diff options
Diffstat (limited to 'src/util/tokenpipe.cpp')
-rw-r--r-- | src/util/tokenpipe.cpp | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/src/util/tokenpipe.cpp b/src/util/tokenpipe.cpp new file mode 100644 index 0000000000..4c091cd2e6 --- /dev/null +++ b/src/util/tokenpipe.cpp @@ -0,0 +1,109 @@ +// Copyright (c) 2021 The Bitcoin Core developers +// Distributed under the MIT software license, see the accompanying +// file COPYING or http://www.opensource.org/licenses/mit-license.php. +#include <util/tokenpipe.h> + +#include <config/bitcoin-config.h> + +#ifndef WIN32 + +#include <errno.h> +#include <fcntl.h> +#include <optional> +#include <unistd.h> + +TokenPipeEnd TokenPipe::TakeReadEnd() +{ + TokenPipeEnd res(m_fds[0]); + m_fds[0] = -1; + return res; +} + +TokenPipeEnd TokenPipe::TakeWriteEnd() +{ + TokenPipeEnd res(m_fds[1]); + m_fds[1] = -1; + return res; +} + +TokenPipeEnd::TokenPipeEnd(int fd) : m_fd(fd) +{ +} + +TokenPipeEnd::~TokenPipeEnd() +{ + Close(); +} + +int TokenPipeEnd::TokenWrite(uint8_t token) +{ + while (true) { + ssize_t result = write(m_fd, &token, 1); + if (result < 0) { + // Failure. It's possible that the write was interrupted by a signal, + // in that case retry. + if (errno != EINTR) { + return TS_ERR; + } + } else if (result == 0) { + return TS_EOS; + } else { // ==1 + return 0; + } + } +} + +int TokenPipeEnd::TokenRead() +{ + uint8_t token; + while (true) { + ssize_t result = read(m_fd, &token, 1); + if (result < 0) { + // Failure. Check if the read was interrupted by a signal, + // in that case retry. + if (errno != EINTR) { + return TS_ERR; + } + } else if (result == 0) { + return TS_EOS; + } else { // ==1 + return token; + } + } + return token; +} + +void TokenPipeEnd::Close() +{ + if (m_fd != -1) close(m_fd); + m_fd = -1; +} + +std::optional<TokenPipe> TokenPipe::Make() +{ + int fds[2] = {-1, -1}; +#if HAVE_O_CLOEXEC && HAVE_DECL_PIPE2 + if (pipe2(fds, O_CLOEXEC) != 0) { + return std::nullopt; + } +#else + if (pipe(fds) != 0) { + return std::nullopt; + } +#endif + return TokenPipe(fds); +} + +TokenPipe::~TokenPipe() +{ + Close(); +} + +void TokenPipe::Close() +{ + if (m_fds[0] != -1) close(m_fds[0]); + if (m_fds[1] != -1) close(m_fds[1]); + m_fds[0] = m_fds[1] = -1; +} + +#endif // WIN32 |