create a new CPU. + * + * This function initializes enough of the _PRCPU structure so + * that it can be accessed safely by a global thread or another + * CPU. This function does not create the native thread that + * will run the CPU nor does it initialize the parts of _PRCPU + * that must be initialized by that native thread. + * + * The reason we cannot simply have the native thread create + * and fully initialize a new CPU is that we need to be able to + * create a usable _pr_primordialCPU in _PR_InitCPUs without + * assuming that the primordial CPU thread we created can run + * during NSPR initialization. For example, on Windows while + * new threads can be created by DllMain, they won't be able + * to run during DLL initialization. If NSPR is initialized + * by DllMain, the primordial CPU thread won't run until DLL + * initialization is finished. + */ +static _PRCPU *_PR_CreateCPU(void) +{ + _PRCPU *cpu; + + cpu = PR_NEWZAP(_PRCPU); + if (cpu) { + cpu->queue = _PR_CreateCPUQueue(); + if (!cpu->queue) { + PR_DELETE(cpu); + return NULL; + } + } + return cpu; +} + +/* + * Start a new CPU. + * + * 'cpu' is a _PRCPU structure created by _PR_CreateCPU(). + * 'thread' is the native thread that will run the CPU. + * + * If this function fails, 'cpu' is destroyed. + */ +static PRStatus _PR_StartCPU(_PRCPU *cpu, PRThread *thread) +{ + /* + ** Start a new cpu. The assumption this code makes is that the + ** underlying operating system creates a stack to go with the new + ** native thread. That stack will be used by the cpu when pausing. + */ + + PR_ASSERT(!_native_threads_only); + + cpu->last_clock = PR_IntervalNow(); + + /* Before we create any threads on this CPU we have to + * set the current CPU + */ + _PR_MD_SET_CURRENT_CPU(cpu); + _PR_MD_INIT_RUNNING_CPU(cpu); + thread->cpu = cpu; + + cpu->idle_thread = _PR_CreateThread(PR_SYSTEM_THREAD, + _PR_CPU_Idle, + (void *)cpu, + PR_PRIORITY_NORMAL, + PR_LOCAL_THREAD, + PR_UNJOINABLE_THREAD, + 0, + _PR_IDLE_THREAD); + + if (!cpu->idle_thread) { + /* didn't clean up CPU queue XXXMB */ + PR_DELETE(cpu); + return PR_FAILURE; + } + PR_ASSERT(cpu->idle_thread->cpu == cpu); + + cpu->idle_thread->no_sched = 0; + + cpu->thread = thread; + + if (_pr_cpu_affinity_mask) + PR_SetThreadAffinityMask(thread, _pr_cpu_affinity_mask); + + /* Created and started a new CPU */ + _PR_CPU_LIST_LOCK(); + cpu->id = _pr_cpuID++; + PR_APPEND_LINK(&cpu->links, &_PR_CPUQ()); + _PR_CPU_LIST_UNLOCK(); + + return PR_SUCCESS; +} + +#if !defined(_PR_GLOBAL_THREADS_ONLY) && !defined(_PR_LOCAL_THREADS_ONLY) +/* +** This code is used during a cpu's initial creation. +*/ +static void _PR_RunCPU(void *arg) +{ + _PRCPU *cpu = (_PRCPU *)arg; + PRThread *me = _PR_MD_CURRENT_THREAD(); + + PR_ASSERT(NULL != me); + + /* + * _PR_StartCPU calls _PR_CreateThread to create the + * idle thread. Because _PR_CreateThread calls PR_Lock, + * the current thread has to remain a global thread + * during the _PR_StartCPU call so that it can wait for + * the lock if the lock is held by another thread. If + * we clear the _PR_GLOBAL_SCOPE flag in + * _PR_MD_CREATE_PRIMORDIAL_THREAD, the current thread + * will be treated as a local thread and have trouble + * waiting for the lock because the CPU is not fully + * constructed yet. + * + * After the CPU is started, it is safe to mark the + * current thread as a local thread. + */ + +#ifdef HAVE_CUSTOM_USER_THREADS + _PR_MD_CREATE_PRIMORDIAL_USER_THREAD(me); +#endif + + me->no_sched = 1; + _PR_StartCPU(cpu, me); + +#ifdef HAVE_CUSTOM_USER_THREADS + me->flags &= (~_PR_GLOBAL_SCOPE); +#endif + + _PR_MD_SET_CURRENT_CPU(cpu); + _PR_MD_SET_CURRENT_THREAD(cpu->thread); + me->cpu = cpu; + + while(1) { + PRInt32 is; + if (!_PR_IS_NATIVE_THREAD(me)) _PR_INTSOFF(is); + _PR_MD_START_INTERRUPTS(); + _PR_MD_SWITCH_CONTEXT(me); + } +} +#endif + +static void PR_CALLBACK _PR_CPU_Idle(void *_cpu) +{ + _PRCPU *cpu = (_PRCPU *)_cpu; + PRThread *me = _PR_MD_CURRENT_THREAD(); + + PR_ASSERT(NULL != me); + + me->cpu = cpu; + cpu->idle_thread = me; + if (_MD_LAST_THREAD()) + _MD_LAST_THREAD()->no_sched = 0; + if (!_PR_IS_NATIVE_THREAD(me)) _PR_MD_SET_INTSOFF(0); + while(1) { + PRInt32 is; + PRIntervalTime timeout; + if (!_PR_IS_NATIVE_THREAD(me)) _PR_INTSOFF(is); + + _PR_RUNQ_LOCK(cpu); +#if !defined(_PR_LOCAL_THREADS_ONLY) && !defined(_PR_GLOBAL_THREADS_ONLY) +#ifdef _PR_HAVE_ATOMIC_OPS + _PR_MD_ATOMIC_INCREMENT(&_pr_md_idle_cpus); +#else + _PR_MD_LOCK(&_pr_md_idle_cpus_lock); + _pr_md_idle_cpus++; + _PR_MD_UNLOCK(&_pr_md_idle_cpus_lock); +#endif /* _PR_HAVE_ATOMIC_OPS */ +#endif + /* If someone on runq; do a nonblocking PAUSECPU */ + if (_PR_RUNQREADYMASK(me->cpu) != 0) { + _PR_RUNQ_UNLOCK(cpu); + timeout = PR_INTERVAL_NO_WAIT; + } else { + _PR_RUNQ_UNLOCK(cpu); + + _PR_SLEEPQ_LOCK(cpu); + if (PR_CLIST_IS_EMPTY(&_PR_SLEEPQ(me->cpu))) { + timeout = PR_INTERVAL_NO_TIMEOUT; + } else { + PRThread *wakeThread; + wakeThread = _PR_THREAD_PTR(_PR_SLEEPQ(me->cpu).next); + timeout = wakeThread->sleep; + } + _PR_SLEEPQ_UNLOCK(cpu); + } + + /* Wait for an IO to complete */ + (void)_PR_MD_PAUSE_CPU(timeout); + +#ifdef WINNT + if (_pr_cpus_exit) { + /* _PR_CleanupCPUs tells us to exit */ + _PR_MD_END_THREAD(); + } +#endif + +#if !defined(_PR_LOCAL_THREADS_ONLY) && !defined(_PR_GLOBAL_THREADS_ONLY) +#ifdef _PR_HAVE_ATOMIC_OPS + _PR_MD_ATOMIC_DECREMENT(&_pr_md_idle_cpus); +#else + _PR_MD_LOCK(&_pr_md_idle_cpus_lock); + _pr_md_idle_cpus--; + _PR_MD_UNLOCK(&_pr_md_idle_cpus_lock); +#endif /* _PR_HAVE_ATOMIC_OPS */ +#endif + + _PR_ClockInterrupt(); + + /* Now schedule any thread that is on the runq + * INTS must be OFF when calling PR_Schedule() + */ + me->state = _PR_RUNNABLE; + _PR_MD_SWITCH_CONTEXT(me); + if (!_PR_IS_NATIVE_THREAD(me)) _PR_FAST_INTSON(is); + } +} +#endif /* _PR_GLOBAL_THREADS_ONLY */ + +PR_IMPLEMENT(void) PR_SetConcurrency(PRUintn numCPUs) +{ +#if defined(_PR_GLOBAL_THREADS_ONLY) || defined(_PR_LOCAL_THREADS_ONLY) + + /* do nothing */ + +#else /* combined, MxN thread model */ + + PRUintn newCPU; + _PRCPU *cpu; + PRThread *thr; + + + if (!_pr_initialized) _PR_ImplicitInitialization(); + + if (_native_threads_only) + return; + + _PR_CPU_LIST_LOCK(); + if (_pr_numCPU < numCPUs) { + newCPU = numCPUs - _pr_numCPU; + _pr_numCPU = numCPUs; + } else newCPU = 0; + _PR_CPU_LIST_UNLOCK(); + + for (; newCPU; newCPU--) { + cpu = _PR_CreateCPU(); + thr = _PR_CreateThread(PR_SYSTEM_THREAD, + _PR_RunCPU, + cpu, + PR_PRIORITY_NORMAL, + PR_GLOBAL_THREAD, + PR_UNJOINABLE_THREAD, + 0, + _PR_IDLE_THREAD); + } +#endif +} + +PR_IMPLEMENT(_PRCPU *) _PR_GetPrimordialCPU(void) +{ + if (_pr_primordialCPU) + return _pr_primordialCPU; + else + return _PR_MD_CURRENT_CPU(); +} |