test/testloadso.c
author Sam Lantinga <slouken@libsdl.org>
Sun, 07 Jul 2019 09:10:56 -0700
changeset 12928 3c4a4b1077cd
parent 12503 806492103856
permissions -rw-r--r--
Fixed bug 4710 - audio/alsa: avoid configuring hardware parameters with only a single period

Anthony Pesch

The previous code first configured the period size using snd_pcm_hw_par-
ams_set_period_size_near. Then, it further narrowed the configuration
space by calling snd_pcm_hw_params_set_buffer_size_near using a buffer
size of 2 times the _requested_ period size in order to try and get a
configuration with only 2 periods. If the configured period size was
larger than the requested size, the second call could inadvertently
narrow the configuration space to contain only a single period.

Rather than fixing the call to snd_pcm_hw_params_set_buffer_size_near
to use a size of 2 times the configured period size, the code has been
changed to use snd_pcm_hw_params_set_periods_min in order to more
clearly explain the intent.
     1 /*
     2   Copyright (C) 1997-2019 Sam Lantinga <slouken@libsdl.org>
     3 
     4   This software is provided 'as-is', without any express or implied
     5   warranty.  In no event will the authors be held liable for any damages
     6   arising from the use of this software.
     7 
     8   Permission is granted to anyone to use this software for any purpose,
     9   including commercial applications, and to alter it and redistribute it
    10   freely.
    11 */
    12 
    13 /* Test program to test dynamic loading with the loadso subsystem.
    14 */
    15 
    16 #include <stdio.h>
    17 #include <stdlib.h>
    18 #include <string.h>
    19 
    20 #include "SDL.h"
    21 
    22 typedef int (*fntype) (const char *);
    23 
    24 int
    25 main(int argc, char *argv[])
    26 {
    27     int retval = 0;
    28     int hello = 0;
    29     const char *libname = NULL;
    30     const char *symname = NULL;
    31     void *lib = NULL;
    32     fntype fn = NULL;
    33 
    34     if (argc != 3) {
    35         const char *app = argv[0];
    36         SDL_Log("USAGE: %s <library> <functionname>\n", app);
    37         SDL_Log("       %s --hello <lib with puts()>\n", app);
    38         return 1;
    39     }
    40 
    41     /* Initialize SDL */
    42     if (SDL_Init(0) < 0) {
    43         SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't initialize SDL: %s\n", SDL_GetError());
    44         return 2;
    45     }
    46 
    47     if (strcmp(argv[1], "--hello") == 0) {
    48         hello = 1;
    49         libname = argv[2];
    50         symname = "puts";
    51     } else {
    52         libname = argv[1];
    53         symname = argv[2];
    54     }
    55 
    56     lib = SDL_LoadObject(libname);
    57     if (lib == NULL) {
    58         SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "SDL_LoadObject('%s') failed: %s\n",
    59                 libname, SDL_GetError());
    60         retval = 3;
    61     } else {
    62         fn = (fntype) SDL_LoadFunction(lib, symname);
    63         if (fn == NULL) {
    64             SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "SDL_LoadFunction('%s') failed: %s\n",
    65                     symname, SDL_GetError());
    66             retval = 4;
    67         } else {
    68             SDL_Log("Found %s in %s at %p\n", symname, libname, fn);
    69             if (hello) {
    70                 SDL_Log("Calling function...\n");
    71                 fflush(stdout);
    72                 fn("     HELLO, WORLD!\n");
    73                 SDL_Log("...apparently, we survived.  :)\n");
    74                 SDL_Log("Unloading library...\n");
    75                 fflush(stdout);
    76             }
    77         }
    78         SDL_UnloadObject(lib);
    79     }
    80     SDL_Quit();
    81     return retval;
    82 }