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-rw-r--r--nsprpub/pr/src/threads/combined/prucpu.c424
1 files changed, 424 insertions, 0 deletions
diff --git a/nsprpub/pr/src/threads/combined/prucpu.c b/nsprpub/pr/src/threads/combined/prucpu.c
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+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 "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_ARRAY_SIZE(cpuQueue->runQ); 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();
+ }
+}
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