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Simple drawing example.

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This commit is contained in:
James Grogan 2022-12-05 10:59:45 +00:00
parent d7fe11913f
commit f0091f9e04
27 changed files with 450 additions and 68 deletions
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70
src/core/memory/SharedMemory.cpp
View file

@ -12,63 +12,63 @@
void SharedMemory::allocate(const std::string& namePrefix, std::size_t size)
{
createFile(namePrefix);
createFile(namePrefix);
if (!mIsValid)
{
return;
}
if (!mIsValid)
{
return;
}
#ifdef __linux__
int ret{-1};
do {
ret = ftruncate(mFileDescriptor, size);
} while (ret < 0 && errno == EINTR);
int ret{-1};
do {
ret = ftruncate(mFileDescriptor, size);
} while (ret < 0 && errno == EINTR);
if (ret < 0)
{
close(mFileDescriptor);
mIsValid = false;
}
if (ret < 0)
{
close(mFileDescriptor);
mIsValid = false;
}
#endif
}
int SharedMemory::getFileDescriptor() const
{
return mFileDescriptor;
return mFileDescriptor;
}
bool SharedMemory::isValid() const
{
return mIsValid;
return mIsValid;
}
void SharedMemory::createFile(const std::string& namePrefix)
{
#ifdef __linux__
unsigned retries = 100;
do {
const auto name = getRandomName(namePrefix);
--retries;
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);
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);
#endif
}
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;
std::string randomSuffix;
for (const auto entry : RandomUtils::getRandomVecUnsigned(6))
{
randomSuffix += std::to_string(entry);
}
return namePrefix + randomSuffix;
}

14
src/core/memory/SharedMemory.h
View file

@ -5,18 +5,18 @@
class SharedMemory
{
public:
void allocate(const std::string& namePrefix, std::size_t size);
void allocate(const std::string& namePrefix, std::size_t size);
int getFileDescriptor() const;
int getFileDescriptor() const;
bool isValid() const;
bool isValid() const;
private:
void createFile(const std::string& namePrefix);
void createFile(const std::string& namePrefix);
std::string getRandomName(const std::string& namePrefix) const;
std::string getRandomName(const std::string& namePrefix) const;
int mFileDescriptor{0};
bool mIsValid{false};
int mFileDescriptor{0};
bool mIsValid{false};
};