static void comm_task_wrapper(void* arg) {
thread_private_data_t* tp;
tp = (thread_private_data_t*) chpl_mem_alloc(sizeof(thread_private_data_t),
CHPL_RT_MD_THREAD_PRV_DATA,
0, 0);
tp->ptask = (task_pool_p) chpl_mem_alloc(sizeof(task_pool_t),
CHPL_RT_MD_TASK_POOL_DESC,
0, 0);
tp->ptask->id = get_next_task_id();
tp->ptask->fun = comm_task_fn;
tp->ptask->arg = arg;
tp->ptask->is_executeOn = false;
tp->ptask->filename = CHPL_FILE_IDX_COMM_TASK;
tp->ptask->lineno = 0;
tp->ptask->p_list_head = NULL;
tp->ptask->next = NULL;
//
// The comm (polling) task shouldn't really need this information.
//
tp->ptask->chpl_data.prvdata.serial_state = true;
tp->lockRprt = NULL;
chpl_thread_setPrivateData(tp);
(*comm_task_fn)(arg);
}
static void setup_main_thread_private_data(void)
{
thread_private_data_t* tp;
tp = (thread_private_data_t*) chpl_mem_alloc(sizeof(thread_private_data_t),
CHPL_RT_MD_THREAD_PRV_DATA,
0, 0);
tp->ptask = (task_pool_p) chpl_mem_alloc(sizeof(task_pool_t),
CHPL_RT_MD_TASK_POOL_DESC,
0, 0);
tp->lockRprt = NULL;
tp->ptask->p_list_head = NULL;
tp->ptask->list_next = NULL;
tp->ptask->list_prev = NULL;
tp->ptask->next = NULL;
tp->ptask->prev = NULL;
// serial_state starts out true; it is set to false in chpl_std_module_init().
tp->ptask->bundle.serial_state = true;
tp->ptask->bundle.countRunning = false;
tp->ptask->bundle.is_executeOn = false;
tp->ptask->bundle.lineno = 0;
tp->ptask->bundle.filename = CHPL_FILE_IDX_MAIN_PROGRAM;
tp->ptask->bundle.requestedSubloc = c_sublocid_any_val;
tp->ptask->bundle.requested_fid = FID_NONE;
tp->ptask->bundle.requested_fn = NULL;
tp->ptask->bundle.id = get_next_task_id();
chpl_thread_setPrivateData(tp);
}
static void comm_task_wrapper(void* arg) {
thread_private_data_t* tp;
tp = (thread_private_data_t*) chpl_mem_alloc(sizeof(thread_private_data_t),
CHPL_RT_MD_THREAD_PRV_DATA,
0, 0);
tp->ptask = (task_pool_p) chpl_mem_alloc(sizeof(task_pool_t),
CHPL_RT_MD_TASK_POOL_DESC,
0, 0);
tp->lockRprt = NULL;
tp->ptask->p_list_head = NULL;
tp->ptask->list_next = NULL;
tp->ptask->list_prev = NULL;
tp->ptask->next = NULL;
tp->ptask->prev = NULL;
tp->ptask->bundle.serial_state = false;
tp->ptask->bundle.countRunning = false;
tp->ptask->bundle.is_executeOn = false;
tp->ptask->bundle.lineno = 0;
tp->ptask->bundle.filename = CHPL_FILE_IDX_COMM_TASK;
tp->ptask->bundle.requestedSubloc = c_sublocid_any_val;
tp->ptask->bundle.requested_fid = FID_NONE;
tp->ptask->bundle.requested_fn = NULL;
tp->ptask->bundle.id = get_next_task_id();
chpl_thread_setPrivateData(tp);
(*comm_task_fn)(arg);
}
static void setup_main_thread_private_data(void)
{
thread_private_data_t* tp;
tp = (thread_private_data_t*) chpl_mem_alloc(sizeof(thread_private_data_t),
CHPL_RT_MD_THREAD_PRV_DATA,
0, 0);
tp->ptask = (task_pool_p) chpl_mem_alloc(sizeof(task_pool_t),
CHPL_RT_MD_TASK_POOL_DESC,
0, 0);
tp->ptask->id = get_next_task_id();
tp->ptask->fun = NULL;
tp->ptask->arg = NULL;
tp->ptask->is_executeOn = false;
tp->ptask->filename = CHPL_FILE_IDX_MAIN_PROGRAM;
tp->ptask->lineno = 0;
tp->ptask->p_list_head = NULL;
tp->ptask->next = NULL;
tp->lockRprt = NULL;
// Set up task-private data for locale (architectural) support.
tp->ptask->chpl_data.prvdata.serial_state = true; // Set to false in chpl_task_callMain().
chpl_thread_setPrivateData(tp);
}
chpl_thread_mutex_p chpl_thread_mutexNew(void) {
chpl_thread_mutex_p m;
m = (chpl_thread_mutex_p) chpl_mem_alloc(sizeof(chpl_thread_mutex_t),
CHPL_RT_MD_MUTEX, 0, 0);
chpl_thread_mutexInit(m);
return m;
}
void chpl_task_startMovedTask(chpl_fn_p fp,
void* a,
c_sublocid_t subloc,
chpl_taskID_t id,
chpl_bool serial_state) {
movedTaskWrapperDesc_t* pmtwd;
chpl_task_prvDataImpl_t private = {
.prvdata = { .serial_state = serial_state } };
assert(subloc == 0 || subloc == c_sublocid_any);
assert(id == chpl_nullTaskID);
pmtwd = (movedTaskWrapperDesc_t*)
chpl_mem_alloc(sizeof(*pmtwd),
CHPL_RT_MD_THREAD_PRV_DATA,
0, 0);
*pmtwd = (movedTaskWrapperDesc_t)
{ fp, a, canCountRunningTasks,
private };
// begin critical section
chpl_thread_mutexLock(&threading_lock);
(void) add_to_task_pool(movedTaskWrapper, pmtwd, true, pmtwd->chpl_data,
NULL, false, 0, CHPL_FILE_IDX_UNKNOWN);
// end critical section
chpl_thread_mutexUnlock(&threading_lock);
}
static void libfabric_init_addrvec(int rx_ctx_cnt, int rx_ctx_bits) {
struct gather_info* my_addr_info;
void* addr_infos;
char* addrs;
char* tai;
size_t my_addr_len;
size_t addr_info_len;
int i, j;
// Assumes my_addr_len is the same on all nodes
my_addr_len = 0;
OFICHKRET(fi_getname(&ofi.ep->fid, NULL, &my_addr_len), -FI_ETOOSMALL);
addr_info_len = sizeof(struct gather_info) + my_addr_len;
my_addr_info = chpl_mem_alloc(addr_info_len,
CHPL_RT_MD_COMM_UTIL,
0, 0);
my_addr_info->node = chpl_nodeID;
OFICHKERR(fi_getname(&ofi.ep->fid, &my_addr_info->info, &my_addr_len));
addr_infos = chpl_mem_allocMany(chpl_numNodes, addr_info_len,
CHPL_RT_MD_COMM_PER_LOC_INFO,
0, 0);
chpl_comm_ofi_oob_allgather(my_addr_info, addr_infos, addr_info_len);
addrs = chpl_mem_allocMany(chpl_numNodes, my_addr_len,
CHPL_RT_MD_COMM_PER_LOC_INFO,
0, 0);
for (tai = addr_infos, i = 0; i < chpl_numNodes; i++) {
struct gather_info* ai = (struct gather_info*) tai;
assert(i >= 0);
assert(i < chpl_numNodes);
memcpy(addrs + ai->node * my_addr_len, ai->info, my_addr_len);
tai += addr_info_len;
}
ofi.fi_addrs = chpl_mem_allocMany(chpl_numNodes, sizeof(ofi.fi_addrs[0]),
CHPL_RT_MD_COMM_PER_LOC_INFO,
0, 0);
OFICHKRET(fi_av_insert(ofi.av, addrs, chpl_numNodes,
ofi.fi_addrs, 0, NULL), chpl_numNodes);
ofi.rx_addrs = chpl_mem_allocMany(chpl_numNodes, sizeof(ofi.rx_addrs[0]),
CHPL_RT_MD_COMM_PER_LOC_INFO,
0, 0);
for (i = 0; i < chpl_numNodes; i++) {
ofi.rx_addrs[i] = chpl_mem_allocMany(rx_ctx_cnt,
sizeof(ofi.rx_addrs[i][0]),
CHPL_RT_MD_COMM_PER_LOC_INFO,
0, 0);
for (j = 0; j < rx_ctx_cnt; j++) {
ofi.rx_addrs[i][j] = fi_rx_addr(ofi.fi_addrs[i], j, rx_ctx_bits);
}
}
chpl_mem_free(my_addr_info, 0, 0);
chpl_mem_free(addr_infos, 0, 0);
chpl_mem_free(addrs, 0, 0);
}
/* This function returns a string from src_locale located at src_addr.
*
* src_locale: node id
* src_addr: string address on remote node
* src_len: length
*
*/
c_string_copy remoteStringCopy(c_nodeid_t src_locale,
c_string src_addr, int64_t src_len,
int32_t lineno, c_string filename) {
char* ret;
if (src_addr == NULL) return NULL;
ret = chpl_mem_alloc(src_len+1, CHPL_RT_MD_STRING_COPY_REMOTE,
lineno, filename);
chpl_gen_comm_get((void*)ret, src_locale, (void*)src_addr, sizeof(char),
CHPL_TYPE_uint8_t, src_len+1, lineno, filename);
return (c_string)ret;
}
char *getNodeListOpt() {
const char *nodeList = getenv("CHPL_LAUNCHER_NODELIST");
char *nodeListOpt = NULL;
if (nodeList) {
nodeListOpt = chpl_mem_alloc(strlen(getNodeListStr())+strlen(nodeList)+1,
CHPL_RT_MD_COMMAND_BUFFER, -1, 0);
strcpy(nodeListOpt, getNodeListStr());
strcat(nodeListOpt, nodeList);
}
return nodeListOpt;
}
// create a task from the given function pointer and arguments
// and append it to the end of the task pool
// assumes threading_lock has already been acquired!
static inline
task_pool_p add_to_task_pool(chpl_fn_p fp,
void* a,
chpl_bool is_executeOn,
chpl_task_prvDataImpl_t chpl_data,
task_pool_p* p_task_list_head,
chpl_bool is_begin_stmt,
int lineno, int32_t filename) {
task_pool_p ptask =
(task_pool_p) chpl_mem_alloc(sizeof(task_pool_t),
CHPL_RT_MD_TASK_POOL_DESC,
0, 0);
ptask->id = get_next_task_id();
ptask->fun = fp;
ptask->arg = a;
ptask->is_executeOn = is_executeOn;
ptask->chpl_data = chpl_data;
ptask->filename = filename;
ptask->lineno = lineno;
ptask->p_list_head = NULL;
ptask->next = NULL;
enqueue_task(ptask, p_task_list_head);
chpl_task_do_callbacks(chpl_task_cb_event_kind_create,
ptask->filename,
ptask->lineno,
ptask->id,
ptask->is_executeOn);
if (do_taskReport) {
chpl_thread_mutexLock(&taskTable_lock);
chpldev_taskTable_add(ptask->id,
ptask->lineno, ptask->filename,
(uint64_t) (intptr_t) ptask);
chpl_thread_mutexUnlock(&taskTable_lock);
}
//
// If we now have more tasks than threads to run them on (taking
// into account that the current parent of a structured parallel
// construct can run at least one of that construct's children),
// try to start another thread.
//
if (queued_task_cnt > idle_thread_cnt &&
(p_task_list_head == NULL || ptask->list_next != NULL || is_begin_stmt)) {
maybe_add_thread();
}
return ptask;
}
void string_from_c_string(chpl_string *ret, c_string str, int haslen, int64_t len, int32_t lineno, chpl_string filename)
{
char* s;
if( str == NULL ) {
*ret = NULL;
return;
}
if( ! haslen ) len = strlen(str);
s = (char*)chpl_mem_alloc(len+1, CHPL_RT_MD_STRING_COPY_DATA,
lineno, filename);
chpl_memcpy(s, str, len);
s[len] = '\0';
*ret = s;
}
static void* pthread_func(void* arg) {
chpl_thread_id_t my_thread_id;
thread_list_p tlp;
// disable cancellation immediately
// enable only while waiting for new work
pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
// add us to the list of threads
tlp = (thread_list_p) chpl_mem_alloc(sizeof(struct thread_list),
CHPL_RT_MD_THREAD_LIST_DESC, 0, 0);
tlp->thread = pthread_self();
tlp->next = NULL;
pthread_mutex_lock(&thread_info_lock);
if (exiting) {
pthread_mutex_unlock(&thread_info_lock);
chpl_mem_free(tlp, 0, 0);
return NULL;
}
my_thread_id = --curr_thread_id;
if (thread_list_head == NULL)
thread_list_head = tlp;
else
thread_list_tail->next = tlp;
thread_list_tail = tlp;
pthread_mutex_unlock(&thread_info_lock);
CHPL_TLS_SET(chpl_thread_id, (intptr_t) my_thread_id);
if (saved_threadEndFn == NULL)
(*saved_threadBeginFn)(arg);
else {
pthread_cleanup_push((void (*)(void*)) saved_threadEndFn, NULL);
(*saved_threadBeginFn)(arg);
pthread_cleanup_pop(1); // Shouldn't we run the thread
// end function even if not cancelled?
}
return NULL;
}
void wide_string_from_c_string(chpl____wide_chpl_string *ret, c_string str, int haslen, int64_t len, int32_t lineno, chpl_string filename)
{
char* s;
ret->locale = chpl_gen_getLocaleID();
if( str == NULL ) {
ret->addr = NULL;
ret->size = 0;
return;
}
if( ! haslen ) len = strlen(str);
s = chpl_mem_alloc(len+1, CHPL_RT_MD_STRING_COPY_DATA, lineno, filename);
chpl_memcpy(s, str, len);
s[len] = '\0';
ret->addr = s;
ret->size = len + 1; // this size includes the terminating NUL
}
//
// This function should be called exactly once per thread (not task!),
// including the main thread. It should be called before the first task
// this thread was created to do is started.
//
// Our handling of lock report list entries could be improved. We
// allocate one each time this function is called, and this is called
// just before each task wrapper is called. We never remove these
// from the list or deallocate them. If we do traverse the list while
// reporting a deadlock, we just skip the leaked ones, because they
// don't say "blocked".
//
static void initializeLockReportForThread(void) {
lockReport_t* newLockReport;
newLockReport = (lockReport_t*) chpl_mem_alloc(sizeof(lockReport_t),
CHPL_RT_MD_LOCK_REPORT_DATA,
0, 0);
newLockReport->maybeLocked = false;
newLockReport->next = NULL;
get_thread_private_data()->lockRprt = newLockReport;
// Begin critical section
chpl_thread_mutexLock(&block_report_lock);
if (lockReportHead) {
lockReportTail->next = newLockReport;
lockReportTail = newLockReport;
} else {
lockReportHead = newLockReport;
lockReportTail = newLockReport;
}
// End critical section
chpl_thread_mutexUnlock(&block_report_lock);
}
// Even if allocation is done here, the returned string is already owned
// elsewhere. So we return a c_string, not a c_string_copy.
c_string_copy stringMove(c_string_copy dest, c_string src, int64_t len,
int32_t lineno, c_string filename) {
char *ret;
if (src == NULL)
return NULL;
if (dest == NULL ||
// TODO: Want to deprecate indicating an empty string by a string of zero
// length. This works OK if the string is unallocated (such as a string
// literal), but does not work well with an allocated string. An
// allocated string of zero length still occupies memory (one byte for
// the NUL, at least), so that leaves us with a dilemma. Which is it?
strlen(dest) == 0)
ret = chpl_mem_alloc(len+1, CHPL_RT_MD_STRING_MOVE_DATA, lineno, filename);
else
// reuse the buffer
// The cast is necessary so we can write into the buffer (which is declared
// to be const).
ret = (char *) dest;
snprintf(ret, len+1, "%s", src);
return (c_string) ret;
}
static inline
void taskCallBody(chpl_fn_p fp, void* arg, void* arg_copy,
c_sublocid_t subloc, chpl_bool serial_state,
int lineno, int32_t filename) {
taskCallWrapperDesc_t* ptcwd;
chpl_task_prvDataImpl_t private = {
.prvdata = { .serial_state = serial_state } };
ptcwd = (taskCallWrapperDesc_t*)
chpl_mem_alloc(sizeof(*ptcwd),
CHPL_RT_MD_THREAD_PRV_DATA,
0, 0);
*ptcwd = (taskCallWrapperDesc_t)
{ fp, arg, arg_copy, canCountRunningTasks, private };
// begin critical section
chpl_thread_mutexLock(&threading_lock);
(void) add_to_task_pool(taskCallWrapper, ptcwd, true, ptcwd->chpl_data,
NULL, false, lineno, filename);
// end critical section
chpl_thread_mutexUnlock(&threading_lock);
}
static void* chpl_gmp_alloc(size_t sz) {
return chpl_mem_alloc(sz, CHPL_RT_MD_GMP, 0, 0);
}
//
// When we create a thread it runs this wrapper function, which just
// executes tasks out of the pool as they become available.
//
static void
thread_begin(void* ptask_void) {
task_pool_p ptask;
thread_private_data_t *tp;
tp = (thread_private_data_t*) chpl_mem_alloc(sizeof(thread_private_data_t),
CHPL_RT_MD_THREAD_PRV_DATA,
0, 0);
chpl_thread_setPrivateData(tp);
tp->lockRprt = NULL;
if (blockreport)
initializeLockReportForThread();
while (true) {
//
// wait for a task to be present in the task pool
//
// In revision 22137, we investigated whether it was beneficial to
// implement this while loop in a hybrid style, where depending on
// the number of tasks available, idle threads would either yield or
// wait on a condition variable to waken them. Through analysis, we
// realized this could potential create a case where a thread would
// become stranded, waiting for a condition signal that would never
// come. A potential solution to this was to keep a count of threads
// that were waiting on the signal, but since there was a performance
// impact from keeping it as a hybrid as opposed to merely yielding,
// it was decided that we would return to the simple yield case.
while (!task_pool_head) {
if (set_block_loc(0, CHPL_FILE_IDX_IDLE_TASK)) {
// all other tasks appear to be blocked
struct timeval deadline, now;
gettimeofday(&deadline, NULL);
deadline.tv_sec += 1;
do {
chpl_thread_yield();
if (!task_pool_head)
gettimeofday(&now, NULL);
} while (!task_pool_head
&& (now.tv_sec < deadline.tv_sec
|| (now.tv_sec == deadline.tv_sec
&& now.tv_usec < deadline.tv_usec)));
if (!task_pool_head) {
check_for_deadlock();
}
}
else {
do {
chpl_thread_yield();
} while (!task_pool_head);
}
unset_block_loc();
}
//
// Just now the pool had at least one task in it. Lock and see if
// there's something still there.
//
chpl_thread_mutexLock(&threading_lock);
if (!task_pool_head) {
chpl_thread_mutexUnlock(&threading_lock);
continue;
}
//
// We've found a task to run.
//
if (blockreport)
progress_cnt++;
//
// start new task; increment running count and remove task from pool
// also add to task to task-table (structure in ChapelRuntime that keeps
// track of currently running tasks for task-reports on deadlock or
// Ctrl+C).
//
ptask = task_pool_head;
idle_thread_cnt--;
running_task_cnt++;
dequeue_task(ptask);
// end critical section
chpl_thread_mutexUnlock(&threading_lock);
tp->ptask = ptask;
if (do_taskReport) {
chpl_thread_mutexLock(&taskTable_lock);
chpldev_taskTable_set_active(ptask->id);
chpl_thread_mutexUnlock(&taskTable_lock);
}
chpl_task_do_callbacks(chpl_task_cb_event_kind_begin,
ptask->filename,
ptask->lineno,
ptask->id,
ptask->is_executeOn);
(*ptask->fun)(ptask->arg);
chpl_task_do_callbacks(chpl_task_cb_event_kind_end,
ptask->filename,
ptask->lineno,
ptask->id,
ptask->is_executeOn);
if (do_taskReport) {
chpl_thread_mutexLock(&taskTable_lock);
chpldev_taskTable_remove(ptask->id);
chpl_thread_mutexUnlock(&taskTable_lock);
}
tp->ptask = NULL;
chpl_mem_free(ptask, 0, 0);
// begin critical section
chpl_thread_mutexLock(&threading_lock);
//
// finished task; decrement running count and increment idle count
//
assert(running_task_cnt > 0);
running_task_cnt--;
idle_thread_cnt++;
// end critical section
chpl_thread_mutexUnlock(&threading_lock);
}
}
void chpl_task_init(void) {
chpl_thread_mutexInit(&threading_lock);
chpl_thread_mutexInit(&extra_task_lock);
chpl_thread_mutexInit(&task_id_lock);
chpl_thread_mutexInit(&task_list_lock);
queued_task_cnt = 0;
running_task_cnt = 1; // only main task running
blocked_thread_cnt = 0;
idle_thread_cnt = 0;
extra_task_cnt = 0;
task_pool_head = task_pool_tail = NULL;
chpl_thread_init(thread_begin, thread_end);
//
// Set main thread private data, so that things that require access
// to it, like chpl_task_getID() and chpl_task_setSerial(), can be
// called early (notably during standard module initialization).
//
// This needs to be done after the threading layer initialization,
// because it's based on thread layer capabilities, but before we
// install the signal handlers, because when those are invoked they
// may use the thread private data.
//
{
thread_private_data_t* tp;
tp = (thread_private_data_t*) chpl_mem_alloc(sizeof(thread_private_data_t),
CHPL_RT_MD_THREAD_PRV_DATA,
0, 0);
tp->ptask = (task_pool_p) chpl_mem_alloc(sizeof(task_pool_t),
CHPL_RT_MD_TASK_POOL_DESC,
0, 0);
tp->ptask->id = get_next_task_id();
tp->ptask->fun = NULL;
tp->ptask->arg = NULL;
tp->ptask->is_executeOn = false;
tp->ptask->filename = CHPL_FILE_IDX_MAIN_PROGRAM;
tp->ptask->lineno = 0;
tp->ptask->p_list_head = NULL;
tp->ptask->next = NULL;
tp->lockRprt = NULL;
// Set up task-private data for locale (architectural) support.
tp->ptask->chpl_data.prvdata.serial_state = true; // Set to false in chpl_task_callMain().
chpl_thread_setPrivateData(tp);
}
if (blockreport) {
progress_cnt = 0;
chpl_thread_mutexInit(&block_report_lock);
initializeLockReportForThread();
}
if (blockreport || taskreport) {
signal(SIGINT, SIGINT_handler);
}
initialized = true;
}
// create a task from the given function pointer and arguments
// and append it to the end of the task pool
// assumes threading_lock has already been acquired!
static inline
task_pool_p add_to_task_pool(chpl_fn_int_t fid, chpl_fn_p fp,
chpl_task_bundle_t* a, size_t a_size,
chpl_bool serial_state,
chpl_bool countRunningTasks,
chpl_bool is_executeOn,
task_pool_p* p_task_list_head,
chpl_bool is_begin_stmt,
int lineno, int32_t filename) {
size_t payload_size;
task_pool_p ptask;
chpl_task_prvDataImpl_t pv;
memset(&pv, 0, sizeof(pv));
assert(a_size >= sizeof(chpl_task_bundle_t));
payload_size = a_size - sizeof(chpl_task_bundle_t);
ptask = (task_pool_p) chpl_mem_alloc(sizeof(task_pool_t) + payload_size,
CHPL_RT_MD_TASK_ARG_AND_POOL_DESC,
lineno, filename);
memcpy(&ptask->bundle, a, a_size);
ptask->p_list_head = NULL;
ptask->list_next = NULL;
ptask->list_prev = NULL;
ptask->next = NULL;
ptask->prev = NULL;
ptask->chpl_data = pv;
ptask->bundle.serial_state = serial_state;
ptask->bundle.countRunning = countRunningTasks;
ptask->bundle.is_executeOn = is_executeOn;
ptask->bundle.lineno = lineno;
ptask->bundle.filename = filename;
ptask->bundle.requestedSubloc = c_sublocid_any_val;
ptask->bundle.requested_fid = fid;
ptask->bundle.requested_fn = fp;
ptask->bundle.id = get_next_task_id();
enqueue_task(ptask, p_task_list_head);
chpl_task_do_callbacks(chpl_task_cb_event_kind_create,
ptask->bundle.requested_fid,
ptask->bundle.filename,
ptask->bundle.lineno,
ptask->bundle.id,
ptask->bundle.is_executeOn);
if (do_taskReport) {
chpl_thread_mutexLock(&taskTable_lock);
chpldev_taskTable_add(ptask->bundle.id,
ptask->bundle.lineno, ptask->bundle.filename,
(uint64_t) (intptr_t) ptask);
chpl_thread_mutexUnlock(&taskTable_lock);
}
//
// If we now have more tasks than threads to run them on (taking
// into account that the current parent of a structured parallel
// construct can run at least one of that construct's children),
// try to start another thread.
//
if (queued_task_cnt > idle_thread_cnt &&
(p_task_list_head == NULL || ptask->list_next != NULL || is_begin_stmt)) {
maybe_add_thread();
}
return ptask;
}