From 04878ef74512df49803d1119c72c49cd8f1bfe10 Mon Sep 17 00:00:00 2001
From: Michael Brown
Date: Mon, 10 Aug 2009 01:09:41 +0100
Subject: [process] Make it safe to call process_add() multiple times

---
 src/core/process.c         | 13 ++++++++++---
 src/include/gpxe/process.h |  1 +
 src/net/infiniband.c       |  1 +
 src/net/netdevice.c        |  1 +
 src/net/retry.c            |  1 +
 5 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/src/core/process.c b/src/core/process.c
index 6dacd665..9c13e020 100644
--- a/src/core/process.c
+++ b/src/core/process.c
@@ -37,11 +37,18 @@ static LIST_HEAD ( run_queue );
  * Add process to process list
  *
  * @v process		Process
+ *
+ * It is safe to call process_add() multiple times; further calls will
+ * have no effect.
  */
 void process_add ( struct process *process ) {
-	DBGC ( process, "PROCESS %p starting\n", process );
-	ref_get ( process->refcnt );
-	list_add_tail ( &process->list, &run_queue );
+	if ( list_empty ( &process->list ) ) {
+		DBGC ( process, "PROCESS %p starting\n", process );
+		ref_get ( process->refcnt );
+		list_add_tail ( &process->list, &run_queue );
+	} else {
+		DBGC ( process, "PROCESS %p already started\n", process );
+	}
 }
 
 /**
diff --git a/src/include/gpxe/process.h b/src/include/gpxe/process.h
index a4609191..944858d7 100644
--- a/src/include/gpxe/process.h
+++ b/src/include/gpxe/process.h
@@ -47,6 +47,7 @@ static inline __attribute__ (( always_inline )) void
 process_init_stopped ( struct process *process,
 		       void ( * step ) ( struct process *process ),
 		       struct refcnt *refcnt ) {
+	INIT_LIST_HEAD ( &process->list );
 	process->step = step;
 	process->refcnt = refcnt;
 }
diff --git a/src/net/infiniband.c b/src/net/infiniband.c
index 2d8b63ec..539c5290 100644
--- a/src/net/infiniband.c
+++ b/src/net/infiniband.c
@@ -802,6 +802,7 @@ static void ib_step ( struct process *process __unused ) {
 
 /** Infiniband event queue process */
 struct process ib_process __permanent_process = {
+	.list = LIST_HEAD_INIT ( ib_process.list ),
 	.step = ib_step,
 };
 
diff --git a/src/net/netdevice.c b/src/net/netdevice.c
index e16ebaa0..3bb0574d 100644
--- a/src/net/netdevice.c
+++ b/src/net/netdevice.c
@@ -625,5 +625,6 @@ static void net_step ( struct process *process __unused ) {
 
 /** Networking stack process */
 struct process net_process __permanent_process = {
+	.list = LIST_HEAD_INIT ( net_process.list ),
 	.step = net_step,
 };
diff --git a/src/net/retry.c b/src/net/retry.c
index 3ca69362..40f656f2 100644
--- a/src/net/retry.c
+++ b/src/net/retry.c
@@ -187,5 +187,6 @@ static void retry_step ( struct process *process __unused ) {
 
 /** Retry timer process */
 struct process retry_process __permanent_process = {
+	.list = LIST_HEAD_INIT ( retry_process.list ),
 	.step = retry_step,
 };
-- 
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