source: src/libcfa/concurrency/monitor @ 121ac13

//
// Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
//
// monitor --
//
// Author           : Thierry Delisle
// Created On       : Thd Feb 23 12:27:26 2017
// Last Modified By : Peter A. Buhr
// Last Modified On : Sat Oct  7 18:06:45 2017
// Update Count     : 10
//

#pragma once

#include <stddef.h>

#include <assert.h>
#include "invoke.h"
#include "stdlib"

trait is_monitor(dtype T) {
        monitor_desc * get_monitor( T & );
        void ^?{}( T & mutex );
};

static inline void ?{}(monitor_desc & this) {
        (this.lock){};
        (this.entry_queue){};
        (this.signal_stack){};
        this.owner         = NULL;
        this.recursion     = 0;
        this.mask.accepted = NULL;
        this.mask.clauses  = NULL;
        this.mask.size     = 0;
        this.dtor_node     = NULL;
}

struct monitor_guard_t {
        monitor_desc ** m;
        __lock_size_t   count;
        monitor_desc ** prev_mntrs;
        __lock_size_t   prev_count;
        fptr_t          prev_func;
};

void ?{}( monitor_guard_t & this, monitor_desc ** m, __lock_size_t count, void (*func)() );
void ^?{}( monitor_guard_t & this );

struct monitor_dtor_guard_t {
        monitor_desc * m;
        monitor_desc ** prev_mntrs;
        __lock_size_t   prev_count;
        fptr_t          prev_func;
};

void ?{}( monitor_dtor_guard_t & this, monitor_desc ** m, void (*func)() );
void ^?{}( monitor_dtor_guard_t & this );

static inline forall( dtype T | sized(T) | { void ^?{}( T & mutex ); } )
void delete( T * th ) {
        ^(*th){};
        free( th );
}

//-----------------------------------------------------------------------------
// Internal scheduling

struct __condition_criterion_t {
        // Whether or not the criterion is met (True if met)
        bool ready;

        // The monitor this criterion concerns
        monitor_desc * target;

        // The parent node to which this criterion belongs
        struct __condition_node_t * owner;

        // Intrusive linked list Next field
        __condition_criterion_t * next;
};

struct __condition_node_t {
        // Thread that needs to be woken when all criteria are met
        thread_desc * waiting_thread;

        // Array of criteria (Criterions are contiguous in memory)
        __condition_criterion_t * criteria;

        // Number of criterions in the criteria
        __lock_size_t count;

        // Intrusive linked list Next field
        __condition_node_t * next;

        // Custom user info accessible before signalling
        uintptr_t user_info;
};

struct __condition_blocked_queue_t {
        __condition_node_t * head;
        __condition_node_t ** tail;
};

void ?{}(__condition_node_t & this, thread_desc * waiting_thread, __lock_size_t count, uintptr_t user_info );
void ?{}(__condition_criterion_t & this );
void ?{}(__condition_criterion_t & this, monitor_desc * target, __condition_node_t * owner );

void ?{}( __condition_blocked_queue_t & );
void append( __condition_blocked_queue_t &, __condition_node_t * );
__condition_node_t * pop_head( __condition_blocked_queue_t & );

struct condition {
        // Link list which contains the blocked threads as-well as the information needed to unblock them
        __condition_blocked_queue_t blocked;

        // Array of monitor pointers (Monitors are NOT contiguous in memory)
        monitor_desc ** monitors;

        // Number of monitors in the array
        __lock_size_t monitor_count;
};

static inline void ?{}( condition & this ) {
        this.monitors = NULL;
        this.monitor_count = 0;
}

static inline void ^?{}( condition & this ) {
        free( this.monitors );
}

              void wait        ( condition & this, uintptr_t user_info = 0 );
              bool signal      ( condition & this );
              bool signal_block( condition & this );
static inline bool is_empty    ( condition & this ) { return !this.blocked.head; }
         uintptr_t front       ( condition & this );

//-----------------------------------------------------------------------------
// External scheduling

struct __acceptable_t {
        __monitor_group_t;
        bool is_dtor;
};

void __waitfor_internal( const __waitfor_mask_t & mask, int duration );

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