egl: add EGL_KHR_reusable_sync to egl_dri
This patch enables an EGL extension, EGL_KHR_reusable_sync.
This new extension basically provides a way for multiple APIs or
threads to be excuted synchronously via a "reusable sync"
primitive shared by those threads/API calls.
This was implemented based on the specification at
https://www.khronos.org/registry/egl/extensions/KHR/EGL_KHR_reusable_sync.txt
v2
- use thread functions defined in C11/threads.h instead of
using direct pthread calls
- make the timeout set with reference to CLOCK_MONOTONIC
- cleaned up the way expiration time is calculated
- (bug fix) in dri2_client_wait_sync, case EGL_SYNC_CL_EVENT_KHR
has been added.
- (bug fix) in dri2_destroy_sync, return from cond_broadcast
call is now stored in 'err' intead of 'ret' to prevent 'ret'
from being reset to 'EGL_FALSE' even in successful case
- corrected minor syntax problems
v3
- dri2_egl_unref_sync now became 'void' type. No more error check
is needed for this function call as a result.
- (bug fix) resolved issue with duplicated unlocking of display in
eglClientWaitSync when type of sync is "EGL_KHR_REUSABLE_SYNC"
Signed-off-by: Dongwon Kim <dongwon.kim@intel.com>
Signed-off-by: Marek Olšák <marek.olsak@amd.com>
diff --git a/src/egl/drivers/dri2/egl_dri2.c b/src/egl/drivers/dri2/egl_dri2.c
index 8f50f0c..490b040 100644
--- a/src/egl/drivers/dri2/egl_dri2.c
+++ b/src/egl/drivers/dri2/egl_dri2.c
@@ -38,6 +38,8 @@
#include <fcntl.h>
#include <errno.h>
#include <unistd.h>
+#include <c11/threads.h>
+#include <time.h>
#ifdef HAVE_LIBDRM
#include <xf86drm.h>
#include <drm_fourcc.h>
@@ -623,6 +625,8 @@
disp->Extensions.KHR_cl_event2 = EGL_TRUE;
}
+ disp->Extensions.KHR_reusable_sync = EGL_TRUE;
+
if (dri2_dpy->image) {
if (dri2_dpy->image->base.version >= 10 &&
dri2_dpy->image->getCapabilities != NULL) {
@@ -2394,7 +2398,12 @@
struct dri2_egl_sync *dri2_sync)
{
if (p_atomic_dec_zero(&dri2_sync->refcount)) {
- dri2_dpy->fence->destroy_fence(dri2_dpy->dri_screen, dri2_sync->fence);
+ if (dri2_sync->base.Type == EGL_SYNC_REUSABLE_KHR)
+ cnd_destroy(&dri2_sync->cond);
+
+ if (dri2_sync->fence)
+ dri2_dpy->fence->destroy_fence(dri2_dpy->dri_screen, dri2_sync->fence);
+
free(dri2_sync);
}
}
@@ -2408,6 +2417,8 @@
struct dri2_egl_display *dri2_dpy = dri2_egl_display(dpy);
struct dri2_egl_context *dri2_ctx = dri2_egl_context(ctx);
struct dri2_egl_sync *dri2_sync;
+ EGLint ret;
+ pthread_condattr_t attr;
dri2_sync = calloc(1, sizeof(struct dri2_egl_sync));
if (!dri2_sync) {
@@ -2450,6 +2461,37 @@
dri2_sync->fence, 0, 0))
dri2_sync->base.SyncStatus = EGL_SIGNALED_KHR;
break;
+
+ case EGL_SYNC_REUSABLE_KHR:
+ /* intialize attr */
+ ret = pthread_condattr_init(&attr);
+
+ if (ret) {
+ _eglError(EGL_BAD_ACCESS, "eglCreateSyncKHR");
+ free(dri2_sync);
+ return NULL;
+ }
+
+ /* change clock attribute to CLOCK_MONOTONIC */
+ ret = pthread_condattr_setclock(&attr, CLOCK_MONOTONIC);
+
+ if (ret) {
+ _eglError(EGL_BAD_ACCESS, "eglCreateSyncKHR");
+ free(dri2_sync);
+ return NULL;
+ }
+
+ ret = pthread_cond_init(&dri2_sync->cond, &attr);
+
+ if (ret) {
+ _eglError(EGL_BAD_ACCESS, "eglCreateSyncKHR");
+ free(dri2_sync);
+ return NULL;
+ }
+
+ /* initial status of reusable sync must be "unsignaled" */
+ dri2_sync->base.SyncStatus = EGL_UNSIGNALED_KHR;
+ break;
}
p_atomic_set(&dri2_sync->refcount, 1);
@@ -2461,9 +2503,27 @@
{
struct dri2_egl_display *dri2_dpy = dri2_egl_display(dpy);
struct dri2_egl_sync *dri2_sync = dri2_egl_sync(sync);
+ EGLint ret = EGL_TRUE;
+ EGLint err;
+ /* if type of sync is EGL_SYNC_REUSABLE_KHR and it is not signaled yet,
+ * then unlock all threads possibly blocked by the reusable sync before
+ * destroying it.
+ */
+ if (dri2_sync->base.Type == EGL_SYNC_REUSABLE_KHR &&
+ dri2_sync->base.SyncStatus == EGL_UNSIGNALED_KHR) {
+ dri2_sync->base.SyncStatus = EGL_SIGNALED_KHR;
+ /* unblock all threads currently blocked by sync */
+ err = cnd_broadcast(&dri2_sync->cond);
+
+ if (err) {
+ _eglError(EGL_BAD_ACCESS, "eglDestroySyncKHR");
+ ret = EGL_FALSE;
+ }
+ }
dri2_egl_unref_sync(dri2_dpy, dri2_sync);
- return EGL_TRUE;
+
+ return ret;
}
static EGLint
@@ -2471,10 +2531,16 @@
EGLint flags, EGLTime timeout)
{
_EGLContext *ctx = _eglGetCurrentContext();
+ struct dri2_egl_driver *dri2_drv = dri2_egl_driver(drv);
struct dri2_egl_display *dri2_dpy = dri2_egl_display(dpy);
struct dri2_egl_context *dri2_ctx = dri2_egl_context(ctx);
struct dri2_egl_sync *dri2_sync = dri2_egl_sync(sync);
unsigned wait_flags = 0;
+
+ /* timespecs for cnd_timedwait */
+ struct timespec current;
+ xtime expire;
+
EGLint ret = EGL_CONDITION_SATISFIED_KHR;
/* The EGL_KHR_fence_sync spec states:
@@ -2488,17 +2554,130 @@
/* the sync object should take a reference while waiting */
dri2_egl_ref_sync(dri2_sync);
- if (dri2_dpy->fence->client_wait_sync(dri2_ctx ? dri2_ctx->dri_context : NULL,
+ switch (sync->Type) {
+ case EGL_SYNC_FENCE_KHR:
+ case EGL_SYNC_CL_EVENT_KHR:
+ if (dri2_dpy->fence->client_wait_sync(dri2_ctx ? dri2_ctx->dri_context : NULL,
dri2_sync->fence, wait_flags,
timeout))
- dri2_sync->base.SyncStatus = EGL_SIGNALED_KHR;
- else
- ret = EGL_TIMEOUT_EXPIRED_KHR;
+ dri2_sync->base.SyncStatus = EGL_SIGNALED_KHR;
+ else
+ ret = EGL_TIMEOUT_EXPIRED_KHR;
+ break;
+ case EGL_SYNC_REUSABLE_KHR:
+ if (dri2_ctx && dri2_sync->base.SyncStatus == EGL_UNSIGNALED_KHR &&
+ (flags & EGL_SYNC_FLUSH_COMMANDS_BIT_KHR)) {
+ /* flush context if EGL_SYNC_FLUSH_COMMANDS_BIT_KHR is set */
+ if (dri2_drv->glFlush)
+ dri2_drv->glFlush();
+ }
+
+ /* if timeout is EGL_FOREVER_KHR, it should wait without any timeout.*/
+ if (timeout == EGL_FOREVER_KHR) {
+ if (mtx_lock(&dri2_sync->mutex)) {
+ ret = EGL_FALSE;
+ goto cleanup;
+ }
+
+ ret = cnd_wait(&dri2_sync->cond, &dri2_sync->mutex);
+
+ if (mtx_unlock(&dri2_sync->mutex)) {
+ ret = EGL_FALSE;
+ goto cleanup;
+ }
+
+ if (ret) {
+ _eglError(EGL_BAD_PARAMETER, "eglClientWaitSyncKHR");
+ ret = EGL_FALSE;
+ }
+ } else {
+ /* if reusable sync has not been yet signaled */
+ if (dri2_sync->base.SyncStatus != EGL_SIGNALED_KHR) {
+ clock_gettime(CLOCK_MONOTONIC, ¤t);
+
+ /* calculating when to expire */
+ expire.nsec = timeout % 1000000000L;
+ expire.sec = timeout / 1000000000L;
+
+ expire.nsec += current.tv_nsec;
+ expire.sec += current.tv_sec;
+
+ /* expire.nsec now is a number between 0 and 1999999998 */
+ if (expire.nsec > 999999999L) {
+ expire.sec++;
+ expire.nsec -= 1000000000L;
+ }
+
+ if (mtx_lock(&dri2_sync->mutex)) {
+ ret = EGL_FALSE;
+ goto cleanup;
+ }
+
+ ret = cnd_timedwait(&dri2_sync->cond, &dri2_sync->mutex, &expire);
+
+ if (mtx_unlock(&dri2_sync->mutex)) {
+ ret = EGL_FALSE;
+ goto cleanup;
+ }
+
+ if (ret)
+ if (ret == thrd_busy) {
+ if (dri2_sync->base.SyncStatus == EGL_UNSIGNALED_KHR) {
+ ret = EGL_TIMEOUT_EXPIRED_KHR;
+ } else {
+ _eglError(EGL_BAD_ACCESS, "eglClientWaitSyncKHR");
+ ret = EGL_FALSE;
+ }
+ }
+ }
+ }
+ break;
+ }
+
+ cleanup:
dri2_egl_unref_sync(dri2_dpy, dri2_sync);
+
+ if (ret == EGL_FALSE) {
+ _eglError(EGL_BAD_ACCESS, "eglClientWaitSyncKHR");
+ return EGL_FALSE;
+ }
+
return ret;
}
+static EGLBoolean
+dri2_signal_sync(_EGLDriver *drv, _EGLDisplay *dpy, _EGLSync *sync,
+ EGLenum mode)
+{
+ struct dri2_egl_sync *dri2_sync = dri2_egl_sync(sync);
+ EGLint ret;
+
+ if (sync->Type != EGL_SYNC_REUSABLE_KHR) {
+ _eglError(EGL_BAD_MATCH, "eglSignalSyncKHR");
+ return EGL_FALSE;
+ }
+
+ if (mode != EGL_SIGNALED_KHR && mode != EGL_UNSIGNALED_KHR) {
+ _eglError(EGL_BAD_ATTRIBUTE, "eglSignalSyncKHR");
+ return EGL_FALSE;
+ }
+
+ dri2_sync->base.SyncStatus = mode;
+
+ if (mode == EGL_SIGNALED_KHR) {
+ ret = cnd_broadcast(&dri2_sync->cond);
+
+ /* fail to broadcast */
+ if (ret) {
+ _eglError(EGL_BAD_ACCESS, "eglSignalSyncKHR");
+ return EGL_FALSE;
+ }
+ }
+
+ return EGL_TRUE;
+}
+
static EGLint
dri2_server_wait_sync(_EGLDriver *drv, _EGLDisplay *dpy, _EGLSync *sync)
{
@@ -2620,6 +2799,7 @@
dri2_drv->base.API.GetSyncValuesCHROMIUM = dri2_get_sync_values_chromium;
dri2_drv->base.API.CreateSyncKHR = dri2_create_sync;
dri2_drv->base.API.ClientWaitSyncKHR = dri2_client_wait_sync;
+ dri2_drv->base.API.SignalSyncKHR = dri2_signal_sync;
dri2_drv->base.API.WaitSyncKHR = dri2_server_wait_sync;
dri2_drv->base.API.DestroySyncKHR = dri2_destroy_sync;
diff --git a/src/egl/drivers/dri2/egl_dri2.h b/src/egl/drivers/dri2/egl_dri2.h
index 52ad92b..ef79939 100644
--- a/src/egl/drivers/dri2/egl_dri2.h
+++ b/src/egl/drivers/dri2/egl_dri2.h
@@ -307,6 +307,8 @@
struct dri2_egl_sync {
_EGLSync base;
+ mtx_t mutex;
+ cnd_t cond;
int refcount;
void *fence;
};
diff --git a/src/egl/main/eglapi.c b/src/egl/main/eglapi.c
index 8886759..64ffe92 100644
--- a/src/egl/main/eglapi.c
+++ b/src/egl/main/eglapi.c
@@ -1469,9 +1469,24 @@
if (s->SyncStatus == EGL_SIGNALED_KHR)
RETURN_EGL_EVAL(disp, EGL_CONDITION_SATISFIED_KHR);
+ /* if sync type is EGL_SYNC_REUSABLE_KHR, dpy should be
+ * unlocked here to allow other threads also to be able to
+ * go into waiting state.
+ */
+
+ if (s->Type == EGL_SYNC_REUSABLE_KHR)
+ _eglUnlockDisplay(dpy);
+
ret = drv->API.ClientWaitSyncKHR(drv, disp, s, flags, timeout);
- RETURN_EGL_EVAL(disp, ret);
+ /*
+ * 'disp' is already unlocked for reusable sync type,
+ * so passing 'NULL' to bypass unlocking display.
+ */
+ if (s->Type == EGL_SYNC_REUSABLE_KHR)
+ RETURN_EGL_EVAL(NULL, ret);
+ else
+ RETURN_EGL_EVAL(disp, ret);
}
diff --git a/src/egl/main/eglsync.c b/src/egl/main/eglsync.c
index 999cb48..33625e9 100644
--- a/src/egl/main/eglsync.c
+++ b/src/egl/main/eglsync.c
@@ -152,7 +152,8 @@
/* update the sync status */
if (sync->SyncStatus != EGL_SIGNALED_KHR &&
(sync->Type == EGL_SYNC_FENCE_KHR ||
- sync->Type == EGL_SYNC_CL_EVENT_KHR))
+ sync->Type == EGL_SYNC_CL_EVENT_KHR ||
+ sync->Type == EGL_SYNC_REUSABLE_KHR))
drv->API.ClientWaitSyncKHR(drv, dpy, sync, 0, 0);
*value = sync->SyncStatus;