source: libcfa/src/concurrency/thread.cfa @ 466787a

//
// 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.
//
// thread.c --
//
// Author           : Thierry Delisle
// Created On       : Tue Jan 17 12:27:26 2017
// Last Modified By : Peter A. Buhr
// Last Modified On : Sun Dec 11 20:56:54 2022
// Update Count     : 102
//

#define __cforall_thread__
#define _GNU_SOURCE

#include "thread.hfa"

#include "exception.hfa"
#include "kernel/private.hfa"
#include "limits.hfa"

#define __CFA_INVOKE_PRIVATE__
#include "invoke.h"

extern size_t __global_random_seed;
extern size_t __global_random_prime;
extern bool __global_random_mask;

#pragma GCC visibility push(default)

//-----------------------------------------------------------------------------
// Thread ctors and dtors
void ?{}( thread$ & this, const char * const name, cluster & cl, void * storage, size_t storageSize ) with( this ) {
        context{ 0p, 0p };
        self_cor{ name, storage, storageSize };
        ticket = TICKET_RUNNING;
        state = Start;
        preempted = __NO_PREEMPTION;
        corctx_flag = false;
        curr_cor = &self_cor;
        self_mon.owner = &this;
        self_mon.recursion = 1;
        self_mon_p = &self_mon;
        curr_cluster = &cl;
        rdy_link.next = 0p;
        rdy_link.ts   = MAX;
        user_link.next = 0p;
        user_link.prev = 0p;
        cltr_link.next = 0p;
        cltr_link.prev = 0p;
        preferred = ready_queue_new_preferred();
        last_proc = 0p;
        PRNG_SET_SEED( random_state, __global_random_mask ? __global_random_prime : __global_random_prime ^ rdtscl() );
        #if defined( __CFA_WITH_VERIFY__ )
                executing = 0p;
                canary = 0x0D15EA5E0D15EA5Ep;
        #endif

        clh_node = malloc( );
        *clh_node = false;

        doregister(curr_cluster, this);
        monitors{ &self_mon_p, 1, (fptr_t)0 };
}

void ^?{}(thread$& this) with( this ) {
        #if defined( __CFA_WITH_VERIFY__ )
                canary = 0xDEADDEADDEADDEADp;
        #endif
        free(clh_node);
        unregister(curr_cluster, this);
        ^self_cor{};
}

forall(T &)
void copy(ThreadCancelled(T) * dst, ThreadCancelled(T) * src) {
        dst->virtual_table = src->virtual_table;
        dst->the_thread = src->the_thread;
        dst->the_exception = src->the_exception;
}

forall(T &)
const char * msg(ThreadCancelled(T) *) {
        return "ThreadCancelled(...)";
}

forall(T &)
static void default_thread_cancel_handler(ThreadCancelled(T) & ) {
        // Improve this error message, can I do formatting?
        abort( "Unhandled thread cancellation.\n" );
}

forall(T & | is_thread(T) | IS_EXCEPTION(ThreadCancelled(T))
    | { EHM_DEFAULT_VTABLE(ThreadCancelled(T)); })
void ?{}( thread_dtor_guard_t & this,
                T & thrd, void(*cancelHandler)(ThreadCancelled(T) &)) {
        monitor$ * m = get_monitor(thrd);
        thread$ * desc = get_thread(thrd);

        // Setup the monitor guard
        void (*dtor)(T& mutex this) = ^?{};
        bool join = cancelHandler != (void(*)(ThreadCancelled(T)&))0;
        (this.mg){&m, (void(*)())dtor, join};


        /* paranoid */ verifyf( Halted == desc->state || Cancelled == desc->state, "Expected thread to be Halted or Cancelled, was %d\n", (int)desc->state );

        // After the guard set-up and any wait, check for cancellation.
        struct _Unwind_Exception * cancellation = desc->self_cor.cancellation;
        if ( likely( 0p == cancellation ) ) {
                return;
        } else if ( Cancelled == desc->state ) {
                return;
        }
        desc->state = Cancelled;
        void(*defaultResumptionHandler)(ThreadCancelled(T) &) =
                join ? cancelHandler : default_thread_cancel_handler;

        // TODO: Remove explitate vtable set once trac#186 is fixed.
        ThreadCancelled(T) except;
        except.virtual_table = &_default_vtable;
        except.the_thread = &thrd;
        except.the_exception = __cfaehm_cancellation_exception( cancellation );
        // Why is this cast required?
        throwResume (ThreadCancelled(T) &)except;

        except.the_exception->virtual_table->free( except.the_exception );
        free( cancellation );
        desc->self_cor.cancellation = 0p;
}

void ^?{}( thread_dtor_guard_t & this ) {
        ^(this.mg){};
}

//-----------------------------------------------------------------------------
// Starting and stopping threads
forall( T & | is_thread(T) )
void __thrd_start( T & this, void (*main_p)(T &) ) {
        thread$ * this_thrd = get_thread(this);

        disable_interrupts();
        __cfactx_start(main_p, get_coroutine(this), this, __cfactx_invoke_thread);

        this_thrd->context.[SP, FP] = this_thrd->self_cor.context.[SP, FP];
        /* paranoid */ verify( this_thrd->context.SP );

        schedule_thread$( this_thrd, UNPARK_LOCAL );
        enable_interrupts();
}

//-----------------------------------------------------------------------------
// Support for threads that don't ues the thread keyword
forall( T & | sized(T) | is_thread(T) | { void ?{}(T&); } )
void ?{}( scoped(T)& this ) with( this ) {
        handle{};
        __thrd_start(handle, main);
}

forall( T &, P... | sized(T) | is_thread(T) | { void ?{}(T&, P); } )
void ?{}( scoped(T)& this, P params ) with( this ) {
        handle{ params };
        __thrd_start(handle, main);
}

forall( T & | sized(T) | is_thread(T) )
void ^?{}( scoped(T)& this ) with( this ) {
        ^handle{};
}

//-----------------------------------------------------------------------------
forall(T & | is_thread(T) | IS_RESUMPTION_EXCEPTION(ThreadCancelled(T))
        | { EHM_DEFAULT_VTABLE(ThreadCancelled(T)); })
T & join( T & this ) {
        thread_dtor_guard_t guard = { this, defaultResumptionHandler };
        return this;
}

//-----------------------------------------------------------------------------
bool migrate( thread$ * thrd, struct cluster & cl ) {
        monitor$ * tmon = get_monitor(thrd);
        monitor$ * __monitors[] = { tmon };
        monitor_guard_t __guard = { __monitors, 1 };
        {
                // if nothing needs to be done, return false
                if( thrd->curr_cluster == &cl ) return false;

                // are we migrating ourself?
                const bool local = thrd == active_thread();

                /* paranoid */ verify( !local || &cl != active_cluster() );
                /* paranoid */ verify( !local || thrd->curr_cluster == active_cluster() );
                /* paranoid */ verify( !local || thrd->curr_cluster == active_processor()->cltr );
                /* paranoid */ verify( local || tmon->signal_stack.top->owner->waiting_thread == thrd );
                /* paranoid */ verify( local || tmon->signal_stack.top );

                // make sure we aren't interrupted while doing this
                // not as important if we aren't local
                disable_interrupts();

                // actually move the thread
                unregister( thrd->curr_cluster, *thrd );
                thrd->curr_cluster = &cl;
                doregister( thrd->curr_cluster, *thrd );

                // restore interrupts
                enable_interrupts();

                // if this is the local thread, we are still running on the old cluster
                if(local) yield();

                /* paranoid */ verify( !local || &cl == active_cluster() );
                /* paranoid */ verify( !local || thrd->curr_cluster == active_cluster() );
                /* paranoid */ verify( !local || thrd->curr_cluster == active_processor()->cltr );
                /* paranoid */ verify(  local || tmon->signal_stack.top );
                /* paranoid */ verify(  local || tmon->signal_stack.top->owner->waiting_thread == thrd );

                return true;
        }
}

//-----------------------------------------------------------------------------

void set_seed( size_t seed ) {
        PRNG_STATE_T & state = active_thread()->random_state;
        PRNG_SET_SEED( state, seed );
        __global_random_seed = seed;
        __global_random_prime = seed;
        __global_random_mask = true;
} // set_seed

size_t prng( void ) {                                                                   // [0,UINT_MAX]
        return PRNG_NAME( active_thread()->random_state );
} // prng

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