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;
}