vdpau_wrapper.c: Track dynamic library handles and free them on exit using...

vdpau_wrapper.c: Track dynamic library handles and free them on exit using __attribute__((destructor))
Signed-off-by: Kiran Pawar <kpawar@nvidia.com>
Tested-by: Aaron Plattner <aplattner@nvidia.com>
Signed-off-by: Aaron Plattner <aplattner@nvidia.com>

src/vdpau_wrapper.c

@@ -40,6 +40,17 @@ typedef void SetDllHandle(
     void * driver_dll_handle
 );
 
+static void * _vdp_backend_dll;
+static void * _vdp_trace_dll;
+static void * _vdp_driver_dll;
+static VdpDeviceCreateX11 * _vdp_imp_device_create_x11_proc;
+
+#if defined(__GNUC__)
+
+static void _vdp_close_driver(void) __attribute__((destructor));
+
+#endif
+
 #if DEBUG
 
 static void _vdp_wrapper_error_breakpoint(char const * file, int line, char const * function)
@@ -87,23 +98,16 @@ static char * _vdp_get_driver_name_from_dri2(
     return driver_name;
 }
 
-VdpStatus vdp_device_create_x11(
+static VdpStatus _vdp_open_driver(
     Display *             display,
-    int                   screen,
-    /* output parameters follow */
-    VdpDevice *           device,
-    VdpGetProcAddress * * get_proc_address
-)
+    int                   screen)
 {
     char const * vdpau_driver;
     char * vdpau_driver_dri2 = NULL;
     char         vdpau_driver_lib[PATH_MAX];
-    void *       backend_dll;
     char const * vdpau_trace;
     char const * func_name;
 
-    VdpDeviceCreateX11 * vdp_imp_device_create_x11;
-
     vdpau_driver = getenv("VDPAU_DRIVER");
     if (!vdpau_driver) {
         vdpau_driver = vdpau_driver_dri2 =
@@ -125,13 +129,13 @@ VdpStatus vdp_device_create_x11(
         return VDP_STATUS_NO_IMPLEMENTATION;
     }
 
-    backend_dll = dlopen(vdpau_driver_lib, RTLD_NOW | RTLD_GLOBAL);
-    if (!backend_dll) {
+    _vdp_driver_dll = dlopen(vdpau_driver_lib, RTLD_NOW | RTLD_GLOBAL);
+    if (!_vdp_driver_dll) {
         /* Try again using the old path, which is guaranteed to fit in PATH_MAX
          * if the complete path fit above. */
         snprintf(vdpau_driver_lib, sizeof(vdpau_driver_lib), DRIVER_LIB_FORMAT,
                  "", vdpau_driver, "");
-        backend_dll = dlopen(vdpau_driver_lib, RTLD_NOW | RTLD_GLOBAL);
+        _vdp_driver_dll = dlopen(vdpau_driver_lib, RTLD_NOW | RTLD_GLOBAL);
     }
 
     if (vdpau_driver_dri2) {
@@ -139,26 +143,28 @@ VdpStatus vdp_device_create_x11(
         vdpau_driver_dri2 = NULL;
     }
 
-    if (!backend_dll) {
+    if (!_vdp_driver_dll) {
         fprintf(stderr, "Failed to open VDPAU backend %s\n", dlerror());
         _VDP_ERROR_BREAKPOINT();
         return VDP_STATUS_NO_IMPLEMENTATION;
     }
 
+    _vdp_backend_dll = _vdp_driver_dll;
+
     vdpau_trace = getenv("VDPAU_TRACE");
     if (vdpau_trace && atoi(vdpau_trace)) {
-        void *         trace_dll;
         SetDllHandle * set_dll_handle;
 
-        trace_dll = dlopen(VDPAU_MODULEDIR "/libvdpau_trace.so.1", RTLD_NOW | RTLD_GLOBAL);
-        if (!trace_dll) {
+        _vdp_trace_dll = dlopen(VDPAU_MODULEDIR "/libvdpau_trace.so.1",
+                                RTLD_NOW | RTLD_GLOBAL);
+        if (!_vdp_trace_dll) {
             fprintf(stderr, "Failed to open VDPAU trace library %s\n", dlerror());
             _VDP_ERROR_BREAKPOINT();
             return VDP_STATUS_NO_IMPLEMENTATION;
         }
 
         set_dll_handle = (SetDllHandle*)dlsym(
-            trace_dll,
+            _vdp_trace_dll,
             "vdp_trace_set_backend_handle"
         );
         if (!set_dll_handle) {
@@ -167,9 +173,9 @@ VdpStatus vdp_device_create_x11(
             return VDP_STATUS_NO_IMPLEMENTATION;
         }
 
-        set_dll_handle(backend_dll);
+        set_dll_handle(_vdp_backend_dll);
 
-        backend_dll = trace_dll;
+        _vdp_backend_dll = _vdp_trace_dll;
 
         func_name = "vdp_trace_device_create_x11";
     }
@@ -177,17 +183,52 @@ VdpStatus vdp_device_create_x11(
         func_name = "vdp_imp_device_create_x11";
     }
 
-    vdp_imp_device_create_x11 = (VdpDeviceCreateX11*)dlsym(
-        backend_dll,
+    _vdp_imp_device_create_x11_proc = (VdpDeviceCreateX11*)dlsym(
+        _vdp_backend_dll,
         func_name
     );
-    if (!vdp_imp_device_create_x11) {
+    if (!_vdp_imp_device_create_x11_proc) {
         fprintf(stderr, "%s\n", dlerror());
         _VDP_ERROR_BREAKPOINT();
         return VDP_STATUS_NO_IMPLEMENTATION;
     }
 
-    return vdp_imp_device_create_x11(
+    return VDP_STATUS_OK;
+}
+
+static void _vdp_close_driver(void)
+{
+    if (_vdp_driver_dll) {
+        dlclose(_vdp_driver_dll);
+        _vdp_driver_dll = NULL;
+    }
+    if (_vdp_trace_dll) {
+        dlclose(_vdp_trace_dll);
+        _vdp_trace_dll = NULL;
+    }
+    _vdp_backend_dll = NULL;
+    _vdp_imp_device_create_x11_proc = NULL;
+}
+
+VdpStatus vdp_device_create_x11(
+    Display *             display,
+    int                   screen,
+    /* output parameters follow */
+    VdpDevice *           device,
+    VdpGetProcAddress * * get_proc_address
+)
+{
+    VdpStatus status;
+
+    if (!_vdp_imp_device_create_x11_proc) {
+        status = _vdp_open_driver(display, screen);
+        if (status != VDP_STATUS_OK) {
+            _vdp_close_driver();
+            return status;
+        }
+    }
+
+    return _vdp_imp_device_create_x11_proc(
         display,
         screen,
         device,