minigbm: refactor cros_gralloc_driver to be a singleton

Only a single cros_gralloc_driver instance is allowed to exist in a
process. However, currently when Gralloc3.0 or Gralloc4.0 is used, it's
possible for 2 independent driver instances to be created. This change
refactors cros_gralloc_driver to be a singleton and ensures the driver
initialization only happens once per process.

BUG=b:191895066
TEST=No regression of gralloc0 in ARCVM

Change-Id: I3cb8b7c3d13717cfe531b557b9d69b72efdbf3da
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/minigbm/+/3002266
Tested-by: Yiwei Zhang <zzyiwei@chromium.org>
Tested-by: Jason Macnak <natsu@google.com>
Tested-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Gurchetan Singh <gurchetansingh@chromium.org>
Reviewed-by: Jason Macnak <natsu@google.com>
Commit-Queue: Yiwei Zhang <zzyiwei@chromium.org>

11 files changed, 43 insertions, 114 deletions

diff --git a/cros_gralloc/cros_gralloc_driver.cc b/cros_gralloc/cros_gralloc_driver.cc
index f0c0392..aa53537 100644
--- a/cros_gralloc/cros_gralloc_driver.cc
+++ b/cros_gralloc/cros_gralloc_driver.cc
@@ -45,21 +45,16 @@ int memfd_create_wrapper(const char *name, unsigned int flags)
 	return fd;
 }
 
-cros_gralloc_driver::cros_gralloc_driver() : drv_(nullptr)
+cros_gralloc_driver *cros_gralloc_driver::get_instance()
 {
-}
+	static cros_gralloc_driver s_instance;
 
-cros_gralloc_driver::~cros_gralloc_driver()
-{
-	buffers_.clear();
-	handles_.clear();
-
-	if (drv_) {
-		int fd = drv_get_fd(drv_);
-		drv_destroy(drv_);
-		drv_ = nullptr;
-		close(fd);
+	if (!s_instance.is_initialized()) {
+		drv_log("Failed to initialize driver.\n");
+		return nullptr;
 	}
+
+	return &s_instance;
 }
 
 static struct driver *init_try_node(int idx, char const *str)
@@ -84,7 +79,7 @@ static struct driver *init_try_node(int idx, char const *str)
 	return drv;
 }
 
-int32_t cros_gralloc_driver::init()
+cros_gralloc_driver::cros_gralloc_driver()
 {
 	/*
 	 * Create a driver from render nodes first, then try card
@@ -105,17 +100,33 @@ int32_t cros_gralloc_driver::init()
 	for (uint32_t i = min_render_node; i < max_render_node; i++) {
 		drv_ = init_try_node(i, render_nodes_fmt);
 		if (drv_)
-			return 0;
+			return;
 	}
 
 	// Try card nodes... for vkms mostly.
 	for (uint32_t i = min_card_node; i < max_card_node; i++) {
 		drv_ = init_try_node(i, card_nodes_fmt);
 		if (drv_)
-			return 0;
+			return;
 	}
+}
 
-	return -ENODEV;
+cros_gralloc_driver::~cros_gralloc_driver()
+{
+	buffers_.clear();
+	handles_.clear();
+
+	if (drv_) {
+		int fd = drv_get_fd(drv_);
+		drv_destroy(drv_);
+		drv_ = nullptr;
+		close(fd);
+	}
+}
+
+bool cros_gralloc_driver::is_initialized()
+{
+	return drv_ != nullptr;
 }
 
 bool cros_gralloc_driver::is_supported(const struct cros_gralloc_buffer_descriptor *descriptor)
diff --git a/cros_gralloc/cros_gralloc_driver.h b/cros_gralloc/cros_gralloc_driver.h
index ef9e21f..580605c 100644
--- a/cros_gralloc/cros_gralloc_driver.h
+++ b/cros_gralloc/cros_gralloc_driver.h
@@ -16,10 +16,7 @@
 class cros_gralloc_driver
 {
       public:
-	cros_gralloc_driver();
-	~cros_gralloc_driver();
-
-	int32_t init();
+	static cros_gralloc_driver *get_instance();
 	bool is_supported(const struct cros_gralloc_buffer_descriptor *descriptor);
 	int32_t allocate(const struct cros_gralloc_buffer_descriptor *descriptor,
 			 buffer_handle_t *out_handle);
@@ -47,12 +44,13 @@ class cros_gralloc_driver
 	void for_each_handle(const std::function<void(cros_gralloc_handle_t)> &function);
 
       private:
-	cros_gralloc_driver(cros_gralloc_driver const &);
-	cros_gralloc_driver operator=(cros_gralloc_driver const &);
+	cros_gralloc_driver();
+	~cros_gralloc_driver();
+	bool is_initialized();
 	cros_gralloc_buffer *get_buffer(cros_gralloc_handle_t hnd);
 	void emplace_buffer(struct bo *bo, struct cros_gralloc_handle *hnd);
 
-	struct driver *drv_;
+	struct driver *drv_ = nullptr;
 	std::mutex mutex_;
 	std::unordered_map<uint32_t, cros_gralloc_buffer *> buffers_;
 	std::unordered_map<cros_gralloc_handle_t, std::pair<cros_gralloc_buffer *, int32_t>>
diff --git a/cros_gralloc/gralloc0/gralloc0.cc b/cros_gralloc/gralloc0/gralloc0.cc
index 386a90a..8570150 100644
--- a/cros_gralloc/gralloc0/gralloc0.cc
+++ b/cros_gralloc/gralloc0/gralloc0.cc
@@ -15,7 +15,7 @@
 struct gralloc0_module {
 	gralloc_module_t base;
 	std::unique_ptr<alloc_device_t> alloc;
-	std::unique_ptr<cros_gralloc_driver> driver;
+	cros_gralloc_driver *driver;
 	bool initialized;
 	std::mutex initialization_mutex;
 };
@@ -224,11 +224,9 @@ static int gralloc0_init(struct gralloc0_module *mod, bool initialize_alloc)
 	if (mod->initialized)
 		return 0;
 
-	mod->driver = std::make_unique<cros_gralloc_driver>();
-	if (mod->driver->init()) {
-		drv_log("Failed to initialize driver.\n");
+	mod->driver = cros_gralloc_driver::get_instance();
+	if (!mod->driver)
 		return -ENODEV;
-	}
 
 	if (initialize_alloc) {
 		mod->alloc = std::make_unique<alloc_device_t>();
diff --git a/cros_gralloc/gralloc3/CrosGralloc3Allocator.cc b/cros_gralloc/gralloc3/CrosGralloc3Allocator.cc
index 57c49e9..bb9ff97 100644
--- a/cros_gralloc/gralloc3/CrosGralloc3Allocator.cc
+++ b/cros_gralloc/gralloc3/CrosGralloc3Allocator.cc
@@ -24,13 +24,6 @@ using android::hardware::graphics::mapper::V3_0::Error;
 using BufferDescriptorInfo =
         android::hardware::graphics::mapper::V3_0::IMapper::BufferDescriptorInfo;
 
-CrosGralloc3Allocator::CrosGralloc3Allocator() : mDriver(std::make_unique<cros_gralloc_driver>()) {
-    if (mDriver->init()) {
-        drv_log("Failed to initialize driver.\n");
-        mDriver = nullptr;
-    }
-}
-
 Error CrosGralloc3Allocator::allocate(const BufferDescriptorInfo& descriptor, uint32_t* outStride,
                                       hidl_handle* outHandle) {
     if (!mDriver) {
diff --git a/cros_gralloc/gralloc3/CrosGralloc3Allocator.h b/cros_gralloc/gralloc3/CrosGralloc3Allocator.h
index 655143c..24a34bd 100644
--- a/cros_gralloc/gralloc3/CrosGralloc3Allocator.h
+++ b/cros_gralloc/gralloc3/CrosGralloc3Allocator.h
@@ -11,7 +11,7 @@
 
 class CrosGralloc3Allocator : public android::hardware::graphics::allocator::V3_0::IAllocator {
   public:
-    CrosGralloc3Allocator();
+    CrosGralloc3Allocator() = default;
 
     android::hardware::Return<void> allocate(
             const android::hardware::hidl_vec<uint32_t>& descriptor, uint32_t count,
@@ -25,5 +25,5 @@ class CrosGralloc3Allocator : public android::hardware::graphics::allocator::V3_
                     description,
             uint32_t* outStride, android::hardware::hidl_handle* outHandle);
 
-    std::unique_ptr<cros_gralloc_driver> mDriver;
+    cros_gralloc_driver* mDriver = cros_gralloc_driver::get_instance();
 };
diff --git a/cros_gralloc/gralloc3/CrosGralloc3Mapper.cc b/cros_gralloc/gralloc3/CrosGralloc3Mapper.cc
index 08da016..a0b19f0 100644
--- a/cros_gralloc/gralloc3/CrosGralloc3Mapper.cc
+++ b/cros_gralloc/gralloc3/CrosGralloc3Mapper.cc
@@ -23,13 +23,6 @@ using android::hardware::graphics::mapper::V3_0::Error;
 using android::hardware::graphics::mapper::V3_0::IMapper;
 using android::hardware::graphics::mapper::V3_0::YCbCrLayout;
 
-CrosGralloc3Mapper::CrosGralloc3Mapper() : mDriver(std::make_unique<cros_gralloc_driver>()) {
-    if (mDriver->init()) {
-        drv_log("Failed to initialize driver.\n");
-        mDriver = nullptr;
-    }
-}
-
 Return<void> CrosGralloc3Mapper::createDescriptor(const BufferDescriptorInfo& description,
                                                   createDescriptor_cb hidlCb) {
     hidl_vec<uint32_t> descriptor;
diff --git a/cros_gralloc/gralloc3/CrosGralloc3Mapper.h b/cros_gralloc/gralloc3/CrosGralloc3Mapper.h
index 7ec92d5..54db61e 100644
--- a/cros_gralloc/gralloc3/CrosGralloc3Mapper.h
+++ b/cros_gralloc/gralloc3/CrosGralloc3Mapper.h
@@ -13,7 +13,7 @@
 
 class CrosGralloc3Mapper : public android::hardware::graphics::mapper::V3_0::IMapper {
   public:
-    CrosGralloc3Mapper();
+    CrosGralloc3Mapper() = default;
 
     android::hardware::Return<void> createDescriptor(const BufferDescriptorInfo& description,
                                                      createDescriptor_cb hidlCb) override;
@@ -58,7 +58,7 @@ class CrosGralloc3Mapper : public android::hardware::graphics::mapper::V3_0::IMa
                             const Rect& accessRegion,
                             const android::hardware::hidl_handle& acquireFence);
 
-    std::unique_ptr<cros_gralloc_driver> mDriver;
+    cros_gralloc_driver* mDriver = cros_gralloc_driver::get_instance();
 };
 
 extern "C" android::hardware::graphics::mapper::V3_0::IMapper* HIDL_FETCH_IMapper(const char* name);
diff --git a/cros_gralloc/gralloc4/CrosGralloc4Allocator.cc b/cros_gralloc/gralloc4/CrosGralloc4Allocator.cc
index e7e5f3a..200b939 100644
--- a/cros_gralloc/gralloc4/CrosGralloc4Allocator.cc
+++ b/cros_gralloc/gralloc4/CrosGralloc4Allocator.cc
@@ -23,13 +23,6 @@ using android::hardware::graphics::mapper::V4_0::Error;
 using BufferDescriptorInfo =
         android::hardware::graphics::mapper::V4_0::IMapper::BufferDescriptorInfo;
 
-CrosGralloc4Allocator::CrosGralloc4Allocator() : mDriver(std::make_unique<cros_gralloc_driver>()) {
-    if (mDriver->init()) {
-        drv_log("Failed to initialize driver.\n");
-        mDriver = nullptr;
-    }
-}
-
 Error CrosGralloc4Allocator::allocate(const BufferDescriptorInfo& descriptor, uint32_t* outStride,
                                       hidl_handle* outHandle) {
     if (!mDriver) {
diff --git a/cros_gralloc/gralloc4/CrosGralloc4Allocator.h b/cros_gralloc/gralloc4/CrosGralloc4Allocator.h
index 21ad7ad..cb3b4b8 100644
--- a/cros_gralloc/gralloc4/CrosGralloc4Allocator.h
+++ b/cros_gralloc/gralloc4/CrosGralloc4Allocator.h
@@ -11,7 +11,7 @@
 
 class CrosGralloc4Allocator : public android::hardware::graphics::allocator::V4_0::IAllocator {
   public:
-    CrosGralloc4Allocator();
+    CrosGralloc4Allocator() = default;
 
     android::hardware::Return<void> allocate(const android::hardware::hidl_vec<uint8_t>& descriptor,
                                              uint32_t count, allocate_cb hidl_cb) override;
@@ -22,5 +22,5 @@ class CrosGralloc4Allocator : public android::hardware::graphics::allocator::V4_
                     description,
             uint32_t* outStride, android::hardware::hidl_handle* outHandle);
 
-    std::unique_ptr<cros_gralloc_driver> mDriver;
+    cros_gralloc_driver* mDriver = cros_gralloc_driver::get_instance();
 };
diff --git a/cros_gralloc/gralloc4/CrosGralloc4Mapper.cc b/cros_gralloc/gralloc4/CrosGralloc4Mapper.cc
index 1bfd442..807eba1 100644
--- a/cros_gralloc/gralloc4/CrosGralloc4Mapper.cc
+++ b/cros_gralloc/gralloc4/CrosGralloc4Mapper.cc
@@ -31,62 +31,6 @@ using android::hardware::graphics::common::V1_2::PixelFormat;
 using android::hardware::graphics::mapper::V4_0::Error;
 using android::hardware::graphics::mapper::V4_0::IMapper;
 
-namespace {
-
-// Provides a single instance of cros_gralloc_driver to all active instances of
-// CrosGralloc4Mapper in a single process while destroying the cros_gralloc_driver
-// when there are no active instances of CrosGralloc4Mapper.
-class DriverProvider {
-  public:
-    static DriverProvider* Get() {
-        static DriverProvider* instance = new DriverProvider();
-        return instance;
-    }
-
-    cros_gralloc_driver* GetAndReferenceDriver() {
-        std::lock_guard<std::mutex> lock(mMutex);
-        if (!mDriver) {
-            mDriver = std::make_unique<cros_gralloc_driver>();
-            if (mDriver->init()) {
-                drv_log("Failed to initialize driver.\n");
-                mDriver.reset();
-                return nullptr;
-            }
-        }
-
-        ++mReferenceCount;
-        return mDriver.get();
-    }
-
-    void UnreferenceDriver() {
-        std::lock_guard<std::mutex> lock(mMutex);
-
-        --mReferenceCount;
-
-        if (mReferenceCount == 0) {
-            mDriver.reset();
-        }
-    }
-
-  private:
-    DriverProvider() = default;
-
-    std::mutex mMutex;
-    std::unique_ptr<cros_gralloc_driver> mDriver;
-    std::size_t mReferenceCount = 0;
-};
-
-}  // namespace
-
-CrosGralloc4Mapper::CrosGralloc4Mapper() {
-    mDriver = DriverProvider::Get()->GetAndReferenceDriver();
-}
-
-CrosGralloc4Mapper::~CrosGralloc4Mapper() {
-    mDriver = nullptr;
-    DriverProvider::Get()->UnreferenceDriver();
-}
-
 Return<void> CrosGralloc4Mapper::createDescriptor(const BufferDescriptorInfo& description,
                                                   createDescriptor_cb hidlCb) {
     hidl_vec<uint8_t> descriptor;
diff --git a/cros_gralloc/gralloc4/CrosGralloc4Mapper.h b/cros_gralloc/gralloc4/CrosGralloc4Mapper.h
index 3c159a2..0641b29 100644
--- a/cros_gralloc/gralloc4/CrosGralloc4Mapper.h
+++ b/cros_gralloc/gralloc4/CrosGralloc4Mapper.h
@@ -11,8 +11,7 @@
 
 class CrosGralloc4Mapper : public android::hardware::graphics::mapper::V4_0::IMapper {
   public:
-    CrosGralloc4Mapper();
-    ~CrosGralloc4Mapper();
+    CrosGralloc4Mapper() = default;
 
     android::hardware::Return<void> createDescriptor(const BufferDescriptorInfo& description,
                                                      createDescriptor_cb hidlCb) override;
@@ -75,7 +74,7 @@ class CrosGralloc4Mapper : public android::hardware::graphics::mapper::V4_0::IMa
     int getResolvedDrmFormat(android::hardware::graphics::common::V1_2::PixelFormat pixelFormat,
                              uint64_t bufferUsage, uint32_t* outDrmFormat);
 
-    cros_gralloc_driver* mDriver = nullptr;
+    cros_gralloc_driver* mDriver = cros_gralloc_driver::get_instance();
 };
 
 extern "C" android::hardware::graphics::mapper::V4_0::IMapper* HIDL_FETCH_IMapper(const char* name);