Overview

c-block are extremely lightweight macros designed for eliminate callback hell, inspired by Duff's device and Protothreads. c-block provide sequential flow of control that is similar to the await of c#.

Callback hell style code:

void stat_cb(uv_fs_t* req) {
  printf("stat result:%d\n", req->result);
  uv_fs_req_cleanup(req);
  free(req);
}

uv_fs_stat(uv_default_loop(), req, "./test.exe", stat_cb);

c-block style code:

int task_clousre(struct task *ctx) {
  c_begin(ctx, task_clousre);
  ctx->u.stat.loop = uv_default_loop();
  ctx->u.stat.path = "./test.exe";
  c_await(&ctx->u.stat, c_fs_stat);
  uv_fs_req_cleanup(&ctx->u.stat.req);
  c_end();
  free(ctx);
  return 0;
}

For full version code, see c-block-uv

Features

• Low cost, each block use only 12 bytes (on 32bit system)
• No dependences.
• Support all platforms.

Warning

• Do not use local variables. Local variables are not preserved across source lines which containing c-block codes. Put the variables into the context struct.
• Do not use switch-case between c_begin and c_end. see Duff's device.

Examples

• c-block-uv
• c-block-mysql