source: libcfa/src/concurrency/coroutine.hfa @ aa00626

ADTarm-ehast-experimentalcleanup-dtorsenumforall-pointer-decayjacob/cs343-translationjenkins-sandboxnew-astnew-ast-unique-exprpthread-emulationqualifiedEnum
Last change on this file since aa00626 was aa00626, checked in by Thierry Delisle <tdelisle@…>, 5 years ago

resume now return a referece to its parameter for chainning

  • Property mode set to 100644
File size: 6.1 KB
Line 
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//
7// coroutine --
8//
9// Author           : Thierry Delisle
10// Created On       : Mon Nov 28 12:27:26 2016
11// Last Modified By : Peter A. Buhr
12// Last Modified On : Fri Mar 30 18:23:45 2018
13// Update Count     : 8
14//
15
16#pragma once
17
18#include <assert.h>
19#include "invoke.h"
20
21//-----------------------------------------------------------------------------
22// Coroutine trait
23// Anything that implements this trait can be resumed.
24// Anything that is resumed is a coroutine.
25trait is_coroutine(dtype T) {
26      void main(T & this);
27      coroutine_desc * get_coroutine(T & this);
28};
29
30#define DECL_COROUTINE(X) static inline coroutine_desc* get_coroutine(X& this) { return &this.__cor; } void main(X& this)
31
32//-----------------------------------------------------------------------------
33// Ctors and dtors
34// void ?{}( coStack_t & this );
35// void ^?{}( coStack_t & this );
36
37void ?{}( coroutine_desc & this, const char * name, void * storage, size_t storageSize );
38void ^?{}( coroutine_desc & this );
39
40static inline void ?{}( coroutine_desc & this)                                       { this{ "Anonymous Coroutine", NULL, 0 }; }
41static inline void ?{}( coroutine_desc & this, size_t stackSize)                     { this{ "Anonymous Coroutine", NULL, stackSize }; }
42static inline void ?{}( coroutine_desc & this, void * storage, size_t storageSize )  { this{ "Anonymous Coroutine", storage, storageSize }; }
43static inline void ?{}( coroutine_desc & this, const char * name)                    { this{ name, NULL, 0 }; }
44static inline void ?{}( coroutine_desc & this, const char * name, size_t stackSize ) { this{ name, NULL, stackSize }; }
45
46//-----------------------------------------------------------------------------
47// Public coroutine API
48static inline void suspend(void);
49
50forall(dtype T | is_coroutine(T))
51static inline void resume(T & cor);
52
53forall(dtype T | is_coroutine(T))
54void prime(T & cor);
55
56//-----------------------------------------------------------------------------
57// PRIVATE exposed because of inline
58
59// Start coroutine routines
60extern "C" {
61      forall(dtype T | is_coroutine(T))
62      void CtxInvokeCoroutine(T * this);
63
64      forall(dtype T | is_coroutine(T))
65      void CtxStart(T * this, void ( *invoke)(T *));
66
67        extern void _CtxCoroutine_Unwind(struct _Unwind_Exception * storage, struct coroutine_desc *) __attribute__ ((__noreturn__));
68
69        extern void CtxSwitch( struct __stack_context_t * from, struct __stack_context_t * to ) asm ("CtxSwitch");
70}
71
72// Private wrappers for context switch and stack creation
73// Wrapper for co
74static inline void CoroutineCtxSwitch(coroutine_desc* src, coroutine_desc* dst) {
75        // set state of current coroutine to inactive
76        src->state = src->state == Halted ? Halted : Inactive;
77
78        // set new coroutine that task is executing
79        TL_GET( this_thread )->curr_cor = dst;
80
81        // context switch to specified coroutine
82        verify( dst->context.SP );
83        CtxSwitch( &src->context, &dst->context );
84        // when CtxSwitch returns we are back in the src coroutine
85
86        // set state of new coroutine to active
87        src->state = Active;
88
89        if( unlikely(src->cancellation != NULL) ) {
90                _CtxCoroutine_Unwind(src->cancellation, src);
91        }
92}
93
94extern void __stack_prepare   ( __stack_info_t * this, size_t size /* ignored if storage already allocated */);
95
96// Suspend implementation inlined for performance
97static inline void suspend(void) {
98        // optimization : read TLS once and reuse it
99        // Safety note: this is preemption safe since if
100        // preemption occurs after this line, the pointer
101        // will also migrate which means this value will
102        // stay in syn with the TLS
103        coroutine_desc * src = TL_GET( this_thread )->curr_cor;
104
105        assertf( src->last != 0,
106                "Attempt to suspend coroutine \"%.256s\" (%p) that has never been resumed.\n"
107                "Possible cause is a suspend executed in a member called by a coroutine user rather than by the coroutine main.",
108                src->name, src );
109        assertf( src->last->state != Halted,
110                "Attempt by coroutine \"%.256s\" (%p) to suspend back to terminated coroutine \"%.256s\" (%p).\n"
111                "Possible cause is terminated coroutine's main routine has already returned.",
112                src->name, src, src->last->name, src->last );
113
114        CoroutineCtxSwitch( src, src->last );
115}
116
117// Resume implementation inlined for performance
118forall(dtype T | is_coroutine(T))
119static inline T & resume(T & cor) {
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
125        coroutine_desc * src = TL_GET( this_thread )->curr_cor;
126        coroutine_desc * dst = get_coroutine(cor);
127
128        if( unlikely(dst->context.SP == NULL) ) {
129                __stack_prepare(&dst->stack, 65000);
130                CtxStart(&cor, CtxInvokeCoroutine);
131        }
132
133        // not resuming self ?
134        if ( src != dst ) {
135                assertf( dst->state != Halted ,
136                        "Attempt by coroutine %.256s (%p) to resume terminated coroutine %.256s (%p).\n"
137                        "Possible cause is terminated coroutine's main routine has already returned.",
138                        src->name, src, dst->name, dst );
139
140                // set last resumer
141                dst->last = src;
142                dst->starter = dst->starter ? dst->starter : src;
143        }
144
145        // always done for performance testing
146        CoroutineCtxSwitch( src, dst );
147
148        return cor;
149}
150
151static inline void resume(coroutine_desc * dst) {
152        // optimization : read TLS once and reuse it
153        // Safety note: this is preemption safe since if
154        // preemption occurs after this line, the pointer
155        // will also migrate which means this value will
156        // stay in syn with the TLS
157        coroutine_desc * src = TL_GET( this_thread )->curr_cor;
158
159        // not resuming self ?
160        if ( src != dst ) {
161                assertf( dst->state != Halted ,
162                        "Attempt by coroutine %.256s (%p) to resume terminated coroutine %.256s (%p).\n"
163                        "Possible cause is terminated coroutine's main routine has already returned.",
164                        src->name, src, dst->name, dst );
165
166                // set last resumer
167                dst->last = src;
168        }
169
170        // always done for performance testing
171        CoroutineCtxSwitch( src, dst );
172}
173
174// Local Variables: //
175// mode: c //
176// tab-width: 4 //
177// End: //
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