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/* |
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* Copyright (c) 2001-2012 Marc Alexander Lehmann <schmorp@schmorp.de> |
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* |
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* Redistribution and use in source and binary forms, with or without modifica- |
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* tion, are permitted provided that the following conditions are met: |
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* |
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* 1. Redistributions of source code must retain the above copyright notice, |
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* this list of conditions and the following disclaimer. |
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* |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in the |
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* documentation and/or other materials provided with the distribution. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED |
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* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER- |
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* CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO |
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* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE- |
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* CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; |
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* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH- |
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* ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED |
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* OF THE POSSIBILITY OF SUCH DAMAGE. |
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* |
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* Alternatively, the contents of this file may be used under the terms of |
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* the GNU General Public License ("GPL") version 2 or any later version, |
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* in which case the provisions of the GPL are applicable instead of |
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* the above. If you wish to allow the use of your version of this file |
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* only under the terms of the GPL and not to allow others to use your |
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* version of this file under the BSD license, indicate your decision |
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* by deleting the provisions above and replace them with the notice |
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* and other provisions required by the GPL. If you do not delete the |
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* provisions above, a recipient may use your version of this file under |
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* either the BSD or the GPL. |
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* |
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* This library is modelled strictly after Ralf S. Engelschalls article at |
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* http://www.gnu.org/software/pth/rse-pmt.ps. So most of the credit must |
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* go to Ralf S. Engelschall <rse@engelschall.com>. |
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* |
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* This coroutine library is very much stripped down. You should either |
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* build your own process abstraction using it or - better - just use GNU |
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* Portable Threads, http://www.gnu.org/software/pth/. |
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* |
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*/ |
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|
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/* |
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* 2006-10-26 Include stddef.h on OS X to work around one of its bugs. |
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* Reported by Michael_G_Schwern. |
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* 2006-11-26 Use _setjmp instead of setjmp on GNU/Linux. |
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* 2007-04-27 Set unwind frame info if gcc 3+ and ELF is detected. |
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* Use _setjmp instead of setjmp on _XOPEN_SOURCE >= 600. |
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* 2007-05-02 Add assembly versions for x86 and amd64 (to avoid reliance |
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* on SIGUSR2 and sigaltstack in Crossfire). |
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* 2008-01-21 Disable CFI usage on anything but GNU/Linux. |
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* 2008-03-02 Switched to 2-clause BSD license with GPL exception. |
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* 2008-04-04 New (but highly unrecommended) pthreads backend. |
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* 2008-04-24 Reinstate CORO_LOSER (had wrong stack adjustments). |
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* 2008-10-30 Support assembly method on x86 with and without frame pointer. |
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* 2008-11-03 Use a global asm statement for CORO_ASM, idea by pippijn. |
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* 2008-11-05 Hopefully fix misaligned stacks with CORO_ASM/SETJMP. |
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* 2008-11-07 rbp wasn't saved in CORO_ASM on x86_64. |
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* introduce coro_destroy, which is a nop except for pthreads. |
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* speed up CORO_PTHREAD. Do no longer leak threads either. |
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* coro_create now allows one to create source coro_contexts. |
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* do not rely on makecontext passing a void * correctly. |
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* try harder to get _setjmp/_longjmp. |
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* major code cleanup/restructuring. |
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* 2008-11-10 the .cfi hacks are no longer needed. |
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* 2008-11-16 work around a freebsd pthread bug. |
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* 2008-11-19 define coro_*jmp symbols for easier porting. |
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* 2009-06-23 tentative win32-backend support for mingw32 (Yasuhiro Matsumoto). |
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* 2010-12-03 tentative support for uclibc (which lacks all sorts of things). |
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* 2011-05-30 set initial callee-saved-registers to zero with CORO_ASM. |
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* use .cfi_undefined rip on linux-amd64 for better backtraces. |
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* 2011-06-08 maybe properly implement weird windows amd64 calling conventions. |
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* 2011-07-03 rely on __GCC_HAVE_DWARF2_CFI_ASM for cfi detection. |
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* 2011-08-08 cygwin trashes stacks, use pthreads with double stack on cygwin. |
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* 2012-12-04 reduce misprediction penalty for x86/amd64 assembly switcher. |
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* 2012-12-05 experimental fiber backend (allocates stack twice). |
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* 2012-12-07 API version 3 - add coro_stack_alloc/coro_stack_free. |
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*/ |
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|
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#ifndef CORO_H |
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#define CORO_H |
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|
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#if __cplusplus |
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extern "C" { |
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#endif |
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|
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/* |
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* This library consists of only three files |
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* coro.h, coro.c and LICENSE (and optionally README) |
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* |
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* It implements what is known as coroutines, in a hopefully |
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* portable way. |
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* |
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* All compiletime symbols must be defined both when including coro.h |
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* (using libcoro) as well as when compiling coro.c (the implementation). |
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* |
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* You can manually specify which flavour you want. If you don't define |
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* any of these, libcoro tries to choose a safe and fast default: |
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* |
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* -DCORO_UCONTEXT |
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* |
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* This flavour uses SUSv2's get/set/swap/makecontext functions that |
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* unfortunately only some unices support, and is quite slow. |
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* |
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* -DCORO_SJLJ |
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* |
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* This flavour uses SUSv2's setjmp/longjmp and sigaltstack functions to |
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* do it's job. Coroutine creation is much slower than UCONTEXT, but |
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* context switching is a bit cheaper. It should work on almost all unices. |
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* |
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* -DCORO_LINUX |
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* |
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* CORO_SJLJ variant. |
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* Old GNU/Linux systems (<= glibc-2.1) only work with this implementation |
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* (it is very fast and therefore recommended over other methods, but |
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* doesn't work with anything newer). |
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* |
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* -DCORO_LOSER |
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* |
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* CORO_SJLJ variant. |
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* Microsoft's highly proprietary platform doesn't support sigaltstack, and |
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* this selects a suitable workaround for this platform. It might not work |
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* with your compiler though - it has only been tested with MSVC 6. |
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* |
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* -DCORO_FIBER |
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* |
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* Slower, but probably more portable variant for the Microsoft operating |
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* system, using fibers. Ignores the passed stack and allocates it internally. |
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* Also, due to bugs in cygwin, this does not work with cygwin. |
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* |
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* -DCORO_IRIX |
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* |
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* CORO_SJLJ variant. |
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* For SGI's version of Microsoft's NT ;) |
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* |
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* -DCORO_ASM |
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* |
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* Hand coded assembly, known to work only on a few architectures/ABI: |
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* GCC + x86/IA32 and amd64/x86_64 + GNU/Linux and a few BSDs. Fastest choice, |
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* if it works. |
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* |
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* -DCORO_PTHREAD |
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* |
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* Use the pthread API. You have to provide <pthread.h> and -lpthread. |
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* This is likely the slowest backend, and it also does not support fork(), |
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* so avoid it at all costs. |
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* |
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* If you define neither of these symbols, coro.h will try to autodetect |
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* the best/safest model. To help with the autodetection, you should check |
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* (e.g. using autoconf) and define the following symbols: HAVE_UCONTEXT_H |
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* / HAVE_SETJMP_H / HAVE_SIGALTSTACK. |
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*/ |
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|
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/* |
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* Changes when the API changes incompatibly. |
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* This is ONLY the API version - there is no ABI compatibility between releases. |
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* |
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* Changes in API version 2: |
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* replaced bogus -DCORO_LOOSE with grammatically more correct -DCORO_LOSER |
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* Changes in API version 3: |
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* introduced stack management (CORO_STACKALLOC) |
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*/ |
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#define CORO_VERSION 3 |
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|
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#include <stddef.h> |
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|
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/* |
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* This is the type for the initialization function of a new coroutine. |
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*/ |
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typedef void (*coro_func)(void *); |
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|
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/* |
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* A coroutine state is saved in the following structure. Treat it as an |
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* opaque type. errno and sigmask might be saved, but don't rely on it, |
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* implement your own switching primitive if you need that. |
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*/ |
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typedef struct coro_context coro_context; |
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|
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/* |
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* This function creates a new coroutine. Apart from a pointer to an |
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* uninitialised coro_context, it expects a pointer to the entry function |
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* and the single pointer value that is given to it as argument. |
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* |
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* Allocating/deallocating the stack is your own responsibility. |
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* |
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* As a special case, if coro, arg, sptr and ssze are all zero, |
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* then an "empty" coro_context will be created that is suitable |
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* as an initial source for coro_transfer. |
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* |
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* This function is not reentrant, but putting a mutex around it |
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* will work. |
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*/ |
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void coro_create (coro_context *ctx, /* an uninitialised coro_context */ |
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coro_func coro, /* the coroutine code to be executed */ |
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void *arg, /* a single pointer passed to the coro */ |
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void *sptr, /* start of stack area */ |
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size_t ssze); /* size of stack area in bytes */ |
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|
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/* |
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* The following prototype defines the coroutine switching function. It is |
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* sometimes implemented as a macro, so watch out. |
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* |
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* This function is thread-safe and reentrant. |
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*/ |
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#if 0 |
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void coro_transfer (coro_context *prev, coro_context *next); |
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#endif |
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|
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/* |
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* The following prototype defines the coroutine destroy function. It |
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* is sometimes implemented as a macro, so watch out. It also serves no |
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* purpose unless you want to use the CORO_PTHREAD backend, where it is |
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* used to clean up the thread. You are responsible for freeing the stack |
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* and the context itself. |
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* |
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* This function is thread-safe and reentrant. |
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*/ |
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#if 0 |
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void coro_destroy (coro_context *ctx); |
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#endif |
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|
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/*****************************************************************************/ |
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/* optional stack management */ |
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/*****************************************************************************/ |
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/* |
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* You can disable all of the stack management functions by |
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* defining CORO_STACKALLOC to 0. Otherwise, they are enabled by default. |
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* |
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* If stack management is enabled, you can influence the implementation via these |
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* symbols: |
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* |
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* -DCORO_USE_VALGRIND |
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* |
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* If defined, then libcoro will include valgrind/valgrind.h and register |
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* and unregister stacks with valgrind. |
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* |
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* -DCORO_GUARDPAGES=n |
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* |
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* libcoro will try to use the specified number of guard pages to protect against |
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* stack overflow. If n is 0, then the feature will be disabled. If it isn't |
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* defined, then libcoro will choose a suitable default. If guardpages are not |
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* supported on the platform, then the feature will be silently disabled. |
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*/ |
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#ifndef CORO_STACKALLOC |
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# define CORO_STACKALLOC 1 |
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#endif |
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|
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#if CORO_STACKALLOC |
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|
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/* |
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* The only allowed operations on these struct members is to read the |
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* "sptr" and "ssze" members to pass it to coro_create, to read the "sptr" |
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* member to see if it is false, in which case the stack isn't allocated, |
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* and to set the "sptr" member to 0, to indicate to coro_stack_free to |
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* not actually do anything. |
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*/ |
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|
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struct coro_stack |
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{ |
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void *sptr; |
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size_t ssze; |
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#if CORO_USE_VALGRIND |
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int valgrind_id; |
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#endif |
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}; |
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|
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/* |
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* Try to allocate a stack of at least the given size and return true if |
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* successful, or false otherwise. |
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* |
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* The size is *NOT* specified in bytes, but in units of sizeof (void *), |
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* i.e. the stack is typically 4(8) times larger on 32 bit(64 bit) platforms |
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* then the size passed in. |
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* |
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* If size is 0, then a "suitable" stack size is chosen (usually 1-2MB). |
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*/ |
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int coro_stack_alloc (struct coro_stack *stack, unsigned int size); |
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|
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/* |
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* Free the stack allocated by coro_stack_alloc again. It is safe to |
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* call this function on the coro_stack structure even if coro_stack_alloc |
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* failed. |
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*/ |
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void coro_stack_free (struct coro_stack *stack); |
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|
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#endif |
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|
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/* |
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* That was it. No other user-serviceable parts below here. |
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*/ |
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|
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/*****************************************************************************/ |
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|
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#if !defined CORO_LOSER && !defined CORO_UCONTEXT \ |
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&& !defined CORO_SJLJ && !defined CORO_LINUX \ |
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&& !defined CORO_IRIX && !defined CORO_ASM \ |
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&& !defined CORO_PTHREAD && !defined CORO_FIBER |
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# if defined WINDOWS && (defined __i386 || (__x86_64 || defined _M_IX86 || defined _M_AMD64) |
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# define CORO_ASM 1 |
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# elif defined WINDOWS || defined _WIN32 |
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# define CORO_LOSER 1 /* you don't win with windoze */ |
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# elif __linux && (__i386 || (__x86_64 && !__ILP32)) |
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# define CORO_ASM 1 |
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# elif defined HAVE_UCONTEXT_H |
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# define CORO_UCONTEXT 1 |
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# elif defined HAVE_SETJMP_H && defined HAVE_SIGALTSTACK |
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# define CORO_SJLJ 1 |
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# else |
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error unknown or unsupported architecture |
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# endif |
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#endif |
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|
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/*****************************************************************************/ |
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|
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#if CORO_UCONTEXT |
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|
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# include <ucontext.h> |
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|
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struct coro_context |
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{ |
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ucontext_t uc; |
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}; |
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|
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# define coro_transfer(p,n) swapcontext (&((p)->uc), &((n)->uc)) |
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# define coro_destroy(ctx) (void *)(ctx) |
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|
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#elif CORO_SJLJ || CORO_LOSER || CORO_LINUX || CORO_IRIX |
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|
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# if defined(CORO_LINUX) && !defined(_GNU_SOURCE) |
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# define _GNU_SOURCE /* for glibc */ |
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# endif |
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|
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# if !CORO_LOSER |
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# include <unistd.h> |
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# endif |
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|
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/* solaris is hopelessly borked, it expands _XOPEN_UNIX to nothing */ |
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# if __sun |
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# undef _XOPEN_UNIX |
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# define _XOPEN_UNIX 1 |
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# endif |
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|
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# include <setjmp.h> |
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|
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# if _XOPEN_UNIX > 0 || defined (_setjmp) |
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# define coro_jmp_buf jmp_buf |
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# define coro_setjmp(env) _setjmp (env) |
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# define coro_longjmp(env) _longjmp ((env), 1) |
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# elif CORO_LOSER |
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# define coro_jmp_buf jmp_buf |
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# define coro_setjmp(env) setjmp (env) |
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# define coro_longjmp(env) longjmp ((env), 1) |
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# else |
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# define coro_jmp_buf sigjmp_buf |
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# define coro_setjmp(env) sigsetjmp (env, 0) |
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# define coro_longjmp(env) siglongjmp ((env), 1) |
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# endif |
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|
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struct coro_context |
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{ |
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coro_jmp_buf env; |
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}; |
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|
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# define coro_transfer(p,n) do { if (!coro_setjmp ((p)->env)) coro_longjmp ((n)->env); } while (0) |
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# define coro_destroy(ctx) (void *)(ctx) |
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|
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#elif CORO_ASM |
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|
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struct coro_context |
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{ |
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void **sp; /* must be at offset 0 */ |
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}; |
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|
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void __attribute__ ((__noinline__, __regparm__(2))) |
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coro_transfer (coro_context *prev, coro_context *next); |
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|
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# define coro_destroy(ctx) (void *)(ctx) |
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|
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#elif CORO_PTHREAD |
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|
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# include <pthread.h> |
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|
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extern pthread_mutex_t coro_mutex; |
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|
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struct coro_context |
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{ |
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pthread_cond_t cv; |
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pthread_t id; |
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}; |
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|
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void coro_transfer (coro_context *prev, coro_context *next); |
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void coro_destroy (coro_context *ctx); |
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|
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#elif CORO_FIBER |
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|
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struct coro_context |
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{ |
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void *fiber; |
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/* only used for initialisation */ |
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coro_func coro; |
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void *arg; |
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}; |
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|
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void coro_transfer (coro_context *prev, coro_context *next); |
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void coro_destroy (coro_context *ctx); |
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|
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#endif |
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|
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#if __cplusplus |
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} |
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#endif |
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|
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#endif |
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|