The R Project SVN R

/*
 *    Stack-less Just-In-Time compiler
 *
 *    Copyright 2009-2012 Zoltan Herczeg (hzmester@freemail.hu). All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are
 * permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright notice, this list of
 *      conditions and the following disclaimer.
 *
 *   2. Redistributions in binary form must reproduce the above copyright notice, this list
 *      of conditions and the following disclaimer in the documentation and/or other materials
 *      provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) AND CONTRIBUTORS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
 * SHALL THE COPYRIGHT HOLDER(S) OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/* ------------------------------------------------------------------------ */
/*  Locks                                                                   */
/* ------------------------------------------------------------------------ */

#if (defined SLJIT_EXECUTABLE_ALLOCATOR && SLJIT_EXECUTABLE_ALLOCATOR) || (defined SLJIT_UTIL_GLOBAL_LOCK && SLJIT_UTIL_GLOBAL_LOCK)

#if (defined SLJIT_SINGLE_THREADED && SLJIT_SINGLE_THREADED)

#if (defined SLJIT_EXECUTABLE_ALLOCATOR && SLJIT_EXECUTABLE_ALLOCATOR)

static SLJIT_INLINE void allocator_grab_lock(void)
{
    /* Always successful. */
}

static SLJIT_INLINE void allocator_release_lock(void)
{
    /* Always successful. */
}

#endif /* SLJIT_EXECUTABLE_ALLOCATOR */

#if (defined SLJIT_UTIL_GLOBAL_LOCK && SLJIT_UTIL_GLOBAL_LOCK)

SLJIT_API_FUNC_ATTRIBUTE void SLJIT_CALL sljit_grab_lock(void)
{
    /* Always successful. */
}

SLJIT_API_FUNC_ATTRIBUTE void SLJIT_CALL sljit_release_lock(void)
{
    /* Always successful. */
}

#endif /* SLJIT_UTIL_GLOBAL_LOCK */

#elif defined(_WIN32) /* SLJIT_SINGLE_THREADED */

#include "windows.h"

#if (defined SLJIT_EXECUTABLE_ALLOCATOR && SLJIT_EXECUTABLE_ALLOCATOR)

static HANDLE allocator_mutex = 0;

static SLJIT_INLINE void allocator_grab_lock(void)
{
    /* No idea what to do if an error occures. Static mutexes should never fail... */
    if (!allocator_mutex)
        allocator_mutex = CreateMutex(NULL, TRUE, NULL);
    else
        WaitForSingleObject(allocator_mutex, INFINITE);
}

static SLJIT_INLINE void allocator_release_lock(void)
{
    ReleaseMutex(allocator_mutex);
}

#endif /* SLJIT_EXECUTABLE_ALLOCATOR */

#if (defined SLJIT_UTIL_GLOBAL_LOCK && SLJIT_UTIL_GLOBAL_LOCK)

static HANDLE global_mutex = 0;

SLJIT_API_FUNC_ATTRIBUTE void SLJIT_CALL sljit_grab_lock(void)
{
    /* No idea what to do if an error occures. Static mutexes should never fail... */
    if (!global_mutex)
        global_mutex = CreateMutex(NULL, TRUE, NULL);
    else
        WaitForSingleObject(global_mutex, INFINITE);
}

SLJIT_API_FUNC_ATTRIBUTE void SLJIT_CALL sljit_release_lock(void)
{
    ReleaseMutex(global_mutex);
}

#endif /* SLJIT_UTIL_GLOBAL_LOCK */

#else /* _WIN32 */

#if (defined SLJIT_EXECUTABLE_ALLOCATOR && SLJIT_EXECUTABLE_ALLOCATOR)

#include <pthread.h>

static pthread_mutex_t allocator_mutex = PTHREAD_MUTEX_INITIALIZER;

static SLJIT_INLINE void allocator_grab_lock(void)
{
    pthread_mutex_lock(&allocator_mutex);
}

static SLJIT_INLINE void allocator_release_lock(void)
{
    pthread_mutex_unlock(&allocator_mutex);
}

#endif /* SLJIT_EXECUTABLE_ALLOCATOR */

#if (defined SLJIT_UTIL_GLOBAL_LOCK && SLJIT_UTIL_GLOBAL_LOCK)

#include <pthread.h>

static pthread_mutex_t global_mutex = PTHREAD_MUTEX_INITIALIZER;

SLJIT_API_FUNC_ATTRIBUTE void SLJIT_CALL sljit_grab_lock(void)
{
    pthread_mutex_lock(&global_mutex);
}

SLJIT_API_FUNC_ATTRIBUTE void SLJIT_CALL sljit_release_lock(void)
{
    pthread_mutex_unlock(&global_mutex);
}

#endif /* SLJIT_UTIL_GLOBAL_LOCK */

#endif /* _WIN32 */

/* ------------------------------------------------------------------------ */
/*  Stack                                                                   */
/* ------------------------------------------------------------------------ */

#if (defined SLJIT_UTIL_STACK && SLJIT_UTIL_STACK) || (defined SLJIT_EXECUTABLE_ALLOCATOR && SLJIT_EXECUTABLE_ALLOCATOR)

#ifdef _WIN32
#include "windows.h"
#else
/* Provides mmap function. */
#include <sys/mman.h>
/* For detecting the page size. */
#include <unistd.h>

#ifndef MAP_ANON

#include <fcntl.h>

/* Some old systems does not have MAP_ANON. */
static sljit_si dev_zero = -1;

#if (defined SLJIT_SINGLE_THREADED && SLJIT_SINGLE_THREADED)

static SLJIT_INLINE sljit_si open_dev_zero(void)
{
    dev_zero = open("/dev/zero", O_RDWR);
    return dev_zero < 0;
}

#else /* SLJIT_SINGLE_THREADED */

#include <pthread.h>

static pthread_mutex_t dev_zero_mutex = PTHREAD_MUTEX_INITIALIZER;

static SLJIT_INLINE sljit_si open_dev_zero(void)
{
    pthread_mutex_lock(&dev_zero_mutex);
    dev_zero = open("/dev/zero", O_RDWR);
    pthread_mutex_unlock(&dev_zero_mutex);
    return dev_zero < 0;
}

#endif /* SLJIT_SINGLE_THREADED */

#endif

#endif

#endif /* SLJIT_UTIL_STACK || SLJIT_EXECUTABLE_ALLOCATOR */

#if (defined SLJIT_UTIL_STACK && SLJIT_UTIL_STACK)

/* Planning to make it even more clever in the future. */
static sljit_sw sljit_page_align = 0;

SLJIT_API_FUNC_ATTRIBUTE struct sljit_stack* SLJIT_CALL sljit_allocate_stack(sljit_uw limit, sljit_uw max_limit)
{
    struct sljit_stack *stack;
    union {
        void *ptr;
        sljit_uw uw;
    } base;
#ifdef _WIN32
    SYSTEM_INFO si;
#endif

    if (limit > max_limit || limit < 1)
        return NULL;

#ifdef _WIN32
    if (!sljit_page_align) {
        GetSystemInfo(&si);
        sljit_page_align = si.dwPageSize - 1;
    }
#else
    if (!sljit_page_align) {
        sljit_page_align = sysconf(_SC_PAGESIZE);
        /* Should never happen. */
        if (sljit_page_align < 0)
            sljit_page_align = 4096;
        sljit_page_align--;
    }
#endif

    /* Align limit and max_limit. */
    max_limit = (max_limit + sljit_page_align) & ~sljit_page_align;

    stack = (struct sljit_stack*)SLJIT_MALLOC(sizeof(struct sljit_stack));
    if (!stack)
        return NULL;

#ifdef _WIN32
    base.ptr = VirtualAlloc(NULL, max_limit, MEM_RESERVE, PAGE_READWRITE);
    if (!base.ptr) {
        SLJIT_FREE(stack);
        return NULL;
    }
    stack->base = base.uw;
    stack->limit = stack->base;
    stack->max_limit = stack->base + max_limit;
    if (sljit_stack_resize(stack, stack->base + limit)) {
        sljit_free_stack(stack);
        return NULL;
    }
#else
#ifdef MAP_ANON
    base.ptr = mmap(NULL, max_limit, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
#else
    if (dev_zero < 0) {
        if (open_dev_zero()) {
            SLJIT_FREE(stack);
            return NULL;
        }
    }
    base.ptr = mmap(NULL, max_limit, PROT_READ | PROT_WRITE, MAP_PRIVATE, dev_zero, 0);
#endif
    if (base.ptr == MAP_FAILED) {
        SLJIT_FREE(stack);
        return NULL;
    }
    stack->base = base.uw;
    stack->limit = stack->base + limit;
    stack->max_limit = stack->base + max_limit;
#endif
    stack->top = stack->base;
    return stack;
}

#undef PAGE_ALIGN

SLJIT_API_FUNC_ATTRIBUTE void SLJIT_CALL sljit_free_stack(struct sljit_stack* stack)
{
#ifdef _WIN32
    VirtualFree((void*)stack->base, 0, MEM_RELEASE);
#else
    munmap((void*)stack->base, stack->max_limit - stack->base);
#endif
    SLJIT_FREE(stack);
}

SLJIT_API_FUNC_ATTRIBUTE sljit_sw SLJIT_CALL sljit_stack_resize(struct sljit_stack* stack, sljit_uw new_limit)
{
    sljit_uw aligned_old_limit;
    sljit_uw aligned_new_limit;

    if ((new_limit > stack->max_limit) || (new_limit < stack->base))
        return -1;
#ifdef _WIN32
    aligned_new_limit = (new_limit + sljit_page_align) & ~sljit_page_align;
    aligned_old_limit = (stack->limit + sljit_page_align) & ~sljit_page_align;
    if (aligned_new_limit != aligned_old_limit) {
        if (aligned_new_limit > aligned_old_limit) {
            if (!VirtualAlloc((void*)aligned_old_limit, aligned_new_limit - aligned_old_limit, MEM_COMMIT, PAGE_READWRITE))
                return -1;
        }
        else {
            if (!VirtualFree((void*)aligned_new_limit, aligned_old_limit - aligned_new_limit, MEM_DECOMMIT))
                return -1;
        }
    }
    stack->limit = new_limit;
    return 0;
#else
    if (new_limit >= stack->limit) {
        stack->limit = new_limit;
        return 0;
    }
    aligned_new_limit = (new_limit + sljit_page_align) & ~sljit_page_align;
    aligned_old_limit = (stack->limit + sljit_page_align) & ~sljit_page_align;
    /* If madvise is available, we release the unnecessary space. */
#if defined(MADV_DONTNEED)
    if (aligned_new_limit < aligned_old_limit)
        madvise((void*)aligned_new_limit, aligned_old_limit - aligned_new_limit, MADV_DONTNEED);
#elif defined(POSIX_MADV_DONTNEED)
    if (aligned_new_limit < aligned_old_limit)
        posix_madvise((void*)aligned_new_limit, aligned_old_limit - aligned_new_limit, POSIX_MADV_DONTNEED);
#endif
    stack->limit = new_limit;
    return 0;
#endif
}

#endif /* SLJIT_UTIL_STACK */

#endif