From 59c7b88198af8af29deffb2eee7b7b2329e9197e Mon Sep 17 00:00:00 2001 From: Jeff Hostetler Date: Mon, 15 Mar 2021 21:08:23 +0000 Subject: simple-ipc: add win32 implementation Create Windows implementation of "simple-ipc" using named pipes. Signed-off-by: Jeff Hostetler Signed-off-by: Junio C Hamano --- compat/simple-ipc/ipc-shared.c | 28 ++ compat/simple-ipc/ipc-win32.c | 751 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 779 insertions(+) create mode 100644 compat/simple-ipc/ipc-shared.c create mode 100644 compat/simple-ipc/ipc-win32.c (limited to 'compat') diff --git a/compat/simple-ipc/ipc-shared.c b/compat/simple-ipc/ipc-shared.c new file mode 100644 index 0000000000..1edec81595 --- /dev/null +++ b/compat/simple-ipc/ipc-shared.c @@ -0,0 +1,28 @@ +#include "cache.h" +#include "simple-ipc.h" +#include "strbuf.h" +#include "pkt-line.h" +#include "thread-utils.h" + +#ifdef SUPPORTS_SIMPLE_IPC + +int ipc_server_run(const char *path, const struct ipc_server_opts *opts, + ipc_server_application_cb *application_cb, + void *application_data) +{ + struct ipc_server_data *server_data = NULL; + int ret; + + ret = ipc_server_run_async(&server_data, path, opts, + application_cb, application_data); + if (ret) + return ret; + + ret = ipc_server_await(server_data); + + ipc_server_free(server_data); + + return ret; +} + +#endif /* SUPPORTS_SIMPLE_IPC */ diff --git a/compat/simple-ipc/ipc-win32.c b/compat/simple-ipc/ipc-win32.c new file mode 100644 index 0000000000..8f89c02037 --- /dev/null +++ b/compat/simple-ipc/ipc-win32.c @@ -0,0 +1,751 @@ +#include "cache.h" +#include "simple-ipc.h" +#include "strbuf.h" +#include "pkt-line.h" +#include "thread-utils.h" + +#ifndef GIT_WINDOWS_NATIVE +#error This file can only be compiled on Windows +#endif + +static int initialize_pipe_name(const char *path, wchar_t *wpath, size_t alloc) +{ + int off = 0; + struct strbuf realpath = STRBUF_INIT; + + if (!strbuf_realpath(&realpath, path, 0)) + return -1; + + off = swprintf(wpath, alloc, L"\\\\.\\pipe\\"); + if (xutftowcs(wpath + off, realpath.buf, alloc - off) < 0) + return -1; + + /* Handle drive prefix */ + if (wpath[off] && wpath[off + 1] == L':') { + wpath[off + 1] = L'_'; + off += 2; + } + + for (; wpath[off]; off++) + if (wpath[off] == L'/') + wpath[off] = L'\\'; + + strbuf_release(&realpath); + return 0; +} + +static enum ipc_active_state get_active_state(wchar_t *pipe_path) +{ + if (WaitNamedPipeW(pipe_path, NMPWAIT_USE_DEFAULT_WAIT)) + return IPC_STATE__LISTENING; + + if (GetLastError() == ERROR_SEM_TIMEOUT) + return IPC_STATE__NOT_LISTENING; + + if (GetLastError() == ERROR_FILE_NOT_FOUND) + return IPC_STATE__PATH_NOT_FOUND; + + return IPC_STATE__OTHER_ERROR; +} + +enum ipc_active_state ipc_get_active_state(const char *path) +{ + wchar_t pipe_path[MAX_PATH]; + + if (initialize_pipe_name(path, pipe_path, ARRAY_SIZE(pipe_path)) < 0) + return IPC_STATE__INVALID_PATH; + + return get_active_state(pipe_path); +} + +#define WAIT_STEP_MS (50) + +static enum ipc_active_state connect_to_server( + const wchar_t *wpath, + DWORD timeout_ms, + const struct ipc_client_connect_options *options, + int *pfd) +{ + DWORD t_start_ms, t_waited_ms; + DWORD step_ms; + HANDLE hPipe = INVALID_HANDLE_VALUE; + DWORD mode = PIPE_READMODE_BYTE; + DWORD gle; + + *pfd = -1; + + for (;;) { + hPipe = CreateFileW(wpath, GENERIC_READ | GENERIC_WRITE, + 0, NULL, OPEN_EXISTING, 0, NULL); + if (hPipe != INVALID_HANDLE_VALUE) + break; + + gle = GetLastError(); + + switch (gle) { + case ERROR_FILE_NOT_FOUND: + if (!options->wait_if_not_found) + return IPC_STATE__PATH_NOT_FOUND; + if (!timeout_ms) + return IPC_STATE__PATH_NOT_FOUND; + + step_ms = (timeout_ms < WAIT_STEP_MS) ? + timeout_ms : WAIT_STEP_MS; + sleep_millisec(step_ms); + + timeout_ms -= step_ms; + break; /* try again */ + + case ERROR_PIPE_BUSY: + if (!options->wait_if_busy) + return IPC_STATE__NOT_LISTENING; + if (!timeout_ms) + return IPC_STATE__NOT_LISTENING; + + t_start_ms = (DWORD)(getnanotime() / 1000000); + + if (!WaitNamedPipeW(wpath, timeout_ms)) { + if (GetLastError() == ERROR_SEM_TIMEOUT) + return IPC_STATE__NOT_LISTENING; + + return IPC_STATE__OTHER_ERROR; + } + + /* + * A pipe server instance became available. + * Race other client processes to connect to + * it. + * + * But first decrement our overall timeout so + * that we don't starve if we keep losing the + * race. But also guard against special + * NPMWAIT_ values (0 and -1). + */ + t_waited_ms = (DWORD)(getnanotime() / 1000000) - t_start_ms; + if (t_waited_ms < timeout_ms) + timeout_ms -= t_waited_ms; + else + timeout_ms = 1; + break; /* try again */ + + default: + return IPC_STATE__OTHER_ERROR; + } + } + + if (!SetNamedPipeHandleState(hPipe, &mode, NULL, NULL)) { + CloseHandle(hPipe); + return IPC_STATE__OTHER_ERROR; + } + + *pfd = _open_osfhandle((intptr_t)hPipe, O_RDWR|O_BINARY); + if (*pfd < 0) { + CloseHandle(hPipe); + return IPC_STATE__OTHER_ERROR; + } + + /* fd now owns hPipe */ + + return IPC_STATE__LISTENING; +} + +/* + * The default connection timeout for Windows clients. + * + * This is not currently part of the ipc_ API (nor the config settings) + * because of differences between Windows and other platforms. + * + * This value was chosen at random. + */ +#define WINDOWS_CONNECTION_TIMEOUT_MS (30000) + +enum ipc_active_state ipc_client_try_connect( + const char *path, + const struct ipc_client_connect_options *options, + struct ipc_client_connection **p_connection) +{ + wchar_t wpath[MAX_PATH]; + enum ipc_active_state state = IPC_STATE__OTHER_ERROR; + int fd = -1; + + *p_connection = NULL; + + trace2_region_enter("ipc-client", "try-connect", NULL); + trace2_data_string("ipc-client", NULL, "try-connect/path", path); + + if (initialize_pipe_name(path, wpath, ARRAY_SIZE(wpath)) < 0) + state = IPC_STATE__INVALID_PATH; + else + state = connect_to_server(wpath, WINDOWS_CONNECTION_TIMEOUT_MS, + options, &fd); + + trace2_data_intmax("ipc-client", NULL, "try-connect/state", + (intmax_t)state); + trace2_region_leave("ipc-client", "try-connect", NULL); + + if (state == IPC_STATE__LISTENING) { + (*p_connection) = xcalloc(1, sizeof(struct ipc_client_connection)); + (*p_connection)->fd = fd; + } + + return state; +} + +void ipc_client_close_connection(struct ipc_client_connection *connection) +{ + if (!connection) + return; + + if (connection->fd != -1) + close(connection->fd); + + free(connection); +} + +int ipc_client_send_command_to_connection( + struct ipc_client_connection *connection, + const char *message, struct strbuf *answer) +{ + int ret = 0; + + strbuf_setlen(answer, 0); + + trace2_region_enter("ipc-client", "send-command", NULL); + + if (write_packetized_from_buf_no_flush(message, strlen(message), + connection->fd) < 0 || + packet_flush_gently(connection->fd) < 0) { + ret = error(_("could not send IPC command")); + goto done; + } + + FlushFileBuffers((HANDLE)_get_osfhandle(connection->fd)); + + if (read_packetized_to_strbuf( + connection->fd, answer, + PACKET_READ_GENTLE_ON_EOF | PACKET_READ_GENTLE_ON_READ_ERROR) < 0) { + ret = error(_("could not read IPC response")); + goto done; + } + +done: + trace2_region_leave("ipc-client", "send-command", NULL); + return ret; +} + +int ipc_client_send_command(const char *path, + const struct ipc_client_connect_options *options, + const char *message, struct strbuf *response) +{ + int ret = -1; + enum ipc_active_state state; + struct ipc_client_connection *connection = NULL; + + state = ipc_client_try_connect(path, options, &connection); + + if (state != IPC_STATE__LISTENING) + return ret; + + ret = ipc_client_send_command_to_connection(connection, message, response); + + ipc_client_close_connection(connection); + + return ret; +} + +/* + * Duplicate the given pipe handle and wrap it in a file descriptor so + * that we can use pkt-line on it. + */ +static int dup_fd_from_pipe(const HANDLE pipe) +{ + HANDLE process = GetCurrentProcess(); + HANDLE handle; + int fd; + + if (!DuplicateHandle(process, pipe, process, &handle, 0, FALSE, + DUPLICATE_SAME_ACCESS)) { + errno = err_win_to_posix(GetLastError()); + return -1; + } + + fd = _open_osfhandle((intptr_t)handle, O_RDWR|O_BINARY); + if (fd < 0) { + errno = err_win_to_posix(GetLastError()); + CloseHandle(handle); + return -1; + } + + /* + * `handle` is now owned by `fd` and will be automatically closed + * when the descriptor is closed. + */ + + return fd; +} + +/* + * Magic numbers used to annotate callback instance data. + * These are used to help guard against accidentally passing the + * wrong instance data across multiple levels of callbacks (which + * is easy to do if there are `void*` arguments). + */ +enum magic { + MAGIC_SERVER_REPLY_DATA, + MAGIC_SERVER_THREAD_DATA, + MAGIC_SERVER_DATA, +}; + +struct ipc_server_reply_data { + enum magic magic; + int fd; + struct ipc_server_thread_data *server_thread_data; +}; + +struct ipc_server_thread_data { + enum magic magic; + struct ipc_server_thread_data *next_thread; + struct ipc_server_data *server_data; + pthread_t pthread_id; + HANDLE hPipe; +}; + +/* + * On Windows, the conceptual "ipc-server" is implemented as a pool of + * n idential/peer "server-thread" threads. That is, there is no + * hierarchy of threads; and therefore no controller thread managing + * the pool. Each thread has an independent handle to the named pipe, + * receives incoming connections, processes the client, and re-uses + * the pipe for the next client connection. + * + * Therefore, the "ipc-server" only needs to maintain a list of the + * spawned threads for eventual "join" purposes. + * + * A single "stop-event" is visible to all of the server threads to + * tell them to shutdown (when idle). + */ +struct ipc_server_data { + enum magic magic; + ipc_server_application_cb *application_cb; + void *application_data; + struct strbuf buf_path; + wchar_t wpath[MAX_PATH]; + + HANDLE hEventStopRequested; + struct ipc_server_thread_data *thread_list; + int is_stopped; +}; + +enum connect_result { + CR_CONNECTED = 0, + CR_CONNECT_PENDING, + CR_CONNECT_ERROR, + CR_WAIT_ERROR, + CR_SHUTDOWN, +}; + +static enum connect_result queue_overlapped_connect( + struct ipc_server_thread_data *server_thread_data, + OVERLAPPED *lpo) +{ + if (ConnectNamedPipe(server_thread_data->hPipe, lpo)) + goto failed; + + switch (GetLastError()) { + case ERROR_IO_PENDING: + return CR_CONNECT_PENDING; + + case ERROR_PIPE_CONNECTED: + SetEvent(lpo->hEvent); + return CR_CONNECTED; + + default: + break; + } + +failed: + error(_("ConnectNamedPipe failed for '%s' (%lu)"), + server_thread_data->server_data->buf_path.buf, + GetLastError()); + return CR_CONNECT_ERROR; +} + +/* + * Use Windows Overlapped IO to wait for a connection or for our event + * to be signalled. + */ +static enum connect_result wait_for_connection( + struct ipc_server_thread_data *server_thread_data, + OVERLAPPED *lpo) +{ + enum connect_result r; + HANDLE waitHandles[2]; + DWORD dwWaitResult; + + r = queue_overlapped_connect(server_thread_data, lpo); + if (r != CR_CONNECT_PENDING) + return r; + + waitHandles[0] = server_thread_data->server_data->hEventStopRequested; + waitHandles[1] = lpo->hEvent; + + dwWaitResult = WaitForMultipleObjects(2, waitHandles, FALSE, INFINITE); + switch (dwWaitResult) { + case WAIT_OBJECT_0 + 0: + return CR_SHUTDOWN; + + case WAIT_OBJECT_0 + 1: + ResetEvent(lpo->hEvent); + return CR_CONNECTED; + + default: + return CR_WAIT_ERROR; + } +} + +/* + * Forward declare our reply callback function so that any compiler + * errors are reported when we actually define the function (in addition + * to any errors reported when we try to pass this callback function as + * a parameter in a function call). The former are easier to understand. + */ +static ipc_server_reply_cb do_io_reply_callback; + +/* + * Relay application's response message to the client process. + * (We do not flush at this point because we allow the caller + * to chunk data to the client thru us.) + */ +static int do_io_reply_callback(struct ipc_server_reply_data *reply_data, + const char *response, size_t response_len) +{ + if (reply_data->magic != MAGIC_SERVER_REPLY_DATA) + BUG("reply_cb called with wrong instance data"); + + return write_packetized_from_buf_no_flush(response, response_len, + reply_data->fd); +} + +/* + * Receive the request/command from the client and pass it to the + * registered request-callback. The request-callback will compose + * a response and call our reply-callback to send it to the client. + * + * Simple-IPC only contains one round trip, so we flush and close + * here after the response. + */ +static int do_io(struct ipc_server_thread_data *server_thread_data) +{ + struct strbuf buf = STRBUF_INIT; + struct ipc_server_reply_data reply_data; + int ret = 0; + + reply_data.magic = MAGIC_SERVER_REPLY_DATA; + reply_data.server_thread_data = server_thread_data; + + reply_data.fd = dup_fd_from_pipe(server_thread_data->hPipe); + if (reply_data.fd < 0) + return error(_("could not create fd from pipe for '%s'"), + server_thread_data->server_data->buf_path.buf); + + ret = read_packetized_to_strbuf( + reply_data.fd, &buf, + PACKET_READ_GENTLE_ON_EOF | PACKET_READ_GENTLE_ON_READ_ERROR); + if (ret >= 0) { + ret = server_thread_data->server_data->application_cb( + server_thread_data->server_data->application_data, + buf.buf, do_io_reply_callback, &reply_data); + + packet_flush_gently(reply_data.fd); + + FlushFileBuffers((HANDLE)_get_osfhandle((reply_data.fd))); + } + else { + /* + * The client probably disconnected/shutdown before it + * could send a well-formed message. Ignore it. + */ + } + + strbuf_release(&buf); + close(reply_data.fd); + + return ret; +} + +/* + * Handle IPC request and response with this connected client. And reset + * the pipe to prepare for the next client. + */ +static int use_connection(struct ipc_server_thread_data *server_thread_data) +{ + int ret; + + ret = do_io(server_thread_data); + + FlushFileBuffers(server_thread_data->hPipe); + DisconnectNamedPipe(server_thread_data->hPipe); + + return ret; +} + +/* + * Thread proc for an IPC server worker thread. It handles a series of + * connections from clients. It cleans and reuses the hPipe between each + * client. + */ +static void *server_thread_proc(void *_server_thread_data) +{ + struct ipc_server_thread_data *server_thread_data = _server_thread_data; + HANDLE hEventConnected = INVALID_HANDLE_VALUE; + OVERLAPPED oConnect; + enum connect_result cr; + int ret; + + assert(server_thread_data->hPipe != INVALID_HANDLE_VALUE); + + trace2_thread_start("ipc-server"); + trace2_data_string("ipc-server", NULL, "pipe", + server_thread_data->server_data->buf_path.buf); + + hEventConnected = CreateEventW(NULL, TRUE, FALSE, NULL); + + memset(&oConnect, 0, sizeof(oConnect)); + oConnect.hEvent = hEventConnected; + + for (;;) { + cr = wait_for_connection(server_thread_data, &oConnect); + + switch (cr) { + case CR_SHUTDOWN: + goto finished; + + case CR_CONNECTED: + ret = use_connection(server_thread_data); + if (ret == SIMPLE_IPC_QUIT) { + ipc_server_stop_async( + server_thread_data->server_data); + goto finished; + } + if (ret > 0) { + /* + * Ignore (transient) IO errors with this + * client and reset for the next client. + */ + } + break; + + case CR_CONNECT_PENDING: + /* By construction, this should not happen. */ + BUG("ipc-server[%s]: unexpeced CR_CONNECT_PENDING", + server_thread_data->server_data->buf_path.buf); + + case CR_CONNECT_ERROR: + case CR_WAIT_ERROR: + /* + * Ignore these theoretical errors. + */ + DisconnectNamedPipe(server_thread_data->hPipe); + break; + + default: + BUG("unandled case after wait_for_connection"); + } + } + +finished: + CloseHandle(server_thread_data->hPipe); + CloseHandle(hEventConnected); + + trace2_thread_exit(); + return NULL; +} + +static HANDLE create_new_pipe(wchar_t *wpath, int is_first) +{ + HANDLE hPipe; + DWORD dwOpenMode, dwPipeMode; + LPSECURITY_ATTRIBUTES lpsa = NULL; + + dwOpenMode = PIPE_ACCESS_INBOUND | PIPE_ACCESS_OUTBOUND | + FILE_FLAG_OVERLAPPED; + + dwPipeMode = PIPE_TYPE_MESSAGE | PIPE_READMODE_BYTE | PIPE_WAIT | + PIPE_REJECT_REMOTE_CLIENTS; + + if (is_first) { + dwOpenMode |= FILE_FLAG_FIRST_PIPE_INSTANCE; + + /* + * On Windows, the first server pipe instance gets to + * set the ACL / Security Attributes on the named + * pipe; subsequent instances inherit and cannot + * change them. + * + * TODO Should we allow the application layer to + * specify security attributes, such as `LocalService` + * or `LocalSystem`, when we create the named pipe? + * This question is probably not important when the + * daemon is started by a foreground user process and + * only needs to talk to the current user, but may be + * if the daemon is run via the Control Panel as a + * System Service. + */ + } + + hPipe = CreateNamedPipeW(wpath, dwOpenMode, dwPipeMode, + PIPE_UNLIMITED_INSTANCES, 1024, 1024, 0, lpsa); + + return hPipe; +} + +int ipc_server_run_async(struct ipc_server_data **returned_server_data, + const char *path, const struct ipc_server_opts *opts, + ipc_server_application_cb *application_cb, + void *application_data) +{ + struct ipc_server_data *server_data; + wchar_t wpath[MAX_PATH]; + HANDLE hPipeFirst = INVALID_HANDLE_VALUE; + int k; + int ret = 0; + int nr_threads = opts->nr_threads; + + *returned_server_data = NULL; + + ret = initialize_pipe_name(path, wpath, ARRAY_SIZE(wpath)); + if (ret < 0) { + errno = EINVAL; + return -1; + } + + hPipeFirst = create_new_pipe(wpath, 1); + if (hPipeFirst == INVALID_HANDLE_VALUE) { + errno = EADDRINUSE; + return -2; + } + + server_data = xcalloc(1, sizeof(*server_data)); + server_data->magic = MAGIC_SERVER_DATA; + server_data->application_cb = application_cb; + server_data->application_data = application_data; + server_data->hEventStopRequested = CreateEvent(NULL, TRUE, FALSE, NULL); + strbuf_init(&server_data->buf_path, 0); + strbuf_addstr(&server_data->buf_path, path); + wcscpy(server_data->wpath, wpath); + + if (nr_threads < 1) + nr_threads = 1; + + for (k = 0; k < nr_threads; k++) { + struct ipc_server_thread_data *std; + + std = xcalloc(1, sizeof(*std)); + std->magic = MAGIC_SERVER_THREAD_DATA; + std->server_data = server_data; + std->hPipe = INVALID_HANDLE_VALUE; + + std->hPipe = (k == 0) + ? hPipeFirst + : create_new_pipe(server_data->wpath, 0); + + if (std->hPipe == INVALID_HANDLE_VALUE) { + /* + * If we've reached a pipe instance limit for + * this path, just use fewer threads. + */ + free(std); + break; + } + + if (pthread_create(&std->pthread_id, NULL, + server_thread_proc, std)) { + /* + * Likewise, if we're out of threads, just use + * fewer threads than requested. + * + * However, we just give up if we can't even get + * one thread. This should not happen. + */ + if (k == 0) + die(_("could not start thread[0] for '%s'"), + path); + + CloseHandle(std->hPipe); + free(std); + break; + } + + std->next_thread = server_data->thread_list; + server_data->thread_list = std; + } + + *returned_server_data = server_data; + return 0; +} + +int ipc_server_stop_async(struct ipc_server_data *server_data) +{ + if (!server_data) + return 0; + + /* + * Gently tell all of the ipc_server threads to shutdown. + * This will be seen the next time they are idle (and waiting + * for a connection). + * + * We DO NOT attempt to force them to drop an active connection. + */ + SetEvent(server_data->hEventStopRequested); + return 0; +} + +int ipc_server_await(struct ipc_server_data *server_data) +{ + DWORD dwWaitResult; + + if (!server_data) + return 0; + + dwWaitResult = WaitForSingleObject(server_data->hEventStopRequested, INFINITE); + if (dwWaitResult != WAIT_OBJECT_0) + return error(_("wait for hEvent failed for '%s'"), + server_data->buf_path.buf); + + while (server_data->thread_list) { + struct ipc_server_thread_data *std = server_data->thread_list; + + pthread_join(std->pthread_id, NULL); + + server_data->thread_list = std->next_thread; + free(std); + } + + server_data->is_stopped = 1; + + return 0; +} + +void ipc_server_free(struct ipc_server_data *server_data) +{ + if (!server_data) + return; + + if (!server_data->is_stopped) + BUG("cannot free ipc-server while running for '%s'", + server_data->buf_path.buf); + + strbuf_release(&server_data->buf_path); + + if (server_data->hEventStopRequested != INVALID_HANDLE_VALUE) + CloseHandle(server_data->hEventStopRequested); + + while (server_data->thread_list) { + struct ipc_server_thread_data *std = server_data->thread_list; + + server_data->thread_list = std->next_thread; + free(std); + } + + free(server_data); +} -- cgit v1.2.3 From 7cd5dbcaba44914c07a51377e75c4e8bbe31f319 Mon Sep 17 00:00:00 2001 From: Jeff Hostetler Date: Mon, 22 Mar 2021 10:29:47 +0000 Subject: simple-ipc: add Unix domain socket implementation Create Unix domain socket based implementation of "simple-ipc". A set of `ipc_client` routines implement a client library to connect to an `ipc_server` over a Unix domain socket, send a simple request, and receive a single response. Clients use blocking IO on the socket. A set of `ipc_server` routines implement a thread pool to listen for and concurrently service client connections. The server creates a new Unix domain socket at a known location. If a socket already exists with that name, the server tries to determine if another server is already listening on the socket or if the socket is dead. If socket is busy, the server exits with an error rather than stealing the socket. If the socket is dead, the server creates a new one and starts up. If while running, the server detects that its socket has been stolen by another server, it automatically exits. Signed-off-by: Jeff Hostetler Signed-off-by: Junio C Hamano --- compat/simple-ipc/ipc-unix-socket.c | 999 ++++++++++++++++++++++++++++++++++++ 1 file changed, 999 insertions(+) create mode 100644 compat/simple-ipc/ipc-unix-socket.c (limited to 'compat') diff --git a/compat/simple-ipc/ipc-unix-socket.c b/compat/simple-ipc/ipc-unix-socket.c new file mode 100644 index 0000000000..38689b278d --- /dev/null +++ b/compat/simple-ipc/ipc-unix-socket.c @@ -0,0 +1,999 @@ +#include "cache.h" +#include "simple-ipc.h" +#include "strbuf.h" +#include "pkt-line.h" +#include "thread-utils.h" +#include "unix-socket.h" +#include "unix-stream-server.h" + +#ifdef NO_UNIX_SOCKETS +#error compat/simple-ipc/ipc-unix-socket.c requires Unix sockets +#endif + +enum ipc_active_state ipc_get_active_state(const char *path) +{ + enum ipc_active_state state = IPC_STATE__OTHER_ERROR; + struct ipc_client_connect_options options + = IPC_CLIENT_CONNECT_OPTIONS_INIT; + struct stat st; + struct ipc_client_connection *connection_test = NULL; + + options.wait_if_busy = 0; + options.wait_if_not_found = 0; + + if (lstat(path, &st) == -1) { + switch (errno) { + case ENOENT: + case ENOTDIR: + return IPC_STATE__NOT_LISTENING; + default: + return IPC_STATE__INVALID_PATH; + } + } + + /* also complain if a plain file is in the way */ + if ((st.st_mode & S_IFMT) != S_IFSOCK) + return IPC_STATE__INVALID_PATH; + + /* + * Just because the filesystem has a S_IFSOCK type inode + * at `path`, doesn't mean it that there is a server listening. + * Ping it to be sure. + */ + state = ipc_client_try_connect(path, &options, &connection_test); + ipc_client_close_connection(connection_test); + + return state; +} + +/* + * Retry frequency when trying to connect to a server. + * + * This value should be short enough that we don't seriously delay our + * caller, but not fast enough that our spinning puts pressure on the + * system. + */ +#define WAIT_STEP_MS (50) + +/* + * Try to connect to the server. If the server is just starting up or + * is very busy, we may not get a connection the first time. + */ +static enum ipc_active_state connect_to_server( + const char *path, + int timeout_ms, + const struct ipc_client_connect_options *options, + int *pfd) +{ + int k; + + *pfd = -1; + + for (k = 0; k < timeout_ms; k += WAIT_STEP_MS) { + int fd = unix_stream_connect(path, options->uds_disallow_chdir); + + if (fd != -1) { + *pfd = fd; + return IPC_STATE__LISTENING; + } + + if (errno == ENOENT) { + if (!options->wait_if_not_found) + return IPC_STATE__PATH_NOT_FOUND; + + goto sleep_and_try_again; + } + + if (errno == ETIMEDOUT) { + if (!options->wait_if_busy) + return IPC_STATE__NOT_LISTENING; + + goto sleep_and_try_again; + } + + if (errno == ECONNREFUSED) { + if (!options->wait_if_busy) + return IPC_STATE__NOT_LISTENING; + + goto sleep_and_try_again; + } + + return IPC_STATE__OTHER_ERROR; + + sleep_and_try_again: + sleep_millisec(WAIT_STEP_MS); + } + + return IPC_STATE__NOT_LISTENING; +} + +/* + * The total amount of time that we are willing to wait when trying to + * connect to a server. + * + * When the server is first started, it might take a little while for + * it to become ready to service requests. Likewise, the server may + * be very (temporarily) busy and not respond to our connections. + * + * We should gracefully and silently handle those conditions and try + * again for a reasonable time period. + * + * The value chosen here should be long enough for the server + * to reliably heal from the above conditions. + */ +#define MY_CONNECTION_TIMEOUT_MS (1000) + +enum ipc_active_state ipc_client_try_connect( + const char *path, + const struct ipc_client_connect_options *options, + struct ipc_client_connection **p_connection) +{ + enum ipc_active_state state = IPC_STATE__OTHER_ERROR; + int fd = -1; + + *p_connection = NULL; + + trace2_region_enter("ipc-client", "try-connect", NULL); + trace2_data_string("ipc-client", NULL, "try-connect/path", path); + + state = connect_to_server(path, MY_CONNECTION_TIMEOUT_MS, + options, &fd); + + trace2_data_intmax("ipc-client", NULL, "try-connect/state", + (intmax_t)state); + trace2_region_leave("ipc-client", "try-connect", NULL); + + if (state == IPC_STATE__LISTENING) { + (*p_connection) = xcalloc(1, sizeof(struct ipc_client_connection)); + (*p_connection)->fd = fd; + } + + return state; +} + +void ipc_client_close_connection(struct ipc_client_connection *connection) +{ + if (!connection) + return; + + if (connection->fd != -1) + close(connection->fd); + + free(connection); +} + +int ipc_client_send_command_to_connection( + struct ipc_client_connection *connection, + const char *message, struct strbuf *answer) +{ + int ret = 0; + + strbuf_setlen(answer, 0); + + trace2_region_enter("ipc-client", "send-command", NULL); + + if (write_packetized_from_buf_no_flush(message, strlen(message), + connection->fd) < 0 || + packet_flush_gently(connection->fd) < 0) { + ret = error(_("could not send IPC command")); + goto done; + } + + if (read_packetized_to_strbuf( + connection->fd, answer, + PACKET_READ_GENTLE_ON_EOF | PACKET_READ_GENTLE_ON_READ_ERROR) < 0) { + ret = error(_("could not read IPC response")); + goto done; + } + +done: + trace2_region_leave("ipc-client", "send-command", NULL); + return ret; +} + +int ipc_client_send_command(const char *path, + const struct ipc_client_connect_options *options, + const char *message, struct strbuf *answer) +{ + int ret = -1; + enum ipc_active_state state; + struct ipc_client_connection *connection = NULL; + + state = ipc_client_try_connect(path, options, &connection); + + if (state != IPC_STATE__LISTENING) + return ret; + + ret = ipc_client_send_command_to_connection(connection, message, answer); + + ipc_client_close_connection(connection); + + return ret; +} + +static int set_socket_blocking_flag(int fd, int make_nonblocking) +{ + int flags; + + flags = fcntl(fd, F_GETFL, NULL); + + if (flags < 0) + return -1; + + if (make_nonblocking) + flags |= O_NONBLOCK; + else + flags &= ~O_NONBLOCK; + + return fcntl(fd, F_SETFL, flags); +} + +/* + * Magic numbers used to annotate callback instance data. + * These are used to help guard against accidentally passing the + * wrong instance data across multiple levels of callbacks (which + * is easy to do if there are `void*` arguments). + */ +enum magic { + MAGIC_SERVER_REPLY_DATA, + MAGIC_WORKER_THREAD_DATA, + MAGIC_ACCEPT_THREAD_DATA, + MAGIC_SERVER_DATA, +}; + +struct ipc_server_reply_data { + enum magic magic; + int fd; + struct ipc_worker_thread_data *worker_thread_data; +}; + +struct ipc_worker_thread_data { + enum magic magic; + struct ipc_worker_thread_data *next_thread; + struct ipc_server_data *server_data; + pthread_t pthread_id; +}; + +struct ipc_accept_thread_data { + enum magic magic; + struct ipc_server_data *server_data; + + struct unix_ss_socket *server_socket; + + int fd_send_shutdown; + int fd_wait_shutdown; + pthread_t pthread_id; +}; + +/* + * With unix-sockets, the conceptual "ipc-server" is implemented as a single + * controller "accept-thread" thread and a pool of "worker-thread" threads. + * The former does the usual `accept()` loop and dispatches connections + * to an idle worker thread. The worker threads wait in an idle loop for + * a new connection, communicate with the client and relay data to/from + * the `application_cb` and then wait for another connection from the + * server thread. This avoids the overhead of constantly creating and + * destroying threads. + */ +struct ipc_server_data { + enum magic magic; + ipc_server_application_cb *application_cb; + void *application_data; + struct strbuf buf_path; + + struct ipc_accept_thread_data *accept_thread; + struct ipc_worker_thread_data *worker_thread_list; + + pthread_mutex_t work_available_mutex; + pthread_cond_t work_available_cond; + + /* + * Accepted but not yet processed client connections are kept + * in a circular buffer FIFO. The queue is empty when the + * positions are equal. + */ + int *fifo_fds; + int queue_size; + int back_pos; + int front_pos; + + int shutdown_requested; + int is_stopped; +}; + +/* + * Remove and return the oldest queued connection. + * + * Returns -1 if empty. + */ +static int fifo_dequeue(struct ipc_server_data *server_data) +{ + /* ASSERT holding mutex */ + + int fd; + + if (server_data->back_pos == server_data->front_pos) + return -1; + + fd = server_data->fifo_fds[server_data->front_pos]; + server_data->fifo_fds[server_data->front_pos] = -1; + + server_data->front_pos++; + if (server_data->front_pos == server_data->queue_size) + server_data->front_pos = 0; + + return fd; +} + +/* + * Push a new fd onto the back of the queue. + * + * Drop it and return -1 if queue is already full. + */ +static int fifo_enqueue(struct ipc_server_data *server_data, int fd) +{ + /* ASSERT holding mutex */ + + int next_back_pos; + + next_back_pos = server_data->back_pos + 1; + if (next_back_pos == server_data->queue_size) + next_back_pos = 0; + + if (next_back_pos == server_data->front_pos) { + /* Queue is full. Just drop it. */ + close(fd); + return -1; + } + + server_data->fifo_fds[server_data->back_pos] = fd; + server_data->back_pos = next_back_pos; + + return fd; +} + +/* + * Wait for a connection to be queued to the FIFO and return it. + * + * Returns -1 if someone has already requested a shutdown. + */ +static int worker_thread__wait_for_connection( + struct ipc_worker_thread_data *worker_thread_data) +{ + /* ASSERT NOT holding mutex */ + + struct ipc_server_data *server_data = worker_thread_data->server_data; + int fd = -1; + + pthread_mutex_lock(&server_data->work_available_mutex); + for (;;) { + if (server_data->shutdown_requested) + break; + + fd = fifo_dequeue(server_data); + if (fd >= 0) + break; + + pthread_cond_wait(&server_data->work_available_cond, + &server_data->work_available_mutex); + } + pthread_mutex_unlock(&server_data->work_available_mutex); + + return fd; +} + +/* + * Forward declare our reply callback function so that any compiler + * errors are reported when we actually define the function (in addition + * to any errors reported when we try to pass this callback function as + * a parameter in a function call). The former are easier to understand. + */ +static ipc_server_reply_cb do_io_reply_callback; + +/* + * Relay application's response message to the client process. + * (We do not flush at this point because we allow the caller + * to chunk data to the client thru us.) + */ +static int do_io_reply_callback(struct ipc_server_reply_data *reply_data, + const char *response, size_t response_len) +{ + if (reply_data->magic != MAGIC_SERVER_REPLY_DATA) + BUG("reply_cb called with wrong instance data"); + + return write_packetized_from_buf_no_flush(response, response_len, + reply_data->fd); +} + +/* A randomly chosen value. */ +#define MY_WAIT_POLL_TIMEOUT_MS (10) + +/* + * If the client hangs up without sending any data on the wire, just + * quietly close the socket and ignore this client. + * + * This worker thread is committed to reading the IPC request data + * from the client at the other end of this fd. Wait here for the + * client to actually put something on the wire -- because if the + * client just does a ping (connect and hangup without sending any + * data), our use of the pkt-line read routines will spew an error + * message. + * + * Return -1 if the client hung up. + * Return 0 if data (possibly incomplete) is ready. + */ +static int worker_thread__wait_for_io_start( + struct ipc_worker_thread_data *worker_thread_data, + int fd) +{ + struct ipc_server_data *server_data = worker_thread_data->server_data; + struct pollfd pollfd[1]; + int result; + + for (;;) { + pollfd[0].fd = fd; + pollfd[0].events = POLLIN; + + result = poll(pollfd, 1, MY_WAIT_POLL_TIMEOUT_MS); + if (result < 0) { + if (errno == EINTR) + continue; + goto cleanup; + } + + if (result == 0) { + /* a timeout */ + + int in_shutdown; + + pthread_mutex_lock(&server_data->work_available_mutex); + in_shutdown = server_data->shutdown_requested; + pthread_mutex_unlock(&server_data->work_available_mutex); + + /* + * If a shutdown is already in progress and this + * client has not started talking yet, just drop it. + */ + if (in_shutdown) + goto cleanup; + continue; + } + + if (pollfd[0].revents & POLLHUP) + goto cleanup; + + if (pollfd[0].revents & POLLIN) + return 0; + + goto cleanup; + } + +cleanup: + close(fd); + return -1; +} + +/* + * Receive the request/command from the client and pass it to the + * registered request-callback. The request-callback will compose + * a response and call our reply-callback to send it to the client. + */ +static int worker_thread__do_io( + struct ipc_worker_thread_data *worker_thread_data, + int fd) +{ + /* ASSERT NOT holding lock */ + + struct strbuf buf = STRBUF_INIT; + struct ipc_server_reply_data reply_data; + int ret = 0; + + reply_data.magic = MAGIC_SERVER_REPLY_DATA; + reply_data.worker_thread_data = worker_thread_data; + + reply_data.fd = fd; + + ret = read_packetized_to_strbuf( + reply_data.fd, &buf, + PACKET_READ_GENTLE_ON_EOF | PACKET_READ_GENTLE_ON_READ_ERROR); + if (ret >= 0) { + ret = worker_thread_data->server_data->application_cb( + worker_thread_data->server_data->application_data, + buf.buf, do_io_reply_callback, &reply_data); + + packet_flush_gently(reply_data.fd); + } + else { + /* + * The client probably disconnected/shutdown before it + * could send a well-formed message. Ignore it. + */ + } + + strbuf_release(&buf); + close(reply_data.fd); + + return ret; +} + +/* + * Block SIGPIPE on the current thread (so that we get EPIPE from + * write() rather than an actual signal). + * + * Note that using sigchain_push() and _pop() to control SIGPIPE + * around our IO calls is not thread safe: + * [] It uses a global stack of handler frames. + * [] It uses ALLOC_GROW() to resize it. + * [] Finally, according to the `signal(2)` man-page: + * "The effects of `signal()` in a multithreaded process are unspecified." + */ +static void thread_block_sigpipe(sigset_t *old_set) +{ + sigset_t new_set; + + sigemptyset(&new_set); + sigaddset(&new_set, SIGPIPE); + + sigemptyset(old_set); + pthread_sigmask(SIG_BLOCK, &new_set, old_set); +} + +/* + * Thread proc for an IPC worker thread. It handles a series of + * connections from clients. It pulls the next fd from the queue + * processes it, and then waits for the next client. + * + * Block SIGPIPE in this worker thread for the life of the thread. + * This avoids stray (and sometimes delayed) SIGPIPE signals caused + * by client errors and/or when we are under extremely heavy IO load. + * + * This means that the application callback will have SIGPIPE blocked. + * The callback should not change it. + */ +static void *worker_thread_proc(void *_worker_thread_data) +{ + struct ipc_worker_thread_data *worker_thread_data = _worker_thread_data; + struct ipc_server_data *server_data = worker_thread_data->server_data; + sigset_t old_set; + int fd, io; + int ret; + + trace2_thread_start("ipc-worker"); + + thread_block_sigpipe(&old_set); + + for (;;) { + fd = worker_thread__wait_for_connection(worker_thread_data); + if (fd == -1) + break; /* in shutdown */ + + io = worker_thread__wait_for_io_start(worker_thread_data, fd); + if (io == -1) + continue; /* client hung up without sending anything */ + + ret = worker_thread__do_io(worker_thread_data, fd); + + if (ret == SIMPLE_IPC_QUIT) { + trace2_data_string("ipc-worker", NULL, "queue_stop_async", + "application_quit"); + /* + * The application layer is telling the ipc-server + * layer to shutdown. + * + * We DO NOT have a response to send to the client. + * + * Queue an async stop (to stop the other threads) and + * allow this worker thread to exit now (no sense waiting + * for the thread-pool shutdown signal). + * + * Other non-idle worker threads are allowed to finish + * responding to their current clients. + */ + ipc_server_stop_async(server_data); + break; + } + } + + trace2_thread_exit(); + return NULL; +} + +/* A randomly chosen value. */ +#define MY_ACCEPT_POLL_TIMEOUT_MS (60 * 1000) + +/* + * Accept a new client connection on our socket. This uses non-blocking + * IO so that we can also wait for shutdown requests on our socket-pair + * without actually spinning on a fast timeout. + */ +static int accept_thread__wait_for_connection( + struct ipc_accept_thread_data *accept_thread_data) +{ + struct pollfd pollfd[2]; + int result; + + for (;;) { + pollfd[0].fd = accept_thread_data->fd_wait_shutdown; + pollfd[0].events = POLLIN; + + pollfd[1].fd = accept_thread_data->server_socket->fd_socket; + pollfd[1].events = POLLIN; + + result = poll(pollfd, 2, MY_ACCEPT_POLL_TIMEOUT_MS); + if (result < 0) { + if (errno == EINTR) + continue; + return result; + } + + if (result == 0) { + /* a timeout */ + + /* + * If someone deletes or force-creates a new unix + * domain socket at our path, all future clients + * will be routed elsewhere and we silently starve. + * If that happens, just queue a shutdown. + */ + if (unix_ss_was_stolen( + accept_thread_data->server_socket)) { + trace2_data_string("ipc-accept", NULL, + "queue_stop_async", + "socket_stolen"); + ipc_server_stop_async( + accept_thread_data->server_data); + } + continue; + } + + if (pollfd[0].revents & POLLIN) { + /* shutdown message queued to socketpair */ + return -1; + } + + if (pollfd[1].revents & POLLIN) { + /* a connection is available on server_socket */ + + int client_fd = + accept(accept_thread_data->server_socket->fd_socket, + NULL, NULL); + if (client_fd >= 0) + return client_fd; + + /* + * An error here is unlikely -- it probably + * indicates that the connecting process has + * already dropped the connection. + */ + continue; + } + + BUG("unandled poll result errno=%d r[0]=%d r[1]=%d", + errno, pollfd[0].revents, pollfd[1].revents); + } +} + +/* + * Thread proc for the IPC server "accept thread". This waits for + * an incoming socket connection, appends it to the queue of available + * connections, and notifies a worker thread to process it. + * + * Block SIGPIPE in this thread for the life of the thread. This + * avoids any stray SIGPIPE signals when closing pipe fds under + * extremely heavy loads (such as when the fifo queue is full and we + * drop incomming connections). + */ +static void *accept_thread_proc(void *_accept_thread_data) +{ + struct ipc_accept_thread_data *accept_thread_data = _accept_thread_data; + struct ipc_server_data *server_data = accept_thread_data->server_data; + sigset_t old_set; + + trace2_thread_start("ipc-accept"); + + thread_block_sigpipe(&old_set); + + for (;;) { + int client_fd = accept_thread__wait_for_connection( + accept_thread_data); + + pthread_mutex_lock(&server_data->work_available_mutex); + if (server_data->shutdown_requested) { + pthread_mutex_unlock(&server_data->work_available_mutex); + if (client_fd >= 0) + close(client_fd); + break; + } + + if (client_fd < 0) { + /* ignore transient accept() errors */ + } + else { + fifo_enqueue(server_data, client_fd); + pthread_cond_broadcast(&server_data->work_available_cond); + } + pthread_mutex_unlock(&server_data->work_available_mutex); + } + + trace2_thread_exit(); + return NULL; +} + +/* + * We can't predict the connection arrival rate relative to the worker + * processing rate, therefore we allow the "accept-thread" to queue up + * a generous number of connections, since we'd rather have the client + * not unnecessarily timeout if we can avoid it. (The assumption is + * that this will be used for FSMonitor and a few second wait on a + * connection is better than having the client timeout and do the full + * computation itself.) + * + * The FIFO queue size is set to a multiple of the worker pool size. + * This value chosen at random. + */ +#define FIFO_SCALE (100) + +/* + * The backlog value for `listen(2)`. This doesn't need to huge, + * rather just large enough for our "accept-thread" to wake up and + * queue incoming connections onto the FIFO without the kernel + * dropping any. + * + * This value chosen at random. + */ +#define LISTEN_BACKLOG (50) + +static int create_listener_socket( + const char *path, + const struct ipc_server_opts *ipc_opts, + struct unix_ss_socket **new_server_socket) +{ + struct unix_ss_socket *server_socket = NULL; + struct unix_stream_listen_opts uslg_opts = UNIX_STREAM_LISTEN_OPTS_INIT; + int ret; + + uslg_opts.listen_backlog_size = LISTEN_BACKLOG; + uslg_opts.disallow_chdir = ipc_opts->uds_disallow_chdir; + + ret = unix_ss_create(path, &uslg_opts, -1, &server_socket); + if (ret) + return ret; + + if (set_socket_blocking_flag(server_socket->fd_socket, 1)) { + int saved_errno = errno; + unix_ss_free(server_socket); + errno = saved_errno; + return -1; + } + + *new_server_socket = server_socket; + + trace2_data_string("ipc-server", NULL, "listen-with-lock", path); + return 0; +} + +static int setup_listener_socket( + const char *path, + const struct ipc_server_opts *ipc_opts, + struct unix_ss_socket **new_server_socket) +{ + int ret, saved_errno; + + trace2_region_enter("ipc-server", "create-listener_socket", NULL); + + ret = create_listener_socket(path, ipc_opts, new_server_socket); + + saved_errno = errno; + trace2_region_leave("ipc-server", "create-listener_socket", NULL); + errno = saved_errno; + + return ret; +} + +/* + * Start IPC server in a pool of background threads. + */ +int ipc_server_run_async(struct ipc_server_data **returned_server_data, + const char *path, const struct ipc_server_opts *opts, + ipc_server_application_cb *application_cb, + void *application_data) +{ + struct unix_ss_socket *server_socket = NULL; + struct ipc_server_data *server_data; + int sv[2]; + int k; + int ret; + int nr_threads = opts->nr_threads; + + *returned_server_data = NULL; + + /* + * Create a socketpair and set sv[1] to non-blocking. This + * will used to send a shutdown message to the accept-thread + * and allows the accept-thread to wait on EITHER a client + * connection or a shutdown request without spinning. + */ + if (socketpair(AF_UNIX, SOCK_STREAM, 0, sv) < 0) + return -1; + + if (set_socket_blocking_flag(sv[1], 1)) { + int saved_errno = errno; + close(sv[0]); + close(sv[1]); + errno = saved_errno; + return -1; + } + + ret = setup_listener_socket(path, opts, &server_socket); + if (ret) { + int saved_errno = errno; + close(sv[0]); + close(sv[1]); + errno = saved_errno; + return ret; + } + + server_data = xcalloc(1, sizeof(*server_data)); + server_data->magic = MAGIC_SERVER_DATA; + server_data->application_cb = application_cb; + server_data->application_data = application_data; + strbuf_init(&server_data->buf_path, 0); + strbuf_addstr(&server_data->buf_path, path); + + if (nr_threads < 1) + nr_threads = 1; + + pthread_mutex_init(&server_data->work_available_mutex, NULL); + pthread_cond_init(&server_data->work_available_cond, NULL); + + server_data->queue_size = nr_threads * FIFO_SCALE; + CALLOC_ARRAY(server_data->fifo_fds, server_data->queue_size); + + server_data->accept_thread = + xcalloc(1, sizeof(*server_data->accept_thread)); + server_data->accept_thread->magic = MAGIC_ACCEPT_THREAD_DATA; + server_data->accept_thread->server_data = server_data; + server_data->accept_thread->server_socket = server_socket; + server_data->accept_thread->fd_send_shutdown = sv[0]; + server_data->accept_thread->fd_wait_shutdown = sv[1]; + + if (pthread_create(&server_data->accept_thread->pthread_id, NULL, + accept_thread_proc, server_data->accept_thread)) + die_errno(_("could not start accept_thread '%s'"), path); + + for (k = 0; k < nr_threads; k++) { + struct ipc_worker_thread_data *wtd; + + wtd = xcalloc(1, sizeof(*wtd)); + wtd->magic = MAGIC_WORKER_THREAD_DATA; + wtd->server_data = server_data; + + if (pthread_create(&wtd->pthread_id, NULL, worker_thread_proc, + wtd)) { + if (k == 0) + die(_("could not start worker[0] for '%s'"), + path); + /* + * Limp along with the thread pool that we have. + */ + break; + } + + wtd->next_thread = server_data->worker_thread_list; + server_data->worker_thread_list = wtd; + } + + *returned_server_data = server_data; + return 0; +} + +/* + * Gently tell the IPC server treads to shutdown. + * Can be run on any thread. + */ +int ipc_server_stop_async(struct ipc_server_data *server_data) +{ + /* ASSERT NOT holding mutex */ + + int fd; + + if (!server_data) + return 0; + + trace2_region_enter("ipc-server", "server-stop-async", NULL); + + pthread_mutex_lock(&server_data->work_available_mutex); + + server_data->shutdown_requested = 1; + + /* + * Write a byte to the shutdown socket pair to wake up the + * accept-thread. + */ + if (write(server_data->accept_thread->fd_send_shutdown, "Q", 1) < 0) + error_errno("could not write to fd_send_shutdown"); + + /* + * Drain the queue of existing connections. + */ + while ((fd = fifo_dequeue(server_data)) != -1) + close(fd); + + /* + * Gently tell worker threads to stop processing new connections + * and exit. (This does not abort in-process conversations.) + */ + pthread_cond_broadcast(&server_data->work_available_cond); + + pthread_mutex_unlock(&server_data->work_available_mutex); + + trace2_region_leave("ipc-server", "server-stop-async", NULL); + + return 0; +} + +/* + * Wait for all IPC server threads to stop. + */ +int ipc_server_await(struct ipc_server_data *server_data) +{ + pthread_join(server_data->accept_thread->pthread_id, NULL); + + if (!server_data->shutdown_requested) + BUG("ipc-server: accept-thread stopped for '%s'", + server_data->buf_path.buf); + + while (server_data->worker_thread_list) { + struct ipc_worker_thread_data *wtd = + server_data->worker_thread_list; + + pthread_join(wtd->pthread_id, NULL); + + server_data->worker_thread_list = wtd->next_thread; + free(wtd); + } + + server_data->is_stopped = 1; + + return 0; +} + +void ipc_server_free(struct ipc_server_data *server_data) +{ + struct ipc_accept_thread_data * accept_thread_data; + + if (!server_data) + return; + + if (!server_data->is_stopped) + BUG("cannot free ipc-server while running for '%s'", + server_data->buf_path.buf); + + accept_thread_data = server_data->accept_thread; + if (accept_thread_data) { + unix_ss_free(accept_thread_data->server_socket); + + if (accept_thread_data->fd_send_shutdown != -1) + close(accept_thread_data->fd_send_shutdown); + if (accept_thread_data->fd_wait_shutdown != -1) + close(accept_thread_data->fd_wait_shutdown); + + free(server_data->accept_thread); + } + + while (server_data->worker_thread_list) { + struct ipc_worker_thread_data *wtd = + server_data->worker_thread_list; + + server_data->worker_thread_list = wtd->next_thread; + free(wtd); + } + + pthread_cond_destroy(&server_data->work_available_cond); + pthread_mutex_destroy(&server_data->work_available_mutex); + + strbuf_release(&server_data->buf_path); + + free(server_data->fifo_fds); + free(server_data); +} -- cgit v1.2.3