diff options
Diffstat (limited to 'source/Host/windows/ConnectionGenericFileWindows.cpp')
-rw-r--r-- | source/Host/windows/ConnectionGenericFileWindows.cpp | 354 |
1 files changed, 354 insertions, 0 deletions
diff --git a/source/Host/windows/ConnectionGenericFileWindows.cpp b/source/Host/windows/ConnectionGenericFileWindows.cpp new file mode 100644 index 000000000000..eebf3d4f633c --- /dev/null +++ b/source/Host/windows/ConnectionGenericFileWindows.cpp @@ -0,0 +1,354 @@ +//===-- ConnectionGenericFileWindows.cpp ------------------------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#include "lldb/Core/Error.h" +#include "lldb/Core/Log.h" +#include "lldb/Host/TimeValue.h" +#include "lldb/Host/windows/ConnectionGenericFileWindows.h" + +#include "llvm/ADT/STLExtras.h" +#include "llvm/ADT/StringRef.h" + +using namespace lldb; +using namespace lldb_private; + +namespace +{ +// This is a simple helper class to package up the information needed to return from a Read/Write +// operation function. Since there is a lot of code to be run before exit regardless of whether the +// operation succeeded or failed, combined with many possible return paths, this is the cleanest +// way to represent it. +class ReturnInfo +{ + public: + void + Set(size_t bytes, ConnectionStatus status, DWORD error_code) + { + m_error.SetError(error_code, eErrorTypeWin32); + m_bytes = bytes; + m_status = status; + } + + void + Set(size_t bytes, ConnectionStatus status, llvm::StringRef error_msg) + { + m_error.SetErrorString(error_msg.data()); + m_bytes = bytes; + m_status = status; + } + + size_t + GetBytes() const + { + return m_bytes; + } + ConnectionStatus + GetStatus() const + { + return m_status; + } + const Error & + GetError() const + { + return m_error; + } + + private: + Error m_error; + size_t m_bytes; + ConnectionStatus m_status; +}; +} + +ConnectionGenericFile::ConnectionGenericFile() + : m_file(INVALID_HANDLE_VALUE) + , m_owns_file(false) +{ + ::ZeroMemory(&m_overlapped, sizeof(m_overlapped)); + ::ZeroMemory(&m_file_position, sizeof(m_file_position)); + InitializeEventHandles(); +} + +ConnectionGenericFile::ConnectionGenericFile(lldb::file_t file, bool owns_file) + : m_file(file) + , m_owns_file(owns_file) +{ + ::ZeroMemory(&m_overlapped, sizeof(m_overlapped)); + ::ZeroMemory(&m_file_position, sizeof(m_file_position)); + InitializeEventHandles(); +} + +ConnectionGenericFile::~ConnectionGenericFile() +{ + if (m_owns_file && IsConnected()) + ::CloseHandle(m_file); + + ::CloseHandle(m_event_handles[kBytesAvailableEvent]); + ::CloseHandle(m_event_handles[kInterruptEvent]); +} + +void +ConnectionGenericFile::InitializeEventHandles() +{ + m_event_handles[kInterruptEvent] = CreateEvent(NULL, FALSE, FALSE, NULL); + + // Note, we should use a manual reset event for the hEvent argument of the OVERLAPPED. This + // is because both WaitForMultipleObjects and GetOverlappedResult (if you set the bWait + // argument to TRUE) will wait for the event to be signalled. If we use an auto-reset event, + // WaitForMultipleObjects will reset the event, return successfully, and then + // GetOverlappedResult will block since the event is no longer signalled. + m_event_handles[kBytesAvailableEvent] = ::CreateEvent(NULL, TRUE, FALSE, NULL); +} + +bool +ConnectionGenericFile::IsConnected() const +{ + return m_file && (m_file != INVALID_HANDLE_VALUE); +} + +lldb::ConnectionStatus +ConnectionGenericFile::Connect(const char *s, Error *error_ptr) +{ + Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_CONNECTION)); + if (log) + log->Printf("%p ConnectionGenericFile::Connect (url = '%s')", static_cast<void *>(this), s); + + if (strstr(s, "file://") != s) + { + if (error_ptr) + error_ptr->SetErrorStringWithFormat("unsupported connection URL: '%s'", s); + return eConnectionStatusError; + } + + if (IsConnected()) + { + ConnectionStatus status = Disconnect(error_ptr); + if (status != eConnectionStatusSuccess) + return status; + } + + // file://PATH + const char *path = s + strlen("file://"); + // Open the file for overlapped access. If it does not exist, create it. We open it overlapped + // so that we can issue asynchronous reads and then use WaitForMultipleObjects to allow the read + // to be interrupted by an event object. + m_file = ::CreateFile(path, GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ, NULL, OPEN_ALWAYS, FILE_FLAG_OVERLAPPED, NULL); + if (m_file == INVALID_HANDLE_VALUE) + { + if (error_ptr) + error_ptr->SetError(::GetLastError(), eErrorTypeWin32); + return eConnectionStatusError; + } + + m_owns_file = true; + m_uri.assign(s); + return eConnectionStatusSuccess; +} + +lldb::ConnectionStatus +ConnectionGenericFile::Disconnect(Error *error_ptr) +{ + Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_CONNECTION)); + if (log) + log->Printf("%p ConnectionGenericFile::Disconnect ()", static_cast<void *>(this)); + + if (!IsConnected()) + return eConnectionStatusSuccess; + + // Reset the handle so that after we unblock any pending reads, subsequent calls to Read() will + // see a disconnected state. + HANDLE old_file = m_file; + m_file = INVALID_HANDLE_VALUE; + + // Set the disconnect event so that any blocking reads unblock, then cancel any pending IO operations. + ::CancelIoEx(old_file, &m_overlapped); + + // Close the file handle if we owned it, but don't close the event handles. We could always + // reconnect with the same Connection instance. + if (m_owns_file) + ::CloseHandle(old_file); + + ::ZeroMemory(&m_file_position, sizeof(m_file_position)); + m_owns_file = false; + m_uri.clear(); + return eConnectionStatusSuccess; +} + +size_t +ConnectionGenericFile::Read(void *dst, size_t dst_len, uint32_t timeout_usec, lldb::ConnectionStatus &status, Error *error_ptr) +{ + ReturnInfo return_info; + BOOL result = 0; + DWORD bytes_read = 0; + + if (error_ptr) + error_ptr->Clear(); + + if (!IsConnected()) + { + return_info.Set(0, eConnectionStatusNoConnection, ERROR_INVALID_HANDLE); + goto finish; + } + + m_overlapped.hEvent = m_event_handles[kBytesAvailableEvent]; + + result = ::ReadFile(m_file, dst, dst_len, NULL, &m_overlapped); + if (result || ::GetLastError() == ERROR_IO_PENDING) + { + if (!result) + { + // The expected return path. The operation is pending. Wait for the operation to complete + // or be interrupted. + TimeValue time_value; + time_value.OffsetWithMicroSeconds(timeout_usec); + DWORD milliseconds = time_value.milliseconds(); + DWORD wait_result = ::WaitForMultipleObjects(llvm::array_lengthof(m_event_handles), m_event_handles, FALSE, milliseconds); + // All of the events are manual reset events, so make sure we reset them to non-signalled. + switch (wait_result) + { + case WAIT_OBJECT_0 + kBytesAvailableEvent: + break; + case WAIT_OBJECT_0 + kInterruptEvent: + return_info.Set(0, eConnectionStatusInterrupted, 0); + goto finish; + case WAIT_TIMEOUT: + return_info.Set(0, eConnectionStatusTimedOut, 0); + goto finish; + case WAIT_FAILED: + return_info.Set(0, eConnectionStatusError, ::GetLastError()); + goto finish; + } + } + // The data is ready. Figure out how much was read and return; + if (!::GetOverlappedResult(m_file, &m_overlapped, &bytes_read, FALSE)) + { + DWORD result_error = ::GetLastError(); + // ERROR_OPERATION_ABORTED occurs when someone calls Disconnect() during a blocking read. + // This triggers a call to CancelIoEx, which causes the operation to complete and the + // result to be ERROR_OPERATION_ABORTED. + if (result_error == ERROR_HANDLE_EOF || result_error == ERROR_OPERATION_ABORTED || result_error == ERROR_BROKEN_PIPE) + return_info.Set(bytes_read, eConnectionStatusEndOfFile, 0); + else + return_info.Set(bytes_read, eConnectionStatusError, result_error); + } + else if (bytes_read == 0) + return_info.Set(bytes_read, eConnectionStatusEndOfFile, 0); + else + return_info.Set(bytes_read, eConnectionStatusSuccess, 0); + + goto finish; + } + else if (::GetLastError() == ERROR_BROKEN_PIPE) + { + // The write end of a pipe was closed. This is equivalent to EOF. + return_info.Set(0, eConnectionStatusEndOfFile, 0); + } + else + { + // An unknown error occurred. Fail out. + return_info.Set(0, eConnectionStatusError, ::GetLastError()); + } + goto finish; + +finish: + status = return_info.GetStatus(); + if (error_ptr) + *error_ptr = return_info.GetError(); + + // kBytesAvailableEvent is a manual reset event. Make sure it gets reset here so that any + // subsequent operations don't immediately see bytes available. + ResetEvent(m_event_handles[kBytesAvailableEvent]); + + IncrementFilePointer(return_info.GetBytes()); + Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_CONNECTION)); + if (log) + { + log->Printf("%" PRIxPTR " ConnectionGenericFile::Read() handle = %" PRIxPTR ", dst = %" PRIxPTR ", dst_len = %" PRIu64 + ") => %" PRIu64 ", error = %s", + this, m_file, dst, static_cast<uint64_t>(dst_len), static_cast<uint64_t>(return_info.GetBytes()), + return_info.GetError().AsCString()); + } + + return return_info.GetBytes(); +} + +size_t +ConnectionGenericFile::Write(const void *src, size_t src_len, lldb::ConnectionStatus &status, Error *error_ptr) +{ + ReturnInfo return_info; + DWORD bytes_written = 0; + BOOL result = 0; + + if (error_ptr) + error_ptr->Clear(); + + if (!IsConnected()) + { + return_info.Set(0, eConnectionStatusNoConnection, ERROR_INVALID_HANDLE); + goto finish; + } + + m_overlapped.hEvent = NULL; + + // Writes are not interruptible like reads are, so just block until it's done. + result = ::WriteFile(m_file, src, src_len, NULL, &m_overlapped); + if (!result && ::GetLastError() != ERROR_IO_PENDING) + { + return_info.Set(0, eConnectionStatusError, ::GetLastError()); + goto finish; + } + + if (!::GetOverlappedResult(m_file, &m_overlapped, &bytes_written, TRUE)) + { + return_info.Set(bytes_written, eConnectionStatusError, ::GetLastError()); + goto finish; + } + + return_info.Set(bytes_written, eConnectionStatusSuccess, 0); + goto finish; + +finish: + status = return_info.GetStatus(); + if (error_ptr) + *error_ptr = return_info.GetError(); + + IncrementFilePointer(return_info.GetBytes()); + Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_CONNECTION)); + if (log) + { + log->Printf("%" PRIxPTR " ConnectionGenericFile::Write() handle = %" PRIxPTR ", src = %" PRIxPTR ", src_len = %" PRIu64 + ") => %" PRIu64 ", error = %s", + this, m_file, src, static_cast<uint64_t>(src_len), static_cast<uint64_t>(return_info.GetBytes()), + return_info.GetError().AsCString()); + } + return return_info.GetBytes(); +} + +std::string +ConnectionGenericFile::GetURI() +{ + return m_uri; +} + +bool +ConnectionGenericFile::InterruptRead() +{ + return ::SetEvent(m_event_handles[kInterruptEvent]); +} + +void +ConnectionGenericFile::IncrementFilePointer(DWORD amount) +{ + LARGE_INTEGER old_pos; + old_pos.HighPart = m_overlapped.OffsetHigh; + old_pos.LowPart = m_overlapped.Offset; + old_pos.QuadPart += amount; + m_overlapped.Offset = old_pos.LowPart; + m_overlapped.OffsetHigh = old_pos.HighPart; +} |