// Sligthly modified version by Alogani for the development of NimGo library https://github.com/Alogani/NimGo

/*

Minimal asymmetric stackful cross-platform coroutine library in pure C.

minicoro - v0.2.0 - 15/Nov/2023

Eduardo Bart - [email protected]

https://github.com/edubart/minicoro

Minicoro is single file library for using asymmetric coroutines in C.

The API is inspired by Lua coroutines but with C use in mind.

# Features

- Stackful asymmetric coroutines.

- Supports nesting coroutines (resuming a coroutine from another coroutine).

- Supports custom allocators.

- Storage system to allow passing values between yield and resume.

- Customizable stack size.

- Supports growable stacks and low memory footprint when enabling the virtual memory allocator.

- Coroutine API design inspired by Lua with C use in mind.

- Yield across any C function.

- Made to work in multithread applications.

- Cross platform.

- Minimal, self contained and no external dependencies.

- Readable sources and documented.

- Implemented via assembly, ucontext or fibers.

- Lightweight and very efficient.

- Works in most C89 compilers.

- Error prone API, returning proper error codes on misuse.

- Support running with Valgrind, ASan (AddressSanitizer) and TSan (ThreadSanitizer).

# Supported Platforms

Most platforms are supported through different methods:

| Platform | Assembly Method | Fallback Method |

|--------------|------------------|-------------------|

| Android | ARM/ARM64 | N/A |

| iOS | ARM/ARM64 | N/A |

| Windows | x86_64 | Windows fibers |

| Linux | x86_64/i686 | ucontext |

| Mac OS X | x86_64/ARM/ARM64 | ucontext |

| WebAssembly | N/A | Emscripten fibers / Binaryen asyncify |

| Raspberry Pi | ARM | ucontext |

| RISC-V | rv64/rv32 | ucontext |

The assembly method is used by default if supported by the compiler and CPU,

otherwise ucontext or fiber method is used as a fallback.

The assembly method is very efficient, it just take a few cycles

to create, resume, yield or destroy a coroutine.

# Caveats

- Avoid using coroutines with C++ exceptions, this is not recommended, it may not behave as you expect.

- When using C++ RAII (i.e. destructors) you must resume the coroutine until it dies to properly execute all destructors.

- Some unsupported sanitizers for C may trigger false warnings when using coroutines.

- The `mco_coro` object is not thread safe, you should use a mutex for manipulating it in multithread applications.

- To use in multithread applications, you must compile with C compiler that supports `thread_local` qualifier.

- Avoid using `thread_local` inside coroutine code, the compiler may cache thread local variables pointers which can be invalid when a coroutine switch threads.

- Stack space is limited. By default it has 56KB of space, this can be changed on coroutine creation, or by enabling the virtual memory backed allocator to make it 2040KB.

- Take care to not cause stack overflows (run out of stack space), otherwise your program may crash or not, the behavior is undefined.

- On WebAssembly you must compile with Emscripten flag `-s ASYNCIFY=1`.

- The WebAssembly Binaryen asyncify method can be used when explicitly enabled,

you may want to do this only to use minicoro with WebAssembly native interpreters

(no Web browser). This method is confirmed to work well with Emscripten toolchain,

however it fails on other WebAssembly toolchains like WASI SDK.

# Introduction

A coroutine represents an independent "green" thread of execution.

Unlike threads in multithread systems, however,

a coroutine only suspends its execution by explicitly calling a yield function.

You create a coroutine by calling `mco_create`.

Its sole argument is a `mco_desc` structure with a description for the coroutine.

The `mco_create` function only creates a new coroutine and returns a handle to it, it does not start the coroutine.

You execute a coroutine by calling `mco_resume`.

When calling a resume function the coroutine starts its execution by calling its body function.

After the coroutine starts running, it runs until it terminates or yields.

A coroutine yields by calling `mco_yield`.

When a coroutine yields, the corresponding resume returns immediately,

even if the yield happens inside nested function calls (that is, not in the main function).

The next time you resume the same coroutine, it continues its execution from the point where it yielded.

To associate a persistent value with the coroutine,

you can optionally set `user_data` on its creation and later retrieve with `mco_get_user_data`.

To pass values between resume and yield,

you can optionally use `mco_push` and `mco_pop` APIs,

they are intended to pass temporary values using a LIFO style buffer.

The storage system can also be used to send and receive initial values on coroutine creation or before it finishes.

# Usage

To use minicoro, do the following in one .c file:

```c

#define MINICORO_IMPL

#include "minicoro.h"

```

You can do `#include "minicoro.h"` in other parts of the program just like any other header.

## Minimal Example

The following simple example demonstrates on how to use the library:

```c

#define MINICORO_IMPL

#include "minicoro.h"

#include <stdio.h>

#include <assert.h>

// Coroutine entry function.

void coro_entry(mco_coro* co) {

printf("coroutine 1\n");

mco_yield(co);

printf("coroutine 2\n");

}

int main() {

// First initialize a `desc` object through `mco_desc_init`.

mco_desc desc = mco_desc_init(coro_entry, 0);

// Configure `desc` fields when needed (e.g. customize user_data or allocation functions).

desc.user_data = NULL;

// Call `mco_create` with the output coroutine pointer and `desc` pointer.

mco_coro* co;

mco_result res = mco_create(&co, &desc);

assert(res == MCO_SUCCESS);

// The coroutine should be now in suspended state.

assert(mco_status(co) == MCO_SUSPENDED);

// Call `mco_resume` to start for the first time, switching to its context.

res = mco_resume(co); // Should print "coroutine 1".

assert(res == MCO_SUCCESS);

// We get back from coroutine context in suspended state (because it's unfinished).

assert(mco_status(co) == MCO_SUSPENDED);

// Call `mco_resume` to resume for a second time.

res = mco_resume(co); // Should print "coroutine 2".

assert(res == MCO_SUCCESS);

// The coroutine finished and should be now dead.

assert(mco_status(co) == MCO_DEAD);

// Call `mco_destroy` to destroy the coroutine.

res = mco_destroy(co);

assert(res == MCO_SUCCESS);

return 0;

}

```

_NOTE_: In case you don't want to use the minicoro allocator system you should

allocate a coroutine object yourself using `mco_desc.coro_size` and call `mco_init`,

then later to destroy call `mco_uninit` and deallocate it.

## Yielding from anywhere

You can yield the current running coroutine from anywhere

without having to pass `mco_coro` pointers around,

to this just use `mco_yield(mco_running())`.

## Passing data between yield and resume

The library has the storage interface to assist passing data between yield and resume.

It's usage is straightforward,

use `mco_push` to send data before a `mco_resume` or `mco_yield`,

then later use `mco_pop` after a `mco_resume` or `mco_yield` to receive data.

Take care to not mismatch a push and pop, otherwise these functions will return

an error.

## Error handling

The library return error codes in most of its API in case of misuse or system error,

the user is encouraged to handle them properly.

## Virtual memory backed allocator

The new compile time option `MCO_USE_VMEM_ALLOCATOR` enables a virtual memory backed allocator.

Every stackful coroutine usually have to reserve memory for its full stack,

this typically makes the total memory usage very high when allocating thousands of coroutines,

for example, an application with 100 thousands coroutine with stacks of 56KB would consume as high

as 5GB of memory, however your application may not really full stack usage for every coroutine.

Some developers often prefer stackless coroutines over stackful coroutines

because of this problem, stackless memory footprint is low, therefore often considered more lightweight.

However stackless have many other limitations, like you cannot run unconstrained code inside them.

One remedy to the solution is to make stackful coroutines growable,

to only use physical memory on demand when its really needed,

and there is a nice way to do this relying on virtual memory allocation

when supported by the operating system.

The virtual memory backed allocator will reserve virtual memory in the OS for each coroutine stack,

but not trigger real physical memory usage yet.

While the application virtual memory usage will be high,

the physical memory usage will be low and actually grow on demand (usually every 4KB chunk in Linux).

The virtual memory backed allocator also raises the default stack size to about 2MB,

typically the size of extra threads in Linux,

so you have more space in your coroutines and the risk of stack overflow is low.

As an example, allocating 100 thousands coroutines with nearly 2MB stack reserved space

with the virtual memory allocator uses 783MB of physical memory usage, that is about 8KB per coroutine,

however the virtual memory usage will be at 98GB.

It is recommended to enable this option only if you plan to spawn thousands of coroutines

while wanting to have a low memory footprint.

Not all environments have an OS with virtual memory support, therefore this option is disabled by default.

This option may add an order of magnitude overhead to `mco_create()`/`mco_destroy()`,

because they will request the OS to manage virtual memory page tables,

if this is a problem for you, please customize a custom allocator for your own needs.

## Library customization

The following can be defined to change the library behavior:

- `MCO_API` - Public API qualifier. Default is `extern`.

- `MCO_MIN_STACK_SIZE` - Minimum stack size when creating a coroutine. Default is 32768 (32KB).

- `MCO_DEFAULT_STORAGE_SIZE` - Size of coroutine storage buffer. Default is 1024.

- `MCO_DEFAULT_STACK_SIZE` - Default stack size when creating a coroutine. Default is 57344 (56KB). When `MCO_USE_VMEM_ALLOCATOR` is true the default is 2040KB (nearly 2MB).

- `MCO_ALLOC` - Default allocation function. Default is `calloc`.

- `MCO_DEALLOC` - Default deallocation function. Default is `free`.

- `MCO_USE_VMEM_ALLOCATOR` - Use virtual memory backed allocator, improving memory footprint per coroutine.

- `MCO_NO_DEFAULT_ALLOCATOR` - Disable the default allocator using `MCO_ALLOC` and `MCO_DEALLOC`.

- `MCO_ZERO_MEMORY` - Zero memory of stack when poping storage, intended for garbage collected environments.

- `MCO_DEBUG` - Enable debug mode, logging any runtime error to stdout. Defined automatically unless `NDEBUG` or `MCO_NO_DEBUG` is defined.

- `MCO_NO_DEBUG` - Disable debug mode.

- `MCO_NO_MULTITHREAD` - Disable multithread usage. Multithread is supported when `thread_local` is supported.

- `MCO_USE_ASM` - Force use of assembly context switch implementation.

- `MCO_USE_UCONTEXT` - Force use of ucontext context switch implementation.

- `MCO_USE_FIBERS` - Force use of fibers context switch implementation.

- `MCO_USE_ASYNCIFY` - Force use of Binaryen asyncify context switch implementation.

- `MCO_USE_VALGRIND` - Define if you want run with valgrind to fix accessing memory errors.

# License

Your choice of either Public Domain or MIT No Attribution, see end of file.

*/

#ifndef MINICORO_H

#define MINICORO_H

#ifdef __cplusplus

extern "C" {

#endif

/* Public API qualifier. */

#ifndef MCO_API

#define MCO_API extern

#endif

/* Size of coroutine storage buffer. */

#ifndef MCO_DEFAULT_STORAGE_SIZE

#define MCO_DEFAULT_STORAGE_SIZE 1024

#endif

#include <stddef.h> /* for size_t */

/* ---------------------------------------------------------------------------------------------- */

/* Coroutine states. */

typedef enum mco_state {

MCO_DEAD = 0, /* The coroutine has finished normally or was uninitialized before finishing. */

MCO_NORMAL, /* The coroutine is active but not running (that is, it has resumed another coroutine). */

MCO_RUNNING, /* The coroutine is active and running. */

MCO_SUSPENDED /* The coroutine is suspended (in a call to yield, or it has not started running yet). */

} mco_state;

/* Coroutine result codes. */

typedef enum mco_result {

MCO_SUCCESS = 0,

MCO_GENERIC_ERROR,

MCO_INVALID_POINTER,

MCO_INVALID_COROUTINE,

MCO_NOT_SUSPENDED,

MCO_NOT_RUNNING,

MCO_MAKE_CONTEXT_ERROR,

MCO_SWITCH_CONTEXT_ERROR,

MCO_NOT_ENOUGH_SPACE,

MCO_OUT_OF_MEMORY,

MCO_INVALID_ARGUMENTS,

MCO_INVALID_OPERATION,

MCO_STACK_OVERFLOW

} mco_result;

/* Coroutine structure. */

typedef struct mco_coro mco_coro;

struct mco_coro {

void* context;

mco_state state;

void (*func)(mco_coro* co);

mco_coro* prev_co;

void* user_data;

size_t coro_size;

void* allocator_data;

void (*dealloc_cb)(void* ptr, size_t size, void* allocator_data);

void* stack_base; /* Stack base address, can be used to scan memory in a garbage collector. */

size_t stack_size;

unsigned char* storage;

size_t bytes_stored;

size_t storage_size;

void* asan_prev_stack; /* Used by address sanitizer. */

void* tsan_prev_fiber; /* Used by thread sanitizer. */

void* tsan_fiber; /* Used by thread sanitizer. */

size_t magic_number; /* Used to check stack overflow. */

};

/* Structure used to initialize a coroutine. */

typedef struct mco_desc {

void (*func)(mco_coro* co); /* Entry point function for the coroutine. */

void* user_data; /* Coroutine user data, can be get with `mco_get_user_data`. */

/* Custom allocation interface. */

void* (*alloc_cb)(size_t size, void* allocator_data); /* Custom allocation function. */

void (*dealloc_cb)(void* ptr, size_t size, void* allocator_data); /* Custom deallocation function. */

void* allocator_data; /* User data pointer passed to `alloc`/`dealloc` allocation functions. */

size_t storage_size; /* Coroutine storage size, to be used with the storage APIs. */

/* These must be initialized only through `mco_init_desc`. */

size_t coro_size; /* Coroutine structure size. */

size_t stack_size; /* Coroutine stack size. */

} mco_desc;

/* Coroutine functions. */

MCO_API mco_desc mco_desc_init(void (*func)(mco_coro* co), size_t stack_size); /* Initialize description of a coroutine. When stack size is 0 then MCO_DEFAULT_STACK_SIZE is used. */

MCO_API mco_result mco_init(mco_coro* co, mco_desc* desc); /* Initialize the coroutine. */

MCO_API mco_result mco_uninit(mco_coro* co); /* Uninitialize the coroutine, may fail if it's not dead or suspended. */

MCO_API mco_result mco_create(mco_coro** out_co, mco_desc* desc); /* Allocates and initializes a new coroutine. */

MCO_API mco_result mco_destroy(mco_coro* co); /* Uninitialize and deallocate the coroutine, may fail if it's not dead or suspended. */

MCO_API mco_result mco_resume(mco_coro* co); /* Starts or continues the execution of the coroutine. */

MCO_API mco_result mco_yield(mco_coro* co); /* Suspends the execution of a coroutine. */

MCO_API mco_state mco_status(mco_coro* co); /* Returns the status of the coroutine. */

MCO_API void* mco_get_user_data(mco_coro* co); /* Get coroutine user data supplied on coroutine creation. */

/* Storage interface functions, used to pass values between yield and resume. */

MCO_API mco_result mco_push(mco_coro* co, const void* src, size_t len); /* Push bytes to the coroutine storage. Use to send values between yield and resume. */

MCO_API mco_result mco_pop(mco_coro* co, void* dest, size_t len); /* Pop bytes from the coroutine storage. Use to get values between yield and resume. */

MCO_API mco_result mco_peek(mco_coro* co, void* dest, size_t len); /* Like `mco_pop` but it does not consumes the storage. */

MCO_API size_t mco_get_bytes_stored(mco_coro* co); /* Get the available bytes that can be retrieved with a `mco_pop`. */

MCO_API size_t mco_get_storage_size(mco_coro* co); /* Get the total storage size. */

/* Misc functions. */

MCO_API mco_coro* mco_running(void); /* Returns the running coroutine for the current thread. */

MCO_API const char* mco_result_description(mco_result res); /* Get the description of a result. */

#ifdef __cplusplus

}

#endif

#endif /* MINICORO_H */

#ifdef MINICORO_IMPL

#ifdef __cplusplus

extern "C" {

#endif

#include <stdlib.h>

/* ---------------------------------------------------------------------------------------------- */

/* Minimum stack size when creating a coroutine. */

#ifndef MCO_MIN_STACK_SIZE

#define MCO_MIN_STACK_SIZE 32768

#endif

/* Default stack size when creating a coroutine. */

#ifndef MCO_DEFAULT_STACK_SIZE

/* Use multiples of 64KB minus 8KB, because 8KB is reserved for coroutine internal structures. */

#ifdef MCO_USE_VMEM_ALLOCATOR

#define MCO_DEFAULT_STACK_SIZE 2040*1024 /* 2040KB, nearly the same stack size of a thread in x86_64 Linux. */

#else

#define MCO_DEFAULT_STACK_SIZE 56*1024 /* 56KB */

#endif

#endif

/* Number used only to assist checking for stack overflows. */

#define MCO_MAGIC_NUMBER 0x7E3CB1A9

/* Detect implementation based on OS, arch and compiler. */

#if !defined(MCO_USE_UCONTEXT) && !defined(MCO_USE_FIBERS) && !defined(MCO_USE_ASM) && !defined(MCO_USE_ASYNCIFY)

#if defined(_WIN32)

#if (defined(__GNUC__) && defined(__x86_64__)) || (defined(_MSC_VER) && defined(_M_X64))

#define MCO_USE_ASM

#else

#define MCO_USE_FIBERS

#endif

#elif defined(__CYGWIN__) /* MSYS */

#define MCO_USE_UCONTEXT

#elif defined(__EMSCRIPTEN__)

#define MCO_USE_FIBERS

#elif defined(__wasm__)

#define MCO_USE_ASYNCIFY

#else

#if __GNUC__ >= 3 /* Assembly extension supported. */

#if defined(__x86_64__) || \

defined(__i386) || defined(__i386__) || \

defined(__ARM_EABI__) || defined(__aarch64__) || \

defined(__riscv)

#define MCO_USE_ASM

#else

#define MCO_USE_UCONTEXT

#endif

#else

#define MCO_USE_UCONTEXT

#endif

#endif

#endif

#define _MCO_UNUSED(x) (void)(x)

#if !defined(MCO_NO_DEBUG) && !defined(NDEBUG) && !defined(MCO_DEBUG)

#define MCO_DEBUG

#endif

#ifndef MCO_LOG

#ifdef MCO_DEBUG

#include <stdio.h>

#define MCO_LOG(s) puts(s)

#else

#define MCO_LOG(s)

#endif

#endif

#ifndef MCO_ASSERT

#ifdef MCO_DEBUG

#include <assert.h>

#define MCO_ASSERT(c) assert(c)

#else

#define MCO_ASSERT(c)

#endif

#endif

#ifndef MCO_THREAD_LOCAL

#ifdef MCO_NO_MULTITHREAD

#define MCO_THREAD_LOCAL

#else

#ifdef thread_local

#define MCO_THREAD_LOCAL thread_local

#elif __STDC_VERSION__ >= 201112 && !defined(__STDC_NO_THREADS__)

#define MCO_THREAD_LOCAL _Thread_local

#elif defined(_WIN32) && (defined(_MSC_VER) || defined(__ICL) || defined(__DMC__) || defined(__BORLANDC__))

#define MCO_THREAD_LOCAL __declspec(thread)

#elif defined(__GNUC__) || defined(__SUNPRO_C) || defined(__xlC__)

#define MCO_THREAD_LOCAL __thread

#else /* No thread local support, `mco_running` will be thread unsafe. */

#define MCO_THREAD_LOCAL

#define MCO_NO_MULTITHREAD

#endif

#endif

#endif

#ifndef MCO_FORCE_INLINE

#ifdef _MSC_VER

#define MCO_FORCE_INLINE __forceinline

#elif defined(__GNUC__)

#if defined(__STRICT_ANSI__)

#define MCO_FORCE_INLINE __inline__ __attribute__((always_inline))

#else

#define MCO_FORCE_INLINE inline __attribute__((always_inline))

#endif

#elif defined(__BORLANDC__) || defined(__DMC__) || defined(__SC__) || defined(__WATCOMC__) || defined(__LCC__) || defined(__DECC)

#define MCO_FORCE_INLINE __inline

#else /* No inline support. */

#define MCO_FORCE_INLINE

#endif

#endif

#ifndef MCO_NO_INLINE

#ifdef __GNUC__

#define MCO_NO_INLINE __attribute__((noinline))

#elif defined(_MSC_VER)

#define MCO_NO_INLINE __declspec(noinline)

#else

#define MCO_NO_INLINE

#endif

#endif

#if defined(_WIN32) && (defined(MCO_USE_FIBERS) || defined(MCO_USE_VMEM_ALLOCATOR))

#ifndef _WIN32_WINNT

#define _WIN32_WINNT 0x0400

#endif

#ifndef WIN32_LEAN_AND_MEAN

#define WIN32_LEAN_AND_MEAN

#endif

#include <windows.h>

#endif

#ifndef MCO_NO_DEFAULT_ALLOCATOR

#if defined(MCO_USE_VMEM_ALLOCATOR) && defined(_WIN32)

static void* mco_alloc(size_t size, void* allocator_data) {

_MCO_UNUSED(allocator_data);

return VirtualAlloc(NULL, size, MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);

}

static void mco_dealloc(void* ptr, size_t size, void* allocator_data) {

_MCO_UNUSED(allocator_data);

_MCO_UNUSED(size);

int res = VirtualFree(ptr, 0, MEM_RELEASE);

_MCO_UNUSED(res);

MCO_ASSERT(res != 0);

}

#elif defined(MCO_USE_VMEM_ALLOCATOR) /* POSIX virtual memory allocator */

#include <sys/mman.h>

static void* mco_alloc(size_t size, void* allocator_data) {

_MCO_UNUSED(allocator_data);

void *ptr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);

return ptr != MAP_FAILED ? ptr : NULL;

}

static void mco_dealloc(void* ptr, size_t size, void* allocator_data) {

_MCO_UNUSED(allocator_data);

int res = munmap(ptr, size);

_MCO_UNUSED(res);

MCO_ASSERT(res == 0);

}

#else /* C allocator */

#ifndef MCO_ALLOC

/* We use calloc() so we give a chance for the OS to reserve virtual memory without really using physical memory,

calloc() also has the nice property of initializing the stack to zeros. */

#define MCO_ALLOC(size) calloc(1, size)

#define MCO_DEALLOC(ptr, size) free(ptr)

#endif

static void* mco_alloc(size_t size, void* allocator_data) {

_MCO_UNUSED(allocator_data);

return MCO_ALLOC(size);

}

static void mco_dealloc(void* ptr, size_t size, void* allocator_data) {

_MCO_UNUSED(size);

_MCO_UNUSED(allocator_data);

MCO_DEALLOC(ptr, size);

}

#endif /* MCO_USE_VMEM_ALLOCATOR */

#endif /* MCO_NO_DEFAULT_ALLOCATOR */

#if defined(__has_feature)

#if __has_feature(address_sanitizer)

#define _MCO_USE_ASAN

#endif

#if __has_feature(thread_sanitizer)

#define _MCO_USE_TSAN

#endif

#endif

#if defined(__SANITIZE_ADDRESS__)

#define _MCO_USE_ASAN

#endif

#if defined(__SANITIZE_THREAD__)

#define _MCO_USE_TSAN

#endif

#ifdef _MCO_USE_ASAN

void __sanitizer_start_switch_fiber(void** fake_stack_save, const void *bottom, size_t size);

void __sanitizer_finish_switch_fiber(void* fake_stack_save, const void **bottom_old, size_t *size_old);

#endif

#ifdef _MCO_USE_TSAN

void* __tsan_get_current_fiber(void);

void* __tsan_create_fiber(unsigned flags);

void __tsan_destroy_fiber(void* fiber);

void __tsan_switch_to_fiber(void* fiber, unsigned flags);

#endif

#include <string.h> /* For memcpy and memset. */

/* Utility for aligning addresses. */

static MCO_FORCE_INLINE size_t _mco_align_forward(size_t addr, size_t align) {

return (addr + (align-1)) & ~(align-1);

}

/* Variable holding the current running coroutine per thread. */

static MCO_THREAD_LOCAL mco_coro* mco_current_co = NULL;

static MCO_FORCE_INLINE void _mco_prepare_jumpin(mco_coro* co) {

/* Set the old coroutine to normal state and update it. */

mco_coro* prev_co = mco_running(); /* Must access through `mco_running`. */

MCO_ASSERT(co->prev_co == NULL);

co->prev_co = prev_co;

if(prev_co) {

MCO_ASSERT(prev_co->state == MCO_RUNNING);

prev_co->state = MCO_NORMAL;

}

mco_current_co = co;

#ifdef _MCO_USE_ASAN

if(prev_co) {

void* bottom_old = NULL;

size_t size_old = 0;

__sanitizer_finish_switch_fiber(prev_co->asan_prev_stack, (const void**)&bottom_old, &size_old);

prev_co->asan_prev_stack = NULL;

}

__sanitizer_start_switch_fiber(&co->asan_prev_stack, co->stack_base, co->stack_size);

#endif

#ifdef _MCO_USE_TSAN

co->tsan_prev_fiber = __tsan_get_current_fiber();

__tsan_switch_to_fiber(co->tsan_fiber, 0);

#endif

}

static MCO_FORCE_INLINE void _mco_prepare_jumpout(mco_coro* co) {

/* Switch back to the previous running coroutine. */

/* MCO_ASSERT(mco_running() == co); */

mco_coro* prev_co = co->prev_co;

co->prev_co = NULL;

if(prev_co) {

/* MCO_ASSERT(prev_co->state == MCO_NORMAL); */

prev_co->state = MCO_RUNNING;

}

mco_current_co = prev_co;

#ifdef _MCO_USE_ASAN

void* bottom_old = NULL;

size_t size_old = 0;

__sanitizer_finish_switch_fiber(co->asan_prev_stack, (const void**)&bottom_old, &size_old);

co->asan_prev_stack = NULL;

if(prev_co) {

__sanitizer_start_switch_fiber(&prev_co->asan_prev_stack, bottom_old, size_old);

}

#endif

#ifdef _MCO_USE_TSAN

void* tsan_prev_fiber = co->tsan_prev_fiber;

co->tsan_prev_fiber = NULL;

__tsan_switch_to_fiber(tsan_prev_fiber, 0);

#endif

}

static void _mco_jumpin(mco_coro* co);

static void _mco_jumpout(mco_coro* co);

static MCO_NO_INLINE void _mco_main(mco_coro* co) {

co->func(co); /* Run the coroutine function. */

co->state = MCO_DEAD; /* Coroutine finished successfully, set state to dead. */

_mco_jumpout(co); /* Jump back to the old context .*/

}

/* ---------------------------------------------------------------------------------------------- */

#if defined(MCO_USE_UCONTEXT) || defined(MCO_USE_ASM)

/*

Some of the following assembly code is taken from LuaCoco by Mike Pall.

See https://coco.luajit.org/index.html

MIT license

Copyright (C) 2004-2016 Mike Pall. All rights reserved.

Permission is hereby granted, free of charge, to any person obtaining

a copy of this software and associated documentation files (the

"Software"), to deal in the Software without restriction, including

without limitation the rights to use, copy, modify, merge, publish,

distribute, sublicense, and/or sell copies of the Software, and to

permit persons to whom the Software is furnished to do so, subject to

the following conditions:

The above copyright notice and this permission notice shall be

included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.

IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY

CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,

TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE

SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

*/

#ifdef MCO_USE_ASM

#if defined(__x86_64__) || defined(_M_X64)

#ifdef _WIN32

typedef struct _mco_ctxbuf {

void *rip, *rsp, *rbp, *rbx, *r12, *r13, *r14, *r15, *rdi, *rsi;

void* xmm[20]; /* xmm6, xmm7, xmm8, xmm9, xmm10, xmm11, xmm12, xmm13, xmm14, xmm15 */

void* fiber_storage;

void* dealloc_stack;

void* stack_limit;

void* stack_base;

} _mco_ctxbuf;

#if defined(__GNUC__)

#define _MCO_ASM_BLOB __attribute__((section(".text")))

#elif defined(_MSC_VER)

#define _MCO_ASM_BLOB __declspec(allocate(".text"))

#pragma section(".text")

#endif

_MCO_ASM_BLOB static unsigned char _mco_wrap_main_code[] = {

0x4c, 0x89, 0xe9, /* mov %r13,%rcx */

0x41, 0xff, 0xe4, /* jmpq *%r12 */

0xc3, /* retq */

0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90 /* nop */

};

_MCO_ASM_BLOB static unsigned char _mco_switch_code[] = {

0x48, 0x8d, 0x05, 0x3e, 0x01, 0x00, 0x00, /* lea 0x13e(%rip),%rax */

0x48, 0x89, 0x01, /* mov %rax,(%rcx) */

0x48, 0x89, 0x61, 0x08, /* mov %rsp,0x8(%rcx) */

0x48, 0x89, 0x69, 0x10, /* mov %rbp,0x10(%rcx) */

0x48, 0x89, 0x59, 0x18, /* mov %rbx,0x18(%rcx) */

0x4c, 0x89, 0x61, 0x20, /* mov %r12,0x20(%rcx) */

0x4c, 0x89, 0x69, 0x28, /* mov %r13,0x28(%rcx) */

0x4c, 0x89, 0x71, 0x30, /* mov %r14,0x30(%rcx) */

0x4c, 0x89, 0x79, 0x38, /* mov %r15,0x38(%rcx) */

0x48, 0x89, 0x79, 0x40, /* mov %rdi,0x40(%rcx) */

0x48, 0x89, 0x71, 0x48, /* mov %rsi,0x48(%rcx) */

0x0f, 0x11, 0x71, 0x50, /* movups %xmm6,0x50(%rcx) */

0x0f, 0x11, 0x79, 0x60, /* movups %xmm7,0x60(%rcx) */

0x44, 0x0f, 0x11, 0x41, 0x70, /* movups %xmm8,0x70(%rcx) */

0x44, 0x0f, 0x11, 0x89, 0x80, 0x00, 0x00, 0x00, /* movups %xmm9,0x80(%rcx) */

0x44, 0x0f, 0x11, 0x91, 0x90, 0x00, 0x00, 0x00, /* movups %xmm10,0x90(%rcx) */

0x44, 0x0f, 0x11, 0x99, 0xa0, 0x00, 0x00, 0x00, /* movups %xmm11,0xa0(%rcx) */

0x44, 0x0f, 0x11, 0xa1, 0xb0, 0x00, 0x00, 0x00, /* movups %xmm12,0xb0(%rcx) */

0x44, 0x0f, 0x11, 0xa9, 0xc0, 0x00, 0x00, 0x00, /* movups %xmm13,0xc0(%rcx) */

0x44, 0x0f, 0x11, 0xb1, 0xd0, 0x00, 0x00, 0x00, /* movups %xmm14,0xd0(%rcx) */

0x44, 0x0f, 0x11, 0xb9, 0xe0, 0x00, 0x00, 0x00, /* movups %xmm15,0xe0(%rcx) */

0x65, 0x4c, 0x8b, 0x14, 0x25, 0x30, 0x00, 0x00, 0x00, /* mov %gs:0x30,%r10 */

0x49, 0x8b, 0x42, 0x20, /* mov 0x20(%r10),%rax */

0x48, 0x89, 0x81, 0xf0, 0x00, 0x00, 0x00, /* mov %rax,0xf0(%rcx) */

0x49, 0x8b, 0x82, 0x78, 0x14, 0x00, 0x00, /* mov 0x1478(%r10),%rax */

0x48, 0x89, 0x81, 0xf8, 0x00, 0x00, 0x00, /* mov %rax,0xf8(%rcx) */

0x49, 0x8b, 0x42, 0x10, /* mov 0x10(%r10),%rax */

0x48, 0x89, 0x81, 0x00, 0x01, 0x00, 0x00, /* mov %rax,0x100(%rcx) */

0x49, 0x8b, 0x42, 0x08, /* mov 0x8(%r10),%rax */

0x48, 0x89, 0x81, 0x08, 0x01, 0x00, 0x00, /* mov %rax,0x108(%rcx) */

0x48, 0x8b, 0x82, 0x08, 0x01, 0x00, 0x00, /* mov 0x108(%rdx),%rax */

0x49, 0x89, 0x42, 0x08, /* mov %rax,0x8(%r10) */

0x48, 0x8b, 0x82, 0x00, 0x01, 0x00, 0x00, /* mov 0x100(%rdx),%rax */

0x49, 0x89, 0x42, 0x10, /* mov %rax,0x10(%r10) */

0x48, 0x8b, 0x82, 0xf8, 0x00, 0x00, 0x00, /* mov 0xf8(%rdx),%rax */

0x49, 0x89, 0x82, 0x78, 0x14, 0x00, 0x00, /* mov %rax,0x1478(%r10) */

0x48, 0x8b, 0x82, 0xf0, 0x00, 0x00, 0x00, /* mov 0xf0(%rdx),%rax */

0x49, 0x89, 0x42, 0x20, /* mov %rax,0x20(%r10) */

0x44, 0x0f, 0x10, 0xba, 0xe0, 0x00, 0x00, 0x00, /* movups 0xe0(%rdx),%xmm15 */

0x44, 0x0f, 0x10, 0xb2, 0xd0, 0x00, 0x00, 0x00, /* movups 0xd0(%rdx),%xmm14 */

0x44, 0x0f, 0x10, 0xaa, 0xc0, 0x00, 0x00, 0x00, /* movups 0xc0(%rdx),%xmm13 */

0x44, 0x0f, 0x10, 0xa2, 0xb0, 0x00, 0x00, 0x00, /* movups 0xb0(%rdx),%xmm12 */

0x44, 0x0f, 0x10, 0x9a, 0xa0, 0x00, 0x00, 0x00, /* movups 0xa0(%rdx),%xmm11 */

0x44, 0x0f, 0x10, 0x92, 0x90, 0x00, 0x00, 0x00, /* movups 0x90(%rdx),%xmm10 */

0x44, 0x0f, 0x10, 0x8a, 0x80, 0x00, 0x00, 0x00, /* movups 0x80(%rdx),%xmm9 */

0x44, 0x0f, 0x10, 0x42, 0x70, /* movups 0x70(%rdx),%xmm8 */

0x0f, 0x10, 0x7a, 0x60, /* movups 0x60(%rdx),%xmm7 */

0x0f, 0x10, 0x72, 0x50, /* movups 0x50(%rdx),%xmm6 */

0x48, 0x8b, 0x72, 0x48, /* mov 0x48(%rdx),%rsi */

0x48, 0x8b, 0x7a, 0x40, /* mov 0x40(%rdx),%rdi */

0x4c, 0x8b, 0x7a, 0x38, /* mov 0x38(%rdx),%r15 */

0x4c, 0x8b, 0x72, 0x30, /* mov 0x30(%rdx),%r14 */

0x4c, 0x8b, 0x6a, 0x28, /* mov 0x28(%rdx),%r13 */

0x4c, 0x8b, 0x62, 0x20, /* mov 0x20(%rdx),%r12 */

0x48, 0x8b, 0x5a, 0x18, /* mov 0x18(%rdx),%rbx */

0x48, 0x8b, 0x6a, 0x10, /* mov 0x10(%rdx),%rbp */

0x48, 0x8b, 0x62, 0x08, /* mov 0x8(%rdx),%rsp */

0xff, 0x22, /* jmpq *(%rdx) */

0xc3, /* retq */

0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, /* nop */

0x90, 0x90, /* nop */

};

void (*_mco_wrap_main)(void) = (void(*)(void))(void*)_mco_wrap_main_code;

void (*_mco_switch)(_mco_ctxbuf* from, _mco_ctxbuf* to) = (void(*)(_mco_ctxbuf* from, _mco_ctxbuf* to))(void*)_mco_switch_code;

static mco_result _mco_makectx(mco_coro* co, _mco_ctxbuf* ctx, void* stack_base, size_t stack_size) {

stack_size = stack_size - 32; /* Reserve 32 bytes for the shadow space. */

void** stack_high_ptr = (void**)((size_t)stack_base + stack_size - sizeof(size_t));

stack_high_ptr[0] = (void*)(0xdeaddeaddeaddead); /* Dummy return address. */

ctx->rip = (void*)(_mco_wrap_main);

ctx->rsp = (void*)(stack_high_ptr);

ctx->r12 = (void*)(_mco_main);

ctx->r13 = (void*)(co);

void* stack_top = (void*)((size_t)stack_base + stack_size);

ctx->stack_base = stack_top;

ctx->stack_limit = stack_base;

ctx->dealloc_stack = stack_base;

return MCO_SUCCESS;

}

#else /* not _WIN32 */

typedef struct _mco_ctxbuf {

void *rip, *rsp, *rbp, *rbx, *r12, *r13, *r14, *r15;

} _mco_ctxbuf;

void _mco_wrap_main(void);

int _mco_switch(_mco_ctxbuf* from, _mco_ctxbuf* to);

__asm__(

".text\n"

#ifdef __MACH__ /* Mac OS X assembler */

".globl __mco_wrap_main\n"

"__mco_wrap_main:\n"

#else /* Linux assembler */

".globl _mco_wrap_main\n"

".type _mco_wrap_main @function\n"

".hidden _mco_wrap_main\n"

"_mco_wrap_main:\n"

#endif

" movq %r13, %rdi\n"

" jmpq *%r12\n"

#ifndef __MACH__

".size _mco_wrap_main, .-_mco_wrap_main\n"

#endif

);

__asm__(

".text\n"

#ifdef __MACH__ /* Mac OS assembler */

".globl __mco_switch\n"

"__mco_switch:\n"

#else /* Linux assembler */

".globl _mco_switch\n"

".type _mco_switch @function\n"

".hidden _mco_switch\n"

"_mco_switch:\n"

#endif

" leaq 0x3d(%rip), %rax\n"

" movq %rax, (%rdi)\n"

" movq %rsp, 8(%rdi)\n"

" movq %rbp, 16(%rdi)\n"

" movq %rbx, 24(%rdi)\n"

" movq %r12, 32(%rdi)\n"

" movq %r13, 40(%rdi)\n"

" movq %r14, 48(%rdi)\n"

" movq %r15, 56(%rdi)\n"

" movq 56(%rsi), %r15\n"

" movq 48(%rsi), %r14\n"

" movq 40(%rsi), %r13\n"

" movq 32(%rsi), %r12\n"

" movq 24(%rsi), %rbx\n"

" movq 16(%rsi), %rbp\n"

" movq 8(%rsi), %rsp\n"

" jmpq *(%rsi)\n"

" ret\n"

#ifndef __MACH__

".size _mco_switch, .-_mco_switch\n"

#endif

);

static mco_result _mco_makectx(mco_coro* co, _mco_ctxbuf* ctx, void* stack_base, size_t stack_size) {

stack_size = stack_size - 128; /* Reserve 128 bytes for the Red Zone space (System V AMD64 ABI). */

void** stack_high_ptr = (void**)((size_t)stack_base + stack_size - sizeof(size_t));

stack_high_ptr[0] = (void*)(0xdeaddeaddeaddead); /* Dummy return address. */

ctx->rip = (void*)(_mco_wrap_main);

ctx->rsp = (void*)(stack_high_ptr);

ctx->r12 = (void*)(_mco_main);

ctx->r13 = (void*)(co);

return MCO_SUCCESS;

}

#endif /* not _WIN32 */

#elif defined(__riscv)

typedef struct _mco_ctxbuf {

void* s[12]; /* s0-s11 */

void* ra;

void* pc;

void* sp;

#ifdef __riscv_flen

#if __riscv_flen == 64

double fs[12]; /* fs0-fs11 */

#elif __riscv_flen == 32

float fs[12]; /* fs0-fs11 */

#endif

#endif /* __riscv_flen */

} _mco_ctxbuf;

void _mco_wrap_main(void);

int _mco_switch(_mco_ctxbuf* from, _mco_ctxbuf* to);

__asm__(

".text\n"

".globl _mco_wrap_main\n"

".type _mco_wrap_main @function\n"

".hidden _mco_wrap_main\n"

"_mco_wrap_main:\n"

" mv a0, s0\n"

" jr s1\n"

".size _mco_wrap_main, .-_mco_wrap_main\n"

);

__asm__(

".text\n"

".globl _mco_switch\n"

".type _mco_switch @function\n"

".hidden _mco_switch\n"

"_mco_switch:\n"

#if __riscv_xlen == 64

" sd s0, 0x00(a0)\n"

" sd s1, 0x08(a0)\n"

" sd s2, 0x10(a0)\n"

" sd s3, 0x18(a0)\n"

" sd s4, 0x20(a0)\n"

" sd s5, 0x28(a0)\n"

" sd s6, 0x30(a0)\n"

" sd s7, 0x38(a0)\n"

" sd s8, 0x40(a0)\n"

" sd s9, 0x48(a0)\n"

" sd s10, 0x50(a0)\n"

" sd s11, 0x58(a0)\n"

" sd ra, 0x60(a0)\n"

" sd ra, 0x68(a0)\n" /* pc */

" sd sp, 0x70(a0)\n"

#ifdef __riscv_flen

#if __riscv_flen == 64

" fsd fs0, 0x78(a0)\n"

" fsd fs1, 0x80(a0)\n"

" fsd fs2, 0x88(a0)\n"

" fsd fs3, 0x90(a0)\n"

" fsd fs4, 0x98(a0)\n"

" fsd fs5, 0xa0(a0)\n"

" fsd fs6, 0xa8(a0)\n"

" fsd fs7, 0xb0(a0)\n"

" fsd fs8, 0xb8(a0)\n"

" fsd fs9, 0xc0(a0)\n"

" fsd fs10, 0xc8(a0)\n"

" fsd fs11, 0xd0(a0)\n"

" fld fs0, 0x78(a1)\n"

" fld fs1, 0x80(a1)\n"

" fld fs2, 0x88(a1)\n"

" fld fs3, 0x90(a1)\n"

" fld fs4, 0x98(a1)\n"

" fld fs5, 0xa0(a1)\n"

" fld fs6, 0xa8(a1)\n"

" fld fs7, 0xb0(a1)\n"

" fld fs8, 0xb8(a1)\n"

" fld fs9, 0xc0(a1)\n"

" fld fs10, 0xc8(a1)\n"

" fld fs11, 0xd0(a1)\n"

#else

#error "Unsupported RISC-V FLEN"

#endif

#endif /* __riscv_flen */

" ld s0, 0x00(a1)\n"

" ld s1, 0x08(a1)\n"

" ld s2, 0x10(a1)\n"

" ld s3, 0x18(a1)\n"

" ld s4, 0x20(a1)\n"

" ld s5, 0x28(a1)\n"

" ld s6, 0x30(a1)\n"

" ld s7, 0x38(a1)\n"

" ld s8, 0x40(a1)\n"

" ld s9, 0x48(a1)\n"

" ld s10, 0x50(a1)\n"

" ld s11, 0x58(a1)\n"

" ld ra, 0x60(a1)\n"

" ld a2, 0x68(a1)\n" /* pc */

" ld sp, 0x70(a1)\n"

" jr a2\n"

#elif __riscv_xlen == 32

" sw s0, 0x00(a0)\n"

" sw s1, 0x04(a0)\n"

" sw s2, 0x08(a0)\n"

" sw s3, 0x0c(a0)\n"

" sw s4, 0x10(a0)\n"

" sw s5, 0x14(a0)\n"

" sw s6, 0x18(a0)\n"

" sw s7, 0x1c(a0)\n"

" sw s8, 0x20(a0)\n"

" sw s9, 0x24(a0)\n"

" sw s10, 0x28(a0)\n"

" sw s11, 0x2c(a0)\n"

" sw ra, 0x30(a0)\n"

" sw ra, 0x34(a0)\n" /* pc */

" sw sp, 0x38(a0)\n"

#ifdef __riscv_flen

#if __riscv_flen == 64

" fsd fs0, 0x3c(a0)\n"

" fsd fs1, 0x44(a0)\n"

" fsd fs2, 0x4c(a0)\n"

" fsd fs3, 0x54(a0)\n"

" fsd fs4, 0x5c(a0)\n"

" fsd fs5, 0x64(a0)\n"

" fsd fs6, 0x6c(a0)\n"

" fsd fs7, 0x74(a0)\n"

" fsd fs8, 0x7c(a0)\n"

" fsd fs9, 0x84(a0)\n"

" fsd fs10, 0x8c(a0)\n"

" fsd fs11, 0x94(a0)\n"

" fld fs0, 0x3c(a1)\n"

" fld fs1, 0x44(a1)\n"

" fld fs2, 0x4c(a1)\n"

" fld fs3, 0x54(a1)\n"

" fld fs4, 0x5c(a1)\n"

" fld fs5, 0x64(a1)\n"

" fld fs6, 0x6c(a1)\n"

" fld fs7, 0x74(a1)\n"

" fld fs8, 0x7c(a1)\n"

" fld fs9, 0x84(a1)\n"

" fld fs10, 0x8c(a1)\n"

" fld fs11, 0x94(a1)\n"

#elif __riscv_flen == 32

" fsw fs0, 0x3c(a0)\n"

" fsw fs1, 0x40(a0)\n"

" fsw fs2, 0x44(a0)\n"

" fsw fs3, 0x48(a0)\n"

" fsw fs4, 0x4c(a0)\n"

" fsw fs5, 0x50(a0)\n"

" fsw fs6, 0x54(a0)\n"

" fsw fs7, 0x58(a0)\n"

" fsw fs8, 0x5c(a0)\n"

" fsw fs9, 0x60(a0)\n"

" fsw fs10, 0x64(a0)\n"

" fsw fs11, 0x68(a0)\n"

" flw fs0, 0x3c(a1)\n"

" flw fs1, 0x40(a1)\n"