diff options
Diffstat (limited to 'trunk/src/lib/cothread/x86.c')
-rw-r--r-- | trunk/src/lib/cothread/x86.c | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/trunk/src/lib/cothread/x86.c b/trunk/src/lib/cothread/x86.c new file mode 100644 index 00000000000..2d083995b3d --- /dev/null +++ b/trunk/src/lib/cothread/x86.c @@ -0,0 +1,93 @@ +/* + libco.x86 (2009-10-12) + author: byuu + license: public domain +*/ + +#define LIBCO_C +#include "libco.h" +#include <assert.h> +#include <stdlib.h> + +#ifdef __cplusplus +extern "C" { +#endif + +#if defined(_MSC_VER) + #define fastcall __fastcall +#elif defined(__GNUC__) + #define fastcall __attribute__((fastcall)) +#else + #error "libco: please define fastcall macro" +#endif + +static thread_local long co_active_buffer[64]; +static thread_local cothread_t co_active_handle = 0; +static void (fastcall *co_swap)(cothread_t, cothread_t) = 0; + +//ABI: fastcall +static unsigned char co_swap_function[] = { + 0x89, 0x22, 0x8B, 0x21, 0x58, 0x89, 0x6A, 0x04, 0x89, 0x72, 0x08, 0x89, 0x7A, 0x0C, 0x89, 0x5A, + 0x10, 0x8B, 0x69, 0x04, 0x8B, 0x71, 0x08, 0x8B, 0x79, 0x0C, 0x8B, 0x59, 0x10, 0xFF, 0xE0, +}; + +#ifdef _WIN32 + #include <windows.h> + + void co_init() { + DWORD old_privileges; + VirtualProtect(co_swap_function, sizeof co_swap_function, PAGE_EXECUTE_READWRITE, &old_privileges); + } +#else + #include <unistd.h> + #include <sys/mman.h> + + void co_init() { + unsigned long addr = (unsigned long)co_swap_function; + unsigned long base = addr - (addr % sysconf(_SC_PAGESIZE)); + unsigned long size = (addr - base) + sizeof co_swap_function; + mprotect((void*)base, size, PROT_READ | PROT_WRITE | PROT_EXEC); + } +#endif + +static void crash() { + assert(0); /* called only if cothread_t entrypoint returns */ +} + +cothread_t co_active() { + if(!co_active_handle) co_active_handle = &co_active_buffer; + return co_active_handle; +} + +cothread_t co_create(unsigned int size, void (*entrypoint)(void)) { + cothread_t handle; + if(!co_swap) { + co_init(); + co_swap = (void (fastcall*)(cothread_t, cothread_t))co_swap_function; + } + if(!co_active_handle) co_active_handle = &co_active_buffer; + size += 256; /* allocate additional space for storage */ + size &= ~15; /* align stack to 16-byte boundary */ + + if((handle = (cothread_t)malloc(size))) { + long *p = (long*)((char*)handle + size); /* seek to top of stack */ + *--p = (long)crash; /* crash if entrypoint returns */ + *--p = (long)entrypoint; /* start of function */ + *(long*)handle = (long)p; /* stack pointer */ + } + + return handle; +} + +void co_delete(cothread_t handle) { + free(handle); +} + +void co_switch(cothread_t handle) { + register cothread_t co_previous_handle = co_active_handle; + co_swap(co_active_handle = handle, co_previous_handle); +} + +#ifdef __cplusplus +} +#endif |