mirror of
https://github.com/libretro/RetroArch
synced 2024-12-29 12:31:05 +00:00
81 lines
1.8 KiB
C
81 lines
1.8 KiB
C
/*
|
|
libco.ucontext (2008-01-28)
|
|
author: Nach
|
|
license: public domain
|
|
*/
|
|
|
|
/*
|
|
* WARNING: the overhead of POSIX ucontext is very high,
|
|
* assembly versions of libco or libco_sjlj should be much faster
|
|
*
|
|
* This library only exists for two reasons:
|
|
* 1 - as an initial test for the viability of a ucontext implementation
|
|
* 2 - to demonstrate the power and speed of libco over existing implementations,
|
|
* such as pth (which defaults to wrapping ucontext on unix targets)
|
|
*
|
|
* Use this library only as a *last resort*
|
|
*/
|
|
|
|
#define LIBCO_C
|
|
#include <libco.h>
|
|
#include <stdlib.h>
|
|
#include <ucontext.h>
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
static thread_local ucontext_t co_primary;
|
|
static thread_local ucontext_t *co_running = 0;
|
|
|
|
cothread_t co_active(void)
|
|
{
|
|
if (!co_running)
|
|
co_running = &co_primary;
|
|
return (cothread_t)co_running;
|
|
}
|
|
|
|
cothread_t co_create(unsigned int heapsize, void (*coentry)(void))
|
|
{
|
|
ucontext_t *thread;
|
|
if (!co_running)
|
|
co_running = &co_primary;
|
|
|
|
if ((thread = (ucontext_t*)malloc(sizeof(ucontext_t))))
|
|
{
|
|
if ((!getcontext(thread) && !(thread->uc_stack.ss_sp = 0)) && (thread->uc_stack.ss_sp = malloc(heapsize)))
|
|
{
|
|
thread->uc_link = co_running;
|
|
thread->uc_stack.ss_size = heapsize;
|
|
makecontext(thread, coentry, 0);
|
|
}
|
|
else
|
|
{
|
|
co_delete((cothread_t)thread);
|
|
thread = 0;
|
|
}
|
|
}
|
|
return (cothread_t)thread;
|
|
}
|
|
|
|
void co_delete(cothread_t cothread)
|
|
{
|
|
if (!cothread)
|
|
return;
|
|
|
|
if (((ucontext_t*)cothread)->uc_stack.ss_sp)
|
|
free(((ucontext_t*)cothread)->uc_stack.ss_sp);
|
|
free(cothread);
|
|
}
|
|
|
|
void co_switch(cothread_t cothread)
|
|
{
|
|
ucontext_t *old_thread = co_running;
|
|
co_running = (ucontext_t*)cothread;
|
|
swapcontext(old_thread, co_running);
|
|
}
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|