egl: add base EGL_EXT_device_base implementation

Introduce the API for device query and enumeration. Those at the moment
produce nothing useful since zero devices are actually available.

That contradicts with the spec, so the extension isn't advertised just
yet.

With later commits we'll add support for software (always) and hardware
devices. Each one exposing the respective extension string.

v2:
 - fold API boilerplate into this patch
 - move _eglAddDevice, _eglDeviceSupports, _eglRefreshDeviceList to this
patch (Eric, Mathias)
 - make _eglFiniDevice the one called last

v3:
 - comment on the dummy _egl_device_extension enum entry (Eric)
 - annotate dev as MAYBE_UNUSED (Mathias)

Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Mathias Fröhlich <Mathias.Froehlich@web.de>

src/egl/Makefile.sources

@@ -10,6 +10,8 @@ LIBEGL_C_FILES := \
 	main/eglcurrent.c \
 	main/eglcurrent.h \
 	main/egldefines.h \
+	main/egldevice.c \
+	main/egldevice.h \
 	main/egldisplay.c \
 	main/egldisplay.h \
 	main/egldriver.c \

src/egl/main/eglapi.c

@@ -95,6 +95,7 @@
 #include "egldisplay.h"
 #include "egltypedefs.h"
 #include "eglcurrent.h"
+#include "egldevice.h"
 #include "egldriver.h"
 #include "eglsurface.h"
 #include "eglconfig.h"
@@ -2583,6 +2584,69 @@ eglSetBlobCacheFuncsANDROID(EGLDisplay *dpy, EGLSetBlobFuncANDROID set,
    _eglUnlockDisplay(disp);
 }
 
+static EGLBoolean EGLAPIENTRY
+eglQueryDeviceAttribEXT(EGLDeviceEXT device,
+                        EGLint attribute,
+                        EGLAttrib *value)
+{
+   _EGLDevice *dev = _eglLookupDevice(device);
+   EGLBoolean ret;
+
+   _EGL_FUNC_START(NULL, EGL_NONE, NULL, EGL_FALSE);
+   if (!dev)
+      RETURN_EGL_ERROR(NULL, EGL_BAD_DEVICE_EXT, EGL_FALSE);
+
+   ret = _eglQueryDeviceAttribEXT(dev, attribute, value);
+   RETURN_EGL_EVAL(NULL, ret);
+}
+
+static const char * EGLAPIENTRY
+eglQueryDeviceStringEXT(EGLDeviceEXT device,
+                        EGLint name)
+{
+   _EGLDevice *dev = _eglLookupDevice(device);
+
+   _EGL_FUNC_START(NULL, EGL_NONE, NULL, NULL);
+   if (!dev)
+      RETURN_EGL_ERROR(NULL, EGL_BAD_DEVICE_EXT, NULL);
+
+   RETURN_EGL_EVAL(NULL, _eglQueryDeviceStringEXT(dev, name));
+}
+
+static EGLBoolean EGLAPIENTRY
+eglQueryDevicesEXT(EGLint max_devices,
+                   EGLDeviceEXT *devices,
+                   EGLint *num_devices)
+{
+   EGLBoolean ret;
+
+   _EGL_FUNC_START(NULL, EGL_NONE, NULL, EGL_FALSE);
+   ret = _eglQueryDevicesEXT(max_devices, (_EGLDevice **) devices,
+                             num_devices);
+   RETURN_EGL_EVAL(NULL, ret);
+}
+
+static EGLBoolean EGLAPIENTRY
+eglQueryDisplayAttribEXT(EGLDisplay dpy,
+                         EGLint attribute,
+                         EGLAttrib *value)
+{
+   _EGLDisplay *disp = _eglLockDisplay(dpy);
+   _EGLDriver *drv;
+
+   _EGL_FUNC_START(NULL, EGL_NONE, NULL, EGL_FALSE);
+   _EGL_CHECK_DISPLAY(disp, EGL_FALSE, drv);
+
+   switch (attribute) {
+   case EGL_DEVICE_EXT:
+      *value = (EGLAttrib) disp->Device;
+      break;
+   default:
+      RETURN_EGL_ERROR(disp, EGL_BAD_ATTRIBUTE, EGL_FALSE);
+   }
+   RETURN_EGL_SUCCESS(disp, EGL_TRUE);
+}
+
 __eglMustCastToProperFunctionPointerType EGLAPIENTRY
 eglGetProcAddress(const char *procname)
 {

src/egl/main/egldevice.c

@@ -0,0 +1,179 @@
+/**************************************************************************
+ *
+ * Copyright 2015, 2018 Collabora
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ **************************************************************************/
+
+#include "util/macros.h"
+
+#include "eglcurrent.h"
+#include "egldevice.h"
+#include "eglglobals.h"
+#include "egltypedefs.h"
+
+
+struct _egl_device {
+   _EGLDevice *Next;
+
+   const char *extensions;
+};
+
+void
+_eglFiniDevice(void)
+{
+   _EGLDevice *dev_list, *dev;
+
+   /* atexit function is called with global mutex locked */
+
+   dev_list = _eglGlobal.DeviceList;
+   while (dev_list) {
+      /* pop list head */
+      dev = dev_list;
+      dev_list = dev_list->Next;
+
+      free(dev);
+   }
+
+   _eglGlobal.DeviceList = NULL;
+}
+
+EGLBoolean
+_eglCheckDeviceHandle(EGLDeviceEXT device)
+{
+   _EGLDevice *cur;
+
+   mtx_lock(_eglGlobal.Mutex);
+   cur = _eglGlobal.DeviceList;
+   while (cur) {
+      if (cur == (_EGLDevice *) device)
+         break;
+      cur = cur->Next;
+   }
+   mtx_unlock(_eglGlobal.Mutex);
+   return (cur != NULL);
+}
+
+/* Adds a device in DeviceList, if needed for the given fd.
+ *
+ * If a software device, the fd is ignored.
+ */
+_EGLDevice *
+_eglAddDevice(int fd, bool software)
+{
+   _EGLDevice *dev;
+
+   mtx_lock(_eglGlobal.Mutex);
+
+   dev = NULL;
+
+out:
+   mtx_unlock(_eglGlobal.Mutex);
+   return dev;
+}
+
+EGLBoolean
+_eglDeviceSupports(_EGLDevice *dev, _EGLDeviceExtension ext)
+{
+   switch (ext) {
+   default:
+      assert(0);
+      return EGL_FALSE;
+   };
+}
+
+EGLBoolean
+_eglQueryDeviceAttribEXT(_EGLDevice *dev, EGLint attribute,
+                         EGLAttrib *value)
+{
+   switch (attribute) {
+   default:
+      _eglError(EGL_BAD_ATTRIBUTE, "eglQueryDeviceStringEXT");
+      return EGL_FALSE;
+   }
+}
+
+const char *
+_eglQueryDeviceStringEXT(_EGLDevice *dev, EGLint name)
+{
+   switch (name) {
+   case EGL_EXTENSIONS:
+      return dev->extensions;
+   default:
+      _eglError(EGL_BAD_PARAMETER, "eglQueryDeviceStringEXT");
+      return NULL;
+   };
+}
+
+/* Do a fresh lookup for devices.
+ *
+ * Walks through the DeviceList, discarding no longer available ones
+ * and adding new ones as applicable.
+ *
+ * Must be called with the global lock held.
+ */
+static int
+_eglRefreshDeviceList(void)
+{
+   MAYBE_UNUSED _EGLDevice *dev;
+   int count = 0;
+
+   dev = _eglGlobal.DeviceList;
+
+   return count;
+}
+
+EGLBoolean
+_eglQueryDevicesEXT(EGLint max_devices,
+                    _EGLDevice **devices,
+                    EGLint *num_devices)
+{
+   _EGLDevice *dev, *devs;
+   int i = 0, num_devs;
+
+   if ((devices && max_devices <= 0) || !num_devices)
+      return _eglError(EGL_BAD_PARAMETER, "eglQueryDevicesEXT");
+
+   mtx_lock(_eglGlobal.Mutex);
+
+   num_devs = _eglRefreshDeviceList();
+   devs = _eglGlobal.DeviceList;
+
+   /* bail early if we only care about the count */
+   if (!devices) {
+      *num_devices = num_devs;
+      goto out;
+   }
+
+   *num_devices = MIN2(num_devs, max_devices);
+
+   for (i = 0, dev = devs; i < *num_devices; i++) {
+      devices[i] = dev;
+      dev = dev->Next;
+   }
+
+out:
+   mtx_unlock(_eglGlobal.Mutex);
+
+   return EGL_TRUE;
+}

src/egl/main/egldevice.h

@@ -0,0 +1,83 @@
+/**************************************************************************
+ *
+ * Copyright 2015, 2018 Collabora
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ **************************************************************************/
+
+
+#ifndef EGLDEVICE_INCLUDED
+#define EGLDEVICE_INCLUDED
+
+
+#include <stdbool.h>
+#include "egltypedefs.h"
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void
+_eglFiniDevice(void);
+
+EGLBoolean
+_eglCheckDeviceHandle(EGLDeviceEXT device);
+
+static inline _EGLDevice *
+_eglLookupDevice(EGLDeviceEXT device)
+{
+   _EGLDevice *dev = (_EGLDevice *) device;
+   if (!_eglCheckDeviceHandle(device))
+      dev = NULL;
+   return dev;
+}
+
+_EGLDevice *
+_eglAddDevice(int fd, bool software);
+
+enum _egl_device_extension {
+   EGL_FOOBAR, /* A temporary entry, since enum with zero entries is illegal */
+};
+
+typedef enum _egl_device_extension _EGLDeviceExtension;
+
+EGLBoolean
+_eglDeviceSupports(_EGLDevice *dev, _EGLDeviceExtension ext);
+
+EGLBoolean
+_eglQueryDeviceAttribEXT(_EGLDevice *dev, EGLint attribute,
+                         EGLAttrib *value);
+
+const char *
+_eglQueryDeviceStringEXT(_EGLDevice *dev, EGLint name);
+
+EGLBoolean
+_eglQueryDevicesEXT(EGLint max_devices, _EGLDevice **devices,
+                    EGLint *num_devices);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* EGLDEVICE_INCLUDED */

src/egl/main/egldisplay.h

@@ -159,6 +159,7 @@ struct _egl_display
    _EGLPlatformType Platform; /**< The type of the platform display */
    void *PlatformDisplay;     /**< A pointer to the platform display */
 
+   _EGLDevice *Device;        /**< Device backing the display */
    _EGLDriver *Driver;        /**< Matched driver of the display */
    EGLBoolean Initialized;    /**< True if the display is initialized */
 

src/egl/main/eglentrypoint.h

@@ -56,6 +56,10 @@ EGL_ENTRYPOINT(eglPostSubBufferNV)
 EGL_ENTRYPOINT(eglQueryAPI)
 EGL_ENTRYPOINT(eglQueryContext)
 EGL_ENTRYPOINT(eglQueryDebugKHR)
+EGL_ENTRYPOINT(eglQueryDeviceAttribEXT)
+EGL_ENTRYPOINT(eglQueryDevicesEXT)
+EGL_ENTRYPOINT(eglQueryDeviceStringEXT)
+EGL_ENTRYPOINT(eglQueryDisplayAttribEXT)
 EGL_ENTRYPOINT(eglQueryDmaBufFormatsEXT)
 EGL_ENTRYPOINT(eglQueryDmaBufModifiersEXT)
 EGL_ENTRYPOINT(eglQueryString)

src/egl/main/eglglobals.c

@@ -35,6 +35,7 @@
 #include "c11/threads.h"
 
 #include "eglglobals.h"
+#include "egldevice.h"
 #include "egldisplay.h"
 #include "egldriver.h"
 #include "egllog.h"
@@ -51,11 +52,12 @@ struct _egl_global _eglGlobal =
 {
    .Mutex = &_eglGlobalMutex,
    .DisplayList = NULL,
-   .NumAtExitCalls = 2,
+   .NumAtExitCalls = 3,
    .AtExitCalls = {
       /* default AtExitCalls, called in reverse order */
-      _eglUnloadDrivers, /* always called last */
-      _eglFiniDisplay
+      _eglFiniDevice, /* always called last */
+      _eglUnloadDrivers,
+      _eglFiniDisplay,
    },
 
    .ClientOnlyExtensionString =

src/egl/main/eglglobals.h

@@ -54,6 +54,8 @@ struct _egl_global
    /* the list of all displays */
    _EGLDisplay *DisplayList;
 
+   _EGLDevice *DeviceList;
+
    EGLint NumAtExitCalls;
    void (*AtExitCalls[10])(void);
 

src/egl/main/egltypedefs.h

@@ -46,6 +46,8 @@ typedef struct _egl_config _EGLConfig;
 
 typedef struct _egl_context _EGLContext;
 
+typedef struct _egl_device _EGLDevice;
+
 typedef struct _egl_display _EGLDisplay;
 
 typedef struct _egl_driver _EGLDriver;

src/egl/meson.build

@@ -38,6 +38,8 @@ files_egl = files(
   'main/eglcurrent.c',
   'main/eglcurrent.h',
   'main/egldefines.h',
+  'main/egldevice.c',
+  'main/egldevice.h',
   'main/egldisplay.c',
   'main/egldisplay.h',
   'main/egldriver.c',