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zend_fibers.c
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/*
+----------------------------------------------------------------------+
| Zend Engine |
+----------------------------------------------------------------------+
| Copyright (c) Zend Technologies Ltd. (http://www.zend.com) |
+----------------------------------------------------------------------+
| This source file is subject to version 2.00 of the Zend license, |
| that is bundled with this package in the file LICENSE, and is |
| available through the world-wide-web at the following url: |
| http://www.zend.com/license/2_00.txt. |
| If you did not receive a copy of the Zend license and are unable to |
| obtain it through the world-wide-web, please send a note to |
| [email protected] so we can mail you a copy immediately. |
+----------------------------------------------------------------------+
| Authors: Aaron Piotrowski <[email protected]> |
| Martin Schröder <[email protected]> |
+----------------------------------------------------------------------+
*/
#include "zend.h"
#include "zend_API.h"
#include "zend_ini.h"
#include "zend_variables.h"
#include "zend_vm.h"
#include "zend_exceptions.h"
#include "zend_builtin_functions.h"
#include "zend_observer.h"
#include "zend_mmap.h"
#include "zend_compile.h"
#include "zend_closures.h"
#include "zend_fibers.h"
#include "zend_fibers_arginfo.h"
#ifdef HAVE_VALGRIND
# include <valgrind/valgrind.h>
#endif
#ifdef ZEND_FIBER_UCONTEXT
# include <ucontext.h>
#endif
#ifndef ZEND_WIN32
# include <unistd.h>
# include <sys/mman.h>
# include <limits.h>
# if !defined(MAP_ANONYMOUS) && defined(MAP_ANON)
# define MAP_ANONYMOUS MAP_ANON
# endif
/* FreeBSD require a first (i.e. addr) argument of mmap(2) is not NULL
* if MAP_STACK is passed.
* http://www.FreeBSD.org/cgi/query-pr.cgi?pr=158755 */
# if !defined(MAP_STACK) || defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
# undef MAP_STACK
# define MAP_STACK 0
# endif
# ifndef MAP_FAILED
# define MAP_FAILED ((void * ) -1)
# endif
#endif
#ifdef __SANITIZE_ADDRESS__
# include <sanitizer/asan_interface.h>
# include <sanitizer/common_interface_defs.h>
#endif
# if defined __CET__
# include <cet.h>
# define SHSTK_ENABLED (__CET__ & 0x2)
# define BOOST_CONTEXT_SHADOW_STACK (SHSTK_ENABLED && SHADOW_STACK_SYSCALL)
# define __NR_map_shadow_stack 451
# ifndef SHADOW_STACK_SET_TOKEN
# define SHADOW_STACK_SET_TOKEN 0x1
#endif
#endif
/* Encapsulates the fiber C stack with extension for debugging tools. */
struct _zend_fiber_stack {
void *pointer;
size_t size;
#ifdef HAVE_VALGRIND
unsigned int valgrind_stack_id;
#endif
#ifdef __SANITIZE_ADDRESS__
const void *asan_pointer;
size_t asan_size;
#endif
#ifdef ZEND_FIBER_UCONTEXT
/* Embedded ucontext to avoid unnecessary memory allocations. */
ucontext_t ucontext;
#elif BOOST_CONTEXT_SHADOW_STACK
/* Shadow stack: base, size */
void *ss_base;
size_t ss_size;
#endif
};
/* Zend VM state that needs to be captured / restored during fiber context switch. */
typedef struct _zend_fiber_vm_state {
zend_vm_stack vm_stack;
zval *vm_stack_top;
zval *vm_stack_end;
size_t vm_stack_page_size;
zend_execute_data *current_execute_data;
int error_reporting;
uint32_t jit_trace_num;
JMP_BUF *bailout;
zend_fiber *active_fiber;
#ifdef ZEND_CHECK_STACK_LIMIT
void *stack_base;
void *stack_limit;
#endif
} zend_fiber_vm_state;
static zend_always_inline void zend_fiber_capture_vm_state(zend_fiber_vm_state *state)
{
state->vm_stack = EG(vm_stack);
state->vm_stack_top = EG(vm_stack_top);
state->vm_stack_end = EG(vm_stack_end);
state->vm_stack_page_size = EG(vm_stack_page_size);
state->current_execute_data = EG(current_execute_data);
state->error_reporting = EG(error_reporting);
state->jit_trace_num = EG(jit_trace_num);
state->bailout = EG(bailout);
state->active_fiber = EG(active_fiber);
#ifdef ZEND_CHECK_STACK_LIMIT
state->stack_base = EG(stack_base);
state->stack_limit = EG(stack_limit);
#endif
}
static zend_always_inline void zend_fiber_restore_vm_state(zend_fiber_vm_state *state)
{
EG(vm_stack) = state->vm_stack;
EG(vm_stack_top) = state->vm_stack_top;
EG(vm_stack_end) = state->vm_stack_end;
EG(vm_stack_page_size) = state->vm_stack_page_size;
EG(current_execute_data) = state->current_execute_data;
EG(error_reporting) = state->error_reporting;
EG(jit_trace_num) = state->jit_trace_num;
EG(bailout) = state->bailout;
EG(active_fiber) = state->active_fiber;
#ifdef ZEND_CHECK_STACK_LIMIT
EG(stack_base) = state->stack_base;
EG(stack_limit) = state->stack_limit;
#endif
}
#ifdef ZEND_FIBER_UCONTEXT
ZEND_TLS zend_fiber_transfer *transfer_data;
#else
/* boost_context_data is our customized definition of struct transfer_t as
* provided by boost.context in fcontext.hpp:
*
* typedef void* fcontext_t;
*
* struct transfer_t {
* fcontext_t fctx;
* void *data;
* }; */
typedef struct {
void *handle;
zend_fiber_transfer *transfer;
} boost_context_data;
/* These functions are defined in assembler files provided by boost.context (located in "Zend/asm"). */
extern void *make_fcontext(void *sp, size_t size, void (*fn)(boost_context_data));
extern ZEND_INDIRECT_RETURN boost_context_data jump_fcontext(void *to, zend_fiber_transfer *transfer);
#endif
ZEND_API zend_class_entry *zend_ce_fiber;
static zend_class_entry *zend_ce_fiber_error;
static zend_object_handlers zend_fiber_handlers;
static zend_function zend_fiber_function = { ZEND_INTERNAL_FUNCTION };
ZEND_TLS uint32_t zend_fiber_switch_blocking = 0;
#define ZEND_FIBER_DEFAULT_PAGE_SIZE 4096
static size_t zend_fiber_get_page_size(void)
{
static size_t page_size = 0;
if (!page_size) {
page_size = zend_get_page_size();
if (!page_size || (page_size & (page_size - 1))) {
/* anyway, we have to return a valid result */
page_size = ZEND_FIBER_DEFAULT_PAGE_SIZE;
}
}
return page_size;
}
static zend_fiber_stack *zend_fiber_stack_allocate(size_t size)
{
void *pointer;
const size_t page_size = zend_fiber_get_page_size();
const size_t minimum_stack_size = page_size + ZEND_FIBER_GUARD_PAGES * page_size;
if (size < minimum_stack_size) {
zend_throw_exception_ex(NULL, 0, "Fiber stack size is too small, it needs to be at least %zu bytes", minimum_stack_size);
return NULL;
}
const size_t stack_size = (size + page_size - 1) / page_size * page_size;
const size_t alloc_size = stack_size + ZEND_FIBER_GUARD_PAGES * page_size;
#ifdef ZEND_WIN32
pointer = VirtualAlloc(0, alloc_size, MEM_COMMIT, PAGE_READWRITE);
if (!pointer) {
DWORD err = GetLastError();
char *errmsg = php_win32_error_to_msg(err);
zend_throw_exception_ex(NULL, 0, "Fiber stack allocate failed: VirtualAlloc failed: [0x%08lx] %s", err, errmsg[0] ? errmsg : "Unknown");
php_win32_error_msg_free(errmsg);
return NULL;
}
# if ZEND_FIBER_GUARD_PAGES
DWORD protect;
if (!VirtualProtect(pointer, ZEND_FIBER_GUARD_PAGES * page_size, PAGE_READWRITE | PAGE_GUARD, &protect)) {
DWORD err = GetLastError();
char *errmsg = php_win32_error_to_msg(err);
zend_throw_exception_ex(NULL, 0, "Fiber stack protect failed: VirtualProtect failed: [0x%08lx] %s", err, errmsg[0] ? errmsg : "Unknown");
php_win32_error_msg_free(errmsg);
VirtualFree(pointer, 0, MEM_RELEASE);
return NULL;
}
# endif
#else
pointer = mmap(NULL, alloc_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_STACK, -1, 0);
if (pointer == MAP_FAILED) {
zend_throw_exception_ex(NULL, 0, "Fiber stack allocate failed: mmap failed: %s (%d)", strerror(errno), errno);
return NULL;
}
#if defined(MADV_NOHUGEPAGE)
/* Multiple reasons to fail, ignore all errors only needed
* for linux < 6.8 */
(void) madvise(pointer, alloc_size, MADV_NOHUGEPAGE);
#endif
zend_mmap_set_name(pointer, alloc_size, "zend_fiber_stack");
# if ZEND_FIBER_GUARD_PAGES
if (mprotect(pointer, ZEND_FIBER_GUARD_PAGES * page_size, PROT_NONE) < 0) {
zend_throw_exception_ex(NULL, 0, "Fiber stack protect failed: mprotect failed: %s (%d)", strerror(errno), errno);
munmap(pointer, alloc_size);
return NULL;
}
# endif
#endif
zend_fiber_stack *stack = emalloc(sizeof(zend_fiber_stack));
stack->pointer = (void *) ((uintptr_t) pointer + ZEND_FIBER_GUARD_PAGES * page_size);
stack->size = stack_size;
#if !defined(ZEND_FIBER_UCONTEXT) && BOOST_CONTEXT_SHADOW_STACK
/* shadow stack saves ret address only, need less space */
stack->ss_size= stack_size >> 5;
/* align shadow stack to 8 bytes. */
stack->ss_size = (stack->ss_size + 7) & ~7;
/* issue syscall to create shadow stack for the new fcontext */
/* SHADOW_STACK_SET_TOKEN option will put "restore token" on the new shadow stack */
stack->ss_base = (void *)syscall(__NR_map_shadow_stack, 0, stack->ss_size, SHADOW_STACK_SET_TOKEN);
if (stack->ss_base == MAP_FAILED) {
zend_throw_exception_ex(NULL, 0, "Fiber shadow stack allocate failed: mmap failed: %s (%d)", strerror(errno), errno);
return NULL;
}
#endif
#ifdef VALGRIND_STACK_REGISTER
uintptr_t base = (uintptr_t) stack->pointer;
stack->valgrind_stack_id = VALGRIND_STACK_REGISTER(base, base + stack->size);
#endif
#ifdef __SANITIZE_ADDRESS__
stack->asan_pointer = stack->pointer;
stack->asan_size = stack->size;
#endif
return stack;
}
static void zend_fiber_stack_free(zend_fiber_stack *stack)
{
#ifdef VALGRIND_STACK_DEREGISTER
VALGRIND_STACK_DEREGISTER(stack->valgrind_stack_id);
#endif
const size_t page_size = zend_fiber_get_page_size();
void *pointer = (void *) ((uintptr_t) stack->pointer - ZEND_FIBER_GUARD_PAGES * page_size);
#ifdef __SANITIZE_ADDRESS__
/* If another mmap happens after unmapping, it may trigger the stale stack red zones
* so we have to unpoison it before unmapping. */
ASAN_UNPOISON_MEMORY_REGION(pointer, stack->size + ZEND_FIBER_GUARD_PAGES * page_size);
#endif
#ifdef ZEND_WIN32
VirtualFree(pointer, 0, MEM_RELEASE);
#else
munmap(pointer, stack->size + ZEND_FIBER_GUARD_PAGES * page_size);
#endif
#if !defined(ZEND_FIBER_UCONTEXT) && BOOST_CONTEXT_SHADOW_STACK
munmap(stack->ss_base, stack->ss_size);
#endif
efree(stack);
}
#ifdef ZEND_CHECK_STACK_LIMIT
ZEND_API void* zend_fiber_stack_limit(zend_fiber_stack *stack)
{
zend_ulong reserve = EG(reserved_stack_size);
#ifdef __APPLE__
/* On Apple Clang, the stack probing function ___chkstk_darwin incorrectly
* probes a location that is twice the entered function's stack usage away
* from the stack pointer, when using an alternative stack.
* https://openradar.appspot.com/radar?id=5497722702397440
*/
reserve = reserve * 2;
#endif
/* stack->pointer is the end of the stack */
return (int8_t*)stack->pointer + reserve;
}
ZEND_API void* zend_fiber_stack_base(zend_fiber_stack *stack)
{
return (void*)((uintptr_t)stack->pointer + stack->size);
}
#endif
#ifdef ZEND_FIBER_UCONTEXT
static ZEND_NORETURN void zend_fiber_trampoline(void)
#else
static ZEND_NORETURN void zend_fiber_trampoline(boost_context_data data)
#endif
{
/* Initialize transfer struct with a copy of passed data. */
#ifdef ZEND_FIBER_UCONTEXT
zend_fiber_transfer transfer = *transfer_data;
#else
zend_fiber_transfer transfer = *data.transfer;
#endif
zend_fiber_context *from = transfer.context;
#ifdef __SANITIZE_ADDRESS__
__sanitizer_finish_switch_fiber(NULL, &from->stack->asan_pointer, &from->stack->asan_size);
#endif
#ifndef ZEND_FIBER_UCONTEXT
/* Get the context that resumed us and update its handle to allow for symmetric coroutines. */
from->handle = data.handle;
#endif
/* Ensure that previous fiber will be cleaned up (needed by symmetric coroutines). */
if (from->status == ZEND_FIBER_STATUS_DEAD) {
zend_fiber_destroy_context(from);
}
zend_fiber_context *context = EG(current_fiber_context);
context->function(&transfer);
context->status = ZEND_FIBER_STATUS_DEAD;
/* Final context switch, the fiber must not be resumed afterwards! */
zend_fiber_switch_context(&transfer);
/* Abort here because we are in an inconsistent program state. */
abort();
}
ZEND_API void zend_fiber_switch_block(void)
{
++zend_fiber_switch_blocking;
}
ZEND_API void zend_fiber_switch_unblock(void)
{
ZEND_ASSERT(zend_fiber_switch_blocking && "Fiber switching was not blocked");
--zend_fiber_switch_blocking;
}
ZEND_API bool zend_fiber_switch_blocked(void)
{
return zend_fiber_switch_blocking;
}
ZEND_API zend_result zend_fiber_init_context(zend_fiber_context *context, void *kind, zend_fiber_coroutine coroutine, size_t stack_size)
{
context->stack = zend_fiber_stack_allocate(stack_size);
if (UNEXPECTED(!context->stack)) {
return FAILURE;
}
#ifdef ZEND_FIBER_UCONTEXT
ucontext_t *handle = &context->stack->ucontext;
getcontext(handle);
handle->uc_stack.ss_size = context->stack->size;
handle->uc_stack.ss_sp = context->stack->pointer;
handle->uc_stack.ss_flags = 0;
handle->uc_link = NULL;
makecontext(handle, (void (*)(void)) zend_fiber_trampoline, 0);
context->handle = handle;
#else
// Stack grows down, calculate the top of the stack. make_fcontext then shifts pointer to lower 16-byte boundary.
void *stack = (void *) ((uintptr_t) context->stack->pointer + context->stack->size);
#if BOOST_CONTEXT_SHADOW_STACK
// pass the shadow stack pointer to make_fcontext
// i.e., link the new shadow stack with the new fcontext
// TODO should be a better way?
*((unsigned long*) (stack - 8)) = (unsigned long)context->stack->ss_base + context->stack->ss_size;
#endif
context->handle = make_fcontext(stack, context->stack->size, zend_fiber_trampoline);
ZEND_ASSERT(context->handle != NULL && "make_fcontext() never returns NULL");
#endif
context->kind = kind;
context->function = coroutine;
// Set status in case memory has not been zeroed.
context->status = ZEND_FIBER_STATUS_INIT;
zend_observer_fiber_init_notify(context);
return SUCCESS;
}
ZEND_API void zend_fiber_destroy_context(zend_fiber_context *context)
{
zend_observer_fiber_destroy_notify(context);
if (context->cleanup) {
context->cleanup(context);
}
zend_fiber_stack_free(context->stack);
}
ZEND_API void zend_fiber_switch_context(zend_fiber_transfer *transfer)
{
zend_fiber_context *from = EG(current_fiber_context);
zend_fiber_context *to = transfer->context;
zend_fiber_vm_state state;
ZEND_ASSERT(to && to->handle && to->status != ZEND_FIBER_STATUS_DEAD && "Invalid fiber context");
ZEND_ASSERT(from && "From fiber context must be present");
ZEND_ASSERT(to != from && "Cannot switch into the running fiber context");
/* Assert that all error transfers hold a Throwable value. */
ZEND_ASSERT((
!(transfer->flags & ZEND_FIBER_TRANSFER_FLAG_ERROR) ||
(Z_TYPE(transfer->value) == IS_OBJECT && (
zend_is_unwind_exit(Z_OBJ(transfer->value)) ||
zend_is_graceful_exit(Z_OBJ(transfer->value)) ||
instanceof_function(Z_OBJCE(transfer->value), zend_ce_throwable)
))
) && "Error transfer requires a throwable value");
zend_observer_fiber_switch_notify(from, to);
zend_fiber_capture_vm_state(&state);
to->status = ZEND_FIBER_STATUS_RUNNING;
if (EXPECTED(from->status == ZEND_FIBER_STATUS_RUNNING)) {
from->status = ZEND_FIBER_STATUS_SUSPENDED;
}
/* Update transfer context with the current fiber before switching. */
transfer->context = from;
EG(current_fiber_context) = to;
#ifdef __SANITIZE_ADDRESS__
void *fake_stack = NULL;
__sanitizer_start_switch_fiber(
from->status != ZEND_FIBER_STATUS_DEAD ? &fake_stack : NULL,
to->stack->asan_pointer,
to->stack->asan_size);
#endif
#ifdef ZEND_FIBER_UCONTEXT
transfer_data = transfer;
swapcontext(from->handle, to->handle);
/* Copy transfer struct because it might live on the other fiber's stack that will eventually be destroyed. */
*transfer = *transfer_data;
#else
boost_context_data data = jump_fcontext(to->handle, transfer);
/* Copy transfer struct because it might live on the other fiber's stack that will eventually be destroyed. */
*transfer = *data.transfer;
#endif
to = transfer->context;
#ifndef ZEND_FIBER_UCONTEXT
/* Get the context that resumed us and update its handle to allow for symmetric coroutines. */
to->handle = data.handle;
#endif
#ifdef __SANITIZE_ADDRESS__
__sanitizer_finish_switch_fiber(fake_stack, &to->stack->asan_pointer, &to->stack->asan_size);
#endif
EG(current_fiber_context) = from;
zend_fiber_restore_vm_state(&state);
/* Destroy prior context if it has been marked as dead. */
if (to->status == ZEND_FIBER_STATUS_DEAD) {
zend_fiber_destroy_context(to);
}
}
static void zend_fiber_cleanup(zend_fiber_context *context)
{
zend_fiber *fiber = zend_fiber_from_context(context);
zend_vm_stack current_stack = EG(vm_stack);
EG(vm_stack) = fiber->vm_stack;
zend_vm_stack_destroy();
EG(vm_stack) = current_stack;
fiber->execute_data = NULL;
fiber->stack_bottom = NULL;
fiber->caller = NULL;
}
static ZEND_STACK_ALIGNED void zend_fiber_execute(zend_fiber_transfer *transfer)
{
ZEND_ASSERT(Z_TYPE(transfer->value) == IS_NULL && "Initial transfer value to fiber context must be NULL");
ZEND_ASSERT(!transfer->flags && "No flags should be set on initial transfer");
zend_fiber *fiber = EG(active_fiber);
/* Determine the current error_reporting ini setting. */
zend_long error_reporting = INI_INT("error_reporting");
/* If error_reporting is 0 and not explicitly set to 0, INI_STR returns a null pointer. */
if (!error_reporting && !INI_STR("error_reporting")) {
error_reporting = E_ALL;
}
EG(vm_stack) = NULL;
zend_first_try {
zend_vm_stack stack = zend_vm_stack_new_page(ZEND_FIBER_VM_STACK_SIZE, NULL);
EG(vm_stack) = stack;
EG(vm_stack_top) = stack->top + ZEND_CALL_FRAME_SLOT;
EG(vm_stack_end) = stack->end;
EG(vm_stack_page_size) = ZEND_FIBER_VM_STACK_SIZE;
fiber->execute_data = (zend_execute_data *) stack->top;
fiber->stack_bottom = fiber->execute_data;
memset(fiber->execute_data, 0, sizeof(zend_execute_data));
fiber->execute_data->func = &zend_fiber_function;
fiber->stack_bottom->prev_execute_data = EG(current_execute_data);
EG(current_execute_data) = fiber->execute_data;
EG(jit_trace_num) = 0;
EG(error_reporting) = error_reporting;
#ifdef ZEND_CHECK_STACK_LIMIT
EG(stack_base) = zend_fiber_stack_base(fiber->context.stack);
EG(stack_limit) = zend_fiber_stack_limit(fiber->context.stack);
#endif
fiber->fci.retval = &fiber->result;
zend_call_function(&fiber->fci, &fiber->fci_cache);
/* Cleanup callback and unset field to prevent GC / duplicate dtor issues. */
zval_ptr_dtor(&fiber->fci.function_name);
ZVAL_UNDEF(&fiber->fci.function_name);
if (EG(exception)) {
if (!(fiber->flags & ZEND_FIBER_FLAG_DESTROYED)
|| !(zend_is_graceful_exit(EG(exception)) || zend_is_unwind_exit(EG(exception)))
) {
fiber->flags |= ZEND_FIBER_FLAG_THREW;
transfer->flags = ZEND_FIBER_TRANSFER_FLAG_ERROR;
ZVAL_OBJ_COPY(&transfer->value, EG(exception));
}
zend_clear_exception();
}
} zend_catch {
fiber->flags |= ZEND_FIBER_FLAG_BAILOUT;
transfer->flags = ZEND_FIBER_TRANSFER_FLAG_BAILOUT;
} zend_end_try();
fiber->context.cleanup = &zend_fiber_cleanup;
fiber->vm_stack = EG(vm_stack);
transfer->context = fiber->caller;
}
/* Handles forwarding of result / error from a transfer into the running fiber. */
static zend_always_inline void zend_fiber_delegate_transfer_result(
zend_fiber_transfer *transfer, INTERNAL_FUNCTION_PARAMETERS
) {
if (transfer->flags & ZEND_FIBER_TRANSFER_FLAG_ERROR) {
/* Use internal throw to skip the Throwable-check that would fail for (graceful) exit. */
zend_throw_exception_internal(Z_OBJ(transfer->value));
RETURN_THROWS();
}
if (return_value != NULL) {
RETURN_COPY_VALUE(&transfer->value);
} else {
zval_ptr_dtor(&transfer->value);
}
}
static zend_always_inline zend_fiber_transfer zend_fiber_switch_to(
zend_fiber_context *context, zval *value, bool exception
) {
zend_fiber_transfer transfer = {
.context = context,
.flags = exception ? ZEND_FIBER_TRANSFER_FLAG_ERROR : 0,
};
if (value) {
ZVAL_COPY(&transfer.value, value);
} else {
ZVAL_NULL(&transfer.value);
}
zend_fiber_switch_context(&transfer);
/* Forward bailout into current fiber. */
if (UNEXPECTED(transfer.flags & ZEND_FIBER_TRANSFER_FLAG_BAILOUT)) {
EG(active_fiber) = NULL;
zend_bailout();
}
return transfer;
}
static zend_always_inline zend_fiber_transfer zend_fiber_resume_internal(zend_fiber *fiber, zval *value, bool exception)
{
zend_fiber *previous = EG(active_fiber);
if (previous) {
previous->execute_data = EG(current_execute_data);
}
fiber->caller = EG(current_fiber_context);
EG(active_fiber) = fiber;
zend_fiber_transfer transfer = zend_fiber_switch_to(fiber->previous, value, exception);
EG(active_fiber) = previous;
return transfer;
}
static zend_always_inline zend_fiber_transfer zend_fiber_suspend_internal(zend_fiber *fiber, zval *value)
{
ZEND_ASSERT(!(fiber->flags & ZEND_FIBER_FLAG_DESTROYED));
ZEND_ASSERT(fiber->context.status == ZEND_FIBER_STATUS_RUNNING || fiber->context.status == ZEND_FIBER_STATUS_SUSPENDED);
ZEND_ASSERT(fiber->caller != NULL);
zend_fiber_context *caller = fiber->caller;
fiber->previous = EG(current_fiber_context);
fiber->caller = NULL;
fiber->execute_data = EG(current_execute_data);
return zend_fiber_switch_to(caller, value, false);
}
ZEND_API zend_result zend_fiber_start(zend_fiber *fiber, zval *return_value)
{
ZEND_ASSERT(fiber->context.status == ZEND_FIBER_STATUS_INIT);
if (zend_fiber_init_context(&fiber->context, zend_ce_fiber, zend_fiber_execute, EG(fiber_stack_size)) == FAILURE) {
return FAILURE;
}
fiber->previous = &fiber->context;
zend_fiber_transfer transfer = zend_fiber_resume_internal(fiber, NULL, false);
zend_fiber_delegate_transfer_result(&transfer, EG(current_execute_data), return_value);
return SUCCESS;
}
ZEND_API void zend_fiber_resume(zend_fiber *fiber, zval *value, zval *return_value)
{
ZEND_ASSERT(fiber->context.status == ZEND_FIBER_STATUS_SUSPENDED && fiber->caller == NULL);
fiber->stack_bottom->prev_execute_data = EG(current_execute_data);
zend_fiber_transfer transfer = zend_fiber_resume_internal(fiber, value, /* exception */ false);
zend_fiber_delegate_transfer_result(&transfer, EG(current_execute_data), return_value);
}
ZEND_API void zend_fiber_resume_exception(zend_fiber *fiber, zval *exception, zval *return_value)
{
ZEND_ASSERT(fiber->context.status == ZEND_FIBER_STATUS_SUSPENDED && fiber->caller == NULL);
fiber->stack_bottom->prev_execute_data = EG(current_execute_data);
zend_fiber_transfer transfer = zend_fiber_resume_internal(fiber, exception, /* exception */ true);
zend_fiber_delegate_transfer_result(&transfer, EG(current_execute_data), return_value);
}
ZEND_API void zend_fiber_suspend(zend_fiber *fiber, zval *value, zval *return_value)
{
fiber->stack_bottom->prev_execute_data = NULL;
zend_fiber_transfer transfer = zend_fiber_suspend_internal(fiber, value);
zend_fiber_delegate_transfer_result(&transfer, EG(current_execute_data), return_value);
}
static zend_object *zend_fiber_object_create(zend_class_entry *ce)
{
zend_fiber *fiber = emalloc(sizeof(zend_fiber));
memset(fiber, 0, sizeof(zend_fiber));
zend_object_std_init(&fiber->std, ce);
return &fiber->std;
}
static void zend_fiber_object_destroy(zend_object *object)
{
zend_fiber *fiber = (zend_fiber *) object;
if (fiber->context.status != ZEND_FIBER_STATUS_SUSPENDED) {
return;
}
zend_object *exception = EG(exception);
EG(exception) = NULL;
zval graceful_exit;
ZVAL_OBJ(&graceful_exit, zend_create_graceful_exit());
fiber->flags |= ZEND_FIBER_FLAG_DESTROYED;
zend_fiber_transfer transfer = zend_fiber_resume_internal(fiber, &graceful_exit, true);
zval_ptr_dtor(&graceful_exit);
if (transfer.flags & ZEND_FIBER_TRANSFER_FLAG_ERROR) {
EG(exception) = Z_OBJ(transfer.value);
if (!exception && EG(current_execute_data) && EG(current_execute_data)->func
&& ZEND_USER_CODE(EG(current_execute_data)->func->common.type)) {
zend_rethrow_exception(EG(current_execute_data));
}
zend_exception_set_previous(EG(exception), exception);
if (!EG(current_execute_data)) {
zend_exception_error(EG(exception), E_ERROR);
}
} else {
zval_ptr_dtor(&transfer.value);
EG(exception) = exception;
}
}
static void zend_fiber_object_free(zend_object *object)
{
zend_fiber *fiber = (zend_fiber *) object;
zval_ptr_dtor(&fiber->fci.function_name);
zval_ptr_dtor(&fiber->result);
zend_object_std_dtor(&fiber->std);
}
static HashTable *zend_fiber_object_gc(zend_object *object, zval **table, int *num)
{
zend_fiber *fiber = (zend_fiber *) object;
zend_get_gc_buffer *buf = zend_get_gc_buffer_create();
zend_get_gc_buffer_add_zval(buf, &fiber->fci.function_name);
zend_get_gc_buffer_add_zval(buf, &fiber->result);
if (fiber->context.status != ZEND_FIBER_STATUS_SUSPENDED || fiber->caller != NULL) {
zend_get_gc_buffer_use(buf, table, num);
return NULL;
}
HashTable *lastSymTable = NULL;
zend_execute_data *ex = fiber->execute_data;
for (; ex; ex = ex->prev_execute_data) {
HashTable *symTable = zend_unfinished_execution_gc_ex(ex, ex->func && ZEND_USER_CODE(ex->func->type) ? ex->call : NULL, buf, false);
if (symTable) {
if (lastSymTable) {
zval *val;
ZEND_HASH_FOREACH_VAL(lastSymTable, val) {
if (EXPECTED(Z_TYPE_P(val) == IS_INDIRECT)) {
val = Z_INDIRECT_P(val);
}
zend_get_gc_buffer_add_zval(buf, val);
} ZEND_HASH_FOREACH_END();
}
lastSymTable = symTable;
}
}
zend_get_gc_buffer_use(buf, table, num);
return lastSymTable;
}
ZEND_METHOD(Fiber, __construct)
{
zend_fcall_info fci;
zend_fcall_info_cache fcc;
ZEND_PARSE_PARAMETERS_START(1, 1)
Z_PARAM_FUNC(fci, fcc)
ZEND_PARSE_PARAMETERS_END();
zend_fiber *fiber = (zend_fiber *) Z_OBJ_P(ZEND_THIS);
if (UNEXPECTED(fiber->context.status != ZEND_FIBER_STATUS_INIT || Z_TYPE(fiber->fci.function_name) != IS_UNDEF)) {
zend_throw_error(zend_ce_fiber_error, "Cannot call constructor twice");
RETURN_THROWS();
}
fiber->fci = fci;
fiber->fci_cache = fcc;
// Keep a reference to closures or callable objects while the fiber is running.
Z_TRY_ADDREF(fiber->fci.function_name);
}
ZEND_METHOD(Fiber, start)
{
zend_fiber *fiber = (zend_fiber *) Z_OBJ_P(ZEND_THIS);
ZEND_PARSE_PARAMETERS_START(0, -1)
Z_PARAM_VARIADIC_WITH_NAMED(fiber->fci.params, fiber->fci.param_count, fiber->fci.named_params);
ZEND_PARSE_PARAMETERS_END();
if (UNEXPECTED(zend_fiber_switch_blocked())) {
zend_throw_error(zend_ce_fiber_error, "Cannot switch fibers in current execution context");
RETURN_THROWS();
}
if (fiber->context.status != ZEND_FIBER_STATUS_INIT) {
zend_throw_error(zend_ce_fiber_error, "Cannot start a fiber that has already been started");
RETURN_THROWS();
}
if (zend_fiber_init_context(&fiber->context, zend_ce_fiber, zend_fiber_execute, EG(fiber_stack_size)) == FAILURE) {
RETURN_THROWS();
}
fiber->previous = &fiber->context;
zend_fiber_transfer transfer = zend_fiber_resume_internal(fiber, NULL, false);
zend_fiber_delegate_transfer_result(&transfer, INTERNAL_FUNCTION_PARAM_PASSTHRU);
}
ZEND_METHOD(Fiber, suspend)
{
zval *value = NULL;
ZEND_PARSE_PARAMETERS_START(0, 1)
Z_PARAM_OPTIONAL
Z_PARAM_ZVAL(value);
ZEND_PARSE_PARAMETERS_END();
zend_fiber *fiber = EG(active_fiber);
if (UNEXPECTED(!fiber)) {
zend_throw_error(zend_ce_fiber_error, "Cannot suspend outside of a fiber");
RETURN_THROWS();
}
if (UNEXPECTED(fiber->flags & ZEND_FIBER_FLAG_DESTROYED)) {
zend_throw_error(zend_ce_fiber_error, "Cannot suspend in a force-closed fiber");
RETURN_THROWS();
}
if (UNEXPECTED(zend_fiber_switch_blocked())) {
zend_throw_error(zend_ce_fiber_error, "Cannot switch fibers in current execution context");
RETURN_THROWS();
}
ZEND_ASSERT(fiber->context.status == ZEND_FIBER_STATUS_RUNNING || fiber->context.status == ZEND_FIBER_STATUS_SUSPENDED);
fiber->stack_bottom->prev_execute_data = NULL;
zend_fiber_transfer transfer = zend_fiber_suspend_internal(fiber, value);
zend_fiber_delegate_transfer_result(&transfer, INTERNAL_FUNCTION_PARAM_PASSTHRU);
}
ZEND_METHOD(Fiber, resume)
{
zend_fiber *fiber;
zval *value = NULL;
ZEND_PARSE_PARAMETERS_START(0, 1)
Z_PARAM_OPTIONAL
Z_PARAM_ZVAL(value);
ZEND_PARSE_PARAMETERS_END();
if (UNEXPECTED(zend_fiber_switch_blocked())) {
zend_throw_error(zend_ce_fiber_error, "Cannot switch fibers in current execution context");
RETURN_THROWS();
}
fiber = (zend_fiber *) Z_OBJ_P(ZEND_THIS);
if (UNEXPECTED(fiber->context.status != ZEND_FIBER_STATUS_SUSPENDED || fiber->caller != NULL)) {
zend_throw_error(zend_ce_fiber_error, "Cannot resume a fiber that is not suspended");
RETURN_THROWS();
}
fiber->stack_bottom->prev_execute_data = EG(current_execute_data);
zend_fiber_transfer transfer = zend_fiber_resume_internal(fiber, value, false);
zend_fiber_delegate_transfer_result(&transfer, INTERNAL_FUNCTION_PARAM_PASSTHRU);
}
ZEND_METHOD(Fiber, throw)
{
zend_fiber *fiber;
zval *exception;
ZEND_PARSE_PARAMETERS_START(1, 1)
Z_PARAM_OBJECT_OF_CLASS(exception, zend_ce_throwable)
ZEND_PARSE_PARAMETERS_END();
if (UNEXPECTED(zend_fiber_switch_blocked())) {
zend_throw_error(zend_ce_fiber_error, "Cannot switch fibers in current execution context");
RETURN_THROWS();
}
fiber = (zend_fiber *) Z_OBJ_P(ZEND_THIS);
if (UNEXPECTED(fiber->context.status != ZEND_FIBER_STATUS_SUSPENDED || fiber->caller != NULL)) {
zend_throw_error(zend_ce_fiber_error, "Cannot resume a fiber that is not suspended");
RETURN_THROWS();
}
fiber->stack_bottom->prev_execute_data = EG(current_execute_data);
zend_fiber_transfer transfer = zend_fiber_resume_internal(fiber, exception, true);
zend_fiber_delegate_transfer_result(&transfer, INTERNAL_FUNCTION_PARAM_PASSTHRU);
}
ZEND_METHOD(Fiber, isStarted)
{
zend_fiber *fiber;
ZEND_PARSE_PARAMETERS_NONE();
fiber = (zend_fiber *) Z_OBJ_P(ZEND_THIS);
RETURN_BOOL(fiber->context.status != ZEND_FIBER_STATUS_INIT);
}