diff options
Diffstat (limited to 'applause.c')
| -rw-r--r-- | applause.c | 63 |
1 files changed, 63 insertions, 0 deletions
@@ -7,6 +7,7 @@ #include <stdint.h> #include <signal.h> #include <unistd.h> +#include <poll.h> #include <errno.h> #include <assert.h> @@ -760,6 +761,40 @@ do_command(lua_State *L, const char *command) */ static pthread_mutex_t lua_mutex = PTHREAD_MUTEX_INITIALIZER; +/** + * Thread monitoring the client file desciptor. + * This will set the interrupted flag if the remote + * end closes its write part of the socket. + * That's why we need the length header at the beginning + * of requests. + * There seems to be no easy way to find out whether the + * read part has been shut down (or the entire connection) + * without doing I/O. + * On the other hand, this is how "socat -,ignoreeof TCP:127.0.0.1:10000" + * behaves and socat does close the connection properly when + * interrupted in contrast to netcat. + * So either we stay with this solution or implement a + * stand-alone applause_cat just for sending commands (which + * would give us more liberties, though). + */ +static void * +monitor_thread_cb(void *user_data) +{ + int fd = *(int *)user_data; + + struct pollfd pfd = {fd, POLLRDHUP}; + + /* + * poll() is a cancellation point, so when + * do_command() terminates, we will cancel here. + */ + while (poll(&pfd, 1, -1) != 1 || + !(pfd.revents & (POLLRDHUP | POLLERR | POLLHUP))); + + interrupted = 1; + return NULL; +} + /* * FIXME: This should perhaps be the only interface to the * applause Lua state with the REPL loop implemented as a Lua @@ -802,6 +837,8 @@ command_server(void *user_data) size_t length; char *command; + pthread_t monitor_thread; + int old_stdout, old_stderr; int client_fd = accept(socket_fd, NULL, NULL); @@ -842,6 +879,24 @@ command_server(void *user_data) pthread_mutex_lock(&lua_mutex); /* + * Start another thread monitoring client_fd and setting + * the interrupted flag in case the remote end terminates + * prematurely. This has the effect of ^C in SciTECO interrupting + * the current command (e.g. play()) at least when using + * socat (see monitor_thread_cb()). + * A monitoring thread is started instead of running do_command() + * in yet another thread since the monitoring thread is easier + * to terminate. + */ + if (pthread_create(&monitor_thread, NULL, monitor_thread_cb, &client_fd)) { + perror("pthread_create"); + pthread_mutex_unlock(&lua_mutex); + free(command); + close(client_fd); + continue; + } + + /* * Redirect stdout and stderr to client_fd. * This way, we capture all the output that the command * may have. @@ -865,6 +920,14 @@ command_server(void *user_data) free(command); /* + * Terminate the monitoring thread. + * It will already be terminated if the remote end terminates + * prematurely. + */ + pthread_cancel(monitor_thread); + pthread_join(monitor_thread, NULL); + + /* * Restore stdout/stderr. */ close(1); |