// Test that thrd succeeds or fails gracefully.
// This file was modified from the xv6-based forktest.c
// Tiny executable so that the limit can be filling the proc table.

#include "kernel/types.h"
#include "kernel/stat.h"
#include "user/user.h"

// N should be set HIGHER than the limit!
#define N  10

void
print(const char *s)
{
  write(1, s, strlen(s));
}

void printdec(unsigned int i) {
	if (i == 0) {
		print("0");
		return;
	}
	char foo[11];
	int idx = 10;
	while (i > 0) {
		idx--;
		foo[idx] = '0' + (i%10);
		i /= 10;
	}
	foo[10] = 0;
	print(foo+idx);
}

void thrdf(uint64 thrdnum) {
  print("Hello from thread #"); printdec((int)thrdnum); print("\n");
  int i, j, ch, pr;
  pr = 7-(getpid() % 4);
  ch = '0'+pr;
  prio(getpid(), pr, 4);
  //sleep(1);
  for (i = 0; i < 100; i++) {
	for (j = 0; j < 256; j++) {
	  ch++;
	}
	char str[2];
	str[0] = (char)ch;
	str[1] = 0;
	print(str);
  }
  exit(0);
}

void
thrdtest(void)
{
  int n, pid;

  print("thrd test\n");
  
  print("thrdf is at "); printdec((int)(uint64)&thrdf); print("\n");
  //print("testing printdec(12345)="); printdec(12345); print("\n");
  print("attempting to launch up to N="); printdec(N); print(" processes in the same address space...\n");

  for(n=0; n<N; n++){
    char* stack = malloc(1024);
    print("stack at "); printdec((int)(uint64)stack); print("\n");
    if (!stack) {
      print("malloc failed\n");
      break;
    }
    int i = 1024;
    // Align stack, since this probably won't be guaranteed by a simple malloc
    // And may differ by compiler/settings/etc.!!
    while (((uint64)(stack+i)) % 16) {
      i--;
    }
    pid = thrd(getpid(), &thrdf, stack+i, n);
    if(pid < 0) {
      print("thrd() syscall failed\n");
      break;
    }
  }
  
  
  print("spawned "); printdec(n); print(n == 1 ? " thread\n" : " threads\n");

  if(n == N){
    print("thrd() claimed to work N times! thrdtest can be updated so N is greater than the kernel's NPROC!\n");
    //exit(1);
  }

  for(; n > 0; n--){
    if(wait(0) < 0){
      print("wait stopped early\n");
      exit(1);
    }
  }

  if(wait(0) != -1){
    print("wait got too many\n");
    exit(1);
  }

  print("\nthrd() test OK\n");
}

int
main(void)
{
  thrdtest();
  exit(0);
}