[libcamera-devel] [RFC PATCH 03/10] libcamera: File: Manage fd by ScopedFD

[Hirokazu Honda]

File owns the file descriptor for a file. It should be managed
by ScopedFD to avoid the leakage.

Signed-off-by: Hirokazu Honda <hiroh at chromium.org>
---
 include/libcamera/internal/file.h |  5 +++--
 src/libcamera/file.cpp            | 26 +++++++++++++-------------
 2 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/include/libcamera/internal/file.h b/include/libcamera/internal/file.h
index f0b313a5..e6eb7f04 100644
--- a/include/libcamera/internal/file.h
+++ b/include/libcamera/internal/file.h
@@ -12,6 +12,7 @@
 #include <sys/types.h>
 
 #include <libcamera/class.h>
+#include <libcamera/scoped_file_descriptor.h>
 #include <libcamera/span.h>
 
 namespace libcamera {
@@ -40,7 +41,7 @@ public:
 	bool exists() const;
 
 	bool open(OpenMode mode);
-	bool isOpen() const { return fd_ != -1; }
+	bool isOpen() const { return fd_.isValid(); }
 	OpenMode openMode() const { return mode_; }
 	void close();
 
@@ -65,7 +66,7 @@ private:
 	void unmapAll();
 
 	std::string name_;
-	int fd_;
+	ScopedFD fd_;
 	OpenMode mode_;
 
 	int error_;
diff --git a/src/libcamera/file.cpp b/src/libcamera/file.cpp
index bce2b613..4db9a8d3 100644
--- a/src/libcamera/file.cpp
+++ b/src/libcamera/file.cpp
@@ -73,7 +73,7 @@ LOG_DEFINE_CATEGORY(File)
  * before performing I/O operations.
  */
 File::File(const std::string &name)
-	: name_(name), fd_(-1), mode_(NotOpen), error_(0)
+	: name_(name), mode_(NotOpen), error_(0)
 {
 }
 
@@ -84,7 +84,7 @@ File::File(const std::string &name)
  * setFileName().
  */
 File::File()
-	: fd_(-1), mode_(NotOpen), error_(0)
+	: mode_(NotOpen), error_(0)
 {
 }
 
@@ -167,12 +167,13 @@ bool File::open(File::OpenMode mode)
 	if (mode & WriteOnly)
 		flags |= O_CREAT;
 
-	fd_ = ::open(name_.c_str(), flags, 0666);
-	if (fd_ < 0) {
+	int fd = ::open(name_.c_str(), flags, 0666);
+	if (fd < 0) {
 		error_ = -errno;
 		return false;
 	}
 
+	fd_ = ScopedFD(fd);
 	mode_ = mode;
 	error_ = 0;
 	return true;
@@ -199,11 +200,10 @@ bool File::open(File::OpenMode mode)
  */
 void File::close()
 {
-	if (fd_ == -1)
+	if (!fd_.isValid())
 		return;
 
-	::close(fd_);
-	fd_ = -1;
+	fd_.reset();
 	mode_ = NotOpen;
 }
 
@@ -233,7 +233,7 @@ ssize_t File::size() const
 		return -EINVAL;
 
 	struct stat st;
-	int ret = fstat(fd_, &st);
+	int ret = fstat(fd_.get(), &st);
 	if (ret < 0)
 		return -errno;
 
@@ -252,7 +252,7 @@ off_t File::pos() const
 	if (!isOpen())
 		return 0;
 
-	return lseek(fd_, 0, SEEK_CUR);
+	return lseek(fd_.get(), 0, SEEK_CUR);
 }
 
 /**
@@ -266,7 +266,7 @@ off_t File::seek(off_t pos)
 	if (!isOpen())
 		return -EINVAL;
 
-	off_t ret = lseek(fd_, pos, SEEK_SET);
+	off_t ret = lseek(fd_.get(), pos, SEEK_SET);
 	if (ret < 0)
 		return -errno;
 
@@ -298,7 +298,7 @@ ssize_t File::read(const Span<uint8_t> &data)
 
 	/* Retry in case of interrupted system calls. */
 	while (readBytes < data.size()) {
-		ret = ::read(fd_, data.data() + readBytes,
+		ret = ::read(fd_.get(), data.data() + readBytes,
 			     data.size() - readBytes);
 		if (ret <= 0)
 			break;
@@ -335,7 +335,7 @@ ssize_t File::write(const Span<const uint8_t> &data)
 
 	/* Retry in case of interrupted system calls. */
 	while (writtenBytes < data.size()) {
-		ssize_t ret = ::write(fd_, data.data() + writtenBytes,
+		ssize_t ret = ::write(fd_.get(), data.data() + writtenBytes,
 				      data.size() - writtenBytes);
 		if (ret <= 0)
 			break;
@@ -398,7 +398,7 @@ Span<uint8_t> File::map(off_t offset, ssize_t size, enum File::MapFlag flags)
 	if (flags & MapPrivate)
 		prot |= PROT_WRITE;
 
-	void *map = mmap(NULL, size, prot, mmapFlags, fd_, offset);
+	void *map = mmap(NULL, size, prot, mmapFlags, fd_.get(), offset);
 	if (map == MAP_FAILED) {
 		error_ = -errno;
 		return {};
-- 
2.31.1.368.gbe11c130af-goog