ult.c

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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>

#include <arch/ult.h>
#include <core/core.h>
#include <scheduler/process.h>
#include <mm/dymelor.h>

__thread kernel_context_t kernel_context;

#if defined(OS_LINUX)

void *get_ult_stack(size_t size)
{
    void *stack;
    size_t reminder;
    size_t page_size;

    // Sanity check
    if (unlikely(size <= 0)) {
        size = LP_STACK_SIZE;
    }
    // Align the size to the page boundary (by increasing the stack size)
    page_size = getpagesize();
    reminder = size % page_size;
    if (unlikely(reminder != 0)) {
        size += page_size - reminder;
    }
    // The first call to the LP malloc subsystem gives page-aligned memory
    stack = rsalloc(size);
    if (stack == NULL) {
        rootsim_error(true,
                  "Error allocating LP stack: not enough memory.\n");
    }

    bzero(stack, size);

    return stack;
}

#elif defined(OS_WINDOWS) || defined(OS_CYGWIN)

void context_create(LP_context_t * context, void (*entry_point)(void *), void *args, void *stack, size_t stack_size)
{

     (void)stack;

    // BUG? was this intended to be used when the contexts were setup by a single thread?
    static bool once = false;

    if (unlikely(once == false)) {
        once = true;
        // Convert the current thread to a fiber. This allows to schedule other fibers.
        kernel_context.jb = ConvertThreadToFiber(NULL);
    }
    // Create a new fiber
    context->jb = CreateFiber(stack_size, (LPFIBER_START_ROUTINE) entry_point, args);
}

#endif /* OS */