egl: Change the way drivers are loaded.

Driver is chosen and preloaded when eglGetDisplay is called.  Later when
eglInitialize is called, the same driver is matched to initialize the
display.  Also, add new, but unused, hooks to EGLDriver to allow a
driver to probe a display or unload itself.

Signed-off-by: Chia-I Wu <olvaffe@gmail.com>

1 files changed, 181 insertions, 88 deletions

diff --git a/src/egl/main/egldriver.c b/src/egl/main/egldriver.c
index a8ac7b3..36cc294 100644
--- a/src/egl/main/egldriver.c
+++ b/src/egl/main/egldriver.c
@@ -114,11 +114,12 @@ _eglChooseDRMDriver(int card)
 #endif
 }
 
+
 /**
  * XXX this function is totally subject change!!!
  *
  *
- * Determine/return the name of the driver to use for the given _EGLDisplay.
+ * Determine/return the path of the driver to use for the given native display.
  *
  * Try to be clever and determine if nativeDisplay is an Xlib Display
  * ptr or a string (naming a driver or screen number, etc).
@@ -128,89 +129,69 @@ _eglChooseDRMDriver(int card)
  * Else if the first character is '!' we interpret it as specific driver name
  * (i.e. "!r200" or "!i830".
  *
- * Whatever follows ':' is copied and put into dpy->DriverArgs.
+ * Whatever follows ':' is interpreted as arguments.
  *
- * The caller may free() the returned string.
+ * The caller may free() the returned strings.
  */
-const char *
-_eglChooseDriver(_EGLDisplay *dpy)
+static char *
+_eglChooseDriver(_EGLDisplay *dpy, char **argsRet)
 {
-   /* Under Windows, the NativeDisplay is an HDC handle, therefore */
-   /* it can't be interpreted as a string or a pointer. */
-#if defined(_EGL_PLATFORM_WINDOWS)
-   const char *displayString = NULL;
-#else
-   const char *displayString = (const char *) dpy->NativeDisplay;
-#endif
-   const char *driverName = NULL;
+   char *path = NULL;
+   const char *args = NULL;
 
-   (void) DefaultDriverName;
+   path = getenv("EGL_DRIVER");
+   if (path)
+      path = _eglstrdup(path);
 
 #if defined(_EGL_PLATFORM_X)
-   /* First, if the EGL_DRIVER env var is set, use that */
-   driverName = getenv("EGL_DRIVER");
-   if (driverName)
-      return _eglstrdup(driverName);
-#endif
+   (void) DefaultDriverName;
 
-#if 0
-   if (!displayString) {
-      /* choose a default */
-      displayString = DefaultDriverName;
-   }
-#endif
-   /* extract default DriverArgs = whatever follows ':' */
-   if (displayString &&
-       (displayString[0] == '!' ||
-        displayString[0] == ':')) {
-      const char *args = strchr(displayString, ':');
-      if (args)
-         dpy->DriverArgs = _eglstrdup(args + 1);
-   }
+   if (!path && dpy->NativeDisplay) {
+      const char *dpyString = (const char *) dpy->NativeDisplay;
+      char *p;
+      /* parse the display string */
+      if (dpyString[0] == '!' || dpyString[0] == ':') {
+         if (dpyString[0] == '!') {
+            path = _eglstrdup(dpyString);
+            p = strchr(path, ':');
+            if (p)
+               *p++ = '\0';
+         } else {
+            p = strchr(dpyString, ':');
+            if (p)
+               p++;
+         }
 
-   /* determine driver name now */
-   if (displayString && displayString[0] == ':' &&
-       (displayString[1] >= '0' && displayString[1] <= '9') &&
-       !displayString[2]) {
-      int card = atoi(displayString + 1);
-      driverName = _eglChooseDRMDriver(card);
-   }
-   else if (displayString && displayString[0] == '!') {
-      /* use user-specified driver name */
-      driverName = _eglstrdup(displayString + 1);
-      /* truncate driverName at ':' if present */
-      {
-         char *args = strchr(driverName, ':');
-         if (args) {
-            *args = 0;
+         if (p) {
+            if (!path && p[0] >= '0' && p[0] <= '9' && !p[1]) {
+               int card = atoi(p);
+               path = (char *) _eglChooseDRMDriver(card);
+            }
+            args = p;
          }
       }
+      else {
+         path = (char *) _xeglChooseDriver(dpy);
+      }
    }
-   else 
-   {
-      /* NativeDisplay is not a string! */
-#if defined(_EGL_PLATFORM_X)
-      driverName = _xeglChooseDriver(dpy);
-#else
-      driverName = DefaultDriverName;
-#endif
-   }
+#elif defined(_EGL_PLATFORM_WINDOWS)
+   if (!path)
+      path = _eglstrdup(DefaultDriverName);
+#endif /* _EGL_PLATFORM_X */
 
-   return driverName;
+   if (path && argsRet)
+      *argsRet = (args) ? _eglstrdup(args) : NULL;
+
+   return path;
 }
 
 
 /**
- * Open/load the named driver and call its bootstrap function: _eglMain().
- * By the time this function is called, the dpy->DriverName should have
- * been determined.
- *
- * \return  new _EGLDriver object.
+ * Open the named driver and find its bootstrap function: _eglMain().
  */
-_EGLDriver *
-_eglOpenDriver(_EGLDisplay *dpy, const char *driverName, const char *args)
+static _EGLMain_t
+_eglOpenLibrary(const char *driverName, lib_handle *handle)
 {
-   _EGLDriver *drv;
    _EGLMain_t mainFunc;
    lib_handle lib;
    char driverFilename[1000];
@@ -249,58 +230,170 @@ _eglOpenDriver(_EGLDisplay *dpy, const char *driverName, const char *args)
 
    if (!mainFunc) {
       _eglLog(_EGL_WARNING, "_eglMain not found in %s", driverFilename);
-      close_library(lib);
+      if (lib)
+         close_library(lib);
       return NULL;
    }
 
+   *handle = lib;
+   return mainFunc;
+}
+
+
+/**
+ * Load the named driver.  The path and args passed will be
+ * owned by the driver and freed.
+ */
+static _EGLDriver *
+_eglLoadDriver(_EGLDisplay *dpy, char *path, char *args)
+{
+   _EGLMain_t mainFunc;
+   lib_handle lib;
+   _EGLDriver *drv = NULL;
+
+   mainFunc = _eglOpenLibrary(path, &lib);
+   if (!mainFunc)
+      return NULL;
+
    drv = mainFunc(dpy, args);
    if (!drv) {
-      close_library(lib);
+      if (lib)
+         close_library(lib);
       return NULL;
    }
 
-   /* with a recurvise open you want the inner most handle */
-   if (!drv->LibHandle) {
-      drv->LibHandle = lib;
+   if (!drv->Name) {
+      _eglLog(_EGL_WARNING, "Driver loaded from %s has no name", path);
+      drv->Name = "UNNAMED";
    }
-   else {
-      close_library(lib);
+
+   drv->Path = path;
+   drv->Args = args;
+   drv->LibHandle = lib;
+
+   return drv;
+}
+
+
+/**
+ * Match a display to a preloaded driver.
+ */
+static _EGLDriver *
+_eglMatchDriver(_EGLDisplay *dpy)
+{
+   _EGLDriver *defaultDriver = NULL;
+   EGLint i;
+
+   for (i = 0; i < _eglGlobal.NumDrivers; i++) {
+      _EGLDriver *drv = _eglGlobal.Drivers[i];
+
+      /* display specifies a driver */
+      if (dpy->DriverName) {
+         if (strcmp(dpy->DriverName, drv->Name) == 0)
+            return drv;
+      }
+      else if (drv->Probe) {
+         if (drv->Probe(drv, dpy))
+            return drv;
+      }
+      else {
+         if (!defaultDriver)
+            defaultDriver = drv;
+      }
    }
 
+   return defaultDriver;
+}
+
+
+/**
+ * Load a driver and save it.
+ */
+const char *
+_eglPreloadDriver(_EGLDisplay *dpy)
+{
+   char *path, *args;
+   _EGLDriver *drv;
+   EGLint i;
+
+   path = _eglChooseDriver(dpy, &args);
+   if (!path)
+      return NULL;
+
+   for (i = 0; i < _eglGlobal.NumDrivers; i++) {
+      drv = _eglGlobal.Drivers[i];
+      if (strcmp(drv->Path, path) == 0) {
+         _eglLog(_EGL_DEBUG, "Driver %s is already preloaded",
+                 drv->Name);
+         free(path);
+         if (args)
+            free(args);
+         return drv->Name;
+      }
+   }
+
+   drv = _eglLoadDriver(dpy, path, args);
+   if (!drv)
+      return NULL;
+
    /* update the global notion of supported APIs */
    _eglGlobal.ClientAPIsMask |= drv->ClientAPIsMask;
 
-   _eglSaveDriver(drv);
+   _eglGlobal.Drivers[_eglGlobal.NumDrivers++] = drv;
 
+   return drv->Name;
+}
+
+
+/**
+ * Open a preloaded driver.
+ */
+_EGLDriver *
+_eglOpenDriver(_EGLDisplay *dpy)
+{
+   _EGLDriver *drv = _eglMatchDriver(dpy);
    return drv;
 }
 
 
+/**
+ * Close a preloaded driver.
+ */
 EGLBoolean
 _eglCloseDriver(_EGLDriver *drv, _EGLDisplay *dpy)
 {
-   void *handle = drv->LibHandle;
-   EGLBoolean b;
-
-   _eglLog(_EGL_DEBUG, "Closing %s", drv->Name);
-
    _eglReleaseDisplayResources(drv, dpy);
-
-   b = drv->API.Terminate(drv, dpy);
-
-   close_library(handle);
-
-   return b;
+   drv->API.Terminate(drv, dpy);
+   return EGL_TRUE;
 }
 
 
 /**
- * Save the given driver pointer in the list of all known drivers.
+ * Unload preloaded drivers.
  */
 void
-_eglSaveDriver(_EGLDriver *drv)
+_eglUnloadDrivers(void)
 {
-   _eglGlobal.Drivers[ _eglGlobal.NumDrivers++ ] = drv;
+   EGLint i;
+   for (i = 0; i < _eglGlobal.NumDrivers; i++) {
+      _EGLDriver *drv = _eglGlobal.Drivers[i];
+      lib_handle handle = drv->LibHandle;
+
+      if (drv->Path)
+         free((char *) drv->Path);
+      if (drv->Args)
+         free((char *) drv->Args);
+
+      /* destroy driver */
+      if (drv->Unload)
+         drv->Unload(drv);
+
+      if (handle)
+         close_library(handle);
+      _eglGlobal.Drivers[i] = NULL;
+   }
+
+   _eglGlobal.NumDrivers = 0;
 }