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[Qemu-devel] [PATCH 1/3] qemu-char: Add qemu_chr_fe_claim / _release hel
From: |
Hans de Goede |
Subject: |
[Qemu-devel] [PATCH 1/3] qemu-char: Add qemu_chr_fe_claim / _release helper functions |
Date: |
Wed, 27 Mar 2013 20:29:39 +0100 |
Add qemu_chr_fe_claim / _release helper functions for properly dealing with
avail_connections.
Signed-off-by: Hans de Goede <address@hidden>
---
hw/qdev-properties-system.c | 5 ++---
include/char/char.h | 29 +++++++++++++++++++++++++++++
qemu-char.c | 23 +++++++++++++++++++++++
3 files changed, 54 insertions(+), 3 deletions(-)
diff --git a/hw/qdev-properties-system.c b/hw/qdev-properties-system.c
index 12a87d5..e27d708 100644
--- a/hw/qdev-properties-system.c
+++ b/hw/qdev-properties-system.c
@@ -123,11 +123,10 @@ static int parse_chr(DeviceState *dev, const char *str,
void **ptr)
if (chr == NULL) {
return -ENOENT;
}
- if (chr->avail_connections < 1) {
+ if (qemu_chr_fe_claim(chr) != 0) {
return -EEXIST;
}
*ptr = chr;
- --chr->avail_connections;
return 0;
}
@@ -140,7 +139,7 @@ static void release_chr(Object *obj, const char *name, void
*opaque)
if (chr) {
qemu_chr_add_handlers(chr, NULL, NULL, NULL, NULL);
- ++chr->avail_connections;
+ qemu_chr_fe_release(chr);
}
}
diff --git a/include/char/char.h b/include/char/char.h
index 1457e80..920a5a0 100644
--- a/include/char/char.h
+++ b/include/char/char.h
@@ -188,6 +188,35 @@ int qemu_chr_fe_ioctl(CharDriverState *s, int cmd, void
*arg);
int qemu_chr_fe_get_msgfd(CharDriverState *s);
/**
+ * @qemu_chr_fe_claim:
+ *
+ * Claim a backend before using it, should be called before calling
+ * qemu_chr_add_handlers().
+ *
+ * Returns: -1 if the backend is already in use by another frontend, 0 on
+ * success.
+ */
+int qemu_chr_fe_claim(CharDriverState *s);
+
+/**
+ * @qemu_chr_fe_claim_no_fail:
+ *
+ * Like qemu_chr_fe_claim, but will exit qemu with an error when the
+ * backend is already in use.
+ */
+void qemu_chr_fe_claim_no_fail(CharDriverState *s);
+
+/**
+ * @qemu_chr_fe_claim:
+ *
+ * Release a backend for use by another frontend.
+ *
+ * Returns: -1 if the backend is already in use by another frontend, 0 on
+ * success.
+ */
+void qemu_chr_fe_release(CharDriverState *s);
+
+/**
* @qemu_chr_be_can_write:
*
* Determine how much data the front end can currently accept. This function
diff --git a/qemu-char.c b/qemu-char.c
index edf3779..da6cbe2 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -3418,6 +3418,29 @@ int qemu_chr_fe_add_watch(CharDriverState *s,
GIOCondition cond,
return tag;
}
+int qemu_chr_fe_claim(CharDriverState *s)
+{
+ if (s->avail_connections < 1) {
+ return -1;
+ }
+ s->avail_connections--;
+ return 0;
+}
+
+void qemu_chr_fe_claim_no_fail(CharDriverState *s)
+{
+ if (qemu_chr_fe_claim(s) != 0) {
+ fprintf(stderr, "%s: error chardev \"%s\" already used\n",
+ __func__, s->label);
+ exit(1);
+ }
+}
+
+void qemu_chr_fe_release(CharDriverState *s)
+{
+ s->avail_connections++;
+}
+
void qemu_chr_delete(CharDriverState *chr)
{
QTAILQ_REMOVE(&chardevs, chr, next);
--
1.8.1.4