[6a3d2e7] | 1 | // |
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| 2 | // Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo |
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| 3 | // |
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| 4 | // The contents of this file are covered under the licence agreement in the |
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| 5 | // file "LICENCE" distributed with Cforall. |
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| 6 | // |
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[75a17f1] | 7 | // coroutine.c -- |
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[6a3d2e7] | 8 | // |
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| 9 | // Author : Thierry Delisle |
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| 10 | // Created On : Mon Nov 28 12:27:26 2016 |
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[6b0b624] | 11 | // Last Modified By : Peter A. Buhr |
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[ada0246d] | 12 | // Last Modified On : Tue May 26 22:06:09 2020 |
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| 13 | // Update Count : 21 |
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[6a3d2e7] | 14 | // |
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| 15 | |
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[2026bb6] | 16 | #define __cforall_thread__ |
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| 17 | |
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[58b6d1b] | 18 | #include "coroutine.hfa" |
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[bd98b58] | 19 | |
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[6a3d2e7] | 20 | #include <stddef.h> |
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| 21 | #include <malloc.h> |
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| 22 | #include <errno.h> |
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| 23 | #include <string.h> |
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| 24 | #include <unistd.h> |
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[ada0246d] | 25 | #include <sys/mman.h> // mprotect |
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| 26 | extern "C" { |
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| 27 | // use this define to make unwind.h play nice, definitely a hack |
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[76e069f] | 28 | #define HIDE_EXPORTS |
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| 29 | #include <unwind.h> |
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| 30 | #undef HIDE_EXPORTS |
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[6a3d2e7] | 31 | } |
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| 32 | |
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[73abe95] | 33 | #include "kernel_private.hfa" |
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[6a3d2e7] | 34 | |
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| 35 | #define __CFA_INVOKE_PRIVATE__ |
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| 36 | #include "invoke.h" |
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| 37 | |
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[76e069f] | 38 | extern "C" { |
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[ac2b598] | 39 | void _CtxCoroutine_Unwind(struct _Unwind_Exception * storage, struct $coroutine *) __attribute__ ((__noreturn__)); |
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[b2f6113] | 40 | static void _CtxCoroutine_UnwindCleanup(_Unwind_Reason_Code, struct _Unwind_Exception *) __attribute__ ((__noreturn__)); |
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| 41 | static void _CtxCoroutine_UnwindCleanup(_Unwind_Reason_Code, struct _Unwind_Exception *) { |
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| 42 | abort(); |
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| 43 | } |
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[f019069] | 44 | |
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| 45 | extern void CtxRet( struct __stack_context_t * to ) asm ("CtxRet") __attribute__ ((__noreturn__)); |
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[76e069f] | 46 | } |
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| 47 | |
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[1c01c58] | 48 | //----------------------------------------------------------------------------- |
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[69c5c00] | 49 | FORALL_DATA_INSTANCE(CoroutineCancelled, (dtype coroutine_t), (coroutine_t)) |
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[1c01c58] | 50 | |
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| 51 | struct __cfaehm_node { |
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| 52 | struct _Unwind_Exception unwind_exception; |
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| 53 | struct __cfaehm_node * next; |
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| 54 | int handler_index; |
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| 55 | }; |
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| 56 | |
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| 57 | forall(dtype T) |
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| 58 | void mark_exception(CoroutineCancelled(T) *) {} |
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| 59 | |
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[69c5c00] | 60 | forall(dtype T) |
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[1c01c58] | 61 | void copy(CoroutineCancelled(T) * dst, CoroutineCancelled(T) * src) { |
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| 62 | dst->the_coroutine = src->the_coroutine; |
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| 63 | dst->the_exception = src->the_exception; |
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| 64 | } |
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| 65 | |
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| 66 | forall(dtype T) |
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| 67 | const char * msg(CoroutineCancelled(T) *) { |
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| 68 | return "CoroutineCancelled(...)"; |
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| 69 | } |
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| 70 | |
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| 71 | // This code should not be inlined. It is the error path on resume. |
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| 72 | forall(dtype T | is_coroutine(T)) |
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| 73 | void __cfaehm_cancelled_coroutine( T & cor, $coroutine * desc ) { |
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| 74 | verify( desc->cancellation ); |
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| 75 | desc->state = Cancelled; |
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| 76 | exception_t * except = (exception_t *)(1 + (__cfaehm_node *)desc->cancellation); |
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| 77 | |
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[69c5c00] | 78 | // TODO: Remove explitate vtable set once trac#186 is fixed. |
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[1c01c58] | 79 | CoroutineCancelled(T) except; |
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[69c5c00] | 80 | except.virtual_table = &get_exception_vtable(&except); |
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[1c01c58] | 81 | except.the_coroutine = &cor; |
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| 82 | except.the_exception = except; |
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| 83 | throwResume except; |
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| 84 | |
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| 85 | except->virtual_table->free( except ); |
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| 86 | free( desc->cancellation ); |
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| 87 | desc->cancellation = 0p; |
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| 88 | } |
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| 89 | |
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[6a3d2e7] | 90 | //----------------------------------------------------------------------------- |
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| 91 | // Global state variables |
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| 92 | |
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| 93 | // minimum feasible stack size in bytes |
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| 94 | #define MinStackSize 1000 |
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[b2f6113] | 95 | extern size_t __page_size; // architecture pagesize HACK, should go in proper runtime singleton |
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| 96 | |
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| 97 | void __stack_prepare( __stack_info_t * this, size_t create_size ); |
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[6a3d2e7] | 98 | |
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| 99 | //----------------------------------------------------------------------------- |
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| 100 | // Coroutine ctors and dtors |
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[b2f6113] | 101 | void ?{}( __stack_info_t & this, void * storage, size_t storageSize ) { |
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| 102 | this.storage = (__stack_t *)storage; |
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| 103 | |
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| 104 | // Did we get a piece of storage ? |
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| 105 | if (this.storage || storageSize != 0) { |
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| 106 | // We either got a piece of storage or the user asked for a specific size |
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| 107 | // Immediately create the stack |
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| 108 | // (This is slightly unintuitive that non-default sized coroutines create are eagerly created |
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| 109 | // but it avoids that all coroutines carry an unnecessary size) |
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| 110 | verify( storageSize != 0 ); |
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| 111 | __stack_prepare( &this, storageSize ); |
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| 112 | } |
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[6a3d2e7] | 113 | } |
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| 114 | |
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[b2f6113] | 115 | void ^?{}(__stack_info_t & this) { |
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[8c01e1b] | 116 | bool userStack = ((intptr_t)this.storage & 0x1) != 0; |
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| 117 | if ( ! userStack && this.storage ) { |
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[ffe2fad] | 118 | __attribute__((may_alias)) intptr_t * istorage = (intptr_t *)&this.storage; |
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| 119 | *istorage &= (intptr_t)-1; |
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| 120 | |
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[8c01e1b] | 121 | void * storage = this.storage->limit; |
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[b2f6113] | 122 | __cfaabi_dbg_debug_do( |
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| 123 | storage = (char*)(storage) - __page_size; |
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| 124 | if ( mprotect( storage, __page_size, PROT_READ | PROT_WRITE ) == -1 ) { |
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| 125 | abort( "(coStack_t *)%p.^?{}() : internal error, mprotect failure, error(%d) %s.", &this, errno, strerror( errno ) ); |
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| 126 | } |
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| 127 | ); |
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| 128 | __cfaabi_dbg_print_safe("Kernel : Deleting stack %p\n", storage); |
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| 129 | free( storage ); |
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| 130 | } |
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[6a3d2e7] | 131 | } |
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| 132 | |
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[ac2b598] | 133 | void ?{}( $coroutine & this, const char name[], void * storage, size_t storageSize ) with( this ) { |
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[524627e] | 134 | (this.context){0p, 0p}; |
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[b2f6113] | 135 | (this.stack){storage, storageSize}; |
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| 136 | this.name = name; |
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| 137 | state = Start; |
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[524627e] | 138 | starter = 0p; |
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| 139 | last = 0p; |
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| 140 | cancellation = 0p; |
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[6a3d2e7] | 141 | } |
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| 142 | |
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[ac2b598] | 143 | void ^?{}($coroutine& this) { |
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[3623f9d] | 144 | if(this.state != Halted && this.state != Start && this.state != Primed) { |
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[ac2b598] | 145 | $coroutine * src = TL_GET( this_thread )->curr_cor; |
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| 146 | $coroutine * dst = &this; |
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[b2f6113] | 147 | |
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| 148 | struct _Unwind_Exception storage; |
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| 149 | storage.exception_class = -1; |
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| 150 | storage.exception_cleanup = _CtxCoroutine_UnwindCleanup; |
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| 151 | this.cancellation = &storage; |
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| 152 | this.last = src; |
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| 153 | |
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| 154 | // not resuming self ? |
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| 155 | if ( src == dst ) { |
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| 156 | abort( "Attempt by coroutine %.256s (%p) to terminate itself.\n", src->name, src ); |
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| 157 | } |
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| 158 | |
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[ac2b598] | 159 | $ctx_switch( src, dst ); |
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[b2f6113] | 160 | } |
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[76e069f] | 161 | } |
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[6a3d2e7] | 162 | |
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| 163 | // Part of the Public API |
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| 164 | // Not inline since only ever called once per coroutine |
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| 165 | forall(dtype T | is_coroutine(T)) |
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[83a071f9] | 166 | void prime(T& cor) { |
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[ac2b598] | 167 | $coroutine* this = get_coroutine(cor); |
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[b2f6113] | 168 | assert(this->state == Start); |
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[6a3d2e7] | 169 | |
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[b2f6113] | 170 | this->state = Primed; |
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| 171 | resume(cor); |
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[6a3d2e7] | 172 | } |
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| 173 | |
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[b2f6113] | 174 | [void *, size_t] __stack_alloc( size_t storageSize ) { |
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[0030ada3] | 175 | const size_t stack_data_size = libCeiling( sizeof(__stack_t), 16 ); // minimum alignment |
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[b2f6113] | 176 | assert(__page_size != 0l); |
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| 177 | size_t size = libCeiling( storageSize, 16 ) + stack_data_size; |
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| 178 | |
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| 179 | // If we are running debug, we also need to allocate a guardpage to catch stack overflows. |
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| 180 | void * storage; |
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| 181 | __cfaabi_dbg_debug_do( |
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| 182 | storage = memalign( __page_size, size + __page_size ); |
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| 183 | ); |
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| 184 | __cfaabi_dbg_no_debug_do( |
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| 185 | storage = (void*)malloc(size); |
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| 186 | ); |
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| 187 | |
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| 188 | __cfaabi_dbg_print_safe("Kernel : Created stack %p of size %zu\n", storage, size); |
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| 189 | __cfaabi_dbg_debug_do( |
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| 190 | if ( mprotect( storage, __page_size, PROT_NONE ) == -1 ) { |
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| 191 | abort( "__stack_alloc : internal error, mprotect failure, error(%d) %s.", (int)errno, strerror( (int)errno ) ); |
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| 192 | } |
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| 193 | storage = (void *)(((intptr_t)storage) + __page_size); |
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| 194 | ); |
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| 195 | |
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| 196 | verify( ((intptr_t)storage & (libAlign() - 1)) == 0ul ); |
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| 197 | return [storage, size]; |
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| 198 | } |
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[6a3d2e7] | 199 | |
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[b2f6113] | 200 | void __stack_prepare( __stack_info_t * this, size_t create_size ) { |
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[0030ada3] | 201 | const size_t stack_data_size = libCeiling( sizeof(__stack_t), 16 ); // minimum alignment |
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[b2f6113] | 202 | bool userStack; |
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| 203 | void * storage; |
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| 204 | size_t size; |
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| 205 | if ( !this->storage ) { |
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| 206 | userStack = false; |
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| 207 | [storage, size] = __stack_alloc( create_size ); |
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| 208 | } else { |
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| 209 | userStack = true; |
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[69a61d2] | 210 | __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); |
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[b2f6113] | 211 | |
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| 212 | // The stack must be aligned, advance the pointer to the next align data |
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| 213 | storage = (void*)libCeiling( (intptr_t)this->storage, libAlign()); |
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| 214 | |
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| 215 | // The size needs to be shrinked to fit all the extra data structure and be aligned |
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| 216 | ptrdiff_t diff = (intptr_t)storage - (intptr_t)this->storage; |
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| 217 | size = libFloor(create_size - stack_data_size - diff, libAlign()); |
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| 218 | } // if |
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| 219 | assertf( size >= MinStackSize, "Stack size %zd provides less than minimum of %d bytes for a stack.", size, MinStackSize ); |
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| 220 | |
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| 221 | this->storage = (__stack_t *)((intptr_t)storage + size); |
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| 222 | this->storage->limit = storage; |
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| 223 | this->storage->base = (void*)((intptr_t)storage + size); |
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[1c01c58] | 224 | this->storage->exception_context.top_resume = 0p; |
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| 225 | this->storage->exception_context.current_exception = 0p; |
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[ffe2fad] | 226 | __attribute__((may_alias)) intptr_t * istorage = (intptr_t*)&this->storage; |
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| 227 | *istorage |= userStack ? 0x1 : 0x0; |
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[6a3d2e7] | 228 | } |
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| 229 | |
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[0c92c9f] | 230 | // We need to call suspend from invoke.c, so we expose this wrapper that |
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| 231 | // is not inline (We can't inline Cforall in C) |
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| 232 | extern "C" { |
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[ac2b598] | 233 | void __cfactx_cor_leave( struct $coroutine * src ) { |
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| 234 | $coroutine * starter = src->cancellation != 0 ? src->last : src->starter; |
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[b2f6113] | 235 | |
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| 236 | src->state = Halted; |
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| 237 | |
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| 238 | assertf( starter != 0, |
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| 239 | "Attempt to suspend/leave coroutine \"%.256s\" (%p) that has never been resumed.\n" |
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| 240 | "Possible cause is a suspend executed in a member called by a coroutine user rather than by the coroutine main.", |
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| 241 | src->name, src ); |
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| 242 | assertf( starter->state != Halted, |
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| 243 | "Attempt by coroutine \"%.256s\" (%p) to suspend/leave back to terminated coroutine \"%.256s\" (%p).\n" |
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| 244 | "Possible cause is terminated coroutine's main routine has already returned.", |
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| 245 | src->name, src, starter->name, starter ); |
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| 246 | |
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[ac2b598] | 247 | $ctx_switch( src, starter ); |
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[b2f6113] | 248 | } |
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[09f357ec] | 249 | |
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[ac2b598] | 250 | struct $coroutine * __cfactx_cor_finish(void) { |
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| 251 | struct $coroutine * cor = kernelTLS.this_thread->curr_cor; |
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[09f357ec] | 252 | |
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| 253 | if(cor->state == Primed) { |
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[427854b] | 254 | __cfactx_suspend(); |
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[09f357ec] | 255 | } |
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| 256 | |
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| 257 | cor->state = Active; |
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| 258 | |
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| 259 | return cor; |
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| 260 | } |
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[0c92c9f] | 261 | } |
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| 262 | |
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[6a3d2e7] | 263 | // Local Variables: // |
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| 264 | // mode: c // |
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| 265 | // tab-width: 4 // |
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[4aa2fb2] | 266 | // End: // |
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