test/testthread.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 /* Simple test of the SDL threading code */
    14 
    15 #include <stdio.h>
    16 #include <stdlib.h>
    17 #include <signal.h>
    18 
    19 #include "SDL.h"
    20 
    21 static SDL_TLSID tls;
    22 static int alive = 0;
    23 static int testprio = 0;
    24 
    25 /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
    26 static void
    27 quit(int rc)
    28 {
    29     SDL_Quit();
    30     exit(rc);
    31 }
    32 
    33 static const char *
    34 getprioritystr(SDL_ThreadPriority priority)
    35 {
    36     switch(priority)
    37     {
    38     case SDL_THREAD_PRIORITY_LOW: return "SDL_THREAD_PRIORITY_LOW";
    39     case SDL_THREAD_PRIORITY_NORMAL: return "SDL_THREAD_PRIORITY_NORMAL";
    40     case SDL_THREAD_PRIORITY_HIGH: return "SDL_THREAD_PRIORITY_HIGH";
    41     case SDL_THREAD_PRIORITY_TIME_CRITICAL: return "SDL_THREAD_PRIORITY_TIME_CRITICAL";
    42     }
    43 
    44     return "???";
    45 }
    46 
    47 int SDLCALL
    48 ThreadFunc(void *data)
    49 {
    50     SDL_ThreadPriority prio = SDL_THREAD_PRIORITY_NORMAL;
    51 
    52     SDL_TLSSet(tls, "baby thread", NULL);
    53     SDL_Log("Started thread %s: My thread id is %lu, thread data = %s\n",
    54            (char *) data, SDL_ThreadID(), (const char *)SDL_TLSGet(tls));
    55     while (alive) {
    56         SDL_Log("Thread '%s' is alive!\n", (char *) data);
    57 
    58         if (testprio) {
    59             SDL_Log("SDL_SetThreadPriority(%s):%d\n", getprioritystr(prio), SDL_SetThreadPriority(prio));
    60             if (++prio > SDL_THREAD_PRIORITY_TIME_CRITICAL)
    61                 prio = SDL_THREAD_PRIORITY_LOW;
    62         }
    63 
    64         SDL_Delay(1 * 1000);
    65     }
    66     SDL_Log("Thread '%s' exiting!\n", (char *) data);
    67     return (0);
    68 }
    69 
    70 static void
    71 killed(int sig)
    72 {
    73     SDL_Log("Killed with SIGTERM, waiting 5 seconds to exit\n");
    74     SDL_Delay(5 * 1000);
    75     alive = 0;
    76     quit(0);
    77 }
    78 
    79 int
    80 main(int argc, char *argv[])
    81 {
    82     int arg = 1;
    83     SDL_Thread *thread;
    84 
    85     /* Enable standard application logging */
    86     SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);
    87 
    88     /* Load the SDL library */
    89     if (SDL_Init(0) < 0) {
    90         SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't initialize SDL: %s\n", SDL_GetError());
    91         return (1);
    92     }
    93 
    94     while (argv[arg] && *argv[arg] == '-') {
    95         if (SDL_strcmp(argv[arg], "--prio") == 0) {
    96             testprio = 1;
    97         }
    98         ++arg;
    99     }
   100 
   101     tls = SDL_TLSCreate();
   102     SDL_assert(tls);
   103     SDL_TLSSet(tls, "main thread", NULL);
   104     SDL_Log("Main thread data initially: %s\n", (const char *)SDL_TLSGet(tls));
   105 
   106     alive = 1;
   107     thread = SDL_CreateThread(ThreadFunc, "One", "#1");
   108     if (thread == NULL) {
   109         SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't create thread: %s\n", SDL_GetError());
   110         quit(1);
   111     }
   112     SDL_Delay(5 * 1000);
   113     SDL_Log("Waiting for thread #1\n");
   114     alive = 0;
   115     SDL_WaitThread(thread, NULL);
   116 
   117     SDL_Log("Main thread data finally: %s\n", (const char *)SDL_TLSGet(tls));
   118 
   119     alive = 1;
   120     signal(SIGTERM, killed);
   121     thread = SDL_CreateThread(ThreadFunc, "Two", "#2");
   122     if (thread == NULL) {
   123         SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't create thread: %s\n", SDL_GetError());
   124         quit(1);
   125     }
   126     raise(SIGTERM);
   127 
   128     SDL_Quit();                 /* Never reached */
   129     return (0);                 /* Never reached */
   130 }