jonroach
4 Sep 2025 20:29
1 contributor
| 1 | #include "generator.h" |
| 2 | #include "coroutine.h" |
| 3 | #include <stdlib.h> |
| 4 | #include <stdio.h> |
| 5 | #include <assert.h> |
| 6 | #include "cor_thread_local.h" |
| 7 | |
| 8 | enum { |
| 9 | Generator_Running, |
| 10 | Generator_Deleting, |
| 11 | Generator_Complete |
| 12 | }; |
| 13 | |
| 14 | struct Generator { |
| 15 | Coroutine *coroutine; |
| 16 | Coroutine *caller; |
| 17 | void *(*start)(void *); |
| 18 | void *param; |
| 19 | char state; |
| 20 | }; |
| 21 | |
| 22 | |
| 23 | _Cor_thread_local Generator *g_active_generator = NULL; |
| 24 | |
| 25 | |
| 26 | static void on_yield_gen( |
| 27 | void *this |
| 28 | ){ |
| 29 | Generator *gen = (Generator *)this; |
| 30 | Coroutine_Continue(gen->caller, Coroutine_GetValue(gen->coroutine), true); |
| 31 | } |
| 32 | |
| 33 | |
| 34 | static void on_yield_gen_caller( |
| 35 | void *this |
| 36 | ){ |
| 37 | (void)this; |
| 38 | } |
| 39 | |
| 40 | |
| 41 | static void *do_start( |
| 42 | void *this |
| 43 | ){ |
| 44 | Generator *gen = (Generator *)this; |
| 45 | g_active_generator = this; |
| 46 | assert(gen->state == Generator_Running || gen->state == Generator_Deleting); |
| 47 | void *value; |
| 48 | if (gen->state == Generator_Running){ |
| 49 | g_active_generator = gen; |
| 50 | value = gen->start(gen->param); |
| 51 | g_active_generator = NULL; |
| 52 | } else { |
| 53 | // we are being deleted |
| 54 | value = NULL; |
| 55 | } |
| 56 | gen->state = Generator_Complete; |
| 57 | Coroutine_Continue(gen->caller, value, true); |
| 58 | return value; |
| 59 | } |
| 60 | |
| 61 | |
| 62 | Generator *Generator_New( |
| 63 | void *(*start)(void *), |
| 64 | void *param |
| 65 | ){ |
| 66 | Generator *gen = malloc(sizeof(Generator)); |
| 67 | gen->start = start; |
| 68 | gen->param = param; |
| 69 | gen->coroutine = Coroutine_New(do_start); |
| 70 | gen->state = Generator_Running; |
| 71 | return gen; |
| 72 | } |
| 73 | |
| 74 | |
| 75 | void Generator_Delete( |
| 76 | Generator *gen |
| 77 | ){ |
| 78 | assert(gen->state != Generator_Deleting); |
| 79 | if (gen->state == Generator_Running){ |
| 80 | gen->state = Generator_Deleting; |
| 81 | gen->caller = Coroutine_GetActive(); |
| 82 | Coroutine_Continue(gen->coroutine, gen, true); |
| 83 | Coroutine_Yield(NULL, on_yield_gen_caller, gen); |
| 84 | } |
| 85 | assert(gen->state == Generator_Complete); |
| 86 | Coroutine_Delete(gen->coroutine); |
| 87 | free(gen); |
| 88 | } |
| 89 | |
| 90 | |
| 91 | bool Generator_Next( |
| 92 | Generator *gen, |
| 93 | void **value |
| 94 | ){ |
| 95 | assert(gen->state != Generator_Deleting); |
| 96 | if (gen->state == Generator_Complete){ |
| 97 | return false; |
| 98 | } |
| 99 | gen->caller = Coroutine_GetActive(); |
| 100 | Coroutine_Continue(gen->coroutine, gen, true); |
| 101 | *value = Coroutine_Yield(NULL, on_yield_gen_caller, gen); |
| 102 | return Coroutine_IsRunning(gen->coroutine); |
| 103 | } |
| 104 | |
| 105 | |
| 106 | bool Generator_Yield( |
| 107 | void *value |
| 108 | ) |
| 109 | { |
| 110 | assert(g_active_generator); |
| 111 | Generator *gen = g_active_generator; |
| 112 | g_active_generator = NULL; |
| 113 | Coroutine_Yield(value, on_yield_gen, gen); |
| 114 | g_active_generator = gen; |
| 115 | return gen->state == Generator_Running; |
| 116 | } |
| 117 |