diff options
| -rw-r--r-- | coro.h | 97 |
1 files changed, 82 insertions, 15 deletions
@@ -37,25 +37,96 @@ #ifndef CORO_H #define CORO_H +/* + * This library consists of only three files + * coro.h, coro.c and LICENSE + * + * It implements what is known as coroutines, in a hopefully + * portable way. At the moment you have to define which kind + * of implementation flavour you want: + * + * -DCORO_UCONTEXT + * + * This flavour uses SUSv2's get/set/swap/makecontext functions that + * unfortunately only newer unices support. + * Use this for GNU/Linux + glibc-2.2.3. + * + * -DCORO_SJLJ + * + * This flavour uses SUSv'2 setjmp/longjmp and sigaltstack functions to + * do it's job. Coroutine creation is much slower than UCONTEXT, but + * context switching is often a bit cheaper. It should work on almost + * all unices. Use this for GNU/Linux + glibc-2.2. glibc-2.1 and below + * do not work with any model (neither sigaltstack nor context functions + * are implemented) + * + * -DCORO_LOOSE + * + * Microsoft's highly proprietary platform doesn't support sigaltstack, and + * this automatically selects a suitable workaround for this platform. + * (untested) + * + * If you define neither of these symbols, coro.h will try to autodetect + * the model. This currently works for CORO_LOOSE only. For the other + * alternatives you should check (e.g. using autoconf) and define the + * following symbols: HAVE_UCONTEXT_H / HAVE_SETJMP_H / HAVE_SIGALTSTACK. + */ + +/* + * This is the type for the top function of a new coroutine. + */ typedef void (*coro_func)(void *); -#if defined(WINDOWS) -# define CORO_LOOSE 1 /* you don't win with windoze */ -#elif defined(HAVE_UCONTEXT_H) -# define CORO_UCONTEXT 1 -#elif defined(HAVE_SETJMP_H) && defined(HAVE_SIGALTSTACK) -# define CORO_SJLJ 1 -#else + +/* + * A coroutine state is saved in the following structure. Treat it as a + * opaque type. errno and sigmask might be saved, but don't rely on it, + * implement your own switching primitive. + */ +typedef struct coro_context coro_context; + +/* + * This function creates a new coroutine. Apart from a pointer to an + * uninitialized coro_context, it expects a pointer to the entry function + * and the single pointer value that is given to it as argument. + * + * Allocating/deallocating the stack is your own responsibility, so there is + * no coro_destroy function. + */ +void coro_create(coro_context *ctx, + coro_func coro, void *arg, + void *sptr, long ssize); + +/* + * The following prototype defines the coroutine switching function. It is + * usually implemented as a macro, so watch out. + * +void coro_transfer(coro_context *prev, coro_context *next); + */ + +/* + * That was it. No other user-visible functions are implemented here. + */ + +#if !defined(CORO_LOOSE) && !defined(CORO_UCONTEXT) && !defined(CORO_SJLJ) +# if defined(WINDOWS) +# define CORO_LOOSE 1 /* you don't win with windoze */ +# elif defined(HAVE_UCONTEXT_H) +# define CORO_UCONTEXT 1 +# elif defined(HAVE_SETJMP_H) && defined(HAVE_SIGALTSTACK) +# define CORO_SJLJ 1 +# else error unknown or unsupported architecture +# endif #endif #if CORO_UCONTEXT #include <ucontext.h> -typedef struct { +struct coro_context { ucontext_t uc; -} coro_context; +}; #define coro_transfer(p,n) swapcontext(&((p)->uc), &((n)->uc)) @@ -63,17 +134,13 @@ typedef struct { #include <setjmp.h> -typedef struct { +struct coro_context { jmp_buf env; -} coro_context; +}; #define coro_transfer(p,n) if (!setjmp ((p)->env)) longjmp ((n)->env, 1) #endif -void coro_create(coro_context *ctx, - coro_func coro, void *arg, - void *sptr, long ssize); - #endif |