Fix for distcc issue 102 <http://code.google.com/p/distcc/issues/detail?id=102>:

"all servers busy" dcc_lock_pause is hardcoded at 1 sec, could be tunable.

Makes the pause time tunable via a new env var DISTCC_PAUSE_TIME_MSEC.
The default remains set for 1 second.



git-svn-id: http://distcc.googlecode.com/svn/trunk@760 01de4be4-8c4a-0410-9132-4925637da917

2 files changed, 16 insertions, 3 deletions

diff --git a/man/distcc.1 b/man/distcc.1
index 8f6223c..e335d05 100644
--- a/man/distcc.1
+++ b/man/distcc.1
@@ -769,6 +769,14 @@ takes a long time, consider increasing this value so the job does
 not time out and fallback to a local compile.  By default set to
 300 seconds.
 .TP
+.B "DISTCC_PAUSE_TIME_MSEC"
+Specifies how long (in milliseconds) distcc will pause when all
+compilation servers are in use.
+By default set to 1000 milliseconds (1 second).
+Setting this to a smaller value (e.g. 10 milliconds) may improve
+throughput for some configurations, at the expense of increased CPU
+load on the distcc client machine.
+.TP
 .B "DISTCC_SAVE_TEMPS"
 If set to 1, temporary files are not deleted after use.  Good for
 debugging, or if your disks are too empty.
diff --git a/src/where.c b/src/where.c
index 6e4c5dd..6bd3168 100644
--- a/src/where.c
+++ b/src/where.c
@@ -122,15 +122,20 @@ static void dcc_lock_pause(void)
      * really necessary, and also by making jobs complete very-out-of-order is
      * more likely to find Makefile bugs. */
 
-    unsigned pause_time = 1;
+    unsigned pause_time_ms = 1000;
+
+    char *pt = getenv("DISTCC_PAUSE_TIME_MSEC");
+    if (pt)
+	pause_time_ms = atoi(pt);
 
 	/*	This call to dcc_note_state() is made before the host is known, so it
 		does not make sense and does nothing useful as far as I can tell.	*/
     /*	dcc_note_state(DCC_PHASE_BLOCKED, NULL, NULL, DCC_UNKNOWN);	*/
 
-    rs_trace("nothing available, sleeping %us...", pause_time);
+    rs_trace("nothing available, sleeping %ums...", pause_time_ms);
 
-    sleep(pause_time);
+    if (pause_time_ms > 0)
+	usleep(pause_time_ms * 1000);
 }