Wayland example window

src/core/memory/SharedMemory.cpp

@@ -0,0 +1,68 @@
+#include "SharedMemory.h"
+
+#include "RandomUtils.h"
+
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+void SharedMemory::allocate(const std::string& namePrefix, std::size_t size)
+{
+	createFile(namePrefix);
+
+	if (!mIsValid)
+	{
+		return;
+	}
+
+	int ret{-1};
+	do {
+		ret = ftruncate(mFileDescriptor, size);
+	} while (ret < 0 && errno == EINTR);
+
+	if (ret < 0)
+	{
+		close(mFileDescriptor);
+		mIsValid = false;
+	}
+}
+
+int SharedMemory::getFileDescriptor() const
+{
+	return mFileDescriptor;
+}
+
+bool SharedMemory::isValid() const
+{
+	return mIsValid;
+}
+
+void SharedMemory::createFile(const std::string& namePrefix)
+{
+	unsigned retries = 100;
+	do {
+		const auto name = getRandomName(namePrefix);
+		--retries;
+
+		const int fd = shm_open(name.c_str(), O_RDWR | O_CREAT | O_EXCL, 0600);
+		if (fd >= 0)
+		{
+			shm_unlink(name.c_str());
+			mFileDescriptor = fd;
+			mIsValid = true;
+			break;
+		}
+	} while (retries > 0 && errno == EEXIST);
+}
+
+std::string SharedMemory::getRandomName(const std::string& namePrefix) const
+{
+	std::string randomSuffix;
+	for (const auto entry : RandomUtils::getRandomVecUnsigned(6))
+	{
+		randomSuffix += std::to_string(entry);
+	}
+	return namePrefix + randomSuffix;
+}

src/core/memory/SharedMemory.h

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+#pragma once
+
+#include <string>
+
+class SharedMemory
+{
+public:
+	void allocate(const std::string& namePrefix, std::size_t size);
+
+	int getFileDescriptor() const;
+
+	bool isValid() const;
+
+private:
+
+	void createFile(const std::string& namePrefix);
+
+	std::string getRandomName(const std::string& namePrefix) const;
+
+	int mFileDescriptor{0};
+	bool mIsValid{false};
+};