waitpid: add support for already exited PIDs

diff --git a/misc-utils/waitpid.1.adoc b/misc-utils/waitpid.1.adoc
index 4b566dc8805e4f73f0b8ff21288f8025d542de17..ea9a7cf5c3ad3615bf02ffe7d496d47df215fd2b 100644 (file)
--- a/misc-utils/waitpid.1.adoc
+++ b/misc-utils/waitpid.1.adoc
@@ -29,6 +29,9 @@ Be more verbose.
 *-t*, *--timeout* _seconds_::
 Maximum wait time.
 
+*-e*, *--exited*::
+Don't error on already exited PIDs.
+
 include::man-common/help-version.adoc[]
 
 == EXIT STATUS

diff --git a/misc-utils/waitpid.c b/misc-utils/waitpid.c
index 64f01373cc2f43f220b801613791639b446280e0..ca28b248a193bd07fd4c6ccdf16b0f0462785bc0 100644 (file)
--- a/misc-utils/waitpid.c
+++ b/misc-utils/waitpid.c
@@ -45,6 +45,7 @@
 
 static bool verbose = false;
 static struct timespec timeout;
+static bool allow_exited = false;
 
 static pid_t *parse_pids(size_t n_strings, char * const *strings)
 {
@@ -62,8 +63,13 @@ static int *open_pidfds(size_t n_pids, pid_t *pids)
 
        for (size_t i = 0; i < n_pids; i++) {
                pidfds[i] = pidfd_open(pids[i], 0);
-               if (pidfds[i] == -1)
+               if (pidfds[i] == -1) {
+                       if (allow_exited && errno == ESRCH) {
+                               warnx(_("PID %d has exited, skipping"), pids[i]);
+                               continue;
+                       }
                        err_nosys(EXIT_FAILURE, _("could not open pid %u"), pids[i]);
+               }
        }
 
        return pidfds;
@@ -90,8 +96,9 @@ static int open_timeoutfd(void)
 
 }
 
-static void add_listeners(int epll, size_t n_pids, int * const pidfds, int timeoutfd)
+static size_t add_listeners(int epll, size_t n_pids, int * const pidfds, int timeoutfd)
 {
+       size_t skipped = 0;
        struct epoll_event evt = {
                .events = EPOLLIN,
        };
@@ -103,16 +110,22 @@ static void add_listeners(int epll, size_t n_pids, int * const pidfds, int timeo
        }
 
        for (size_t i = 0; i < n_pids; i++) {
+               if (pidfds[i] == -1) {
+                       skipped++;
+                       continue;
+               }
                evt.data.u64 = i;
                if (epoll_ctl(epll, EPOLL_CTL_ADD, pidfds[i], &evt))
                        err_nosys(EXIT_FAILURE, _("could not add listener"));
        }
+
+       return n_pids - skipped;
 }
 
-static void wait_for_exits(int epll, size_t n_pids, pid_t * const pids,
+static void wait_for_exits(int epll, size_t active_pids, pid_t * const pids,
                           int * const pidfds)
 {
-       while (n_pids) {
+       while (active_pids) {
                struct epoll_event evt;
                int ret, fd;
 
@@ -130,10 +143,10 @@ static void wait_for_exits(int epll, size_t n_pids, pid_t * const pids,
                }
                if (verbose)
                        printf(_("PID %d finished\n"), pids[evt.data.u64]);
-               assert((size_t) ret <= n_pids);
+               assert((size_t) ret <= active_pids);
                fd = pidfds[evt.data.u64];
                epoll_ctl(epll, EPOLL_CTL_DEL, fd, NULL);
-               n_pids -= ret;
+               active_pids -= ret;
        }
 }
 
@@ -147,6 +160,7 @@ static void __attribute__((__noreturn__)) usage(void)
        fputs(USAGE_OPTIONS, out);
        fputs(_(" -v, --verbose           be more verbose\n"), out);
        fputs(_(" -t, --timeout=<timeout> wait at most timeout seconds\n"), out);
+       fputs(_(" -e, --exited            allow exited PIDs\n"), out);
 
        fputs(USAGE_SEPARATOR, out);
        fprintf(out, USAGE_HELP_OPTIONS(23));
@@ -162,12 +176,13 @@ static int parse_options(int argc, char **argv)
        static const struct option longopts[] = {
                { "verbose", no_argument,       NULL, 'v' },
                { "timeout", required_argument, NULL, 't' },
+               { "exited",  no_argument,       NULL, 'e' },
                { "version", no_argument,       NULL, 'V' },
                { "help",    no_argument,       NULL, 'h' },
                { NULL, 0, NULL, 0 },
        };
 
-       while ((c = getopt_long (argc, argv, "vVht:", longopts, NULL)) != -1) {
+       while ((c = getopt_long (argc, argv, "vVht:e", longopts, NULL)) != -1) {
                switch (c) {
                case 'v':
                        verbose = true;
@@ -176,6 +191,9 @@ static int parse_options(int argc, char **argv)
                        strtotimespec_or_err(optarg, &timeout,
                                             _("Could not parse timeout"));
                        break;
+               case 'e':
+                       allow_exited = true;
+                       break;
                case 'V':
                        print_version(EXIT_SUCCESS);
                case 'h':
@@ -190,9 +208,8 @@ static int parse_options(int argc, char **argv)
 
 int main(int argc, char **argv)
 {
-       int pid_idx, epoll;
-       size_t n_pids;
-       int *pidfds, timeoutfd;
+       int pid_idx, epoll, timeoutfd, *pidfds;
+       size_t n_pids, active_pids;
 
        setlocale(LC_ALL, "");
        bindtextdomain(PACKAGE, LOCALEDIR);
@@ -211,6 +228,6 @@ int main(int argc, char **argv)
        if (epoll == -1)
                err_nosys(EXIT_FAILURE, _("could not create epoll"));
 
-       add_listeners(epoll, n_pids, pidfds, timeoutfd);
-       wait_for_exits(epoll, n_pids, pids, pidfds);
+       active_pids = add_listeners(epoll, n_pids, pidfds, timeoutfd);
+       wait_for_exits(epoll, active_pids, pids, pidfds);
 }

diff --git a/tests/expected/misc/waitpid-exited.err b/tests/expected/misc/waitpid-exited.err
new file mode 100644 (file)
index 0000000..53c255b
--- /dev/null
+++ b/tests/expected/misc/waitpid-exited.err
@@ -0,0 +1,2 @@
+waitpid: PID 2147483647 has exited, skipping
+0

diff --git a/tests/ts/misc/waitpid b/tests/ts/misc/waitpid
index effdd2fe064079a5895b26fecf8570c74debb465..599bb47da371577997c2d08b45d89477f543ea62 100755 (executable)
--- a/tests/ts/misc/waitpid
+++ b/tests/ts/misc/waitpid
@@ -43,4 +43,9 @@ ts_init_subtest timeout
 echo $? >> "$TS_OUTPUT"
 ts_finalize_subtest
 
+ts_init_subtest exited
+"$TS_CMD_WAITPID" -e 2147483647 >> "$TS_OUTPUT" 2>> "$TS_ERRLOG"
+echo $? >> "$TS_ERRLOG"
+ts_finalize_subtest
+
 ts_finalize