// Start of context.h

// Eventually it would be nice to move the context definition in here
// instead of generating it in the compiler.  For now it defines
// various helper functions that must be available.

// Internal functions.

static void set_error(struct futhark_context* ctx, char *error) {
  lock_lock(&ctx->error_lock);
  if (ctx->error == NULL) {
    ctx->error = error;
  } else {
    free(error);
  }
  lock_unlock(&ctx->error_lock);
}

// XXX: should be static, but used in ispc_util.h
void lexical_realloc_error(struct futhark_context* ctx, size_t new_size) {
  set_error(ctx,
            msgprintf("Failed to allocate memory.\nAttempted allocation: %12lld bytes\n",
                      (long long) new_size));
}

static int lexical_realloc(struct futhark_context *ctx,
                           unsigned char **ptr,
                           int64_t *old_size,
                           int64_t new_size) {
  unsigned char *new = realloc(*ptr, (size_t)new_size);
  if (new == NULL) {
    lexical_realloc_error(ctx, new_size);
    return FUTHARK_OUT_OF_MEMORY;
  } else {
    *ptr = new;
    *old_size = new_size;
    return FUTHARK_SUCCESS;
  }
}

static void free_all_in_free_list(struct futhark_context* ctx) {
  fl_mem mem;
  free_list_pack(&ctx->free_list);
  while (free_list_first(&ctx->free_list, (fl_mem*)&mem) == 0) {
    free((void*)mem);
  }
}

static int is_small_alloc(size_t size) {
  return size < 1024*1024;
}

static void host_alloc(struct futhark_context* ctx,
                       size_t size, const char* tag, size_t* size_out, void** mem_out) {
  if (is_small_alloc(size) || free_list_find(&ctx->free_list, size, tag, size_out, (fl_mem*)mem_out) != 0) {
    *size_out = size;
    *mem_out = malloc(size);
  }
}

static void host_free(struct futhark_context* ctx,
                      size_t size, const char* tag, void* mem) {
  // Small allocations are handled by malloc()s own free list.  The
  // threshold here is kind of arbitrary, but seems to work OK.
  // Larger allocations are mmap()ed/munmapped() every time, which is
  // very slow, and Futhark programs tend to use a few very large
  // allocations.
  if (is_small_alloc(size)) {
    free(mem);
  } else {
    free_list_insert(&ctx->free_list, size, (fl_mem)mem, tag);
  }
}

static void context_setup(struct futhark_context *ctx) {
  create_lock(&ctx->error_lock);
  create_lock(&ctx->lock);
  free_list_init(&ctx->free_list);
}

static void context_teardown(struct futhark_context *ctx) {
  free_constants(ctx);
  free_all_in_free_list(ctx);
  free_list_destroy(&ctx->free_list);
  free_lock(&ctx->lock);
  free_lock(&ctx->error_lock);
}

// End of context.h