threads/thread-basic/source/main.c

#include <string.h>
#include <stdio.h>
#include <3ds.h>
 
#define NUMTHREADS 3
#define STACKSIZE (4 * 1024)
 
volatile bool runThreads = true;
 
void threadMain(void *arg)
{
    u64 sleepDuration = 1000000ULL * (u32)arg;
    int i = 0;
    while (runThreads)
    {
        printf("thread%d says %d\n", (int)arg, i++);
        svcSleepThread(sleepDuration);
    }
}
 
int main(int argc, char** argv)
{
    gfxInitDefault();
    consoleInit(GFX_TOP, NULL);
 
    Thread threads[NUMTHREADS];
    int i;
    s32 prio = 0;
    svcGetThreadPriority(&prio, CUR_THREAD_HANDLE);
    printf("Main thread prio: 0x%lx\n", prio);
 
    for (i = 0; i < NUMTHREADS; i ++)
    {
        // The priority of these child threads must be higher (aka the value is lower) than that
        // of the main thread, otherwise there is thread starvation due to stdio being locked.
        threads[i] = threadCreate(threadMain, (void*)((i+1)*250), STACKSIZE, prio-1, -2, false);
        printf("created thread %d: %p\n", i, threads[i]);
    }
 
    // Main loop
    while (aptMainLoop())
    {
        gspWaitForVBlank();
        hidScanInput();
 
        u32 kDown = hidKeysDown();
        if (kDown & KEY_START)
            break; // break in order to return to hbmenu
 
        // Flush and swap framebuffers
        gfxFlushBuffers();
        gfxSwapBuffers();
    }
 
    // tell threads to exit & wait for them to exit
    runThreads = false;
    for (i = 0; i < NUMTHREADS; i ++)
    {
        threadJoin(threads[i], U64_MAX);
        threadFree(threads[i]);
    }
 
    gfxExit();
    return 0;
}