From: Sascha Hauer <s.hauer@pengutronix.de>
To: Barebox List <barebox@lists.infradead.org>
Subject: [PATCH 2/2] bootchooser: Add reference counting
Date: Thu, 18 Oct 2018 13:43:51 +0200 [thread overview]
Message-ID: <20181018114351.29022-2-s.hauer@pengutronix.de> (raw)
In-Reply-To: <20181018114351.29022-1-s.hauer@pengutronix.de>
This adds reference counting to the bootchooser. Instead of creating a
new bootchooser instance with each bootchooser_get() we return a
reference to the existing bootchooser.
This makes the behaviour consistent when bootchooser_get() is called
multiple times.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
common/bootchooser.c | 36 +++++++++++++++++++++++++++++++-----
1 file changed, 31 insertions(+), 5 deletions(-)
diff --git a/common/bootchooser.c b/common/bootchooser.c
index 29f61aec7f..c47c734c9c 100644
--- a/common/bootchooser.c
+++ b/common/bootchooser.c
@@ -57,6 +57,7 @@ struct bootchooser {
struct state *state;
char *state_prefix;
+ int refs;
int verbose;
int dryrun;
@@ -344,11 +345,15 @@ static void bootchooser_reset_priorities(struct bootchooser *bc)
bootchooser_target_set_priority(target, -1);
}
+static struct bootchooser *bootchooser;
+
/**
- * bootchooser_get - get a bootchooser instance
+ * bootchooser_get - get a reference to the bootchooser
*
- * This evaluates the different globalvars and eventually state variables,
- * creates a bootchooser instance from it and returns it.
+ * When no bootchooser is initialized this function allocates the bootchooser
+ * and initializes it with the different globalvars and state variables. The
+ * bootchooser is returned. Subsequent calls will return a reference to the same
+ * bootchooser.
*/
struct bootchooser *bootchooser_get(void)
{
@@ -359,6 +364,11 @@ struct bootchooser *bootchooser_get(void)
uint32_t last_chosen;
static int attempts_resetted;
+ if (bootchooser) {
+ bootchooser->refs++;
+ return bootchooser;
+ }
+
bc = xzalloc(sizeof(*bc));
if (*state_prefix) {
@@ -473,6 +483,10 @@ struct bootchooser *bootchooser_get(void)
}
+ bootchooser = bc;
+
+ bootchooser->refs = 1;
+
return bc;
err:
@@ -528,16 +542,26 @@ int bootchooser_save(struct bootchooser *bc)
}
/**
- * bootchooser_put - release a bootchooser instance
+ * bootchooser_put - return a bootchooser reference
* @bc: The bootchooser instance
*
- * This releases a bootchooser instance and the memory associated with it.
+ * This returns a reference to the bootchooser. If it is the last reference the
+ * bootchooser is saved and the associated memory is freed.
+ *
+ * Return: 0 for success or a negative error code. An error can occur when
+ * bootchooser_save fails to write to the storage, nevertheless the
+ * bootchooser reference is still released.
*/
int bootchooser_put(struct bootchooser *bc)
{
struct bootchooser_target *target, *tmp;
int ret;
+ bc->refs--;
+
+ if (bc->refs)
+ return 0;
+
ret = bootchooser_save(bc);
if (ret)
pr_err("Failed to save bootchooser state: %s\n", strerror(-ret));
@@ -552,6 +576,8 @@ int bootchooser_put(struct bootchooser *bc)
free(bc);
+ bootchooser = NULL;
+
return ret;
}
--
2.19.0
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prev parent reply other threads:[~2018-10-18 11:44 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-18 11:43 [PATCH 1/2] bootchooser: put bootchooser after creating a boot entry Sascha Hauer
2018-10-18 11:43 ` Sascha Hauer [this message]
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