[pve-devel] [PATCH common v3] add upid_wait method

[Thomas Lamprecht]

Waits for a process identified by a UPID to end by busy waiting
and is intended for long running workers.

waitfunc gets called every wait cycle after min $sleep_interval
seconds and can be used for outputting/logging something or timing
out the wait.
---

changes v3:
 * do it in a sane way without double waiting

 src/PVE/Tools.pm | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/src/PVE/Tools.pm b/src/PVE/Tools.pm
index 64a57e9..58d943c 100644
--- a/src/PVE/Tools.pm
+++ b/src/PVE/Tools.pm
@@ -940,6 +940,26 @@ sub upid_read_status {
     return "unable to read tail (got $br bytes)";
 }
 
+sub upid_wait {
+    my ($upid, $waitfunc, $sleep_intervall) = @_;
+
+    my $task = upid_decode($upid);
+
+    $sleep_intervall = $sleep_intervall ? $sleep_intervall : 1;
+
+    my $next_time = time + $sleep_intervall;
+
+    while (PVE::ProcFSTools::check_process_running($task->{pid}, $task->{pstart})) {
+
+	if (time >= $next_time && $waitfunc && ref($waitfunc) eq 'CODE'){
+	    &$waitfunc($task);
+	    $next_time = time + $sleep_intervall;
+	}
+
+	CORE::sleep(1);
+    }
+}
+
 # useful functions to store comments in config files 
 sub encode_text {
     my ($text) = @_;
-- 
2.1.4