Clean up System V IPC objects allocated by test.

This commit modifies the test program gdb.base/info-os.c so that
it cleans up all allocated System V IPC objects when a fatal
error occurs.  Without this, it was possible for the program
to leave IPC objects on the system, and such objects persist
until they are manually deleted or the system reboots.

I looked at changing the SysV IPC key for allocating the IPC objects to
IPC_PRIVATE.  That would prevent errors due to namespace conflicts with the
key.  However, the test needs to read the actual key number from the 'info
os' command output, and IPC_PRIVATE won't work for that.

gdb/testsuite/ChangeLog:
2015-02-04  Don Breazeal  <donb@codesourcery.com>

        * gdb.base/info-os.c (shmid, semid, msqid): Make variables static
        and initialize them.
        (ipc_cleanup): New function.
        (main): Don't declare shmid, semid, and msqid.  Add a call to
        atexit so that we call ipc_cleanup on exit.

1 files changed, 18 insertions, 4 deletions

diff --git a/gdb/testsuite/gdb.base/info-os.c b/gdb/testsuite/gdb.base/info-os.c
index ae2606a359d..8ceaaff4268 100644
--- a/gdb/testsuite/gdb.base/info-os.c
+++ b/gdb/testsuite/gdb.base/info-os.c
@@ -26,6 +26,22 @@
 
 static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
 
+/* System V IPC identifiers.  */
+static int shmid = -1, semid = -1, msqid = -1;
+
+/* Delete any System V IPC resources that were allocated.  */
+
+static void
+ipc_cleanup (void)
+{
+  if (shmid >= 0)
+    shmctl (shmid, IPC_RMID, NULL);
+  if (semid >= 0)
+    semctl (semid, 0, IPC_RMID, NULL);
+  if (msqid >= 0)
+    msgctl (msqid, IPC_RMID, NULL);
+}
+
 void *
 thread_proc (void *args)
 {
@@ -38,7 +54,6 @@ main (void)
 {
   const int flags = IPC_CREAT | 0666;
   key_t shmkey = 3925, semkey = 7428, msgkey = 5294;
-  int shmid, semid, msqid;
   FILE *fd;
   pthread_t thread;
   struct sockaddr_in sock_addr;
@@ -47,6 +62,8 @@ main (void)
   socklen_t size;
   int status, try, retries = 1000;
 
+  atexit (ipc_cleanup);
+
   for (try = 0; try < retries; ++try)
     {
       shmid = shmget (shmkey, 4096, flags | IPC_EXCL);
@@ -135,9 +152,6 @@ main (void)
 
   /* Set breakpoint here.  */
 
-  shmctl (shmid, IPC_RMID, NULL);
-  semctl (semid, 0, IPC_RMID, NULL);
-  msgctl (msqid, IPC_RMID, NULL);
   fclose (fd);
   close (sock);