nuThreadPool::JobTicket nuThreadPool::JobArena::entryJob(const nuTaskSet& task_set)
{
Job* p_job = new Job(task_set);
queueEntry(p_job);
setCondition(HAS_DATA);
return JobTicket(p_job);
}
status_t
_user_xsi_semop(int semaphoreID, struct sembuf *ops, size_t numOps)
{
TRACE(("xsi_semop: semaphoreID = %d, ops = %p, numOps = %ld\n",
semaphoreID, ops, numOps));
MutexLocker setHashLocker(sXsiSemaphoreSetLock);
XsiSemaphoreSet *semaphoreSet = sSemaphoreHashTable.Lookup(semaphoreID);
if (semaphoreSet == NULL) {
TRACE_ERROR(("xsi_semop: semaphore set id %d not valid\n",
semaphoreID));
return EINVAL;
}
MutexLocker setLocker(semaphoreSet->Lock());
setHashLocker.Unlock();
if (!IS_USER_ADDRESS(ops)) {
TRACE_ERROR(("xsi_semop: sembuf address is not valid\n"));
return B_BAD_ADDRESS;
}
if (numOps < 0 || numOps >= MAX_XSI_SEMS_PER_TEAM) {
TRACE_ERROR(("xsi_semop: numOps out of range\n"));
return EINVAL;
}
struct sembuf *operations
= (struct sembuf *)malloc(sizeof(struct sembuf) * numOps);
if (operations == NULL) {
TRACE_ERROR(("xsi_semop: failed to allocate sembuf struct\n"));
return B_NO_MEMORY;
}
MemoryDeleter operationsDeleter(operations);
if (user_memcpy(operations, ops,
(sizeof(struct sembuf) * numOps)) < B_OK) {
TRACE_ERROR(("xsi_semop: user_memcpy failed\n"));
return B_BAD_ADDRESS;
}
// We won't do partial request, that is operations
// only on some sempahores belonging to the set and then
// going to sleep. If we must wait on a semaphore, we undo
// all the operations already done and go to sleep, otherwise
// we may caused some unwanted deadlock among threads
// fighting for the same set.
bool notDone = true;
status_t result = 0;
while (notDone) {
XsiSemaphore *semaphore = NULL;
short numberOfSemaphores = semaphoreSet->NumberOfSemaphores();
bool goToSleep = false;
uint32 i = 0;
for (; i < numOps; i++) {
short semaphoreNumber = operations[i].sem_num;
if (semaphoreNumber >= numberOfSemaphores) {
TRACE_ERROR(("xsi_semop: %" B_PRIu32 " invalid semaphore number"
"\n", i));
result = EINVAL;
break;
}
semaphore = semaphoreSet->Semaphore(semaphoreNumber);
unsigned short value = semaphore->Value();
short operation = operations[i].sem_op;
TRACE(("xsi_semop: semaphoreNumber = %d, value = %d\n",
semaphoreNumber, value));
if (operation < 0) {
if (semaphore->Add(operation)) {
if (operations[i].sem_flg & IPC_NOWAIT)
result = EAGAIN;
else
goToSleep = true;
break;
}
} else if (operation == 0) {
if (value == 0)
continue;
else if (operations[i].sem_flg & IPC_NOWAIT) {
result = EAGAIN;
break;
} else {
goToSleep = true;
break;
}
} else {
// Operation must be greater than zero,
// just add the value and continue
semaphore->Add(operation);
}
}
// Either we have to wait or an error occured
if (goToSleep || result != 0) {
// Undo all previously done operations
for (uint32 j = 0; j < i; j++) {
short semaphoreNumber = operations[j].sem_num;
semaphore = semaphoreSet->Semaphore(semaphoreNumber);
short operation = operations[j].sem_op;
if (operation != 0)
semaphore->Revert(operation);
}
if (result != 0)
return result;
// We have to wait: first enqueue the thread
// in the appropriate set waiting list, then
// unlock the set itself and block the thread.
bool waitOnZero = true;
if (operations[i].sem_op != 0)
waitOnZero = false;
Thread *thread = thread_get_current_thread();
queued_thread queueEntry(thread, (int32)operations[i].sem_op);
semaphore->Enqueue(&queueEntry, waitOnZero);
uint32 sequenceNumber = semaphoreSet->SequenceNumber();
TRACE(("xsi_semop: thread %d going to sleep\n", (int)thread->id));
result = semaphore->BlockAndUnlock(thread, &setLocker);
TRACE(("xsi_semop: thread %d back to life\n", (int)thread->id));
// We are back to life. Find out why!
// Make sure the set hasn't been deleted or worst yet
// replaced.
setHashLocker.Lock();
semaphoreSet = sSemaphoreHashTable.Lookup(semaphoreID);
if (result == EIDRM || semaphoreSet == NULL || (semaphoreSet != NULL
&& sequenceNumber != semaphoreSet->SequenceNumber())) {
TRACE_ERROR(("xsi_semop: semaphore set id %d (sequence = "
"%" B_PRIu32 ") got destroyed\n", semaphoreID,
sequenceNumber));
notDone = false;
result = EIDRM;
} else if (result == B_INTERRUPTED) {
TRACE_ERROR(("xsi_semop: thread %d got interrupted while "
"waiting on semaphore set id %d\n",(int)thread->id,
semaphoreID));
semaphore->Deque(&queueEntry, waitOnZero);
result = EINTR;
notDone = false;
} else {
setLocker.Lock();
setHashLocker.Unlock();
}
} else {
// everything worked like a charm (so far)
notDone = false;
TRACE(("xsi_semop: semaphore acquired succesfully\n"));
// We acquired the semaphore, now records the sem_undo
// requests
XsiSemaphore *semaphore = NULL;
uint32 i = 0;
for (; i < numOps; i++) {
short semaphoreNumber = operations[i].sem_num;
semaphore = semaphoreSet->Semaphore(semaphoreNumber);
short operation = operations[i].sem_op;
if (operations[i].sem_flg & SEM_UNDO)
if (semaphoreSet->RecordUndo(semaphoreNumber, operation)
!= B_OK) {
// Unlikely scenario, but we might get here.
// Undo everything!
// Start with semaphore operations
for (uint32 j = 0; j < numOps; j++) {
short semaphoreNumber = operations[j].sem_num;
semaphore = semaphoreSet->Semaphore(semaphoreNumber);
short operation = operations[j].sem_op;
if (operation != 0)
semaphore->Revert(operation);
}
// Remove all previously registered sem_undo request
for (uint32 j = 0; j < i; j++) {
if (operations[j].sem_flg & SEM_UNDO)
semaphoreSet->RevertUndo(operations[j].sem_num,
operations[j].sem_op);
}
result = ENOSPC;
}
}
}
}
// We did it. Set the pid of all semaphores used
if (result == 0) {
for (uint32 i = 0; i < numOps; i++) {
short semaphoreNumber = operations[i].sem_num;
XsiSemaphore *semaphore = semaphoreSet->Semaphore(semaphoreNumber);
semaphore->SetPid(getpid());
}
}
return result;
}
status_t
switch_sem_etc(sem_id semToBeReleased, sem_id id, int32 count,
uint32 flags, bigtime_t timeout)
{
int slot = id % sMaxSems;
int state;
status_t status = B_OK;
if (gKernelStartup)
return B_OK;
if (sSemsActive == false)
return B_NO_MORE_SEMS;
if (!are_interrupts_enabled()) {
panic("switch_sem_etc: called with interrupts disabled for sem %ld\n",
id);
}
if (id < 0)
return B_BAD_SEM_ID;
if (count <= 0
|| (flags & (B_RELATIVE_TIMEOUT | B_ABSOLUTE_TIMEOUT)) == (B_RELATIVE_TIMEOUT | B_ABSOLUTE_TIMEOUT)) {
return B_BAD_VALUE;
}
state = disable_interrupts();
GRAB_SEM_LOCK(sSems[slot]);
if (sSems[slot].id != id) {
TRACE(("switch_sem_etc: bad sem %ld\n", id));
status = B_BAD_SEM_ID;
goto err;
}
// TODO: the B_CHECK_PERMISSION flag should be made private, as it
// doesn't have any use outside the kernel
if ((flags & B_CHECK_PERMISSION) != 0
&& sSems[slot].u.used.owner == team_get_kernel_team_id()) {
dprintf("thread %ld tried to acquire kernel semaphore %ld.\n",
thread_get_current_thread_id(), id);
status = B_NOT_ALLOWED;
goto err;
}
if (sSems[slot].u.used.count - count < 0) {
if ((flags & B_RELATIVE_TIMEOUT) != 0 && timeout <= 0) {
// immediate timeout
status = B_WOULD_BLOCK;
goto err;
} else if ((flags & B_ABSOLUTE_TIMEOUT) != 0 && timeout < 0) {
// absolute negative timeout
status = B_TIMED_OUT;
goto err;
}
}
KTRACE("switch_sem_etc(semToBeReleased: %ld, sem: %ld, count: %ld, "
"flags: 0x%lx, timeout: %lld)", semToBeReleased, id, count, flags,
timeout);
if ((sSems[slot].u.used.count -= count) < 0) {
// we need to block
Thread *thread = thread_get_current_thread();
TRACE(("switch_sem_etc(id = %ld): block name = %s, thread = %p,"
" name = %s\n", id, sSems[slot].u.used.name, thread, thread->name));
// do a quick check to see if the thread has any pending signals
// this should catch most of the cases where the thread had a signal
SpinLocker schedulerLocker(gSchedulerLock);
if (thread_is_interrupted(thread, flags)) {
schedulerLocker.Unlock();
sSems[slot].u.used.count += count;
status = B_INTERRUPTED;
// the other semaphore will be released later
goto err;
}
if ((flags & (B_RELATIVE_TIMEOUT | B_ABSOLUTE_TIMEOUT)) == 0)
timeout = B_INFINITE_TIMEOUT;
// enqueue in the semaphore queue and get ready to wait
queued_thread queueEntry(thread, count);
sSems[slot].queue.Add(&queueEntry);
queueEntry.queued = true;
thread_prepare_to_block(thread, flags, THREAD_BLOCK_TYPE_SEMAPHORE,
(void*)(addr_t)id);
RELEASE_SEM_LOCK(sSems[slot]);
// release the other semaphore, if any
if (semToBeReleased >= 0) {
release_sem_etc(semToBeReleased, 1, B_DO_NOT_RESCHEDULE);
semToBeReleased = -1;
}
schedulerLocker.Lock();
status_t acquireStatus = timeout == B_INFINITE_TIMEOUT
? thread_block_locked(thread)
: thread_block_with_timeout_locked(flags, timeout);
schedulerLocker.Unlock();
GRAB_SEM_LOCK(sSems[slot]);
// If we're still queued, this means the acquiration failed, and we
// need to remove our entry and (potentially) wake up other threads.
if (queueEntry.queued)
remove_thread_from_sem(&queueEntry, &sSems[slot]);
if (acquireStatus >= B_OK) {
sSems[slot].u.used.last_acquirer = thread_get_current_thread_id();
#if DEBUG_SEM_LAST_ACQUIRER
sSems[slot].u.used.last_acquire_count = count;
#endif
}
RELEASE_SEM_LOCK(sSems[slot]);
restore_interrupts(state);
TRACE(("switch_sem_etc(sem %ld): exit block name %s, "
"thread %ld (%s)\n", id, sSems[slot].u.used.name, thread->id,
thread->name));
KTRACE("switch_sem_etc() done: 0x%lx", acquireStatus);
return acquireStatus;
} else {
sSems[slot].u.used.net_count -= count;
sSems[slot].u.used.last_acquirer = thread_get_current_thread_id();
#if DEBUG_SEM_LAST_ACQUIRER
sSems[slot].u.used.last_acquire_count = count;
#endif
}
err:
RELEASE_SEM_LOCK(sSems[slot]);
restore_interrupts(state);
if (status == B_INTERRUPTED && semToBeReleased >= B_OK) {
// depending on when we were interrupted, we need to still
// release the semaphore to always leave in a consistent
// state
release_sem_etc(semToBeReleased, 1, B_DO_NOT_RESCHEDULE);
}
#if 0
if (status == B_NOT_ALLOWED)
_user_debugger("Thread tried to acquire kernel semaphore.");
#endif
KTRACE("switch_sem_etc() done: 0x%lx", status);
return status;
}
