auto_release_temp(); // automatically release temporary memory.
print(">%<", S64_MIN + delta, to_standard_error = true);
print_to_builder(*builder, "Average % us (% / % bytes) ---------", dbg_average/1000, context.temporary_storage.total_bytes_occupied, context.temporary_storage.high_water_mark); // DEBUG


// MEASURE PERFORMANCE
{
    dbg_average := 0; // DEBUG
    dbg_count := 0; // DEBUG

    #import "Basic";
    
    // Cumulative average: CA_n+1 = (x_n+1 + n*CA_n ) / (n + 1)
    start := current_time_monotonic(); // DEBUG
    // ...code to be measured...
    stop := current_time_monotonic(); // DEBUG
    dbg_sample := to_nanoseconds(stop-start); // DEBUG
    dbg_average = (dbg_sample + dbg_count * dbg_average) / (dbg_count + 1); // DEBUG
    dbg_count += 1; // DEBUG
    print("Average % ns.\n", dbg_average); // DEBUG
}
 
// Memory allocator debugging.
print_owner_allocator :: (tag: string, memory: *void) {
    owner := "unkown";
    
    if true == xx context.allocator.proc(.IS_THIS_YOURS, 0, 0, memory, null) then owner = "default";
    else if true == xx temp.proc(.IS_THIS_YOURS, 0, 0, memory, null) then owner = "temp";

    print("'%' belongs to '%'\n", tag, owner);
}

// ttt's database debugging.
print_database :: (db: Database) {
    for db.tasks {
        print("% | % : % : % : % : % : % : %\n", cast(string)it.name,
              it.times[0],
              it.times[1],
              it.times[2],
              it.times[3],
              it.times[4],
              it.times[5],
              it.times[6]
        );
    }
}

// --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- //


// Average cumulative calculation.
average: float64 = 0;
counter: float64 = 0;
t0 := current_time_monotonic();
t1 := current_time_monotonic();
set_cursor_position(2, 47);
sample := cast(float64)to_nanoseconds(t1-t0)/1000;
average = (sample + counter * average) / (counter + 1);
counter += 1;
print(">%us<", average);


// --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- //

// Implementation of tcsetattr, tcgetattr, and tcflush using only 'ioctl' which is provided by jai.

#if USE_LIBC {
    
    libc :: #system_library "libc";

    // https://codebrowser.dev/glibc/glibc/sysdeps/unix/sysv/linux/tcsetattr.c.html
    tcsetattr :: (fd: s32, optional_actions: s32, termios_p : *Terminal_IO_Mode) -> s32 #foreign libc;

    // https://codebrowser.dev/glibc/glibc/sysdeps/unix/sysv/linux/tcgetattr.c.html
    tcgetattr :: (fd: s32, termios_p: *Terminal_IO_Mode) -> s32 #foreign libc;

    // https://codebrowser.dev/glibc/glibc/sysdeps/unix/sysv/linux/tcflush.c.html
    tcflush :: (fd: s32, queue_selector: s32) -> s32 #foreign libc;    
}
else {
    
    // https://codebrowser.dev/glibc/glibc/sysdeps/unix/sysv/linux/tcsetattr.c.html
    tcsetattr :: (fd: s32, optional_actions: s32, termios_p : *Terminal_IO_Mode) -> s32 {
    
        #if OS == .LINUX {
            TCSETS      :: 0x5402;
            TCSETSW     :: 0x5403;
            TCSETSF     :: 0x5404;
            tcflag_t        :: u32;
            cc_t            :: u8;
            __KERNEL_NCCS   :: 19;
            __kernel_termios :: struct {
                c_iflag     : tcflag_t;		// input mode flags
                c_oflag     : tcflag_t;		// output mode flags
                c_cflag     : tcflag_t;		// control mode flags
                c_lflag     : tcflag_t;		// local mode flags
                c_line      : cc_t;		    // line discipline
                c_cc        : [__KERNEL_NCCS]cc_t;     // control characters
              };
        
            k_termios: __kernel_termios;
            cmd: u64;
            if optional_actions == {
                case xx Optional_Actions.TCSANOW;
                    cmd = TCSETS;

                case xx Optional_Actions.TCSADRAIN;
                    cmd = TCSETSW;

                case xx Optional_Actions.TCSAFLUSH;
                    cmd = TCSETSF;

                case;
                    return EINVAL;
            }
            // k_termios.c_iflag = termios_p.c_iflag & ~IBAUD0;
            k_termios.c_iflag = xx termios_p.c_iflag;
            k_termios.c_oflag = xx termios_p.c_oflag;
            k_termios.c_cflag = xx termios_p.c_cflag;
            k_termios.c_lflag = xx termios_p.c_lflag;
            k_termios.c_line = xx termios_p.c_line;
            // #if _HAVE_C_ISPEED && _HAVE_STRUCT_TERMIOS_C_ISPEED
            // k_termios.c_ispeed = termios_p->c_ispeed;
            // #endif
            // #if _HAVE_C_OSPEED && _HAVE_STRUCT_TERMIOS_C_OSPEED
            // k_termios.c_ospeed = termios_p->c_ospeed;
            // #endif
            memcpy(*k_termios.c_cc[0], *termios_p.c_cc[0], __KERNEL_NCCS * 1);//size_of(cc_t));
            return ioctl(fd, cmd, *k_termios);
        }
        #if OS == .MACOS {
            // return __ioctl (fd, TIOCSETAF, termios_p);
            #assert(false, "NOT IMPLEMENTED");
        }
        return 0;
    }
    
    // https://codebrowser.dev/glibc/glibc/sysdeps/unix/sysv/linux/tcgetattr.c.html
    tcgetattr :: (fd: s32, termios_p: *Terminal_IO_Mode) -> s32 {
            TCSETS      :: 0x5402;
            TCSETSW     :: 0x5403;
            TCSETSF     :: 0x5404;
            tcflag_t        :: u32;
            cc_t            :: u8;
            __KERNEL_NCCS   :: 19;
            __kernel_termios :: struct {
                c_iflag     : tcflag_t;		// input mode flags
                c_oflag     : tcflag_t;		// output mode flags
                c_cflag     : tcflag_t;		// control mode flags
                c_lflag     : tcflag_t;		// local mode flags
                c_line      : cc_t;		    // line discipline
                c_cc        : [__KERNEL_NCCS]cc_t;     // control characters
              };

    
        // int
        // __tcgetattr (int fd, struct termios *termios_p)
        // {
          // struct __kernel_termios k_termios;
          k_termios: __kernel_termios;
          retval: int;
          retval = ioctl(fd, TCGETS, *k_termios);
          if retval == 0 {
              termios_p.c_iflag = xx k_termios.c_iflag;
              termios_p.c_oflag = xx k_termios.c_oflag;
              termios_p.c_cflag = xx k_termios.c_cflag;
              termios_p.c_lflag = xx k_termios.c_lflag;
              termios_p.c_line = xx k_termios.c_line;
        // #if _HAVE_STRUCT_TERMIOS_C_ISPEED
        // # if _HAVE_C_ISPEED
              // termios_p->c_ispeed = k_termios.c_ispeed;
        // # else
              // termios_p->c_ispeed = k_termios.c_cflag & (CBAUD | CBAUDEX);
        // # endif
        // #endif
        // #if _HAVE_STRUCT_TERMIOS_C_OSPEED
        // # if _HAVE_C_OSPEED
              // termios_p->c_ospeed = k_termios.c_ospeed;
        // # else
              // termios_p->c_ospeed = k_termios.c_cflag & (CBAUD | CBAUDEX);
        // # endif
        // #endif
            size_of_cc_t := __KERNEL_NCCS * 1;
            memcpy(*termios_p.c_cc[0], *k_termios.c_cc[0], size_of_cc_t);
            // memset(*termios_p.c_cc[0] + size_of_cc_t + 1, _POSIX_VDISABLE, (NCCS - __KERNEL_NCCS) * 1);
            // 
            // if (sizeof (cc_t) == 1 || _POSIX_VDISABLE == 0 || (unsigned char) _POSIX_VDISABLE == (unsigned char) -1) {
                // memset (__mempcpy (&termios_p->c_cc[0], &k_termios.c_cc[0], __KERNEL_NCCS * sizeof (cc_t)), _POSIX_VDISABLE, (NCCS - __KERNEL_NCCS) * sizeof (cc_t));
            // }
            // else
        	// {
        	    // memcpy (&termios_p->c_cc[0], &k_termios.c_cc[0], __KERNEL_NCCS * sizeof (cc_t));
        	    // for (size_t cnt = __KERNEL_NCCS; cnt < NCCS; ++cnt) {
        	        // termios_p->c_cc[cnt] = _POSIX_VDISABLE;
    	        // }
        	// }
    	}
    	return xx retval;
    }
        
    // https://codebrowser.dev/glibc/glibc/sysdeps/unix/sysv/linux/tcflush.c.html
    tcflush :: inline (fd: s32, queue_selector: s32) -> s32 {
        TCFLSH :: 0x540B;
        return ioctl(fd, TCFLSH, queue_selector);
    }
}
 
// --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- //


Step_Iterator :: struct {
    min:  int;
    max:  int;
    step: int;
}

step_iterator :: (min: int, max: int, step: int) -> Step_Iterator {
    return .{ min, max, step };
}

for_expansion :: (iterator: Step_Iterator, body: Code, flags: For_Flags) #expand {
    iteration_count: int;
    for <=cast(bool)(flags & .REVERSE) i: iterator.min..iterator.max {
        iteration_count += 1;
        if iteration_count % iterator.step == 0 continue;

        `it       := i;
        `it_index := void;

        #insert body;
    }
}

for step_iterator(0, 10, 2) {
    log("%", it);
}


// --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- //


// Check what's going on with the temp allocator:
// Is it really the responsible for these paths?
// It seems that the next beta (after 0.1.055b) compiler allows us to check this pretty easily.
//
//
// An example that uses several different allocators, then asks them all
// who owns which memory.
//
// Note that this is probably not the kind of thing you want to do at runtime
// in the steady state, as it may not be very fast, but it could be a very helpful
// debugging facility.
//

#import "Basic";
#import "Pool";
#import "Flat_Pool";
#import "rpmalloc";

main :: () {
    pool: Pool;
    flat: Flat_Pool;

    a := context.default_allocator;
    b := Allocator.{pool_allocator_proc, *pool};
    c := Allocator.{flat_pool_allocator_proc, *flat};
    d := Allocator.{rpmalloc_allocator_proc, null};

    d.proc(.STARTUP, 0, 0, null, null);  // rpmalloc needs explicit init right now, but others don't.
    
    ma := alloc(1000, allocator=a);
    mb := alloc(1000, allocator=b);
    mc := alloc(1000, allocator=c);
    md := alloc(1000, allocator=d);

    report_who_owns(ma, a, b, c, d);
    report_who_owns(mb, a, b, c, d);
    report_who_owns(mc, a, b, c, d);
    report_who_owns(md, a, b, c, d);
}

report_who_owns :: (memory: *void, allocators: .. Allocator) {
    someone_owns_this := false;
    
    print("Querying all allocators for address: %\n", memory);
    
    for allocators {
        caps, name := get_capabilities(it);
        assert((caps & .IS_THIS_YOURS) != 0);  // It had better be claiming to support this!
        
        yours := cast(bool) it.proc(.IS_THIS_YOURS, 0, 0, memory, it.data);
        print("[%] says \"%\"\n", yours, name);

        someone_owns_this ||= yours;
    }

    assert(someone_owns_this);
}


// --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- //


checked_add :: (a: $T, b: T) -> result: T, overflow: bool 
#modify {
    if T.type == .INTEGER return;
    T = null;
}
{
    overflow: bool;
    result: T = a + b;

    info := type_info(T);
    if info.signed {
        // (+A) + (+B) = −C
        // (−A) + (−B) = +C
        if ((a > 0) && (b > 0) && (result < 0)) || ((a < 0) && (b < 0) && (result > 0)) {
            overflow = true;
        }
    } else {
        if result < a {
            overflow = true;
        }
    }

    return result, overflow;
}

checked_sub :: (a: $T, b: T) -> result: T, overflow: bool 
#modify {
    if T.type == .INTEGER return;
    T = null;
}
{
    overflow: bool;
    result: T = a - b;

    info := type_info(T);
    if info.signed {
        // (+A) − (−B) = −C
        // (−A) − (+B) = +C
        if ((a > 0) && (b < 0) && (result < 0)) || ((a < 0) && (b > 0) && (result > 0)) {
            overflow = true;
        }
    } else {
        if result > a {
            overflow = true;
        }
    }

    return result, overflow;
}