everything everywhere

all at once

1 files changed, 80 insertions, 0 deletions

diff --git a/source/core/StarLockFile_windows.cpp b/source/core/StarLockFile_windows.cpp
new file mode 100644
index 0000000..1cf1473
--- /dev/null
+++ b/source/core/StarLockFile_windows.cpp
@@ -0,0 +1,80 @@
+#include "StarLockFile.hpp"
+#include "StarTime.hpp"
+#include "StarThread.hpp"
+
+#include "StarString_windows.hpp"
+
+#include <windows.h>
+
+namespace Star {
+
+int64_t const LockFile::MaximumSleepMillis;
+
+Maybe<LockFile> LockFile::acquireLock(String const& filename, int64_t lockTimeout) {
+  LockFile lock(move(filename));
+  if (lock.lock(lockTimeout))
+    return move(lock);
+  return {};
+}
+
+LockFile::LockFile(String const& filename) : m_filename(move(filename)) {}
+
+LockFile::LockFile(LockFile&& lockFile) {
+  operator=(move(lockFile));
+}
+
+LockFile::~LockFile() {
+  unlock();
+}
+
+LockFile& LockFile::operator=(LockFile&& lockFile) {
+  m_filename = move(lockFile.m_filename);
+  m_handle = move(lockFile.m_handle);
+
+  return *this;
+}
+
+bool LockFile::lock(int64_t timeout) {
+  auto doFLock = [](String const& filename) -> shared_ptr<HANDLE> {
+    HANDLE handle = CreateFileW(
+        stringToUtf16(filename).get(), GENERIC_READ, 0, nullptr, OPEN_ALWAYS, FILE_FLAG_DELETE_ON_CLOSE, nullptr);
+    if (handle == INVALID_HANDLE_VALUE) {
+      if (GetLastError() == ERROR_SHARING_VIOLATION)
+        return {};
+      throw StarException(strf("Could not open lock file %s, error code %s\n", filename, GetLastError()));
+    }
+
+    return make_shared<HANDLE>(handle);
+  };
+
+  if (timeout == 0) {
+    m_handle = doFLock(m_filename);
+    return (bool)m_handle;
+  } else {
+    int64_t startTime = Time::monotonicMilliseconds();
+    while (true) {
+      m_handle = doFLock(m_filename);
+      if (m_handle)
+        return true;
+
+      if (timeout > 0 && Time::monotonicMilliseconds() - startTime > timeout)
+        return false;
+
+      Thread::sleep(min(timeout / 4, MaximumSleepMillis));
+    }
+  }
+}
+
+void LockFile::unlock() {
+  if (m_handle) {
+    HANDLE handle = *(HANDLE*)m_handle.get();
+    CloseHandle(handle);
+    m_handle.reset();
+  }
+}
+
+bool LockFile::isLocked() const {
+  return (bool)m_handle;
+}
+
+}