Fix for distcc issue 103 <http://code.google.com/p/distcc/issues/detail?id=103>:

hardcoded 60 second backoff period should be tunable

Makes the backoff behavior tunable via a new env var DISTCC_BACKOFF_PERIOD.
The default backoff remains set for 60 seconds.

2 files changed, 31 insertions, 2 deletions

diff --git a/man/distcc.1 b/man/distcc.1
index e335d05..9ab9afb 100644
--- a/man/distcc.1
+++ b/man/distcc.1
@@ -762,6 +762,12 @@ variable is set to 0 then fallbacks are disabled and those
 compilations will simply fail.  Note that this does not affect jobs
 which must always be local such as linking.
 .TP
+.B "DISTCC_BACKOFF_PERIOD"
+Specifies how long (in seconds) distcc will avoid trying to use a
+particular compilation server after that server yields a compile
+failure.  By default set to 60 seconds.  To disable the backoff
+behavior altogether, set this to 0.
+.TP
 .B "DISTCC_IO_TIMEOUT"
 Specifies how long (in seconds) distcc will wait before deciding a
 distributed job has timed out.  If a distributed job is expected to
diff --git a/src/backoff.c b/src/backoff.c
index abc86ed..b3d656c 100644
--- a/src/backoff.c
+++ b/src/backoff.c
@@ -50,7 +50,7 @@
 #include "hosts.h"
 
 
-const int dcc_backoff_period = 60; /* seconds */
+static int dcc_backoff_period = 60; /* seconds */
 
 
 /**
@@ -61,12 +61,26 @@ const int dcc_backoff_period = 60; /* seconds */
  **/
 int dcc_enjoyed_host(const struct dcc_hostdef *host)
 {
+    char *bp;
+
+    /* special-case: if DISTCC_BACKOFF_PERIOD==0, don't manage backoff files */
+    bp = getenv("DISTCC_BACKOFF_PERIOD");
+    if (bp && (atoi(bp) == 0))
+	return 0;
+
     return dcc_remove_timefile("backoff", host);
 }
 
 int dcc_disliked_host(const struct dcc_hostdef *host)
 {
-    /* i hate you (but only for 60 seconds) */
+    char *bp;
+
+    /* special-case: if DISTCC_BACKOFF_PERIOD==0, don't manage backoff files */
+    bp = getenv("DISTCC_BACKOFF_PERIOD");
+    if (bp && (atoi(bp) == 0))
+	return 0;
+
+    /* i hate you (but only for dcc_backoff_period seconds) */
     return dcc_mark_timefile("backoff", host);
 }
 
@@ -94,6 +108,15 @@ static int dcc_check_backoff(struct dcc_hostdef *host)
 int dcc_remove_disliked(struct dcc_hostdef **hostlist)
 {
     struct dcc_hostdef *h;
+    char *bp;
+
+    bp = getenv("DISTCC_BACKOFF_PERIOD");
+    if (bp)
+	dcc_backoff_period = atoi(bp);
+
+    /* special-case: if DISTCC_BACKOFF_PERIOD==0, don't manage backoff files */
+    if (dcc_backoff_period == 0)
+	return 0;
 
     while ((h = *hostlist) != NULL) {
         if (dcc_check_backoff(h) != 0) {