From 7fbd79cab2e548eb388bc782dd39f1cde027173b Mon Sep 17 00:00:00 2001

From: Ming-Hung Tsai <mtsai@redhat.com>

Date: Tue, 1 Jun 2021 23:37:36 +0800

Subject: [PATCH 04/10] [thin_dump] Fix leaked shared object handle

---

 thin-provisioning/shared_library_emitter.cc | 113 ++++++++++++++++++++++++----

 1 file changed, 100 insertions(+), 13 deletions(-)

diff --git a/thin-provisioning/shared_library_emitter.cc b/thin-provisioning/shared_library_emitter.cc

index 58f12d2..2e845f3 100644

--- a/thin-provisioning/shared_library_emitter.cc

+++ b/thin-provisioning/shared_library_emitter.cc

@@ -8,22 +8,109 @@ using namespace thin_provisioning;

 //----------------------------------------------------------------

-emitter::ptr

-thin_provisioning::create_custom_emitter(string const &shared_lib, ostream &out)

-{

-	emitter::ptr (*create_fn)(ostream &out;;

-	void *handle = dlopen(shared_lib.c_str(), RTLD_LAZY);

-	if (!handle)

-		throw runtime_error(dlerror());

+struct shared_object {

+public:

+	shared_object(const char *shared_lib) {

+		handle_ = dlopen(shared_lib, RTLD_LAZY);

+		if (!handle_)

+			throw runtime_error(dlerror());

+

+		dlerror();    // Clear any existing error

+	}

+

+	virtual ~shared_object() {

+		dlclose(handle_);

+	}

+

+	void *get_symbol(const char *symbol) {

+		void *sym = dlsym(handle_, symbol);

+

+		char *error = dlerror();

+		if (error)

+			throw runtime_error(error);

+

+		return sym;

+	}

+

+	void *handle_;

+};

+

+class shared_emitter : public emitter {

+public:

+	shared_emitter(const char *shared_lib, ostream &out): sobj_(shared_lib) {

+		emitter::ptr (*create_fn)(ostream &out;;

+		create_fn = reinterpret_cast<emitter::ptr (*)(ostream &)>(

+				sobj_.get_symbol("create_emitter"));

+		inner_ = create_fn(out);

+	}

+

+	virtual ~shared_emitter() {

+	}

+

+	void begin_superblock(std::string const &uuid,

+			      uint64_t time,

+			      uint64_t trans_id,

+			      boost::optional<uint32_t> flags,

+			      boost::optional<uint32_t> version,

+			      uint32_t data_block_size,

+			      uint64_t nr_data_blocks,

+			      boost::optional<uint64_t> metadata_snap) {

+		inner_->begin_superblock(uuid,

+					 time,

+					 trans_id,

+					 flags,

+					 version,

+					 data_block_size,

+					 nr_data_blocks,

+					 metadata_snap);

+	}

-	dlerror();    // Clear any existing error

-	create_fn = reinterpret_cast<emitter::ptr (*)(ostream &)>(dlsym(handle, "create_emitter"));

+	void end_superblock() {

+		inner_->end_superblock();

+	}

-	char *error = dlerror();

-	if (error)

-		throw runtime_error(error);

+	void begin_device(uint32_t dev_id,

+			  uint64_t mapped_blocks,

+			  uint64_t trans_id,

+			  uint64_t creation_time,

+			  uint64_t snap_time) {

+		inner_->begin_device(dev_id, mapped_blocks, trans_id, creation_time, snap_time);

+	}

-	return create_fn(out);

+	void end_device() {

+		inner_->end_device();

+	}

+

+	void begin_named_mapping(std::string const &name) {

+		inner_->begin_named_mapping(name);

+	}

+

+	void end_named_mapping() {

+		inner_->end_named_mapping();

+	}

+

+	void identifier(std::string const &name) {

+		inner_->identifier(name);

+	}

+

+	void range_map(uint64_t origin_begin, uint64_t data_begin, uint32_t time, uint64_t len) {

+		inner_->range_map(origin_begin, data_begin, time, len);

+	}

+

+	void single_map(uint64_t origin_block, uint64_t data_block, uint32_t time) {

+		inner_->single_map(origin_block, data_block, time);

+	}

+

+	shared_object sobj_;

+	emitter::ptr inner_;

+};

+

+//----------------------------------------------------------------

+

+emitter::ptr

+thin_provisioning::create_custom_emitter(string const &shared_lib, ostream &out)

+{

+	return emitter::ptr(new shared_emitter(shared_lib.c_str(), out));

 }

 //----------------------------------------------------------------

-- 

1.8.3.1