[common] added a sleep to the framebuffer spinlock and a sane timeout

This commit is contained in:
Geoffrey McRae 2020-08-10 16:18:08 +10:00
parent 82e0b7b6ab
commit 90d0cd873d
2 changed files with 22 additions and 7 deletions

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@ -1 +1 @@
B2-rc2-33-g2e1b0f2550+1
B2-rc3-0-g82e0b7b6ab+1

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@ -24,8 +24,10 @@ Place, Suite 330, Boston, MA 02111-1307 USA
#include <stdatomic.h>
#include <emmintrin.h>
#include <smmintrin.h>
#include <unistd.h>
#define FB_CHUNK_SIZE 1048576
#define FB_CHUNK_SIZE 1048576 // 1MB
#define FB_SPIN_LIMIT 10000 // 10ms
struct stFrameBuffer
{
@ -40,7 +42,6 @@ void framebuffer_wait(const FrameBuffer * frame, size_t size)
while(atomic_load_explicit(&frame->wp, memory_order_acquire) != size) {}
}
bool framebuffer_read(const FrameBuffer * frame, void * restrict dst,
size_t dstpitch, size_t height, size_t width, size_t bpp, size_t pitch)
{
@ -54,11 +55,18 @@ bool framebuffer_read(const FrameBuffer * frame, void * restrict dst,
while(y < height)
{
uint_least32_t wp;
int spinCount = 0;
/* spinlock */
do
wp = atomic_load_explicit(&frame->wp, memory_order_acquire);
while(wp - rp < pitch);
while(wp - rp < linewidth)
{
if (++spinCount == FB_SPIN_LIMIT)
return false;
usleep(1);
wp = atomic_load_explicit(&frame->wp, memory_order_acquire);
}
_mm_mfence();
__m128i * restrict s = (__m128i *)(frame->data + rp);
@ -104,11 +112,18 @@ bool framebuffer_read_fn(const FrameBuffer * frame, size_t height, size_t width,
while(y < height)
{
uint_least32_t wp;
int spinCount = 0;
/* spinlock */
do
wp = atomic_load_explicit(&frame->wp, memory_order_acquire);
while(wp - rp < pitch);
while(wp - rp < linewidth)
{
if (++spinCount == FB_SPIN_LIMIT)
return false;
usleep(1);
wp = atomic_load_explicit(&frame->wp, memory_order_acquire);
}
if (!fn(opaque, frame->data + rp, linewidth))
return false;