source: libcfa/src/concurrency/coroutine.hfa @ 7eac70e

ADTast-experimental
Last change on this file since 7eac70e was c3b9d639, checked in by Andrew Beach <ajbeach@…>, 2 years ago

Clean-up the exception interface. It should be slightly more like the final - non-macro - interface.

  • Property mode set to 100644
File size: 7.2 KB
RevLine 
[6a3d2e7]1//
2// Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
3//
4// The contents of this file are covered under the licence agreement in the
5// file "LICENCE" distributed with Cforall.
6//
[75a17f1]7// coroutine --
[6a3d2e7]8//
9// Author           : Thierry Delisle
10// Created On       : Mon Nov 28 12:27:26 2016
[91c389a]11// Last Modified By : Peter A. Buhr
[eaf269d]12// Last Modified On : Thu Jan  6 16:33:16 2022
13// Update Count     : 12
[6a3d2e7]14//
15
[6b0b624]16#pragma once
[6a3d2e7]17
[91c389a]18#include <assert.h>
[6a3d2e7]19#include "invoke.h"
[1c01c58]20#include "../exception.hfa"
21
22//-----------------------------------------------------------------------------
23// Exception thrown from resume when a coroutine stack is cancelled.
[c715e5f]24forall(coroutine_t &)
25exception CoroutineCancelled {
[1c01c58]26        coroutine_t * the_coroutine;
27        exception_t * the_exception;
[c715e5f]28};
[1c01c58]29
[fd54fef]30forall(T &)
[1c01c58]31void copy(CoroutineCancelled(T) * dst, CoroutineCancelled(T) * src);
32
[fd54fef]33forall(T &)
[1c01c58]34const char * msg(CoroutineCancelled(T) *);
[6a3d2e7]35
36//-----------------------------------------------------------------------------
37// Coroutine trait
38// Anything that implements this trait can be resumed.
39// Anything that is resumed is a coroutine.
[c3b9d639]40trait is_coroutine(T & | IS_RESUMPTION_EXCEPTION(CoroutineCancelled(T))) {
[1c01c58]41        void main(T & this);
[e84ab3d]42        coroutine$ * get_coroutine(T & this);
[6a3d2e7]43};
44
[e84ab3d]45#define DECL_COROUTINE(X) static inline coroutine$* get_coroutine(X& this) { return &this.__cor; } void main(X& this)
[c84e80a]46
[6a3d2e7]47//-----------------------------------------------------------------------------
48// Ctors and dtors
[de6319f]49// void ?{}( coStack_t & this );
50// void ^?{}( coStack_t & this );
51
[e84ab3d]52void  ?{}( coroutine$ & this, const char name[], void * storage, size_t storageSize );
53void ^?{}( coroutine$ & this );
[de6319f]54
[e84ab3d]55static inline void ?{}( coroutine$ & this)                                       { this{ "Anonymous Coroutine", 0p, 0 }; }
56static inline void ?{}( coroutine$ & this, size_t stackSize)                     { this{ "Anonymous Coroutine", 0p, stackSize }; }
57static inline void ?{}( coroutine$ & this, void * storage, size_t storageSize )  { this{ "Anonymous Coroutine", storage, storageSize }; }
58static inline void ?{}( coroutine$ & this, const char name[])                    { this{ name, 0p, 0 }; }
59static inline void ?{}( coroutine$ & this, const char name[], size_t stackSize ) { this{ name, 0p, stackSize }; }
[6a3d2e7]60
61//-----------------------------------------------------------------------------
62// Public coroutine API
[c3b9d639]63forall(T & | is_coroutine(T) | { EHM_DEFAULT_VTABLE(CoroutineCancelled(T)); })
[83a071f9]64void prime(T & cor);
[6a3d2e7]65
[e84ab3d]66static inline struct coroutine$ * active_coroutine() { return active_thread()->curr_cor; }
[d4e68a6]67
[6a3d2e7]68//-----------------------------------------------------------------------------
69// PRIVATE exposed because of inline
70
71// Start coroutine routines
72extern "C" {
[c7a900a]73        void __cfactx_invoke_coroutine(void (*main)(void *), void * this);
[6a3d2e7]74
[fd54fef]75        forall(T &)
[e84ab3d]76        void __cfactx_start(void (*main)(T &), struct coroutine$ * cor, T & this, void (*invoke)(void (*main)(void *), void *));
[3c06bba]77
[e84ab3d]78        extern void __cfactx_coroutine_unwind(struct _Unwind_Exception * storage, struct coroutine$ *) __attribute__ ((__noreturn__));
[3c06bba]79
[c7a900a]80        extern void __cfactx_switch( struct __stack_context_t * from, struct __stack_context_t * to ) asm ("__cfactx_switch");
[6a3d2e7]81}
82
83// Private wrappers for context switch and stack creation
[3c06bba]84// Wrapper for co
[e84ab3d]85static inline void $ctx_switch( coroutine$ * src, coroutine$ * dst ) __attribute__((nonnull (1, 2))) {
[3c06bba]86        // set state of current coroutine to inactive
[ae7be7a]87        src->state = src->state == Halted ? Halted : Blocked;
[3c06bba]88
[ab5baab]89        // get the active thread once
[e84ab3d]90        thread$ * athrd = active_thread();
[ab5baab]91
92        // Mark the coroutine
93        /* paranoid */ verify( !athrd->corctx_flag );
94        athrd->corctx_flag = true;
95
[3c06bba]96        // set new coroutine that task is executing
[ab5baab]97        athrd->curr_cor = dst;
[3c06bba]98
99        // context switch to specified coroutine
[ab5baab]100        /* paranoid */ verify( dst->context.SP );
[c7a900a]101        __cfactx_switch( &src->context, &dst->context );
102        // when __cfactx_switch returns we are back in the src coroutine
[3c06bba]103
[ab5baab]104        /* paranoid */ verify( athrd->corctx_flag );
105        athrd->corctx_flag = false;
106
[3c06bba]107        // set state of new coroutine to active
108        src->state = Active;
109
[121be3e]110        if( unlikely(src->cancellation != 0p) ) {
[c7a900a]111                __cfactx_coroutine_unwind(src->cancellation, src);
[3c06bba]112        }
113}
114
[bfcf6b9]115extern void __stack_prepare( __stack_info_t * this, size_t size /* ignored if storage already allocated */);
[6a3d2e7]116
117// Suspend implementation inlined for performance
[427854b]118extern "C" {
119        static inline void __cfactx_suspend(void) {
120                // optimization : read TLS once and reuse it
121                // Safety note: this is preemption safe since if
122                // preemption occurs after this line, the pointer
123                // will also migrate which means this value will
124                // stay in syn with the TLS
[e84ab3d]125                coroutine$ * src = active_coroutine();
[427854b]126
127                assertf( src->last != 0,
128                        "Attempt to suspend coroutine \"%.256s\" (%p) that has never been resumed.\n"
129                        "Possible cause is a suspend executed in a member called by a coroutine user rather than by the coroutine main.",
130                        src->name, src );
131                assertf( src->last->state != Halted,
132                        "Attempt by coroutine \"%.256s\" (%p) to suspend back to terminated coroutine \"%.256s\" (%p).\n"
133                        "Possible cause is terminated coroutine's main routine has already returned.",
134                        src->name, src, src->last->name, src->last );
[6a3d2e7]135
[427854b]136                $ctx_switch( src, src->last );
137        }
[6a3d2e7]138}
139
[fd54fef]140forall(T & | is_coroutine(T))
[b583113]141void __cfaehm_cancelled_coroutine(
[c3b9d639]142        T & cor, coroutine$ * desc, EHM_DEFAULT_VTABLE(CoroutineCancelled(T)) );
[1c01c58]143
[6a3d2e7]144// Resume implementation inlined for performance
[c3b9d639]145forall(T & | is_coroutine(T) | { EHM_DEFAULT_VTABLE(CoroutineCancelled(T)); })
[aa00626]146static inline T & resume(T & cor) {
[14a61b5]147        // optimization : read TLS once and reuse it
148        // Safety note: this is preemption safe since if
149        // preemption occurs after this line, the pointer
150        // will also migrate which means this value will
151        // stay in syn with the TLS
[e84ab3d]152        coroutine$ * src = active_coroutine();
153        coroutine$ * dst = get_coroutine(cor);
[6a3d2e7]154
[121be3e]155        if( unlikely(dst->context.SP == 0p) ) {
[eaf269d]156                __stack_prepare(&dst->stack, DEFAULT_STACK_SIZE);
[c7a900a]157                __cfactx_start(main, dst, cor, __cfactx_invoke_coroutine);
[6a3d2e7]158        }
159
[4aa2fb2]160        // not resuming self ?
[6a3d2e7]161        if ( src != dst ) {
[ee897e4b]162                assertf( dst->state != Halted ,
[6a3d2e7]163                        "Attempt by coroutine %.256s (%p) to resume terminated coroutine %.256s (%p).\n"
164                        "Possible cause is terminated coroutine's main routine has already returned.",
165                        src->name, src, dst->name, dst );
166
[4aa2fb2]167                // set last resumer
[6a3d2e7]168                dst->last = src;
[b462670]169                dst->starter = dst->starter ? dst->starter : src;
[14a61b5]170        }
[6a3d2e7]171
[4aa2fb2]172        // always done for performance testing
[ac2b598]173        $ctx_switch( src, dst );
[1c01c58]174        if ( unlikely(dst->cancellation) ) {
[b583113]175                __cfaehm_cancelled_coroutine( cor, dst, _default_vtable );
[1c01c58]176        }
[aa00626]177
178        return cor;
[6a3d2e7]179}
180
[e84ab3d]181static inline void resume( coroutine$ * dst ) __attribute__((nonnull (1))) {
[14a61b5]182        // optimization : read TLS once and reuse it
183        // Safety note: this is preemption safe since if
184        // preemption occurs after this line, the pointer
185        // will also migrate which means this value will
186        // stay in syn with the TLS
[e84ab3d]187        coroutine$ * src = active_coroutine();
[77e6fcb]188
[4aa2fb2]189        // not resuming self ?
[77e6fcb]190        if ( src != dst ) {
[ee897e4b]191                assertf( dst->state != Halted ,
[77e6fcb]192                        "Attempt by coroutine %.256s (%p) to resume terminated coroutine %.256s (%p).\n"
193                        "Possible cause is terminated coroutine's main routine has already returned.",
194                        src->name, src, dst->name, dst );
195
[4aa2fb2]196                // set last resumer
[77e6fcb]197                dst->last = src;
[14a61b5]198        }
[77e6fcb]199
[4aa2fb2]200        // always done for performance testing
[ac2b598]201        $ctx_switch( src, dst );
[77e6fcb]202}
203
[6a3d2e7]204// Local Variables: //
205// mode: c //
206// tab-width: 4 //
207// End: //
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