/*

 * Copyright 2012, 2015 SAP AG. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#ifndef OS_AIX_VM_PORTING_AIX_HPP

#define OS_AIX_VM_PORTING_AIX_HPP

#include <stddef.h>

// PPC port only:

#define assert0(b) assert( (b), "" )

#define guarantee0(b) assert( (b), "" )

template <class T1, class T2> bool is_aligned_to(T1 what, T2 alignment) {

  return  ( ((uintx)(what)) & (((uintx)(alignment)) - 1) ) == 0 ? true : false;

}

// Header file to contain porting-relevant code which does not have a

// home anywhere else and which can not go into os_<platform>.h because

// that header is included inside the os class definition, hence all

// its content is part of the os class.

// Aix' own version of dladdr().

// This function tries to mimick dladdr(3) on Linux

// (see http://linux.die.net/man/3/dladdr)

// dladdr(3) is not POSIX but a GNU extension, and is not available on AIX.

//

// Differences between AIX dladdr and Linux dladdr:

//

// 1) Dl_info.dli_fbase: can never work, is disabled.

//   A loaded image on AIX is divided in multiple segments, at least two

//   (text and data) but potentially also far more. This is because the loader may

//   load each member into an own segment, as for instance happens with the libC.a

// 2) Dl_info.dli_sname: This only works for code symbols (functions); for data, a

//   zero-length string is returned ("").

// 3) Dl_info.dli_saddr: For code, this will return the entry point of the function,

//   not the function descriptor.

typedef struct {

  const char *dli_fname; // file path of loaded library

  // void *dli_fbase;

  const char *dli_sname; // symbol name; "" if not known

  void *dli_saddr;       // address of *entry* of function; not function descriptor;

} Dl_info;

// Note: we export this to use it inside J2se too

#ifdef __cplusplus

extern "C"

#endif

int dladdr(void *addr, Dl_info *info);

// The semantics in this file are thus that codeptr_t is a *real code ptr*.

// This means that any function taking codeptr_t as arguments will assume

// a real codeptr and won't handle function descriptors (eg getFuncName),

// whereas functions taking address as args will deal with function

// descriptors (eg os::dll_address_to_library_name).

typedef unsigned int* codeptr_t;

// helper function - given a program counter, tries to locate the traceback table and

// returns info from it (like, most importantly, function name, displacement of the

// pc inside the function, and the traceback table itself.

#ifdef __cplusplus

extern "C"

#endif

int getFuncName(

      codeptr_t pc,                    // [in] program counter

      char* p_name, size_t namelen,    // [out] optional: user provided buffer for the function name

      int* p_displacement,             // [out] optional: displacement

      const struct tbtable** p_tb,     // [out] optional: ptr to traceback table to get further information

      char* p_errmsg, size_t errmsglen // [out] optional: user provided buffer for error messages

    );

// -------------------------------------------------------------------------

// A simple critical section which shall be based upon OS critical

// sections (CRITICAL_SECTION resp. Posix Mutex) and nothing else.

#include <pthread.h>

namespace MiscUtils {

  typedef pthread_mutex_t critsect_t;

  inline void init_critsect(MiscUtils::critsect_t* cs) {

    pthread_mutex_init(cs, NULL);

  }

  inline void free_critsect(MiscUtils::critsect_t* cs) {

    pthread_mutex_destroy(cs);

  }

  inline void enter_critsect(MiscUtils::critsect_t* cs) {

    pthread_mutex_lock(cs);

  }

  inline void leave_critsect(MiscUtils::critsect_t* cs) {

    pthread_mutex_unlock(cs);

  }

  // Need to wrap this in an object because we need to dynamically initialize

  // critical section (because of windows, where there is no way to initialize

  // a CRITICAL_SECTION statically. On Unix, we could use

  // PTHREAD_MUTEX_INITIALIZER)

  // Note: The critical section does NOT get cleaned up in the destructor. That is

  // by design: the CritSect class is only ever used as global objects whose

  // lifetime spans the whole VM life; in that context we don't want the lock to

  // be cleaned up when global C++ objects are destroyed, but to continue to work

  // correctly right to the very end of the process life.

  class CritSect {

    critsect_t _cs;

  public:

    CritSect()        { init_critsect(&_cs); }

    //~CritSect()       { free_critsect(&_cs); }

    void enter()      { enter_critsect(&_cs); }

    void leave()      { leave_critsect(&_cs); }

  };

  class AutoCritSect {

    CritSect* const _pcsobj;

  public:

    AutoCritSect(CritSect* pcsobj)

      : _pcsobj(pcsobj)

    {

      _pcsobj->enter();

    }

    ~AutoCritSect() {

      _pcsobj->leave();

    }

  };

}

#endif // OS_AIX_VM_PORTING_AIX_HPP