source: libcfa/src/concurrency/coroutine.hfa @ 3c06bba

arm-ehcleanup-dtorsjacob/cs343-translationjenkins-sandboxnew-astnew-ast-unique-expr
Last change on this file since 3c06bba was 3c06bba, checked in by tdelisle <tdelisle@…>, 3 years ago

Inlined coroutine context switch routine

  • Property mode set to 100644
File size: 8.6 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        // void CtxStore ( void * this ) asm ("CtxStore");
71        // void CtxRet   ( void * dst  ) asm ("CtxRet");
72}
73
74// Private wrappers for context switch and stack creation
75// Wrapper for co
76static inline void CoroutineCtxSwitch(coroutine_desc* src, coroutine_desc* dst) {
77        // set state of current coroutine to inactive
78        src->state = src->state == Halted ? Halted : Inactive;
79
80        // set new coroutine that task is executing
81        TL_GET( this_thread )->curr_cor = dst;
82
83        // context switch to specified coroutine
84        verify( dst->context.SP );
85        CtxSwitch( &src->context, &dst->context );
86        // when CtxSwitch returns we are back in the src coroutine
87
88        // set state of new coroutine to active
89        src->state = Active;
90
91        if( unlikely(src->cancellation != NULL) ) {
92                _CtxCoroutine_Unwind(src->cancellation, src);
93        }
94}
95
96extern void __stack_prepare   ( __stack_info_t * this, size_t size /* ignored if storage already allocated */);
97
98// Suspend implementation inlined for performance
99static inline void suspend(void) {
100        // optimization : read TLS once and reuse it
101        // Safety note: this is preemption safe since if
102        // preemption occurs after this line, the pointer
103        // will also migrate which means this value will
104        // stay in syn with the TLS
105        coroutine_desc * src = TL_GET( this_thread )->curr_cor;
106
107        assertf( src->last != 0,
108                "Attempt to suspend coroutine \"%.256s\" (%p) that has never been resumed.\n"
109                "Possible cause is a suspend executed in a member called by a coroutine user rather than by the coroutine main.",
110                src->name, src );
111        assertf( src->last->state != Halted,
112                "Attempt by coroutine \"%.256s\" (%p) to suspend back to terminated coroutine \"%.256s\" (%p).\n"
113                "Possible cause is terminated coroutine's main routine has already returned.",
114                src->name, src, src->last->name, src->last );
115
116        CoroutineCtxSwitch( src, src->last );
117}
118
119// Resume implementation inlined for performance
120forall(dtype T | is_coroutine(T))
121static inline void resume(T & cor) {
122        // optimization : read TLS once and reuse it
123        // Safety note: this is preemption safe since if
124        // preemption occurs after this line, the pointer
125        // will also migrate which means this value will
126        // stay in syn with the TLS
127        coroutine_desc * src = TL_GET( this_thread )->curr_cor;
128        coroutine_desc * dst = get_coroutine(cor);
129
130        if( unlikely(dst->context.SP == NULL) ) {
131                __stack_prepare(&dst->stack, 65000);
132                CtxStart(&cor, CtxInvokeCoroutine);
133        }
134
135        // not resuming self ?
136        if ( src != dst ) {
137                assertf( dst->state != Halted ,
138                        "Attempt by coroutine %.256s (%p) to resume terminated coroutine %.256s (%p).\n"
139                        "Possible cause is terminated coroutine's main routine has already returned.",
140                        src->name, src, dst->name, dst );
141
142                // set last resumer
143                dst->last = src;
144                dst->starter = dst->starter ? dst->starter : src;
145        }
146
147        // always done for performance testing
148        CoroutineCtxSwitch( src, dst );
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
175
176// static inline bool suspend_checkpoint(void) {
177//      // optimization : read TLS once and reuse it
178//      // Safety note: this is preemption safe since if
179//      // preemption occurs after this line, the pointer
180//      // will also migrate which means this value will
181//      // stay in syn with the TLS
182//      // set state of current coroutine to inactive
183//       this->state = Checkpoint;
184
185//       // context switch to specified coroutine
186//       assert( src->stack.context );
187
188//       CtxStore(src->stack.context);
189
190//      bool ret = this->state == Checkpoint;
191
192//       // set state of new coroutine to active
193//       src->state = Active;
194
195//       enable_interrupts( __cfaabi_dbg_ctx );
196//       // Safety note : This could cause some false positives due to preemption
197//       verify( TL_GET( preemption_state.enabled ) || TL_GET( this_processor )->do_terminate );
198
199//       if( unlikely(src->cancellation != NULL) ) {
200//             _CtxCoroutine_Unwind(src->cancellation);
201//       }
202
203//      return ret;
204// }
205
206// static inline void suspend_return(void) {
207//      // optimization : read TLS once and reuse it
208//      // Safety note: this is preemption safe since if
209//      // preemption occurs after this line, the pointer
210//      // will also migrate which means this value will
211//      // stay in syn with the TLS
212//      coroutine_desc * src = TL_GET( this_thread )->curr_cor;
213
214//      assertf( src->last != 0,
215//              "Attempt to suspend coroutine \"%.256s\" (%p) that has never been resumed.\n"
216//              "Possible cause is a suspend executed in a member called by a coroutine user rather than by the coroutine main.",
217//              src->name, src );
218//      assertf( src->last->state != Halted,
219//              "Attempt by coroutine \"%.256s\" (%p) to suspend back to terminated coroutine \"%.256s\" (%p).\n"
220//              "Possible cause is terminated coroutine's main routine has already returned.",
221//              src->name, src, src->last->name, src->last );
222
223//      // Safety note : Preemption must be disabled here since kernelTLS.this_coroutine must always be up to date
224//       verify( TL_GET( preemption_state.enabled ) || TL_GET( this_processor )->do_terminate );
225//       disable_interrupts();
226
227//       // set state of current coroutine to inactive
228//       src->state = src->state == Halted ? Halted : Inactive;
229
230//       // set new coroutine that task is executing
231//       kernelTLS.this_coroutine = dst;
232
233//       // context switch to specified coroutine
234//       assert( src->stack.context );
235//      CtxRet( src->stack.context );
236
237//      abort();
238// }
239
240// Local Variables: //
241// mode: c //
242// tab-width: 4 //
243// End: //
Note: See TracBrowser for help on using the repository browser.