File: Context.h

package info (click to toggle)
ruby3.4 3.4.5-1~exp1
  • links: PTS, VCS
  • area: main
  • in suites: experimental
  • size: 154,784 kB
  • sloc: ruby: 1,259,653; ansic: 829,955; yacc: 28,233; pascal: 7,359; sh: 3,864; python: 1,799; cpp: 1,158; asm: 808; makefile: 801; javascript: 414; lisp: 109; perl: 62; awk: 36; sed: 4; xml: 4
file content (79 lines) | stat: -rw-r--r-- 2,132 bytes parent folder | download | duplicates (3)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
#ifndef COROUTINE_UCONTEXT_CONTEXT_H
#define COROUTINE_UCONTEXT_CONTEXT_H 1

/*
 *  This file is part of the "Coroutine" project and released under the MIT License.
 *
 *  Created by Samuel Williams on 24/6/2019.
 *  Copyright, 2019, by Samuel Williams.
*/

#pragma once

#include <assert.h>
#include <stddef.h>
#include <ucontext.h>

#define COROUTINE __attribute__((noreturn)) void

#ifdef HAVE_STDINT_H
#include <stdint.h>
#if INTPTR_MAX <= INT32_MAX
#define COROUTINE_LIMITED_ADDRESS_SPACE
#endif
#endif

struct coroutine_context
{
    ucontext_t state;
    struct coroutine_context * from;
    void *argument;
};

typedef COROUTINE(* coroutine_start)(struct coroutine_context *from, struct coroutine_context *self);

COROUTINE coroutine_trampoline(void * _start, void * _context);

static inline void coroutine_initialize_main(struct coroutine_context * context) {
    context->from = NULL;
    getcontext(&context->state);
}

static inline void coroutine_initialize(
    struct coroutine_context *context,
    coroutine_start start,
    void *stack,
    size_t size
) {
    assert(start && stack && size >= 1024);

    coroutine_initialize_main(context);

    context->state.uc_stack.ss_size = size;
    // Despite what it's called, this is not actually a stack pointer. It points to the address of the stack allocation (the lowest address).
    context->state.uc_stack.ss_sp = (char*)stack;
    context->state.uc_stack.ss_flags = 0;
    context->state.uc_link = NULL;

    makecontext(&context->state, (void(*)(void))coroutine_trampoline, 2, (void*)start, (void*)context);
}

static inline struct coroutine_context * coroutine_transfer(struct coroutine_context * current, struct coroutine_context * target)
{
    struct coroutine_context * previous = target->from;

    target->from = current;
    swapcontext(&current->state, &target->state);
    target->from = previous;

    return target;
}

static inline void coroutine_destroy(struct coroutine_context * context)
{
    context->state.uc_stack.ss_sp = NULL;
    context->state.uc_stack.ss_size = 0;
    context->from = NULL;
}

#endif /* COROUTINE_UCONTEXT_CONTEXT_H */