Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 457 insertions, 0 deletions

diff --git a/nsprpub/pr/src/threads/combined/prulock.c b/nsprpub/pr/src/threads/combined/prulock.c
new file mode 100644
index 0000000000..69c27d149f
--- /dev/null
+++ b/nsprpub/pr/src/threads/combined/prulock.c
@@ -0,0 +1,457 @@
+/* -*- 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"
+
+#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
+
+
+void _PR_InitLocks(void)
+{
+    _PR_MD_INIT_LOCKS();
+}
+
+/*
+** Deal with delayed interrupts/requested reschedule during interrupt
+** re-enables.
+*/
+void _PR_IntsOn(_PRCPU *cpu)
+{
+    PRUintn missed, pri, i;
+    _PRInterruptTable *it;
+    PRThread *me;
+
+    PR_ASSERT(cpu);   /* Global threads don't have CPUs */
+    PR_ASSERT(_PR_MD_GET_INTSOFF() > 0);
+    me = _PR_MD_CURRENT_THREAD();
+    PR_ASSERT(!(me->flags & _PR_IDLE_THREAD));
+
+    /*
+    ** Process delayed interrupts. This logic is kinda scary because we
+    ** need to avoid losing an interrupt (it's ok to delay an interrupt
+    ** until later).
+    **
+    ** There are two missed state words. _pr_ints.where indicates to the
+    ** interrupt handler which state word is currently safe for
+    ** modification.
+    **
+    ** This code scans both interrupt state words, using the where flag
+    ** to indicate to the interrupt which state word is safe for writing.
+    ** If an interrupt comes in during a scan the other word will be
+    ** modified. This modification will be noticed during the next
+    ** iteration of the loop or during the next call to this routine.
+    */
+    for (i = 0; i < 2; i++) {
+        cpu->where = (1 - i);
+        missed = cpu->u.missed[i];
+        if (missed != 0) {
+            cpu->u.missed[i] = 0;
+            for (it = _pr_interruptTable; it->name; it++) {
+                if (missed & it->missed_bit) {
+                    PR_LOG(_pr_sched_lm, PR_LOG_MIN,
+                           ("IntsOn[0]: %s intr", it->name));
+                    (*it->handler)();
+                }
+            }
+        }
+    }
+
+    if (cpu->u.missed[3] != 0) {
+        _PRCPU *cpu;
+
+        _PR_THREAD_LOCK(me);
+        me->state = _PR_RUNNABLE;
+        pri = me->priority;
+
+        cpu = me->cpu;
+        _PR_RUNQ_LOCK(cpu);
+        _PR_ADD_RUNQ(me, cpu, pri);
+        _PR_RUNQ_UNLOCK(cpu);
+        _PR_THREAD_UNLOCK(me);
+        _PR_MD_SWITCH_CONTEXT(me);
+    }
+}
+
+/*
+** Unblock the first runnable waiting thread. Skip over
+** threads that are trying to be suspended
+** Note: Caller must hold _PR_LOCK_LOCK()
+*/
+void _PR_UnblockLockWaiter(PRLock *lock)
+{
+    PRThread *t = NULL;
+    PRThread *me;
+    PRCList *q;
+
+    q = lock->waitQ.next;
+    PR_ASSERT(q != &lock->waitQ);
+    while (q != &lock->waitQ) {
+        /* Unblock first waiter */
+        t = _PR_THREAD_CONDQ_PTR(q);
+
+        /*
+        ** We are about to change the thread's state to runnable and for local
+        ** threads, we are going to assign a cpu to it.  So, protect thread's
+        ** data structure.
+        */
+        _PR_THREAD_LOCK(t);
+
+        if (t->flags & _PR_SUSPENDING) {
+            q = q->next;
+            _PR_THREAD_UNLOCK(t);
+            continue;
+        }
+
+        /* Found a runnable thread */
+        PR_ASSERT(t->state == _PR_LOCK_WAIT);
+        PR_ASSERT(t->wait.lock == lock);
+        t->wait.lock = 0;
+        PR_REMOVE_LINK(&t->waitQLinks);         /* take it off lock's waitQ */
+
+        /*
+        ** If this is a native thread, nothing else to do except to wake it
+        ** up by calling the machine dependent wakeup routine.
+        **
+        ** If this is a local thread, we need to assign it a cpu and
+        ** put the thread on that cpu's run queue.  There are two cases to
+        ** take care of.  If the currently running thread is also a local
+        ** thread, we just assign our own cpu to that thread and put it on
+        ** the cpu's run queue.  If the the currently running thread is a
+        ** native thread, we assign the primordial cpu to it (on NT,
+        ** MD_WAKEUP handles the cpu assignment).
+        */
+
+        if ( !_PR_IS_NATIVE_THREAD(t) ) {
+
+            t->state = _PR_RUNNABLE;
+
+            me = _PR_MD_CURRENT_THREAD();
+
+            _PR_AddThreadToRunQ(me, t);
+            _PR_THREAD_UNLOCK(t);
+        } else {
+            t->state = _PR_RUNNING;
+            _PR_THREAD_UNLOCK(t);
+        }
+        _PR_MD_WAKEUP_WAITER(t);
+        break;
+    }
+    return;
+}
+
+/************************************************************************/
+
+
+PR_IMPLEMENT(PRLock*) PR_NewLock(void)
+{
+    PRLock *lock;
+
+    if (!_pr_initialized) {
+        _PR_ImplicitInitialization();
+    }
+
+    lock = PR_NEWZAP(PRLock);
+    if (lock) {
+        if (_PR_InitLock(lock) != PR_SUCCESS) {
+            PR_DELETE(lock);
+            return NULL;
+        }
+    }
+    return lock;
+}
+
+PRStatus _PR_InitLock(PRLock *lock)
+{
+    if (_PR_MD_NEW_LOCK(&lock->ilock) != PR_SUCCESS) {
+        return PR_FAILURE;
+    }
+    PR_INIT_CLIST(&lock->links);
+    PR_INIT_CLIST(&lock->waitQ);
+    return PR_SUCCESS;
+}
+
+/*
+** Destroy the given lock "lock". There is no point in making this race
+** free because if some other thread has the pointer to this lock all
+** bets are off.
+*/
+PR_IMPLEMENT(void) PR_DestroyLock(PRLock *lock)
+{
+    _PR_FreeLock(lock);
+    PR_DELETE(lock);
+}
+
+void _PR_FreeLock(PRLock *lock)
+{
+    PR_ASSERT(lock->owner == 0);
+    _PR_MD_FREE_LOCK(&lock->ilock);
+}
+
+extern PRThread *suspendAllThread;
+/*
+** Lock the lock.
+*/
+PR_IMPLEMENT(void) PR_Lock(PRLock *lock)
+{
+    PRThread *me = _PR_MD_CURRENT_THREAD();
+    PRIntn is;
+    PRThread *t;
+    PRCList *q;
+
+    PR_ASSERT(me != suspendAllThread);
+    PR_ASSERT(!(me->flags & _PR_IDLE_THREAD));
+    PR_ASSERT(lock != NULL);
+#ifdef _PR_GLOBAL_THREADS_ONLY
+    _PR_MD_LOCK(&lock->ilock);
+    PR_ASSERT(lock->owner == 0);
+    lock->owner = me;
+    return;
+#else  /* _PR_GLOBAL_THREADS_ONLY */
+
+    if (_native_threads_only) {
+        _PR_MD_LOCK(&lock->ilock);
+        PR_ASSERT(lock->owner == 0);
+        lock->owner = me;
+        return;
+    }
+
+    if (!_PR_IS_NATIVE_THREAD(me)) {
+        _PR_INTSOFF(is);
+    }
+
+    PR_ASSERT(_PR_IS_NATIVE_THREAD(me) || _PR_MD_GET_INTSOFF() != 0);
+
+retry:
+    _PR_LOCK_LOCK(lock);
+    if (lock->owner == 0) {
+        /* Just got the lock */
+        lock->owner = me;
+        lock->priority = me->priority;
+        /* Add the granted lock to this owning thread's lock list */
+        PR_APPEND_LINK(&lock->links, &me->lockList);
+        _PR_LOCK_UNLOCK(lock);
+        if (!_PR_IS_NATIVE_THREAD(me)) {
+            _PR_FAST_INTSON(is);
+        }
+        return;
+    }
+
+    /* If this thread already owns this lock, then it is a deadlock */
+    PR_ASSERT(lock->owner != me);
+
+    PR_ASSERT(_PR_IS_NATIVE_THREAD(me) || _PR_MD_GET_INTSOFF() != 0);
+
+#if 0
+    if (me->priority > lock->owner->priority) {
+        /*
+        ** Give the lock owner a priority boost until we get the
+        ** lock. Record the priority we boosted it to.
+        */
+        lock->boostPriority = me->priority;
+        _PR_SetThreadPriority(lock->owner, me->priority);
+    }
+#endif
+
+    /*
+    Add this thread to the asked for lock's list of waiting threads.  We
+    add this thread thread in the right priority order so when the unlock
+    occurs, the thread with the higher priority will get the lock.
+    */
+    q = lock->waitQ.next;
+    if (q == &lock->waitQ || _PR_THREAD_CONDQ_PTR(q)->priority ==
+        _PR_THREAD_CONDQ_PTR(lock->waitQ.prev)->priority) {
+        /*
+         * If all the threads in the lock waitQ have the same priority,
+         * then avoid scanning the list:  insert the element at the end.
+         */
+        q = &lock->waitQ;
+    } else {
+        /* Sort thread into lock's waitQ at appropriate point */
+        /* Now scan the list for where to insert this entry */
+        while (q != &lock->waitQ) {
+            t = _PR_THREAD_CONDQ_PTR(lock->waitQ.next);
+            if (me->priority > t->priority) {
+                /* Found a lower priority thread to insert in front of */
+                break;
+            }
+            q = q->next;
+        }
+    }
+    PR_INSERT_BEFORE(&me->waitQLinks, q);
+
+    /*
+    Now grab the threadLock since we are about to change the state.  We have
+    to do this since a PR_Suspend or PR_SetThreadPriority type call that takes
+    a PRThread* as an argument could be changing the state of this thread from
+    a thread running on a different cpu.
+    */
+
+    _PR_THREAD_LOCK(me);
+    me->state = _PR_LOCK_WAIT;
+    me->wait.lock = lock;
+    _PR_THREAD_UNLOCK(me);
+
+    _PR_LOCK_UNLOCK(lock);
+
+    _PR_MD_WAIT(me, PR_INTERVAL_NO_TIMEOUT);
+    goto retry;
+
+#endif  /* _PR_GLOBAL_THREADS_ONLY */
+}
+
+/*
+** Unlock the lock.
+*/
+PR_IMPLEMENT(PRStatus) PR_Unlock(PRLock *lock)
+{
+    PRCList *q;
+    PRThreadPriority pri, boost;
+    PRIntn is;
+    PRThread *me = _PR_MD_CURRENT_THREAD();
+
+    PR_ASSERT(lock != NULL);
+    PR_ASSERT(lock->owner == me);
+    PR_ASSERT(me != suspendAllThread);
+    PR_ASSERT(!(me->flags & _PR_IDLE_THREAD));
+    if (lock->owner != me) {
+        return PR_FAILURE;
+    }
+
+#ifdef _PR_GLOBAL_THREADS_ONLY
+    lock->owner = 0;
+    _PR_MD_UNLOCK(&lock->ilock);
+    return PR_SUCCESS;
+#else  /* _PR_GLOBAL_THREADS_ONLY */
+
+    if (_native_threads_only) {
+        lock->owner = 0;
+        _PR_MD_UNLOCK(&lock->ilock);
+        return PR_SUCCESS;
+    }
+
+    if (!_PR_IS_NATIVE_THREAD(me)) {
+        _PR_INTSOFF(is);
+    }
+    _PR_LOCK_LOCK(lock);
+
+    /* Remove the lock from the owning thread's lock list */
+    PR_REMOVE_LINK(&lock->links);
+    pri = lock->priority;
+    boost = lock->boostPriority;
+    if (boost > pri) {
+        /*
+        ** We received a priority boost during the time we held the lock.
+        ** We need to figure out what priority to move to by scanning
+        ** down our list of lock's that we are still holding and using
+        ** the highest boosted priority found.
+        */
+        q = me->lockList.next;
+        while (q != &me->lockList) {
+            PRLock *ll = _PR_LOCK_PTR(q);
+            if (ll->boostPriority > pri) {
+                pri = ll->boostPriority;
+            }
+            q = q->next;
+        }
+        if (pri != me->priority) {
+            _PR_SetThreadPriority(me, pri);
+        }
+    }
+
+    /* Unblock the first waiting thread */
+    q = lock->waitQ.next;
+    if (q != &lock->waitQ) {
+        _PR_UnblockLockWaiter(lock);
+    }
+    lock->boostPriority = PR_PRIORITY_LOW;
+    lock->owner = 0;
+    _PR_LOCK_UNLOCK(lock);
+    if (!_PR_IS_NATIVE_THREAD(me)) {
+        _PR_INTSON(is);
+    }
+    return PR_SUCCESS;
+#endif  /* _PR_GLOBAL_THREADS_ONLY */
+}
+
+/*
+**  If the current thread owns |lock|, this assertion is guaranteed to
+**  succeed.  Otherwise, the behavior of this function is undefined.
+*/
+PR_IMPLEMENT(void) PR_AssertCurrentThreadOwnsLock(PRLock *lock)
+{
+    PRThread *me = _PR_MD_CURRENT_THREAD();
+    PR_ASSERT(lock->owner == me);
+}
+
+/*
+** Test and then lock the lock if it's not already locked by some other
+** thread. Return PR_FALSE if some other thread owned the lock at the
+** time of the call.
+*/
+PR_IMPLEMENT(PRBool) PR_TestAndLock(PRLock *lock)
+{
+    PRThread *me = _PR_MD_CURRENT_THREAD();
+    PRBool rv = PR_FALSE;
+    PRIntn is;
+
+#ifdef _PR_GLOBAL_THREADS_ONLY
+    is = _PR_MD_TEST_AND_LOCK(&lock->ilock);
+    if (is == 0) {
+        lock->owner = me;
+        return PR_TRUE;
+    }
+    return PR_FALSE;
+#else  /* _PR_GLOBAL_THREADS_ONLY */
+
+#ifndef _PR_LOCAL_THREADS_ONLY
+    if (_native_threads_only) {
+        is = _PR_MD_TEST_AND_LOCK(&lock->ilock);
+        if (is == 0) {
+            lock->owner = me;
+            return PR_TRUE;
+        }
+        return PR_FALSE;
+    }
+#endif
+
+    if (!_PR_IS_NATIVE_THREAD(me)) {
+        _PR_INTSOFF(is);
+    }
+
+    _PR_LOCK_LOCK(lock);
+    if (lock->owner == 0) {
+        /* Just got the lock */
+        lock->owner = me;
+        lock->priority = me->priority;
+        /* Add the granted lock to this owning thread's lock list */
+        PR_APPEND_LINK(&lock->links, &me->lockList);
+        rv = PR_TRUE;
+    }
+    _PR_LOCK_UNLOCK(lock);
+
+    if (!_PR_IS_NATIVE_THREAD(me)) {
+        _PR_INTSON(is);
+    }
+    return rv;
+#endif  /* _PR_GLOBAL_THREADS_ONLY */
+}
+
+/************************************************************************/
+/************************************************************************/
+/***********************ROUTINES FOR DCE EMULATION***********************/
+/************************************************************************/
+/************************************************************************/
+PR_IMPLEMENT(PRStatus) PRP_TryLock(PRLock *lock)
+{
+    return (PR_TestAndLock(lock)) ? PR_SUCCESS : PR_FAILURE;
+}