diff options
Diffstat (limited to 'src/backend/libpq/pqcomm.c')
| -rw-r--r-- | src/backend/libpq/pqcomm.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/src/backend/libpq/pqcomm.c b/src/backend/libpq/pqcomm.c index 4c7b1e7bfdf..4cd6d6dfbb9 100644 --- a/src/backend/libpq/pqcomm.c +++ b/src/backend/libpq/pqcomm.c @@ -54,6 +54,9 @@ */ #include "postgres.h" +#ifdef HAVE_POLL_H +#include <poll.h> +#endif #include <signal.h> #include <fcntl.h> #include <grp.h> @@ -1921,3 +1924,40 @@ pq_settcpusertimeout(int timeout, Port *port) return STATUS_OK; } + +/* + * Check if the client is still connected. + */ +bool +pq_check_connection(void) +{ +#if defined(POLLRDHUP) + /* + * POLLRDHUP is a Linux extension to poll(2) to detect sockets closed by + * the other end. We don't have a portable way to do that without + * actually trying to read or write data on other systems. We don't want + * to read because that would be confused by pipelined queries and COPY + * data. Perhaps in future we'll try to write a heartbeat message instead. + */ + struct pollfd pollfd; + int rc; + + pollfd.fd = MyProcPort->sock; + pollfd.events = POLLOUT | POLLIN | POLLRDHUP; + pollfd.revents = 0; + + rc = poll(&pollfd, 1, 0); + + if (rc < 0) + { + ereport(COMMERROR, + (errcode_for_socket_access(), + errmsg("could not poll socket: %m"))); + return false; + } + else if (rc == 1 && (pollfd.revents & (POLLHUP | POLLRDHUP))) + return false; +#endif + + return true; +} |