[RFC,4/4] XXX a command to test the locking facility

Commit Message

Wei Liu June 14, 2017, 5:19 p.m. UTC

Signed-off-by: Wei Liu <[e-mail]>
---
 tools/xl/xl.h          |  2 ++
 tools/xl/xl_cmdtable.c |  5 +++++
 tools/xl/xl_misc.c     | 37 +++++++++++++++++++++++++++++++++++++
 3 files changed, 44 insertions(+)

Patch

diff --git a/tools/xl/xl.h b/tools/xl/xl.h
index 8d667ff444..9cb135baf2 100644
--- a/tools/xl/xl.h
+++ b/tools/xl/xl.h
@@ -209,6 +209,8 @@  int main_psr_cat_show(int argc, char **argv);
 #endif
 int main_qemu_monitor_command(int argc, char **argv);
 
+int main_lock(int argc, char **argv);
+
 void help(const char *command);
 
 extern const char *common_domname;
diff --git a/tools/xl/xl_cmdtable.c b/tools/xl/xl_cmdtable.c
index 30eb93c17f..01db5fb8f4 100644
--- a/tools/xl/xl_cmdtable.c
+++ b/tools/xl/xl_cmdtable.c
@@ -591,6 +591,11 @@  struct cmd_spec cmd_table[] = {
       "Issue a qemu monitor command to the device model of a domain",
       "<Domain> <Command>",
     },
+    { "lock",
+      &main_lock, 0, 0,
+      "Lock a domain, prevent other xl processes from manipulating it",
+      "<Domain>",
+    },
 };
 
 int cmdtable_len = sizeof(cmd_table)/sizeof(struct cmd_spec);
diff --git a/tools/xl/xl_misc.c b/tools/xl/xl_misc.c
index 9c6227af23..772fd7adb4 100644
--- a/tools/xl/xl_misc.c
+++ b/tools/xl/xl_misc.c
@@ -14,6 +14,7 @@ 
 
 #include <limits.h>
 #include <stdlib.h>
+#include <unistd.h>
 
 #include <libxl.h>
 #include <libxl_utils.h>
@@ -344,6 +345,42 @@  int main_config_update(int argc, char **argv)
     return 0;
 }
 
+struct lock_arg {
+    uint32_t domid;
+};
+
+static int lock_fn(void *p)
+{
+    struct lock_arg *arg = p;
+
+    fprintf(stderr, "Now I have the lock for %u\n", arg->domid);
+
+    sleep(10);
+
+    fprintf(stderr, "Done\n");
+
+    return 0;
+}
+
+int main_lock(int argc, char **argv)
+{
+    uint32_t domid;
+    struct lock_arg arg;
+    int rc;
+
+    domid = find_domain(argv[optind++]);
+
+    fprintf(stderr, "About to lock %u\n", domid);
+
+    arg.domid = domid;
+
+    rc = with_lock(domid, lock_fn, &arg);
+    fprintf(stderr, "with_lock returned, rc = %d\n", rc);
+    if (rc)
+        return EXIT_FAILURE;
+    return EXIT_SUCCESS;
+}
+
 /*
  * Local variables:
  * mode: C