From c87187f913f853a650a00ca0328817987298f7d0 Mon Sep 17 00:00:00 2001 From: Nicholas Marriott Date: Sat, 24 Jul 2010 20:11:59 +0000 Subject: [PATCH] When changing so that the client passes its stdout and stderr as well as stdin up to the server, I forgot one essential point - the tmux server could now be both the producer and consumer. This happens when tmux is run inside tmux, as well as when piping tmux commands together. So, using stdio(3) was a bad idea - if sufficient data was written, this could block in write(2). When that happened and the server was both producer and consumer, it deadlocks. Change to use libevent bufferevents for the client stdin, stdout and stderr instead. This is trivial enough for output but requires a callback mechanism to trigger when stdin is finished. This relies on the underlying polling mechanism for libevent to work with whatever devices to which the user could redirect stdin, stdout or stderr, hence the change to use poll(2) over kqueue(2) for tmux. --- cmd-if-shell.c | 3 +- cmd-load-buffer.c | 108 ++++++++++++++++++++++------ cmd-run-shell.c | 5 +- cmd-save-buffer.c | 24 +++---- server-client.c | 180 +++++++++++++++++++++++++++++++++++----------- server-fn.c | 2 +- tmux.h | 16 +++-- 7 files changed, 250 insertions(+), 88 deletions(-) diff --git a/cmd-if-shell.c b/cmd-if-shell.c index 367bb691..bf60fb23 100644 --- a/cmd-if-shell.c +++ b/cmd-if-shell.c @@ -109,8 +109,7 @@ cmd_if_shell_free(void *data) if (ctx->cmdclient != NULL) { ctx->cmdclient->references--; exitdata.retcode = ctx->cmdclient->retcode; - server_write_client( - ctx->cmdclient, MSG_EXIT, &exitdata, sizeof exitdata); + ctx->cmdclient->flags |= CLIENT_EXIT; } if (ctx->curclient != NULL) ctx->curclient->references--; diff --git a/cmd-load-buffer.c b/cmd-load-buffer.c index 0f118490..e28b9c74 100644 --- a/cmd-load-buffer.c +++ b/cmd-load-buffer.c @@ -31,6 +31,7 @@ */ int cmd_load_buffer_exec(struct cmd *, struct cmd_ctx *); +void cmd_load_buffer_callback(struct client *, void *); const struct cmd_entry cmd_load_buffer_entry = { "load-buffer", "loadb", @@ -43,37 +44,55 @@ const struct cmd_entry cmd_load_buffer_entry = { cmd_buffer_print }; +struct cmd_load_buffer_cdata { + struct session *session; + int buffer; +}; + int cmd_load_buffer_exec(struct cmd *self, struct cmd_ctx *ctx) { - struct cmd_buffer_data *data = self->data; - struct session *s; - FILE *f, *close_f; - char *pdata, *new_pdata; - size_t psize; - u_int limit; - int ch; + struct cmd_buffer_data *data = self->data; + struct cmd_load_buffer_cdata *cdata; + struct session *s; + struct client *c = ctx->cmdclient; + FILE *f; + char *pdata, *new_pdata; + size_t psize; + u_int limit; + int ch; if ((s = cmd_find_session(ctx, data->target)) == NULL) return (-1); - if (strcmp(data->arg, "-") == 0 ) { - if (ctx->cmdclient == NULL) { + if (strcmp(data->arg, "-") == 0) { + if (c == NULL) { ctx->error(ctx, "%s: can't read from stdin", data->arg); return (-1); } - f = ctx->cmdclient->stdin_file; - if (isatty(fileno(ctx->cmdclient->stdin_file))) { + if (c->flags & CLIENT_TERMINAL) { ctx->error(ctx, "%s: stdin is a tty", data->arg); return (-1); } - close_f = NULL; - } else { - if ((f = fopen(data->arg, "rb")) == NULL) { - ctx->error(ctx, "%s: %s", data->arg, strerror(errno)); + if (c->stdin_fd == -1) { + ctx->error(ctx, "%s: can't read from stdin", data->arg); return (-1); } - close_f = f; + + cdata = xmalloc(sizeof *cdata); + cdata->session = s; + cdata->buffer = data->buffer; + c->stdin_data = cdata; + c->stdin_callback = cmd_load_buffer_callback; + + c->references++; + bufferevent_enable(c->stdin_event, EV_READ); + return (1); + } + + if ((f = fopen(data->arg, "rb")) == NULL) { + ctx->error(ctx, "%s: %s", data->arg, strerror(errno)); + return (-1); } pdata = NULL; @@ -94,8 +113,8 @@ cmd_load_buffer_exec(struct cmd *self, struct cmd_ctx *ctx) if (pdata != NULL) pdata[psize] = '\0'; - if (close_f != NULL) - fclose(close_f); + fclose(f); + f = NULL; limit = options_get_number(&s->options, "buffer-limit"); if (data->buffer == -1) { @@ -104,7 +123,7 @@ cmd_load_buffer_exec(struct cmd *self, struct cmd_ctx *ctx) } if (paste_replace(&s->buffers, data->buffer, pdata, psize) != 0) { ctx->error(ctx, "no buffer %d", data->buffer); - goto error; + return (-1); } return (0); @@ -112,7 +131,54 @@ cmd_load_buffer_exec(struct cmd *self, struct cmd_ctx *ctx) error: if (pdata != NULL) xfree(pdata); - if (close_f != NULL) - fclose(close_f); + if (f != NULL) + fclose(f); return (-1); } + +void +cmd_load_buffer_callback(struct client *c, void *data) +{ + struct cmd_load_buffer_cdata *cdata = data; + struct session *s = cdata->session; + char *pdata; + size_t psize; + u_int limit; + int idx; + + /* + * Event callback has already checked client is not dead and reduced + * its reference count. But tell it to exit. + */ + c->flags |= CLIENT_EXIT; + + /* Does the target session still exist? */ + if (session_index(s, &idx) != 0) + goto out; + + psize = EVBUFFER_LENGTH(c->stdin_event->input); + if (psize == 0) + goto out; + + pdata = malloc(psize + 1); + if (pdata == NULL) + goto out; + bufferevent_read(c->stdin_event, pdata, psize); + pdata[psize] = '\0'; + + limit = options_get_number(&s->options, "buffer-limit"); + if (cdata->buffer == -1) { + paste_add(&s->buffers, pdata, psize, limit); + goto out; + } + if (paste_replace(&s->buffers, cdata->buffer, pdata, psize) != 0) { + /* No context so can't use server_client_msg_error. */ + evbuffer_add_printf( + c->stderr_event->output, "no buffer %d\n", cdata->buffer); + bufferevent_enable(c->stderr_event, EV_WRITE); + goto out; + } + +out: + xfree(cdata); +} diff --git a/cmd-run-shell.c b/cmd-run-shell.c index f9d1e237..7bfb8916 100644 --- a/cmd-run-shell.c +++ b/cmd-run-shell.c @@ -131,13 +131,10 @@ cmd_run_shell_free(void *data) { struct cmd_run_shell_data *cdata = data; struct cmd_ctx *ctx = &cdata->ctx; - struct msg_exit_data exitdata; if (ctx->cmdclient != NULL) { ctx->cmdclient->references--; - exitdata.retcode = ctx->cmdclient->retcode; - server_write_client( - ctx->cmdclient, MSG_EXIT, &exitdata, sizeof exitdata); + ctx->cmdclient->flags |= CLIENT_EXIT; } if (ctx->curclient != NULL) ctx->curclient->references--; diff --git a/cmd-save-buffer.c b/cmd-save-buffer.c index 57c3f5f0..1d287cd2 100644 --- a/cmd-save-buffer.c +++ b/cmd-save-buffer.c @@ -47,8 +47,8 @@ cmd_save_buffer_exec(struct cmd *self, struct cmd_ctx *ctx) struct cmd_buffer_data *data = self->data; struct session *s; struct paste_buffer *pb; - mode_t mask; - FILE *f, *close_f; + mode_t mask; + FILE *f; if ((s = cmd_find_session(ctx, data->target)) == NULL) return (-1); @@ -70,8 +70,8 @@ cmd_save_buffer_exec(struct cmd *self, struct cmd_ctx *ctx) ctx->error(ctx, "%s: can't write to stdout", data->arg); return (-1); } - f = ctx->cmdclient->stdout_file; - close_f = NULL; + bufferevent_write( + ctx->cmdclient->stdout_event, pb->data, pb->size); } else { mask = umask(S_IRWXG | S_IRWXO); if (cmd_check_flag(data->chflags, 'a')) @@ -83,17 +83,13 @@ cmd_save_buffer_exec(struct cmd *self, struct cmd_ctx *ctx) ctx->error(ctx, "%s: %s", data->arg, strerror(errno)); return (-1); } - close_f = f; + if (fwrite(pb->data, 1, pb->size, f) != pb->size) { + ctx->error(ctx, "%s: fwrite error", data->arg); + fclose(f); + return (-1); + } + fclose(f); } - if (fwrite(pb->data, 1, pb->size, f) != pb->size) { - ctx->error(ctx, "%s: fwrite error", data->arg); - fclose(f); - return (-1); - } - - if (close_f != NULL) - fclose(close_f); - return (0); } diff --git a/server-client.c b/server-client.c index f594f1e3..a27089b4 100644 --- a/server-client.c +++ b/server-client.c @@ -29,9 +29,13 @@ void server_client_handle_key(int, struct mouse_event *, void *); void server_client_repeat_timer(int, short, void *); +void server_client_check_exit(struct client *); void server_client_check_redraw(struct client *); void server_client_set_title(struct client *); void server_client_reset_state(struct client *); +void server_client_in_callback(struct bufferevent *, short, void *); +void server_client_out_callback(struct bufferevent *, short, void *); +void server_client_err_callback(struct bufferevent *, short, void *); int server_client_msg_dispatch(struct client *); void server_client_msg_command(struct client *, struct msg_command_data *); @@ -69,9 +73,9 @@ server_client_create(int fd) ARRAY_INIT(&c->prompt_hdata); - c->stdin_file = NULL; - c->stdout_file = NULL; - c->stderr_file = NULL; + c->stdin_event = NULL; + c->stdout_event = NULL; + c->stderr_event = NULL; c->tty.fd = -1; c->title = NULL; @@ -122,12 +126,18 @@ server_client_lost(struct client *c) if (c->flags & CLIENT_TERMINAL) tty_free(&c->tty); - if (c->stdin_file != NULL) - fclose(c->stdin_file); - if (c->stdout_file != NULL) - fclose(c->stdout_file); - if (c->stderr_file != NULL) - fclose(c->stderr_file); + if (c->stdin_fd != -1) + close(c->stdin_fd); + if (c->stdin_event != NULL) + bufferevent_free(c->stdin_event); + if (c->stdout_fd != -1) + close(c->stdout_fd); + if (c->stdout_event != NULL) + bufferevent_free(c->stdout_event); + if (c->stderr_fd != -1) + close(c->stderr_fd); + if (c->stderr_event != NULL) + bufferevent_free(c->stderr_event); screen_free(&c->status); job_tree_free(&c->status_jobs); @@ -390,11 +400,14 @@ server_client_loop(void) for (i = 0; i < ARRAY_LENGTH(&clients); i++) { c = ARRAY_ITEM(&clients, i); - if (c == NULL || c->session == NULL) + if (c == NULL) continue; - server_client_check_redraw(c); - server_client_reset_state(c); + server_client_check_exit(c); + if (c->session != NULL) { + server_client_check_redraw(c); + server_client_reset_state(c); + } } /* @@ -457,6 +470,28 @@ server_client_repeat_timer(unused int fd, unused short events, void *data) c->flags &= ~(CLIENT_PREFIX|CLIENT_REPEAT); } +/* Check if client should be exited. */ +void +server_client_check_exit(struct client *c) +{ + struct msg_exit_data exitdata; + + if (!(c->flags & CLIENT_EXIT)) + return; + + if (c->stdout_fd != -1 && c->stdout_event != NULL && + EVBUFFER_LENGTH(c->stdout_event->output) != 0) + return; + if (c->stderr_fd != -1 && c->stderr_event != NULL && + EVBUFFER_LENGTH(c->stderr_event->output) != 0) + return; + + exitdata.retcode = c->retcode; + server_write_client(c, MSG_EXIT, &exitdata, sizeof exitdata); + + c->flags &= ~CLIENT_EXIT; +} + /* Check for client redraws. */ void server_client_check_redraw(struct client *c) @@ -523,6 +558,52 @@ server_client_set_title(struct client *c) xfree(title); } +/* + * Error callback for client stdin. Caller must increase reference count when + * enabling event! + */ +void +server_client_in_callback( + unused struct bufferevent *bufev, unused short what, void *data) +{ + struct client *c = data; + + c->references--; + if (c->flags & CLIENT_DEAD) + return; + + bufferevent_disable(c->stdin_event, EV_READ|EV_WRITE); + close(c->stdin_fd); + c->stdin_fd = -1; + + if (c->stdin_callback != NULL) + c->stdin_callback(c, c->stdin_data); +} + +/* Error callback for client stdout. */ +void +server_client_out_callback( + unused struct bufferevent *bufev, unused short what, unused void *data) +{ + struct client *c = data; + + bufferevent_disable(c->stdout_event, EV_READ|EV_WRITE); + close(c->stdout_fd); + c->stdout_fd = -1; +} + +/* Error callback for client stderr. */ +void +server_client_err_callback( + unused struct bufferevent *bufev, unused short what, unused void *data) +{ + struct client *c = data; + + bufferevent_disable(c->stderr_event, EV_READ|EV_WRITE); + close(c->stderr_fd); + c->stderr_fd = -1; +} + /* Dispatch message from client. */ int server_client_msg_dispatch(struct client *c) @@ -532,6 +613,7 @@ server_client_msg_dispatch(struct client *c) struct msg_identify_data identifydata; struct msg_environ_data environdata; ssize_t n, datalen; + int mode; if ((n = imsg_read(&c->ibuf)) == -1 || n == 0) return (-1); @@ -566,9 +648,17 @@ server_client_msg_dispatch(struct client *c) fatalx("MSG_IDENTIFY missing fd"); memcpy(&identifydata, imsg.data, sizeof identifydata); - c->stdin_file = fdopen(imsg.fd, "r"); - if (c->stdin_file == NULL) - fatal("fdopen(stdin) failed"); + c->stdin_fd = imsg.fd; + c->stdin_event = bufferevent_new(imsg.fd, NULL, NULL, + server_client_in_callback, c); + if (c->stdin_event == NULL) + fatalx("failed to create stdin event"); + + if ((mode = fcntl(imsg.fd, F_GETFL)) != -1) + fcntl(imsg.fd, F_SETFL, mode|O_NONBLOCK); + if (fcntl(imsg.fd, F_SETFD, FD_CLOEXEC) == -1) + fatal("fcntl failed"); + server_client_msg_identify(c, &identifydata, imsg.fd); break; case MSG_STDOUT: @@ -577,9 +667,16 @@ server_client_msg_dispatch(struct client *c) if (imsg.fd == -1) fatalx("MSG_STDOUT missing fd"); - c->stdout_file = fdopen(imsg.fd, "w"); - if (c->stdout_file == NULL) - fatal("fdopen(stdout) failed"); + c->stdout_fd = imsg.fd; + c->stdout_event = bufferevent_new(imsg.fd, NULL, NULL, + server_client_out_callback, c); + if (c->stdout_event == NULL) + fatalx("failed to create stdout event"); + + if ((mode = fcntl(imsg.fd, F_GETFL)) != -1) + fcntl(imsg.fd, F_SETFL, mode|O_NONBLOCK); + if (fcntl(imsg.fd, F_SETFD, FD_CLOEXEC) == -1) + fatal("fcntl failed"); break; case MSG_STDERR: if (datalen != 0) @@ -587,9 +684,16 @@ server_client_msg_dispatch(struct client *c) if (imsg.fd == -1) fatalx("MSG_STDERR missing fd"); - c->stderr_file = fdopen(imsg.fd, "w"); - if (c->stderr_file == NULL) - fatal("fdopen(stderr) failed"); + c->stderr_fd = imsg.fd; + c->stderr_event = bufferevent_new(imsg.fd, NULL, NULL, + server_client_err_callback, c); + if (c->stderr_event == NULL) + fatalx("failed to create stderr event"); + + if ((mode = fcntl(imsg.fd, F_GETFL)) != -1) + fcntl(imsg.fd, F_SETFL, mode|O_NONBLOCK); + if (fcntl(imsg.fd, F_SETFD, FD_CLOEXEC) == -1) + fatal("fcntl failed"); break; case MSG_RESIZE: if (datalen != 0) @@ -659,12 +763,10 @@ server_client_msg_error(struct cmd_ctx *ctx, const char *fmt, ...) va_list ap; va_start(ap, fmt); - vfprintf(ctx->cmdclient->stderr_file, fmt, ap); + evbuffer_add_vprintf(ctx->cmdclient->stderr_event->output, fmt, ap); va_end(ap); - fputc('\n', ctx->cmdclient->stderr_file); - fflush(ctx->cmdclient->stderr_file); - + bufferevent_write(ctx->cmdclient->stderr_event, "\n", 1); ctx->cmdclient->retcode = 1; } @@ -675,11 +777,10 @@ server_client_msg_print(struct cmd_ctx *ctx, const char *fmt, ...) va_list ap; va_start(ap, fmt); - vfprintf(ctx->cmdclient->stdout_file, fmt, ap); + evbuffer_add_vprintf(ctx->cmdclient->stdout_event->output, fmt, ap); va_end(ap); - fputc('\n', ctx->cmdclient->stdout_file); - fflush(ctx->cmdclient->stdout_file); + bufferevent_write(ctx->cmdclient->stdout_event, "\n", 1); } /* Callback to send print message to client, if not quiet. */ @@ -692,22 +793,20 @@ server_client_msg_info(struct cmd_ctx *ctx, const char *fmt, ...) return; va_start(ap, fmt); - vfprintf(ctx->cmdclient->stdout_file, fmt, ap); + evbuffer_add_vprintf(ctx->cmdclient->stdout_event->output, fmt, ap); va_end(ap); - fputc('\n', ctx->cmdclient->stdout_file); - fflush(ctx->cmdclient->stdout_file); + bufferevent_write(ctx->cmdclient->stdout_event, "\n", 1); } /* Handle command message. */ void server_client_msg_command(struct client *c, struct msg_command_data *data) { - struct cmd_ctx ctx; - struct cmd_list *cmdlist = NULL; - struct msg_exit_data exitdata; - int argc; - char **argv, *cause; + struct cmd_ctx ctx; + struct cmd_list *cmdlist = NULL; + int argc; + char **argv, *cause; ctx.error = server_client_msg_error; ctx.print = server_client_msg_print; @@ -738,18 +837,15 @@ server_client_msg_command(struct client *c, struct msg_command_data *data) } cmd_free_argv(argc, argv); - if (cmd_list_exec(cmdlist, &ctx) != 1) { - exitdata.retcode = c->retcode; - server_write_client(c, MSG_EXIT, &exitdata, sizeof exitdata); - } + if (cmd_list_exec(cmdlist, &ctx) != 1) + c->flags |= CLIENT_EXIT; cmd_list_free(cmdlist); return; error: if (cmdlist != NULL) cmd_list_free(cmdlist); - exitdata.retcode = c->retcode; - server_write_client(c, MSG_EXIT, &exitdata, sizeof exitdata); + c->flags |= CLIENT_EXIT; } /* Handle identify message. */ diff --git a/server-fn.c b/server-fn.c index 74452fe8..4ecbce9e 100644 --- a/server-fn.c +++ b/server-fn.c @@ -395,7 +395,7 @@ server_destroy_session(struct session *s) continue; if (s_new == NULL) { c->session = NULL; - server_write_client(c, MSG_EXIT, NULL, 0); + c->flags |= CLIENT_EXIT; } else { c->session = s_new; server_redraw_client(c); diff --git a/tmux.h b/tmux.h index 8a4ec29d..e1cd0b7e 100644 --- a/tmux.h +++ b/tmux.h @@ -1096,9 +1096,17 @@ struct client { char *cwd; struct tty tty; - FILE *stdin_file; - FILE *stdout_file; - FILE *stderr_file; + + int stdin_fd; + void *stdin_data; + void (*stdin_callback)(struct client *, void *); + struct bufferevent *stdin_event; + + int stdout_fd; + struct bufferevent *stdout_event; + + int stderr_fd; + struct bufferevent *stderr_event; struct event repeat_timer; @@ -1108,7 +1116,7 @@ struct client { #define CLIENT_TERMINAL 0x1 #define CLIENT_PREFIX 0x2 -/* 0x4 unused */ +#define CLIENT_EXIT 0x4 #define CLIENT_REDRAW 0x8 #define CLIENT_STATUS 0x10 #define CLIENT_REPEAT 0x20 /* allow command to repeat within repeat time */