egl: Simplify driver matching.

Add initialization options that drv->API.Initialize should support.
Replace drv->Probe by TestOnly initialization option and simplify
_eglMatchDriver.

3 files changed, 54 insertions, 84 deletions

diff --git a/src/egl/main/egldisplay.h b/src/egl/main/egldisplay.h
index faeb290647..b42760befa 100644
--- a/src/egl/main/egldisplay.h
+++ b/src/egl/main/egldisplay.h
@@ -90,6 +90,11 @@ struct _egl_display
    _EGLDriver *Driver;        /**< Matched driver of the display */
    EGLBoolean Initialized;    /**< True if the display is initialized */
 
+   /* options that affect how the driver initializes the display */
+   struct {
+      EGLBoolean TestOnly;    /**< Driver should not set fields when true */
+   } Options;
+
    /* these fields are set by the driver during init */
    void *DriverData;          /**< Driver private data */
    EGLint VersionMajor;       /**< EGL major version */
diff --git a/src/egl/main/egldriver.c b/src/egl/main/egldriver.c
index 1ae030db44..7baa24fbf8 100644
--- a/src/egl/main/egldriver.c
+++ b/src/egl/main/egldriver.c
@@ -525,100 +525,75 @@ _eglAddDrivers(void)
 
 
 /**
- * Match a display to a driver.  The display is initialized unless use_probe is
- * true.
- *
- * The matching is done by finding the first driver that can initialize the
- * display, or when use_probe is true, the driver with highest score.
+ * A helper function for _eglMatchDriver.  It finds the first driver that can
+ * initialize the display and return.
  */
-_EGLDriver *
-_eglMatchDriver(_EGLDisplay *dpy, EGLBoolean use_probe)
+static _EGLDriver *
+_eglMatchAndInitialize(_EGLDisplay *dpy)
 {
-   _EGLModule *mod;
-   _EGLDriver *best_drv = NULL;
-   EGLint best_score = 0;
-   EGLint i;
-
-   _eglLockMutex(&_eglModuleMutex);
+   _EGLDriver *drv = NULL;
+   EGLint i = 0;
 
    if (!_eglAddDrivers()) {
-      _eglUnlockMutex(&_eglModuleMutex);
       _eglLog(_EGL_WARNING, "failed to find any driver");
-      return EGL_FALSE;
+      return NULL;
    }
 
-   /* match the loaded modules */
-   for (i = 0; i < _eglModules->Size; i++) {
-      mod = (_EGLModule *) _eglModules->Elements[i];
-      if (!mod->Driver)
-         break;
+   if (dpy->Driver) {
+      drv = dpy->Driver;
+      /* no re-matching? */
+      if (!drv->API.Initialize(drv, dpy))
+         drv = NULL;
+      return drv;
+   }
 
-      if (use_probe) {
-         EGLint score = (mod->Driver->Probe) ?
-            mod->Driver->Probe(mod->Driver, dpy) : 1;
-         if (score > best_score) {
-            best_drv = mod->Driver;
-            best_score = score;
-         }
+   while (i < _eglModules->Size) {
+      _EGLModule *mod = (_EGLModule *) _eglModules->Elements[i];
+
+      if (!_eglLoadModule(mod)) {
+         /* remove invalid modules */
+         _eglEraseArray(_eglModules, i, _eglFreeModule);
+         continue;
+      }
+
+      if (mod->Driver->API.Initialize(mod->Driver, dpy)) {
+         drv = mod->Driver;
+         break;
       }
       else {
-         if (mod->Driver->API.Initialize(mod->Driver, dpy)) {
-            best_drv = mod->Driver;
-            best_score = 100;
-         }
+         i++;
       }
-      /* perfect match */
-      if (best_score >= 100)
-         break;
    }
 
-   /* load more modules */
-   if (!best_drv) {
-      EGLint first_unloaded = i;
+   return drv;
+}
 
-      while (i < _eglModules->Size) {
-         mod = (_EGLModule *) _eglModules->Elements[i];
-         assert(!mod->Driver);
 
-         if (!_eglLoadModule(mod)) {
-            /* remove invalid modules */
-            _eglEraseArray(_eglModules, i, _eglFreeModule);
-            continue;
-         }
+/**
+ * Match a display to a driver.  The display is initialized unless test_only is
+ * true.  The matching is done by finding the first driver that can initialize
+ * the display.
+ */
+_EGLDriver *
+_eglMatchDriver(_EGLDisplay *dpy, EGLBoolean test_only)
+{
+   _EGLDriver *best_drv;
 
-         if (use_probe) {
-            best_score = (mod->Driver->Probe) ?
-               mod->Driver->Probe(mod->Driver, dpy) : 1;
-         }
-         else {
-            if (mod->Driver->API.Initialize(mod->Driver, dpy))
-               best_score = 100;
-         }
+   assert(!dpy->Initialized);
 
-         if (best_score > 0) {
-            best_drv = mod->Driver;
-            /* loaded modules come before unloaded ones */
-            if (first_unloaded != i) {
-               void *tmp = _eglModules->Elements[i];
-               _eglModules->Elements[i] =
-                  _eglModules->Elements[first_unloaded];
-               _eglModules->Elements[first_unloaded] = tmp;
-            }
-            break;
-         }
-         else {
-            _eglUnloadModule(mod);
-            i++;
-         }
-      }
-   }
+   _eglLockMutex(&_eglModuleMutex);
+
+   /* set options */
+   dpy->Options.TestOnly = test_only;
+
+   best_drv = _eglMatchAndInitialize(dpy);
 
    _eglUnlockMutex(&_eglModuleMutex);
 
    if (best_drv) {
-      _eglLog(_EGL_DEBUG, "the best driver is %s (score %d)",
-            best_drv->Name, best_score);
-      if (!use_probe) {
+      _eglLog(_EGL_DEBUG, "the best driver is %s%s",
+            best_drv->Name, (test_only) ? " (test only) " : "");
+      if (!test_only) {
          dpy->Driver = best_drv;
          dpy->Initialized = EGL_TRUE;
       }
diff --git a/src/egl/main/egldriver.h b/src/egl/main/egldriver.h
index d617757919..3cde102d12 100644
--- a/src/egl/main/egldriver.h
+++ b/src/egl/main/egldriver.h
@@ -44,16 +44,6 @@ struct _egl_driver
    const char *Name;  /**< name of this driver */
 
    /**
-    * Probe a display and return a score.
-    *
-    * Roughly,
-    *  50 means the driver supports the display;
-    *  90 means the driver can accelerate the display;
-    * 100 means a perfect match.
-    */
-   EGLint (*Probe)(_EGLDriver *drv, _EGLDisplay *dpy);
-
-   /**
     * Release the driver resource.
     *
     * It is called before dlclose().
@@ -81,7 +71,7 @@ _eglMain(const char *args);
 
 
 extern _EGLDriver *
-_eglMatchDriver(_EGLDisplay *dpy, EGLBoolean probe_only);
+_eglMatchDriver(_EGLDisplay *dpy, EGLBoolean test_only);
 
 
 extern __eglMustCastToProperFunctionPointerType