/*
    Copyright 2005-2014 Intel Corporation.  All Rights Reserved.

    This file is part of Threading Building Blocks. Threading Building Blocks is free software;
    you can redistribute it and/or modify it under the terms of the GNU General Public License
    version 2  as  published  by  the  Free Software Foundation.  Threading Building Blocks is
    distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the
    implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
    See  the GNU General Public License for more details.   You should have received a copy of
    the  GNU General Public License along with Threading Building Blocks; if not, write to the
    Free Software Foundation, Inc.,  51 Franklin St,  Fifth Floor,  Boston,  MA 02110-1301 USA

    As a special exception,  you may use this file  as part of a free software library without
    restriction.  Specifically,  if other files instantiate templates  or use macros or inline
    functions from this file, or you compile this file and link it with other files to produce
    an executable,  this file does not by itself cause the resulting executable to be covered
    by the GNU General Public License. This exception does not however invalidate any other
    reasons why the executable file might be covered by the GNU General Public License.
*/

#include "tbb/tbb_stddef.h"

#include "market.h"
#include "tbb_main.h"
#include "governor.h"
#include "scheduler.h"
#include "itt_notify.h"

namespace tbb {
namespace internal {

void market::insert_arena_into_list ( arena& a ) {
#if __TBB_TASK_PRIORITY
    arena_list_type &arenas = my_priority_levels[a.my_top_priority].arenas;
    arena *&next = my_priority_levels[a.my_top_priority].next_arena;
#else /* !__TBB_TASK_PRIORITY */
    arena_list_type &arenas = my_arenas;
    arena *&next = my_next_arena;
#endif /* !__TBB_TASK_PRIORITY */
    arenas.push_front( a );
    if ( arenas.size() == 1 )
        next = &*arenas.begin();
}

void market::remove_arena_from_list ( arena& a ) {
#if __TBB_TASK_PRIORITY
    arena_list_type &arenas = my_priority_levels[a.my_top_priority].arenas;
    arena *&next = my_priority_levels[a.my_top_priority].next_arena;
#else /* !__TBB_TASK_PRIORITY */
    arena_list_type &arenas = my_arenas;
    arena *&next = my_next_arena;
#endif /* !__TBB_TASK_PRIORITY */
    arena_list_type::iterator it = next;
    __TBB_ASSERT( it != arenas.end(), NULL );
    if ( next == &a ) {
        if ( ++it == arenas.end() && arenas.size() > 1 )
            it = arenas.begin();
        next = &*it;
    }
    arenas.remove( a );
}

//------------------------------------------------------------------------
// market
//------------------------------------------------------------------------

market::market ( unsigned max_num_workers, size_t stack_size )
    : my_ref_count(1)
    , my_stack_size(stack_size)
    , my_max_num_workers(max_num_workers)
#if __TBB_TASK_PRIORITY
    , my_global_top_priority(normalized_normal_priority)
    , my_global_bottom_priority(normalized_normal_priority)
#if __TBB_TRACK_PRIORITY_LEVEL_SATURATION
    , my_lowest_populated_level(normalized_normal_priority)
#endif /* __TBB_TRACK_PRIORITY_LEVEL_SATURATION */
#endif /* __TBB_TASK_PRIORITY */
{
#if __TBB_TASK_PRIORITY
    __TBB_ASSERT( my_global_reload_epoch == 0, NULL );
    my_priority_levels[normalized_normal_priority].workers_available = max_num_workers;
#endif /* __TBB_TASK_PRIORITY */

    // Once created RML server will start initializing workers that will need 
    // global market instance to get worker stack size
    my_server = governor::create_rml_server( *this );
    __TBB_ASSERT( my_server, "Failed to create RML server" );
}


market& market::global_market ( unsigned max_num_workers, size_t stack_size ) {
    global_market_mutex_type::scoped_lock lock( theMarketMutex );
    market *m = theMarket;
    if ( m ) {
        ++m->my_ref_count;
        if ( m->my_stack_size < stack_size )
            runtime_warning( "Newer master request for larger stack cannot be satisfied\n" );
    }
    else {
        max_num_workers = max( governor::default_num_threads() - 1, max_num_workers );
        // at least 1 worker is required to support starvation resistant tasks
        if( max_num_workers==0 ) max_num_workers = 1;
        // Create the global market instance
        size_t size = sizeof(market);
#if __TBB_TASK_GROUP_CONTEXT
        __TBB_ASSERT( __TBB_offsetof(market, my_workers) + sizeof(generic_scheduler*) == sizeof(market),
                      "my_workers must be the last data field of the market class");
        size += sizeof(generic_scheduler*) * (max_num_workers - 1);
#endif /* __TBB_TASK_GROUP_CONTEXT */
        __TBB_InitOnce::add_ref();
        void* storage = NFS_Allocate(1, size, NULL);
        memset( storage, 0, size );
        // Initialize and publish global market
        m = new (storage) market( max_num_workers, stack_size );
        theMarket = m;
    }
    return *m;
}

void market::destroy () {
#if __TBB_COUNT_TASK_NODES
    if ( my_task_node_count )
        runtime_warning( "Leaked %ld task objects\n", (long)my_task_node_count );
#endif /* __TBB_COUNT_TASK_NODES */
    this->~market();
    NFS_Free( this );
    __TBB_InitOnce::remove_ref();
}

void market::release () {
    __TBB_ASSERT( theMarket == this, "Global market instance was destroyed prematurely?" );
    bool do_release = false;
    {
        global_market_mutex_type::scoped_lock lock(theMarketMutex);
        if ( --my_ref_count == 0 ) {
            do_release = true;
            theMarket = NULL;
        }
    }
    if( do_release )
        my_server->request_close_connection();
}

void market::wait_workers () {
    // usable for this kind of scheduler only
    __TBB_ASSERT(governor::needsWaitWorkers(), NULL);
    // wait till terminating last worker decresed my_ref_count
    while (__TBB_load_with_acquire(my_ref_count) > 1)
        __TBB_Yield();
    __TBB_ASSERT(1 == my_ref_count, NULL);
    release();
}

arena& market::create_arena ( unsigned max_num_workers, size_t stack_size ) {
    market &m = global_market( max_num_workers, stack_size ); // increases market's ref count
#if __TBB_TASK_ARENA
    // Prevent cutting an extra slot for task_arena(p,0) with default market (p-1 workers).
    // This is a temporary workaround for 1968 until (TODO:) master slot reservation is reworked
    arena& a = arena::allocate_arena( m, min(max_num_workers, m.my_max_num_workers+1) );
#else
    arena& a = arena::allocate_arena( m, min(max_num_workers, m.my_max_num_workers) );
#endif
    // Add newly created arena into the existing market's list.
    arenas_list_mutex_type::scoped_lock lock(m.my_arenas_list_mutex);
    m.insert_arena_into_list(a);
    return a;
}

/** This method must be invoked under my_arenas_list_mutex. **/
void market::detach_arena ( arena& a ) {
    __TBB_ASSERT( theMarket == this, "Global market instance was destroyed prematurely?" );
#if __TBB_TRACK_PRIORITY_LEVEL_SATURATION
    __TBB_ASSERT( !a.my_num_workers_present, NULL );
#endif /* __TBB_TRACK_PRIORITY_LEVEL_SATURATION */
    __TBB_ASSERT( !a.my_slots[0].my_scheduler, NULL );
    remove_arena_from_list(a);
    if ( a.my_aba_epoch == my_arenas_aba_epoch )
        ++my_arenas_aba_epoch;
}

void market::try_destroy_arena ( arena* a, uintptr_t aba_epoch ) {
    __TBB_ASSERT ( a, NULL );
    arenas_list_mutex_type::scoped_lock lock(my_arenas_list_mutex);
    assert_market_valid();
#if __TBB_TASK_PRIORITY
    for ( int p = my_global_top_priority; p >= my_global_bottom_priority; --p ) {
        priority_level_info &pl = my_priority_levels[p];
        arena_list_type &my_arenas = pl.arenas;
#endif /* __TBB_TASK_PRIORITY */
        arena_list_type::iterator it = my_arenas.begin();
        for ( ; it != my_arenas.end(); ++it ) {
            if ( a == &*it ) {
                if ( it->my_aba_epoch == aba_epoch ) {
                    // Arena is alive
                    if ( !a->my_num_workers_requested && !a->my_references ) {
                        __TBB_ASSERT( !a->my_num_workers_allotted && (a->my_pool_state == arena::SNAPSHOT_EMPTY || !a->my_max_num_workers), "Inconsistent arena state" );
                        // Arena is abandoned. Destroy it.
                        detach_arena( *a );
                        lock.release();
                        a->free_arena();
                    }
                }
                return;
            }
        }
#if __TBB_TASK_PRIORITY
    }
#endif /* __TBB_TASK_PRIORITY */
}

void market::try_destroy_arena ( market* m, arena* a, uintptr_t aba_epoch, bool master ) {
    // Arena may have been orphaned. Or it may have been destroyed.
    // Thus we cannot dereference the pointer to it until its liveness is verified.
    // Arena is alive if it is found in the market's list.

    if ( m != theMarket ) {
        // The market has already been emptied.
        return;
    }
    else if ( master ) {
        // If this is a master thread, market can be destroyed at any moment.
        // So protect it with an extra refcount.
        global_market_mutex_type::scoped_lock lock(theMarketMutex);
        if ( m != theMarket )
            return;
        ++m->my_ref_count;
    }
    m->try_destroy_arena( a, aba_epoch );
    if ( master )
        m->release();
}

/** This method must be invoked under my_arenas_list_mutex. **/
arena* market::arena_in_need ( arena_list_type &arenas, arena *&next ) {
    if ( arenas.empty() )
        return NULL;
    arena_list_type::iterator it = next;
    __TBB_ASSERT( it != arenas.end(), NULL );
    do {
        arena& a = *it;
        if ( ++it == arenas.end() )
            it = arenas.begin();
        if ( a.num_workers_active() < a.my_num_workers_allotted ) {
            a.my_references += 2; // add a worker
#if __TBB_TRACK_PRIORITY_LEVEL_SATURATION
            ++a.my_num_workers_present;
            ++my_priority_levels[a.my_top_priority].workers_present;
#endif /* __TBB_TRACK_PRIORITY_LEVEL_SATURATION */
            as_atomic(next) = &*it; // a subject for innocent data race under the reader lock
            // TODO: rework global round robin policy to local or random to avoid this write
            return &a;
        }
    } while ( it != next );
    return NULL;
}

void market::update_allotment ( arena_list_type& arenas, int workers_demand, int max_workers ) {
    __TBB_ASSERT( workers_demand, NULL );
    max_workers = min(workers_demand, max_workers);
    int carry = 0;
#if TBB_USE_ASSERT
    int assigned = 0;
#endif /* TBB_USE_ASSERT */
    arena_list_type::iterator it = arenas.begin();
    for ( ; it != arenas.end(); ++it ) {
        arena& a = *it;
        if ( a.my_num_workers_requested <= 0 ) {
            __TBB_ASSERT( !a.my_num_workers_allotted, NULL );
            continue;
        }
        int tmp = a.my_num_workers_requested * max_workers + carry;
        int allotted = tmp / workers_demand;
        carry = tmp % workers_demand;
        // a.my_num_workers_requested may temporarily exceed a.my_max_num_workers
        a.my_num_workers_allotted = min( allotted, (int)a.my_max_num_workers );
#if TBB_USE_ASSERT
        assigned += a.my_num_workers_allotted;
#endif /* TBB_USE_ASSERT */
    }
    __TBB_ASSERT( assigned <= workers_demand, NULL );
}

#if __TBB_TASK_PRIORITY
inline void market::update_global_top_priority ( intptr_t newPriority ) {
    GATHER_STATISTIC( ++governor::local_scheduler_if_initialized()->my_counters.market_prio_switches );
    my_global_top_priority = newPriority;
    my_priority_levels[newPriority].workers_available = my_max_num_workers;
    advance_global_reload_epoch();
}

inline void market::reset_global_priority () {
    my_global_bottom_priority = normalized_normal_priority;
    update_global_top_priority(normalized_normal_priority);
#if __TBB_TRACK_PRIORITY_LEVEL_SATURATION
    my_lowest_populated_level = normalized_normal_priority;
#endif /* __TBB_TRACK_PRIORITY_LEVEL_SATURATION */
}

arena* market::arena_in_need ( arena* prev_arena )
{
    if( !has_any_demand() )
        return NULL;
    arenas_list_mutex_type::scoped_lock lock(my_arenas_list_mutex, /*is_writer=*/false);
    assert_market_valid();
#if __TBB_TRACK_PRIORITY_LEVEL_SATURATION
    if ( prev_arena ) {
        priority_level_info &pl = my_priority_levels[prev_arena->my_top_priority];
        --prev_arena->my_num_workers_present;
        --pl.workers_present;
        if ( !--prev_arena->my_references && !prev_arena->my_num_workers_requested ) {
            detach_arena( *a );
            lock.release();
            a->free_arena();
            lock.acquire();
        }
    }
#else
    suppress_unused_warning(prev_arena);
#endif /* __TBB_TRACK_PRIORITY_LEVEL_SATURATION */
    int p = my_global_top_priority;
    arena *a = NULL;
    do {
        priority_level_info &pl = my_priority_levels[p];
#if __TBB_TRACK_PRIORITY_LEVEL_SATURATION
        __TBB_ASSERT( p >= my_lowest_populated_level, NULL );
        if ( pl.workers_present >= pl.workers_requested )
            continue;
#endif /* __TBB_TRACK_PRIORITY_LEVEL_SATURATION */
        a = arena_in_need( pl.arenas, pl.next_arena );
    } while ( !a && --p >= my_global_bottom_priority );
    return a;
}

void market::update_allotment ( intptr_t highest_affected_priority ) {
    intptr_t i = highest_affected_priority;
    int available = my_priority_levels[i].workers_available;
#if __TBB_TRACK_PRIORITY_LEVEL_SATURATION
    my_lowest_populated_level = my_global_bottom_priority;
#endif /* __TBB_TRACK_PRIORITY_LEVEL_SATURATION */
    for ( ; i >= my_global_bottom_priority; --i ) {
        priority_level_info &pl = my_priority_levels[i];
        pl.workers_available = available;
        if ( pl.workers_requested ) {
            update_allotment( pl.arenas, pl.workers_requested, available );
            available -= pl.workers_requested;
            if ( available < 0 ) {
                available = 0;
#if __TBB_TRACK_PRIORITY_LEVEL_SATURATION
                my_lowest_populated_level = i;
#endif /* __TBB_TRACK_PRIORITY_LEVEL_SATURATION */
                break;
            }
        }
    }
    __TBB_ASSERT( i <= my_global_bottom_priority || !available, NULL );
    for ( --i; i >= my_global_bottom_priority; --i ) {
        priority_level_info &pl = my_priority_levels[i];
        pl.workers_available = 0;
        arena_list_type::iterator it = pl.arenas.begin();
        for ( ; it != pl.arenas.end(); ++it ) {
            __TBB_ASSERT( it->my_num_workers_requested || !it->my_num_workers_allotted, NULL );
            it->my_num_workers_allotted = 0;
        }
    }
}
#endif /* __TBB_TASK_PRIORITY */

void market::adjust_demand ( arena& a, int delta ) {
    __TBB_ASSERT( theMarket, "market instance was destroyed prematurely?" );
    if ( !delta )
        return;
    my_arenas_list_mutex.lock();
    int prev_req = a.my_num_workers_requested;
    a.my_num_workers_requested += delta;
    if ( a.my_num_workers_requested <= 0 ) {
        a.my_num_workers_allotted = 0;
        if ( prev_req <= 0 ) {
            my_arenas_list_mutex.unlock();
            return;
        }
        delta = -prev_req;
    }
#if __TBB_TASK_ARENA
    else if ( prev_req < 0 ) {
        delta = a.my_num_workers_requested;
    }
#else  /* __TBB_TASK_ARENA */
    __TBB_ASSERT( prev_req >= 0, "Part-size request to RML?" );
#endif /* __TBB_TASK_ARENA */
#if __TBB_TASK_PRIORITY
    intptr_t p = a.my_top_priority;
    priority_level_info &pl = my_priority_levels[p];
    pl.workers_requested += delta;
    __TBB_ASSERT( pl.workers_requested >= 0, NULL );
#if !__TBB_TASK_ARENA
    __TBB_ASSERT( a.my_num_workers_requested >= 0, NULL );
#else
    //TODO: understand the assertion and modify
#endif
    if ( a.my_num_workers_requested <= 0 ) {
        if ( a.my_top_priority != normalized_normal_priority ) {
            GATHER_STATISTIC( ++governor::local_scheduler_if_initialized()->my_counters.arena_prio_resets );
            update_arena_top_priority( a, normalized_normal_priority );
        }
        a.my_bottom_priority = normalized_normal_priority;
    }
    if ( p == my_global_top_priority ) {
        if ( !pl.workers_requested ) {
            while ( --p >= my_global_bottom_priority && !my_priority_levels[p].workers_requested )
                continue;
            if ( p < my_global_bottom_priority )
                reset_global_priority();
            else
                update_global_top_priority(p);
        }
        update_allotment( my_global_top_priority );
    }
    else if ( p > my_global_top_priority ) {
#if !__TBB_TASK_ARENA
        __TBB_ASSERT( pl.workers_requested > 0, NULL );
#else
        //TODO: understand the assertion and modify
#endif
        update_global_top_priority(p);
        a.my_num_workers_allotted = min( (int)my_max_num_workers, a.my_num_workers_requested );
        my_priority_levels[p - 1].workers_available = my_max_num_workers - a.my_num_workers_allotted;
        update_allotment( p - 1 );
    }
    else if ( p == my_global_bottom_priority ) {
        if ( !pl.workers_requested ) {
            while ( ++p <= my_global_top_priority && !my_priority_levels[p].workers_requested )
                continue;
            if ( p > my_global_top_priority )
                reset_global_priority();
            else {
                my_global_bottom_priority = p;
#if __TBB_TRACK_PRIORITY_LEVEL_SATURATION
                my_lowest_populated_level = max( my_lowest_populated_level, p );
#endif /* __TBB_TRACK_PRIORITY_LEVEL_SATURATION */
            }
        }
        else
            update_allotment( p );
    }
    else if ( p < my_global_bottom_priority ) {
        __TBB_ASSERT( a.my_num_workers_requested > 0, NULL );
        int prev_bottom = my_global_bottom_priority;
        my_global_bottom_priority = p;
        update_allotment( prev_bottom );
    }
    else {
        __TBB_ASSERT( my_global_bottom_priority < p && p < my_global_top_priority, NULL );
        update_allotment( p );
    }
    __TBB_ASSERT( my_global_top_priority >= a.my_top_priority || a.my_num_workers_requested<=0, NULL );
    assert_market_valid();
#else /* !__TBB_TASK_PRIORITY */
    my_total_demand += delta;
    update_allotment();
#endif /* !__TBB_TASK_PRIORITY */
    my_arenas_list_mutex.unlock();
    // Must be called outside of any locks
    my_server->adjust_job_count_estimate( delta );
    GATHER_STATISTIC( governor::local_scheduler_if_initialized() ? ++governor::local_scheduler_if_initialized()->my_counters.gate_switches : 0 );
}

void market::process( job& j ) {
    generic_scheduler& s = static_cast<generic_scheduler&>(j);
    arena *a = NULL;
    __TBB_ASSERT( governor::is_set(&s), NULL );
#if !__TBB_SLEEP_PERMISSION
    while ( (a = arena_in_need(a)) )
        a->process(s);
#else//__TBB_SLEEP_PERMISSION
    enum {
        query_interval = 1000,
        first_interval = 1,
        pause_time = 100 // similar to PauseTime used for the stealing loop
    };
    for(int i = first_interval; ; i--) {
        while ( (a = arena_in_need(a)) )
        {
            a->process(s);
            i = first_interval;
        }
        if( i == 0 ) {
#if __TBB_TASK_PRIORITY
            arena_list_type &al = my_priority_levels[my_global_top_priority].arenas;
#else /* __TBB_TASK_PRIORITY */
            arena_list_type &al = my_arenas;
#endif /* __TBB_TASK_PRIORITY */
            if( al.empty() ) // races if any are innocent TODO: replace by an RML query interface
                break; // no arenas left, perhaps going to shut down
            if( the_global_observer_list.ask_permission_to_leave() )
                break; // go sleep
            __TBB_Yield();
            i = query_interval;
        } else __TBB_Pause(pause_time);
    }
#endif//__TBB_SLEEP_PERMISSION
    GATHER_STATISTIC( ++s.my_counters.market_roundtrips );
}

void market::cleanup( job& j ) {
    __TBB_ASSERT( theMarket != this, NULL );
    generic_scheduler& s = static_cast<generic_scheduler&>(j);
    generic_scheduler* mine = governor::local_scheduler_if_initialized();
    __TBB_ASSERT( !mine || mine->my_arena_index!=0, NULL );
    if( mine!=&s ) {
        governor::assume_scheduler( &s );
        generic_scheduler::cleanup_worker( &s, mine!=NULL );
        governor::assume_scheduler( mine );
    } else {
        generic_scheduler::cleanup_worker( &s, true );
    }
}

void market::acknowledge_close_connection() {
    destroy();
}

::rml::job* market::create_one_job() {
    unsigned index = ++my_num_workers;
    __TBB_ASSERT( index > 0, NULL );
    ITT_THREAD_SET_NAME(_T("TBB Worker Thread"));
    // index serves as a hint decreasing conflicts between workers when they migrate between arenas
    generic_scheduler* s = generic_scheduler::create_worker( *this, index );
#if __TBB_TASK_GROUP_CONTEXT
    __TBB_ASSERT( index <= my_max_num_workers, NULL );
    __TBB_ASSERT( !my_workers[index - 1], NULL );
    my_workers[index - 1] = s;
#endif /* __TBB_TASK_GROUP_CONTEXT */
    governor::sign_on(s);
    return s;
}

#if __TBB_TASK_PRIORITY
void market::update_arena_top_priority ( arena& a, intptr_t new_priority ) {
    GATHER_STATISTIC( ++governor::local_scheduler_if_initialized()->my_counters.arena_prio_switches );
    __TBB_ASSERT( a.my_top_priority != new_priority, NULL );
    priority_level_info &prev_level = my_priority_levels[a.my_top_priority],
                        &new_level = my_priority_levels[new_priority];
    remove_arena_from_list(a);
    a.my_top_priority = new_priority;
    insert_arena_into_list(a);
    ++a.my_reload_epoch; // TODO: synch with global reload epoch in order to optimize usage of local reload epoch
#if __TBB_TRACK_PRIORITY_LEVEL_SATURATION
    // Arena's my_num_workers_present may remain positive for some time after its
    // my_num_workers_requested becomes zero. Thus the following two lines are
    // executed unconditionally.
    prev_level.workers_present -= a.my_num_workers_present;
    new_level.workers_present += a.my_num_workers_present;
#endif /* __TBB_TRACK_PRIORITY_LEVEL_SATURATION */
    prev_level.workers_requested -= a.my_num_workers_requested;
    new_level.workers_requested += a.my_num_workers_requested;
    __TBB_ASSERT( prev_level.workers_requested >= 0 && new_level.workers_requested >= 0, NULL );
}

bool market::lower_arena_priority ( arena& a, intptr_t new_priority, uintptr_t old_reload_epoch ) {
    // TODO: replace the lock with a try_lock loop which performs a double check of the epoch
    arenas_list_mutex_type::scoped_lock lock(my_arenas_list_mutex);
    if ( a.my_reload_epoch != old_reload_epoch ) {
        assert_market_valid();
        return false;
    }
    __TBB_ASSERT( a.my_top_priority > new_priority, NULL );
    __TBB_ASSERT( my_global_top_priority >= a.my_top_priority, NULL );

    intptr_t p = a.my_top_priority;
    update_arena_top_priority( a, new_priority );
    if ( a.my_num_workers_requested > 0 ) {
        if ( my_global_bottom_priority > new_priority ) {
            my_global_bottom_priority = new_priority;
        }
        if ( p == my_global_top_priority && !my_priority_levels[p].workers_requested ) {
            // Global top level became empty
            for ( --p; !my_priority_levels[p].workers_requested; --p ) continue;
            __TBB_ASSERT( p >= my_global_bottom_priority, NULL );
            update_global_top_priority(p);
        }
        update_allotment( p );
    }

    __TBB_ASSERT( my_global_top_priority >= a.my_top_priority, NULL );
    assert_market_valid();
    return true;
}

bool market::update_arena_priority ( arena& a, intptr_t new_priority ) {
    arenas_list_mutex_type::scoped_lock lock(my_arenas_list_mutex);

    __TBB_ASSERT( my_global_top_priority >= a.my_top_priority || a.my_num_workers_requested <= 0, NULL );
    assert_market_valid();
    if ( a.my_top_priority == new_priority ) {
        return false;
    }
    else if ( a.my_top_priority > new_priority ) {
        if ( a.my_bottom_priority > new_priority )
            a.my_bottom_priority = new_priority;
        return false;
    }
    else if ( a.my_num_workers_requested <= 0 ) {
        return false;
    }

    __TBB_ASSERT( my_global_top_priority >= a.my_top_priority, NULL );

    intptr_t p = a.my_top_priority;
    intptr_t highest_affected_level = max(p, new_priority);
    update_arena_top_priority( a, new_priority );

    if ( my_global_top_priority < new_priority ) {
        update_global_top_priority(new_priority);
    }
    else if ( my_global_top_priority == new_priority ) {
        advance_global_reload_epoch();
    }
    else {
        __TBB_ASSERT( new_priority < my_global_top_priority, NULL );
        __TBB_ASSERT( new_priority > my_global_bottom_priority, NULL );
        if ( p == my_global_top_priority && !my_priority_levels[p].workers_requested ) {
            // Global top level became empty
            __TBB_ASSERT( my_global_bottom_priority < p, NULL );
            for ( --p; !my_priority_levels[p].workers_requested; --p ) continue;
            __TBB_ASSERT( p >= new_priority, NULL );
            update_global_top_priority(p);
            highest_affected_level = p;
        }
    }
    if ( p == my_global_bottom_priority ) {
        // Arena priority was increased from the global bottom level.
        __TBB_ASSERT( p < new_priority, NULL );                     // n
        __TBB_ASSERT( new_priority <= my_global_top_priority, NULL );
        while ( !my_priority_levels[my_global_bottom_priority].workers_requested )
            ++my_global_bottom_priority;
        __TBB_ASSERT( my_global_bottom_priority <= new_priority, NULL );
        __TBB_ASSERT( my_priority_levels[my_global_bottom_priority].workers_requested > 0, NULL );
    }
    update_allotment( highest_affected_level );

    __TBB_ASSERT( my_global_top_priority >= a.my_top_priority, NULL );
    assert_market_valid();
    return true;
}
#endif /* __TBB_TASK_PRIORITY */

#if __TBB_COUNT_TASK_NODES 
intptr_t market::workers_task_node_count() {
    intptr_t result = 0;
    ForEachArena(a) {
        result += a.workers_task_node_count();
    } EndForEach();
    return result;
}
#endif /* __TBB_COUNT_TASK_NODES */

} // namespace internal
} // namespace tbb