source: libcfa/src/concurrency/coroutine.cfa @ 342be43

ADTarm-ehast-experimentalenumforall-pointer-decayjacob/cs343-translationnew-ast-unique-exprpthread-emulationqualifiedEnum
Last change on this file since 342be43 was 342be43, checked in by Andrew Beach <ajbeach@…>, 3 years ago

Some exception clean-up that did not require any drastic changes.

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File size: 8.4 KB
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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.c --
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 Oct 23 23:05:24 2020
13// Update Count     : 22
14//
15
16#define __cforall_thread__
17
18#include "coroutine.hfa"
19
20#include <stddef.h>
21#include <malloc.h>
22#include <errno.h>
23#include <string.h>
24#include <unistd.h>
25#include <sys/mman.h>                                                                   // mprotect
26extern "C" {
27// use this define to make unwind.h play nice, definitely a hack
28#define HIDE_EXPORTS
29#include <unwind.h>
30#undef HIDE_EXPORTS
31}
32
33#include "kernel_private.hfa"
34
35#define __CFA_INVOKE_PRIVATE__
36#include "invoke.h"
37
38extern "C" {
39        void _CtxCoroutine_Unwind(struct _Unwind_Exception * storage, struct $coroutine *) __attribute__ ((__noreturn__));
40        static void _CtxCoroutine_UnwindCleanup(_Unwind_Reason_Code, struct _Unwind_Exception *) __attribute__ ((__noreturn__));
41        static void _CtxCoroutine_UnwindCleanup(_Unwind_Reason_Code, struct _Unwind_Exception *) {
42                abort();
43        }
44
45        extern void CtxRet( struct __stack_context_t * to ) asm ("CtxRet") __attribute__ ((__noreturn__));
46}
47
48//-----------------------------------------------------------------------------
49FORALL_DATA_INSTANCE(CoroutineCancelled, (dtype coroutine_t), (coroutine_t))
50
51forall(dtype T)
52void mark_exception(CoroutineCancelled(T) *) {}
53
54forall(dtype T)
55void copy(CoroutineCancelled(T) * dst, CoroutineCancelled(T) * src) {
56        dst->virtual_table = src->virtual_table;
57        dst->the_coroutine = src->the_coroutine;
58        dst->the_exception = src->the_exception;
59}
60
61forall(dtype T)
62const char * msg(CoroutineCancelled(T) *) {
63        return "CoroutineCancelled(...)";
64}
65
66// This code should not be inlined. It is the error path on resume.
67forall(dtype T | is_coroutine(T))
68void __cfaehm_cancelled_coroutine( T & cor, $coroutine * desc ) {
69        verify( desc->cancellation );
70        desc->state = Cancelled;
71        exception_t * except = __cfaehm_cancellation_exception( desc->cancellation );
72
73        // TODO: Remove explitate vtable set once trac#186 is fixed.
74        CoroutineCancelled(T) except;
75        except.virtual_table = &get_exception_vtable(&except);
76        except.the_coroutine = &cor;
77        except.the_exception = except;
78        throwResume except;
79
80        except->virtual_table->free( except );
81        free( desc->cancellation );
82        desc->cancellation = 0p;
83}
84
85//-----------------------------------------------------------------------------
86// Global state variables
87
88// minimum feasible stack size in bytes
89static const size_t MinStackSize = 1000;
90extern size_t __page_size;                              // architecture pagesize HACK, should go in proper runtime singleton
91
92void __stack_prepare( __stack_info_t * this, size_t create_size );
93
94//-----------------------------------------------------------------------------
95// Coroutine ctors and dtors
96void ?{}( __stack_info_t & this, void * storage, size_t storageSize ) {
97        this.storage   = (__stack_t *)storage;
98
99        // Did we get a piece of storage ?
100        if (this.storage || storageSize != 0) {
101                // We either got a piece of storage or the user asked for a specific size
102                // Immediately create the stack
103                // (This is slightly unintuitive that non-default sized coroutines create are eagerly created
104                // but it avoids that all coroutines carry an unnecessary size)
105                verify( storageSize != 0 );
106                __stack_prepare( &this, storageSize );
107        }
108}
109
110void ^?{}(__stack_info_t & this) {
111        bool userStack = ((intptr_t)this.storage & 0x1) != 0;
112        if ( ! userStack && this.storage ) {
113                __attribute__((may_alias)) intptr_t * istorage = (intptr_t *)&this.storage;
114                *istorage &= (intptr_t)-1;
115
116                void * storage = this.storage->limit;
117                __cfaabi_dbg_debug_do(
118                        storage = (char*)(storage) - __page_size;
119                        if ( mprotect( storage, __page_size, PROT_READ | PROT_WRITE ) == -1 ) {
120                                abort( "(coStack_t *)%p.^?{}() : internal error, mprotect failure, error(%d) %s.", &this, errno, strerror( errno ) );
121                        }
122                );
123                __cfaabi_dbg_print_safe("Kernel : Deleting stack %p\n", storage);
124                free( storage );
125        }
126}
127
128void ?{}( $coroutine & this, const char name[], void * storage, size_t storageSize ) with( this ) {
129        (this.context){0p, 0p};
130        (this.stack){storage, storageSize};
131        this.name = name;
132        state = Start;
133        starter = 0p;
134        last = 0p;
135        cancellation = 0p;
136}
137
138void ^?{}($coroutine& this) {
139        if(this.state != Halted && this.state != Start && this.state != Primed) {
140                $coroutine * src = TL_GET( this_thread )->curr_cor;
141                $coroutine * dst = &this;
142
143                struct _Unwind_Exception storage;
144                storage.exception_class = -1;
145                storage.exception_cleanup = _CtxCoroutine_UnwindCleanup;
146                this.cancellation = &storage;
147                this.last = src;
148
149                // not resuming self ?
150                if ( src == dst ) {
151                        abort( "Attempt by coroutine %.256s (%p) to terminate itself.\n", src->name, src );
152                }
153
154                $ctx_switch( src, dst );
155        }
156}
157
158// Part of the Public API
159// Not inline since only ever called once per coroutine
160forall(dtype T | is_coroutine(T))
161void prime(T& cor) {
162        $coroutine* this = get_coroutine(cor);
163        assert(this->state == Start);
164
165        this->state = Primed;
166        resume(cor);
167}
168
169[void *, size_t] __stack_alloc( size_t storageSize ) {
170        const size_t stack_data_size = libCeiling( sizeof(__stack_t), 16 ); // minimum alignment
171        assert(__page_size != 0l);
172        size_t size = libCeiling( storageSize, 16 ) + stack_data_size;
173
174        // If we are running debug, we also need to allocate a guardpage to catch stack overflows.
175        void * storage;
176        __cfaabi_dbg_debug_do(
177                storage = memalign( __page_size, size + __page_size );
178        );
179        __cfaabi_dbg_no_debug_do(
180                storage = (void*)malloc(size);
181        );
182
183        __cfaabi_dbg_print_safe("Kernel : Created stack %p of size %zu\n", storage, size);
184        __cfaabi_dbg_debug_do(
185                if ( mprotect( storage, __page_size, PROT_NONE ) == -1 ) {
186                        abort( "__stack_alloc : internal error, mprotect failure, error(%d) %s.", (int)errno, strerror( (int)errno ) );
187                }
188                storage = (void *)(((intptr_t)storage) + __page_size);
189        );
190
191        verify( ((intptr_t)storage & (libAlign() - 1)) == 0ul );
192        return [storage, size];
193}
194
195void __stack_prepare( __stack_info_t * this, size_t create_size ) {
196        const size_t stack_data_size = libCeiling( sizeof(__stack_t), 16 ); // minimum alignment
197        bool userStack;
198        void * storage;
199        size_t size;
200        if ( !this->storage ) {
201                userStack = false;
202                [storage, size] = __stack_alloc( create_size );
203        } else {
204                userStack = true;
205                __cfaabi_dbg_print_safe("Kernel : stack obj %p using user stack %p(%zd bytes)\n", this, this->storage, (intptr_t)this->storage->limit - (intptr_t)this->storage->base);
206
207                // The stack must be aligned, advance the pointer to the next align data
208                storage = (void*)libCeiling( (intptr_t)this->storage, libAlign());
209
210                // The size needs to be shrinked to fit all the extra data structure and be aligned
211                ptrdiff_t diff = (intptr_t)storage - (intptr_t)this->storage;
212                size = libFloor(create_size - stack_data_size - diff, libAlign());
213        } // if
214        assertf( size >= MinStackSize, "Stack size %zd provides less than minimum of %zd bytes for a stack.", size, MinStackSize );
215
216        this->storage = (__stack_t *)((intptr_t)storage + size);
217        this->storage->limit = storage;
218        this->storage->base  = (void*)((intptr_t)storage + size);
219        this->storage->exception_context.top_resume = 0p;
220        this->storage->exception_context.current_exception = 0p;
221        __attribute__((may_alias)) intptr_t * istorage = (intptr_t*)&this->storage;
222        *istorage |= userStack ? 0x1 : 0x0;
223}
224
225// We need to call suspend from invoke.c, so we expose this wrapper that
226// is not inline (We can't inline Cforall in C)
227extern "C" {
228        void __cfactx_cor_leave( struct $coroutine * src ) {
229                $coroutine * starter = src->cancellation != 0 ? src->last : src->starter;
230
231                src->state = Halted;
232
233                assertf( starter != 0,
234                        "Attempt to suspend/leave coroutine \"%.256s\" (%p) that has never been resumed.\n"
235                        "Possible cause is a suspend executed in a member called by a coroutine user rather than by the coroutine main.",
236                        src->name, src );
237                assertf( starter->state != Halted,
238                        "Attempt by coroutine \"%.256s\" (%p) to suspend/leave back to terminated coroutine \"%.256s\" (%p).\n"
239                        "Possible cause is terminated coroutine's main routine has already returned.",
240                        src->name, src, starter->name, starter );
241
242                $ctx_switch( src, starter );
243        }
244
245        struct $coroutine * __cfactx_cor_finish(void) {
246                struct $coroutine * cor = kernelTLS.this_thread->curr_cor;
247
248                if(cor->state == Primed) {
249                        __cfactx_suspend();
250                }
251
252                cor->state = Active;
253
254                return cor;
255        }
256}
257
258// Local Variables: //
259// mode: c //
260// tab-width: 4 //
261// End: //
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