diff options
Diffstat (limited to 'src/bin/pg_basebackup/pg_basebackup.c')
| -rw-r--r-- | src/bin/pg_basebackup/pg_basebackup.c | 47 |
1 files changed, 45 insertions, 2 deletions
diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c index 8c77c533e64..c1ed7aeeee1 100644 --- a/src/bin/pg_basebackup/pg_basebackup.c +++ b/src/bin/pg_basebackup/pg_basebackup.c @@ -174,6 +174,8 @@ static int bgpipe[2] = {-1, -1}; /* Handle to child process */ static pid_t bgchild = -1; static bool in_log_streamer = false; +/* Flag to indicate if child process exited unexpectedly */ +static volatile sig_atomic_t bgchild_exited = false; /* End position for xlog streaming, empty string if unknown yet */ static XLogRecPtr xlogendptr; @@ -278,6 +280,18 @@ disconnect_atexit(void) #ifndef WIN32 /* + * If the bgchild exits prematurely and raises a SIGCHLD signal, we can abort + * processing rather than wait until the backup has finished and error out at + * that time. On Windows, we use a background thread which can communicate + * without the need for a signal handler. + */ +static void +sigchld_handler(SIGNAL_ARGS) +{ + bgchild_exited = true; +} + +/* * On windows, our background thread dies along with the process. But on * Unix, if we have started a subprocess, we want to kill it off so it * doesn't remain running trying to stream data. @@ -285,7 +299,7 @@ disconnect_atexit(void) static void kill_bgchild_atexit(void) { - if (bgchild > 0) + if (bgchild > 0 && !bgchild_exited) kill(bgchild, SIGTERM); } #endif @@ -572,17 +586,28 @@ LogStreamerMain(logstreamer_param *param) stream.do_sync); if (!ReceiveXlogStream(param->bgconn, &stream)) - + { /* * Any errors will already have been reported in the function process, * but we need to tell the parent that we didn't shutdown in a nice * way. */ +#ifdef WIN32 + /* + * In order to signal the main thread of an ungraceful exit we + * set the same flag that we use on Unix to signal SIGCHLD. + */ + bgchild_exited = true; +#endif return 1; + } if (!stream.walmethod->finish()) { pg_log_error("could not finish writing WAL files: %m"); +#ifdef WIN32 + bgchild_exited = true; +#endif return 1; } @@ -1134,6 +1159,12 @@ ReceiveCopyData(PGconn *conn, WriteDataCallback callback, exit(1); } + if (bgchild_exited) + { + pg_log_error("background process terminated unexpectedly"); + exit(1); + } + (*callback) (r, copybuf, callback_data); PQfreemem(copybuf); @@ -2882,6 +2913,18 @@ main(int argc, char **argv) } atexit(disconnect_atexit); +#ifndef WIN32 + /* + * Trap SIGCHLD to be able to handle the WAL stream process exiting. There + * is no SIGCHLD on Windows, there we rely on the background thread setting + * the signal variable on unexpected but graceful exit. If the WAL stream + * thread crashes on Windows it will bring down the entire process as it's + * a thread, so there is nothing to catch should that happen. A crash on + * UNIX will be caught by the signal handler. + */ + pqsignal(SIGCHLD, sigchld_handler); +#endif + /* * Set umask so that directories/files are created with the same * permissions as directories/files in the source data directory. |