This patch adds:

// New functions to set/get the current default async queue
void acc_set_default_async (int);
int acc_get_default_async (void);

and _async versions of a few existing API functions:

void acc_copyin_async (void *, size_t, int);
void acc_create_async (void *, size_t, int);
void acc_copyout_async (void *, size_t, int);
void acc_delete_async (void *, size_t, int);
void acc_update_device_async (void *, size_t, int);
void acc_update_self_async (void *, size_t, int);
void acc_memcpy_to_device_async (void *, void *, size_t, int);
void acc_memcpy_from_device_async (void *, void *, size_t, int);

These implement part of the additional requirements for OpenACC 2.5
Tested and committed to gomp-4_0-branch.

Chung-Lin

2017-02-13  Chung-Lin Tang  <cltang@codesourcery.com>

        libgomp/
        * oacc-async.c (acc_get_default_async): New API function.
        (acc_set_default_async): Likewise.
        * oacc-init.c ():
        * oacc-int.h (struct goacc_thread): Add default_async field.
        * oacc-mem.c (memcpy_tofrom_device): New function, combined from
        acc_memcpy_to/from_device functions, now with async parameter.
        (acc_memcpy_to_device): Modify to use memcpy_tofrom_device.
        (acc_memcpy_from_device): Likewise.
        (acc_memcpy_to_device_async): New API function.
        (acc_memcpy_from_device_async): Likewise.
        (present_create_copy): Add async parameter.
        (acc_create): Adjust present_create_copy call.
        (acc_copyin): Likewise.
        (acc_present_or_create): Likewise.
        (acc_present_or_copyin): Likewise.
        (acc_create_async): New API function.
        (acc_copyin_async): New API function.
        (delete_copyout): Add async parameter.
        (acc_delete): Adjust delete_copyout call.
        (acc_copyout): Likewise.
        (acc_delete_async): New API function.
        (acc_copyout_async): Likewise.
        (update_dev_host): Add async parameter.
        (acc_update_device): Adjust update_dev_host call.
        (acc_update_self): Likewise.
        (acc_update_device_async): New API function.
        (acc_update_self_async): Likewise.
        * oacc-plugin.c (GOMP_PLUGIN_acc_thread_default_async): New function.
        * oacc-plugin.h (GOMP_PLUGIN_acc_thread_default_async): Declare.
        * openacc.f90 (acc_async_default): Declare.
        (acc_set_default_async): Likewise.
        (acc_get_default_async): Likewise.
        * openacc_lib.h (acc_async_default): Declare.
        (acc_set_default_async): Likewise.
        (acc_get_default_async): Likewise.
        * testsuite/libgomp.oacc-c-c++-common/asyncwait-2.c: New test.
        * testsuite/libgomp.oacc-c-c++-common/lib-94.c: New test.
        * testsuite/libgomp.oacc-c-c++-common/lib-95.c: New test.
        * testsuite/libgomp.oacc-fortran/lib-16.f90: New test.

        include/
        * gomp-constants.h (GOMP_ASYNC_DEFAULT): Define.