[committed][nvptx, libgomp] Fix memleak in GOMP_OFFLOAD_fini_device

[Tom de Vries]

Hi,

I wrote a test-case:
...
int
main (void)
{
  for (unsigned i = 0; i < 128; ++i)
    {
      acc_init (acc_device_nvidia);
      acc_shutdown (acc_device_nvidia);
    }

  return 0;
}
...
and ran it under valgrind.  The only leak location reported with a frequency
of 128, was the allocation of ptx_devices in nvptx_init.

Fix this by freeing ptx_devices in GOMP_OFFLOAD_fini_device, once
instantiated_devices drops to 0.

Committed to trunk.

Thanks,
- Tom

[nvptx, libgomp] Fix memleak in GOMP_OFFLOAD_fini_device

2019-01-24  Tom de Vries  <tdevr...@suse.de>

        * plugin/plugin-nvptx.c (GOMP_OFFLOAD_fini_device): Free ptx_devices
        once instantiated_devices drops to 0.

---
 libgomp/plugin/plugin-nvptx.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/libgomp/plugin/plugin-nvptx.c b/libgomp/plugin/plugin-nvptx.c
index ff90b67cb86..387e7cc6dd3 100644
--- a/libgomp/plugin/plugin-nvptx.c
+++ b/libgomp/plugin/plugin-nvptx.c
@@ -1936,6 +1936,12 @@ GOMP_OFFLOAD_fini_device (int n)
       instantiated_devices--;
     }
 
+  if (instantiated_devices == 0)
+    {
+      free (ptx_devices);
+      ptx_devices = NULL;
+    }
+
   pthread_mutex_unlock (&ptx_dev_lock);
   return true;
 }