nptl: Add struct_rwlock.h

This patch adds a new generic __pthread_rwlock_arch_t definition meant
to be used by new ports.  Its layout mimics the current usage on some
64 bits ports and it allows some ports to use the generic definition.
The arch __pthread_rwlock_arch_t definition is moved from
pthreadtypes-arch.h to another arch-specific header (struct_rwlock.h).

Also the static intialization macro for pthread_rwlock_t is set to use
an arch defined on (__PTHREAD_RWLOCK_INITIALIZER) which simplifies its
implementation.

The default pthread_rwlock_t layout differs from current ports with:

  1. Internal layout is the same for 32 bits and 64 bits.

  2. Internal flag is an unsigned short so it should not required
     additional padding to align for word boundary (if it is the case
     for the ABI).

Checked with a build on affected abis.

Change-Id: I776a6a986c23199929d28a3dcd30272db21cd1d0

1 files changed, 0 insertions, 19 deletions

diff --git a/sysdeps/riscv/nptl/bits/pthreadtypes-arch.h b/sysdeps/riscv/nptl/bits/pthreadtypes-arch.h
index 31f46ecbde..330c302fd2 100644
--- a/sysdeps/riscv/nptl/bits/pthreadtypes-arch.h
+++ b/sysdeps/riscv/nptl/bits/pthreadtypes-arch.h
@@ -38,23 +38,4 @@
 #define __LOCK_ALIGNMENT
 #define __ONCE_ALIGNMENT
 
-/* There is a lot of padding in this structure.  While it's not strictly
-   necessary on RISC-V, we're going to leave it in to be on the safe side in
-   case it's needed in the future.  Most other architectures have the padding,
-   so this gives us the same extensibility as everyone else has.  */
-struct __pthread_rwlock_arch_t
-{
-  unsigned int __readers;
-  unsigned int __writers;
-  unsigned int __wrphase_futex;
-  unsigned int __writers_futex;
-  unsigned int __pad3;
-  unsigned int __pad4;
-  int __cur_writer;
-  int __shared;
-  unsigned long int __pad1;
-  unsigned long int __pad2;
-  unsigned int __flags;
-};
-
 #endif	/* bits/pthreadtypes.h */