21.string.cons.mt.cpp

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#include <string>       // for string
 
#include <cstddef>      // for size_t
 
#include <rw_driver.h>  // for rw_test()
#include <rw_thread.h>  // for rw_thread_pool(), ...
#include <rw_valcmp.h>  // for rw_strncmp()
 
 
#define MAX_THREADS      32
#define MAX_LOOPS    100000
 
const char* const
data [] = {
    /*  0 */ "",
    /*  1 */ "a",
    /*  2 */ "bc",
    /*  3 */ "cde",
    /*  4 */ "defg",
    /*  5 */ "efghi",
    /*  6 */ "fghijk",
    /*  7 */ "ghijklm"
};
 
const std::size_t
nstrings = sizeof data / sizeof *data;
 
const std::string
shared [nstrings] = {
    data [0], data [1], data [2], data [3],
    data [4], data [5], data [6], data [7]
};
 
 
#ifndef _RWSTD_NO_WCHAR_T
 
const wchar_t* const
wdata [] = {
    /*  0 */ L"",
    /*  1 */ L"a",
    /*  2 */ L"bc",
    /*  3 */ L"cde",
    /*  4 */ L"defg",
    /*  5 */ L"efghi",
    /*  6 */ L"fghijk",
    /*  7 */ L"ghijklm"
};
 
const std::wstring
wshared [nstrings] = {
    wdata [0], wdata [1], wdata [2], wdata [3],
    wdata [4], wdata [5], wdata [6], wdata [7]
};
 
#endif   // _RWSTD_NO_WCHAR_T
 
 
#ifdef _RWSTD_REENTRANT
int rw_opt_nthreads = 4;
#else   // if !defined (_RWSTD_REENTRANT)
// in non-threaded builds use just one thread
int rw_opt_nthreads = 1;
#endif   // _RWSTD_REENTRANT
 
// the number of times each thread should iterate
int rw_opt_nloops = MAX_LOOPS;
 
 
template <class T>
void
test_string_cons (const T* const             *pdata,
                  const std::basic_string<T> *pshared,
                  std::size_t                 threadno)
{
    typedef std::basic_string<T> String;
 
    for (std::size_t i = 0; i != std::size_t (rw_opt_nloops); ++i) {
 
        const std::size_t inx1 = (i + threadno) % nstrings;
        const std::size_t inx2 = (inx1 + 1) % nstrings;
 
        // create a copy of the global string
        const String copy (pshared [inx1]);
 
        String assigned (pshared [inx2]);
 
        {
            // create another copy of the same global string
            const String copy2 (pshared [inx1]);
 
            // verify that this copy has the expected length...
            RW_ASSERT (pshared [inx1].length () == copy2.length ());
 
            // ...and the expected data
            RW_ASSERT (0 == rw_strncmp (pdata [inx1], copy2.data ()));
 
            assigned = pshared [inx1];
 
            // copy2 gets destroyed...
        }
 
        // verify that local copy has the expected length...
        RW_ASSERT (pshared [inx1].length () == copy.length ());
 
        // ...and the expected data
        RW_ASSERT (0 == rw_strncmp (pdata [inx1], copy.data ()));
 
        // verify that assigned string has the expected length...
        RW_ASSERT (pshared [inx1].length () == assigned.length ());
 
        // ...and the expected data
        RW_ASSERT (0 == rw_strncmp (pdata [inx1], assigned.data ()));
 
        // reassign and verify again
        assigned = pdata [inx2];
 
        RW_ASSERT (pshared [inx2].length () == assigned.length ());
        RW_ASSERT (0 == rw_strncmp (pdata [inx2], assigned.data ()));
    }
 
}
 
 
extern "C" {
 
bool test_wstring;
 
static void*
thread_func (void *arg)
{
    const rw_thread_t* const pthread = (rw_thread_t*)arg;
 
    // get the 0-based thread number
    const std::size_t threadno = std::size_t (pthread->threadno);
 
    if (test_wstring) {
 
#ifndef _RWSTD_NO_WCHAR_T
 
        test_string_cons<wchar_t>(wdata, wshared, threadno);
 
#endif   // _RWSTD_NO_WCHAR_T
 
    }
    else {
        test_string_cons (data, shared, threadno);
    }
 
    return 0;
}
 
}   // extern "C"
 
 
static int
run_test (int, char**)
{
    rw_info (0, 0, 0,
             "testing std::string with %d thread%{?}s%{;}, "
             "%d iteration%{?}s%{;} each",
             rw_opt_nthreads, 1 != rw_opt_nthreads,
             rw_opt_nloops, 1 != rw_opt_nloops);
 
    test_wstring = false;
 
    // create and start a pool of threads and wait for them to finish
    int result =
        rw_thread_pool (0, std::size_t (rw_opt_nthreads), 0, thread_func, 0);
 
    rw_error (result == 0, 0, __LINE__,
              "rw_thread_pool(0, %d, 0, %{#f}, 0) failed",
              rw_opt_nthreads, thread_func);
 
    for (std::size_t i = 0; i != nstrings; ++i) {
 
        const std::size_t size =
            std::string::traits_type::length (data [i]);
 
        rw_assert (size == shared [i].size (), 0, 0,
                   "shared string modifed from %#s to %{#S}",
                   data [i], &shared [i]);
    }
 
#ifndef _RWSTD_NO_WCHAR_T
 
    rw_info (0, 0, 0,
             "testing std::wstring with %d thread%{?}s%{;}, "
             "%d iteration%{?}s%{;} each",
             rw_opt_nthreads, 1 != rw_opt_nthreads,
             rw_opt_nloops, 1 != rw_opt_nloops);
 
    test_wstring = true;
 
    // start a pool of threads to exercise wstring thread safety
    result =
        rw_thread_pool (0, std::size_t (rw_opt_nthreads), 0, thread_func, 0);
 
    rw_error (result == 0, 0, __LINE__,
              "rw_thread_pool(0, %d, 0, %{#f}, 0) failed",
              rw_opt_nthreads, thread_func);
 
    for (std::size_t i = 0; i != nstrings; ++i) {
 
        const std::size_t size =
            std::wstring::traits_type::length (wdata [i]);
 
        rw_assert (size == wshared [i].size (), 0, 0,
                   "shared string modifed from %#ls to %{#lS}",
                   wdata [i], &wshared [i]);
    }
 
#endif   // _RWSTD_NO_WCHAR_T
 
    return result;
}
 
 
int main (int argc, char *argv[])
{
    return rw_test (argc, argv, __FILE__,
                    "lib.string.cons",
                    "thread safety", run_test,
                    "|-nloops#0 "       // must be non-negative
                    "|-nthreads#0-*",   // must be in [0, MAX_THREADS]
                    &rw_opt_nloops,
                    int (MAX_THREADS),
                    &rw_opt_nthreads);
}