mirror of https://github.com/bsnes-emu/bsnes.git
142 lines
3.3 KiB
C
Executable File
142 lines
3.3 KiB
C
Executable File
/*
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note this was designed for UNIX systems. Based on ideas expressed in a paper by Ralf Engelschall.
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for SJLJ on other systems, one would want to rewrite springboard() and co_create() and hack the jmb_buf stack pointer.
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*/
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#define LIBCO_C
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#include "libco.h"
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#include "settings.h"
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#define _BSD_SOURCE
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#define _XOPEN_SOURCE 500
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#include <stdlib.h>
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#include <signal.h>
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#include <setjmp.h>
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#ifdef __cplusplus
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extern "C" {
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#endif
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typedef struct {
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sigjmp_buf context;
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void (*coentry)(void);
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void* stack;
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} cothread_struct;
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static thread_local cothread_struct co_primary;
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static thread_local cothread_struct* creating;
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static thread_local cothread_struct* co_running = 0;
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static void springboard(int ignored) {
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if(sigsetjmp(creating->context, 0)) {
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co_running->coentry();
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}
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}
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cothread_t co_active() {
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if(!co_running) co_running = &co_primary;
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return (cothread_t)co_running;
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}
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cothread_t co_derive(void* memory, unsigned int size, void (*coentry)(void)) {
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if(!co_running) co_running = &co_primary;
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cothread_struct* thread = (cothread_struct*)memory;
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memory = (unsigned char*)memory + sizeof(cothread_struct);
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size -= sizeof(cothread_struct);
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if(thread) {
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struct sigaction handler;
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struct sigaction old_handler;
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stack_t stack;
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stack_t old_stack;
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thread->coentry = thread->stack = 0;
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stack.ss_flags = 0;
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stack.ss_size = size;
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thread->stack = stack.ss_sp = memory;
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if(stack.ss_sp && !sigaltstack(&stack, &old_stack)) {
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handler.sa_handler = springboard;
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handler.sa_flags = SA_ONSTACK;
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sigemptyset(&handler.sa_mask);
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creating = thread;
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if(!sigaction(SIGUSR1, &handler, &old_handler)) {
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if(!raise(SIGUSR1)) {
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thread->coentry = coentry;
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}
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sigaltstack(&old_stack, 0);
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sigaction(SIGUSR1, &old_handler, 0);
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}
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}
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if(thread->coentry != coentry) {
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co_delete(thread);
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thread = 0;
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}
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}
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return (cothread_t)thread;
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}
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cothread_t co_create(unsigned int size, void (*coentry)(void)) {
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if(!co_running) co_running = &co_primary;
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cothread_struct* thread = (cothread_struct*)malloc(sizeof(cothread_struct));
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if(thread) {
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struct sigaction handler;
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struct sigaction old_handler;
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stack_t stack;
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stack_t old_stack;
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thread->coentry = thread->stack = 0;
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stack.ss_flags = 0;
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stack.ss_size = size;
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thread->stack = stack.ss_sp = malloc(size);
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if(stack.ss_sp && !sigaltstack(&stack, &old_stack)) {
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handler.sa_handler = springboard;
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handler.sa_flags = SA_ONSTACK;
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sigemptyset(&handler.sa_mask);
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creating = thread;
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if(!sigaction(SIGUSR1, &handler, &old_handler)) {
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if(!raise(SIGUSR1)) {
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thread->coentry = coentry;
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}
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sigaltstack(&old_stack, 0);
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sigaction(SIGUSR1, &old_handler, 0);
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}
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}
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if(thread->coentry != coentry) {
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co_delete(thread);
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thread = 0;
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}
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}
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return (cothread_t)thread;
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}
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void co_delete(cothread_t cothread) {
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if(cothread) {
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if(((cothread_struct*)cothread)->stack) {
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free(((cothread_struct*)cothread)->stack);
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}
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free(cothread);
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}
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}
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void co_switch(cothread_t cothread) {
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if(!sigsetjmp(co_running->context, 0)) {
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co_running = (cothread_struct*)cothread;
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siglongjmp(co_running->context, 1);
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}
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}
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#ifdef __cplusplus
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}
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#endif
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