/*
    Copyright 2005-2012 Intel Corporation.  All Rights Reserved.

    This file is part of Threading Building Blocks.

    Threading Building Blocks is free software; you can redistribute it
    and/or modify it under the terms of the GNU General Public License
    version 2 as published by the Free Software Foundation.

    Threading Building Blocks 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 for more details.

    You should have received a copy of the GNU General Public License
    along with Threading Building Blocks; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    As a special exception, you may use this file as part of a free software
    library without restriction.  Specifically, if other files instantiate
    templates or use macros or inline functions from this file, or you compile
    this file and link it with other files to produce an executable, this
    file does not by itself cause the resulting executable to be covered by
    the GNU General Public License.  This exception does not however
    invalidate any other reasons why the executable file might be covered by
    the GNU General Public License.
*/

// Declarations for simple estimate of the memory being used by a program.
// Not yet implemented for Mac.
// This header is an optional part of the test harness.
// It assumes that "harness_assert.h" has already been included.

#if __linux__ || __sun
#include <sys/resource.h>
#include <unistd.h>

#elif __APPLE__
#include <unistd.h>
#include <mach/mach.h>
#include <AvailabilityMacros.h>
#if MAC_OS_X_VERSION_MIN_REQUIRED >= 1060
#include <mach/shared_region.h>
#else
#include <mach/shared_memory_server.h>
#endif
#if SHARED_TEXT_REGION_SIZE || SHARED_DATA_REGION_SIZE
const size_t shared_size = SHARED_TEXT_REGION_SIZE+SHARED_DATA_REGION_SIZE;
#else
const size_t shared_size = 0;
#endif

#elif _WIN32 && !_XBOX
#include <windows.h>
#include <psapi.h>
#if _MSC_VER
#pragma comment(lib, "psapi")
#endif

#endif /* OS selection */

//! Return estimate of number of bytes of memory that this program is currently using.
/* Returns 0 if not implemented on platform. */
size_t GetMemoryUsage() { 
#if _XBOX || __TBB_WIN8UI_SUPPORT
    return 0;
#elif _WIN32
    PROCESS_MEMORY_COUNTERS mem;
    bool status = GetProcessMemoryInfo(GetCurrentProcess(), &mem, sizeof(mem))!=0;
    ASSERT(status, NULL);
    return mem.PagefileUsage;
#elif __linux__
    FILE* statsfile = fopen("/proc/self/statm","r");
    size_t pagesize = getpagesize();
    ASSERT(statsfile, NULL);
    long total_mem;
    int n = fscanf(statsfile,"%lu",&total_mem);
    if( n!=1 ) {
        REPORT("Warning: memory usage statistics wasn't obtained\n");
        return 0;
    }
    fclose(statsfile);
    return total_mem*pagesize;
#elif __APPLE__
    kern_return_t status;
    task_basic_info info;
    mach_msg_type_number_t msg_type = TASK_BASIC_INFO_COUNT;
    status = task_info(mach_task_self(), TASK_BASIC_INFO, reinterpret_cast<task_info_t>(&info), &msg_type);
    ASSERT(status==KERN_SUCCESS, NULL);
    return info.virtual_size - shared_size;
#else
    return 0;
#endif
}

//! Use approximately a specified amount of stack space.
/** Recursion is used here instead of alloca because some implementations of alloca do not use the stack. */
void UseStackSpace( size_t amount, char* top=0 ) {
    char x[1000];
    memset( x, -1, sizeof(x) );
    if( !top ) 
        top = x;
    ASSERT( x<=top, "test assumes that stacks grow downwards" );
    if( size_t(top-x)<amount )
        UseStackSpace( amount, top );
}
