source: libcfa/src/concurrency/thread.cfa @ 1959528

//
// 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 : Wed Jan 12 18:28:18 2022
// Update Count     : 35
//

#define __cforall_thread__
#define _GNU_SOURCE

#include "thread.hfa"

#include "kernel_private.hfa"
#include "exception.hfa"

#define __CFA_INVOKE_PRIVATE__
#include "invoke.h"

uint64_t thread_rand();

extern uint32_t __global_random_seed;

//-----------------------------------------------------------------------------
// 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;
        link.next = 0p;
        link.ts   = -1llu;
        preferred = ready_queue_new_preferred();
        last_proc = 0p;
        random_state = __global_random_seed;
        #if defined( __CFA_WITH_VERIFY__ )
                canary = 0x0D15EA5E0D15EA5Ep;
        #endif

        seqable.next = 0p;
        seqable.back = 0p;

        node.next = 0p;
        node.prev = 0p;
        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
        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;
}

uint64_t thread_rand() {
        disable_interrupts();
        uint64_t ret = __tls_rand();
        enable_interrupts();
        return ret;
}
 
#define GENERATOR LCG

static inline uint32_t MarsagliaXor( uint32_t & state ) {
        uint32_t ret = state;
        state ^= state << 6;
        state ^= state >> 21;
        state ^= state << 7;
        return ret;
} // MarsagliaXor

static inline uint32_t LCG( uint32_t & state ) {                // linear congruential generator
        uint32_t ret = state;
        state = 36969 * (state & 65535) + (state >> 16);        // 36969 is NOT prime! No not change it!
        return ret;
} // LCG

void set_seed( uint32_t seed ) { active_thread()->random_state = seed; __global_random_seed = seed; }
uint32_t prng( void ) { return GENERATOR( active_thread()->random_state ); } // [0,UINT_MAX]

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