Merge "Vulkan: unload builtin driver to reload updated driver if needed"

vulkan/include/hardware/hwvulkan.h

@@ -54,8 +54,9 @@ typedef union {
 /* A hwvulkan_device_t corresponds to an ICD on other systems. Currently there
  * can only be one on a system (HWVULKAN_DEVICE_0). It is opened once per
  * process when the Vulkan API is first used; the hw_device_t::close() function
- * is never called. Any non-trivial resource allocation should be done when
- * the VkInstance is created rather than when the hwvulkan_device_t is opened.
+ * is called upon driver unloading. Any non-trivial resource allocation should
+ * be done when the VkInstance is created rather than when the hwvulkan_device_t
+ * is opened.
  */
 typedef struct hwvulkan_device_t {
     struct hw_device_t common;

vulkan/libvulkan/api.cpp

@@ -1174,23 +1174,18 @@ const LayerChain::ActiveLayer* LayerChain::GetActiveLayers(
 // ----------------------------------------------------------------------------
 
 bool EnsureInitialized() {
-    static std::once_flag once_flag;
-    static bool initialized;
+    static bool initialized = false;
+    static pid_t init_attempted_for_pid = 0;
+    static std::mutex init_lock;
 
-    std::call_once(once_flag, []() {
-        if (driver::OpenHAL()) {
-            initialized = true;
-        }
-    });
+    std::lock_guard<std::mutex> lock(init_lock);
+    if (init_attempted_for_pid == getpid())
+        return initialized;
 
-    {
-        static pid_t pid = getpid() + 1;
-        static std::mutex layer_lock;
-        std::lock_guard<std::mutex> lock(layer_lock);
-        if (pid != getpid()) {
-            pid = getpid();
-            DiscoverLayers();
-        }
+    init_attempted_for_pid = getpid();
+    if (driver::OpenHAL()) {
+        DiscoverLayers();
+        initialized = true;
     }
 
     return initialized;

vulkan/libvulkan/driver.cpp

@@ -84,6 +84,8 @@ class Hal {
     Hal(const Hal&) = delete;
     Hal& operator=(const Hal&) = delete;
 
+    bool ShouldUnloadBuiltinDriver();
+    void UnloadBuiltinDriver();
     bool InitDebugReportIndex();
 
     static Hal hal_;
@@ -243,7 +245,12 @@ bool Hal::Open() {
 
     const nsecs_t openTime = systemTime();
 
-    ALOG_ASSERT(!hal_.dev_, "OpenHAL called more than once");
+    if (hal_.ShouldUnloadBuiltinDriver()) {
+        hal_.UnloadBuiltinDriver();
+    }
+
+    if (hal_.dev_)
+        return true;
 
     // Use a stub device unless we successfully open a real HAL device.
     hal_.dev_ = &stubhal::kDevice;
@@ -288,6 +295,38 @@ bool Hal::Open() {
     return true;
 }
 
+bool Hal::ShouldUnloadBuiltinDriver() {
+    // Should not unload since the driver was not loaded
+    if (!hal_.dev_)
+        return false;
+
+    // Should not unload if stubhal is used on the device
+    if (hal_.dev_ == &stubhal::kDevice)
+        return false;
+
+    // Unload the driver if updated driver is chosen
+    if (android::GraphicsEnv::getInstance().getDriverNamespace())
+        return true;
+
+    return false;
+}
+
+void Hal::UnloadBuiltinDriver() {
+    ATRACE_CALL();
+
+    ALOGD("Unload builtin Vulkan driver.");
+
+    // Close the opened device
+    ALOG_ASSERT(!hal_.dev_->common.close(hal_.dev_->common),
+                "hw_device_t::close() failed.");
+
+    // Close the opened shared library in the hw_module_t
+    dlclose(hal_.dev_->common.module->dso);
+
+    hal_.dev_ = nullptr;
+    hal_.debug_report_index_ = -1;
+}
+
 bool Hal::InitDebugReportIndex() {
     ATRACE_CALL();