diff options
Diffstat (limited to '')
| -rw-r--r-- | cpukit/score/include/rtems/score/thread.h | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/cpukit/score/include/rtems/score/thread.h b/cpukit/score/include/rtems/score/thread.h index 6057cec5c7..5539dc29e2 100644 --- a/cpukit/score/include/rtems/score/thread.h +++ b/cpukit/score/include/rtems/score/thread.h @@ -209,6 +209,21 @@ typedef struct { */ #define THREAD_STATUS_PROXY_BLOCKING 0x1111111 +/** + * @brief Union type to hold a pointer to an immutable or a mutable object. + * + * The main purpose is to enable passing of pointers to read-only send buffers + * in the message passing subsystem. This approach is somewhat fragile since + * it prevents the compiler to check if the operations on objects are valid + * with respect to the constant qualifier. An alternative would be to add a + * third pointer argument for immutable objects, but this would increase the + * structure size. + */ +typedef union { + void *mutable_object; + const void *immutable_object; +} Thread_Wait_information_Object_argument_type; + /** @brief Thread Blocking Management Information * * This contains the information required to manage a thread while it is @@ -219,10 +234,11 @@ typedef struct { Objects_Id id; /** This field is used to return an integer while when blocked. */ uint32_t count; - /** This field is the first pointer to a user return argument. */ + /** This field is for a pointer to a user return argument. */ void *return_argument; - /** This field is the second pointer to a user return argument. */ - void *return_argument_1; + /** This field is for a pointer to a second user return argument. */ + Thread_Wait_information_Object_argument_type + return_argument_second; /** This field contains any options in effect on this blocking operation. */ uint32_t option; /** This field will contain the return status from a blocking operation. |