diff options
Diffstat (limited to 'venv/lib/python3.11/site-packages/greenlet/TStackState.cpp')
| -rw-r--r-- | venv/lib/python3.11/site-packages/greenlet/TStackState.cpp | 265 |
1 files changed, 265 insertions, 0 deletions
diff --git a/venv/lib/python3.11/site-packages/greenlet/TStackState.cpp b/venv/lib/python3.11/site-packages/greenlet/TStackState.cpp new file mode 100644 index 0000000..9aab596 --- /dev/null +++ b/venv/lib/python3.11/site-packages/greenlet/TStackState.cpp @@ -0,0 +1,265 @@ +#ifndef GREENLET_STACK_STATE_CPP +#define GREENLET_STACK_STATE_CPP + +#include "greenlet_greenlet.hpp" + +namespace greenlet { + +#ifdef GREENLET_USE_STDIO +#include <iostream> +using std::cerr; +using std::endl; + +std::ostream& operator<<(std::ostream& os, const StackState& s) +{ + os << "StackState(stack_start=" << (void*)s._stack_start + << ", stack_stop=" << (void*)s.stack_stop + << ", stack_copy=" << (void*)s.stack_copy + << ", stack_saved=" << s._stack_saved + << ", stack_prev=" << s.stack_prev + << ", addr=" << &s + << ")"; + return os; +} +#endif + +StackState::StackState(void* mark, StackState& current) + : _stack_start(nullptr), + stack_stop((char*)mark), + stack_copy(nullptr), + _stack_saved(0), + /* Skip a dying greenlet */ + stack_prev(current._stack_start + ? ¤t + : current.stack_prev) +{ +} + +StackState::StackState() + : _stack_start(nullptr), + stack_stop(nullptr), + stack_copy(nullptr), + _stack_saved(0), + stack_prev(nullptr) +{ +} + +StackState::StackState(const StackState& other) +// can't use a delegating constructor because of +// MSVC for Python 2.7 + : _stack_start(nullptr), + stack_stop(nullptr), + stack_copy(nullptr), + _stack_saved(0), + stack_prev(nullptr) +{ + this->operator=(other); +} + +StackState& StackState::operator=(const StackState& other) +{ + if (&other == this) { + return *this; + } + if (other._stack_saved) { + throw std::runtime_error("Refusing to steal memory."); + } + + //If we have memory allocated, dispose of it + this->free_stack_copy(); + + this->_stack_start = other._stack_start; + this->stack_stop = other.stack_stop; + this->stack_copy = other.stack_copy; + this->_stack_saved = other._stack_saved; + this->stack_prev = other.stack_prev; + return *this; +} + +inline void StackState::free_stack_copy() noexcept +{ + PyMem_Free(this->stack_copy); + this->stack_copy = nullptr; + this->_stack_saved = 0; +} + +inline void StackState::copy_heap_to_stack(const StackState& current) noexcept +{ + + /* Restore the heap copy back into the C stack */ + if (this->_stack_saved != 0) { + memcpy(this->_stack_start, this->stack_copy, this->_stack_saved); + this->free_stack_copy(); + } + StackState* owner = const_cast<StackState*>(¤t); + if (!owner->_stack_start) { + owner = owner->stack_prev; /* greenlet is dying, skip it */ + } + while (owner && owner->stack_stop <= this->stack_stop) { + // cerr << "\tOwner: " << owner << endl; + owner = owner->stack_prev; /* find greenlet with more stack */ + } + this->stack_prev = owner; + // cerr << "\tFinished with: " << *this << endl; +} + +inline int StackState::copy_stack_to_heap_up_to(const char* const stop) noexcept +{ + /* Save more of g's stack into the heap -- at least up to 'stop' + g->stack_stop |________| + | | + | __ stop . . . . . + | | ==> . . + |________| _______ + | | | | + | | | | + g->stack_start | | |_______| g->stack_copy + */ + intptr_t sz1 = this->_stack_saved; + intptr_t sz2 = stop - this->_stack_start; + assert(this->_stack_start); + if (sz2 > sz1) { + char* c = (char*)PyMem_Realloc(this->stack_copy, sz2); + if (!c) { + PyErr_NoMemory(); + return -1; + } + memcpy(c + sz1, this->_stack_start + sz1, sz2 - sz1); + this->stack_copy = c; + this->_stack_saved = sz2; + } + return 0; +} + +inline int StackState::copy_stack_to_heap(char* const stackref, + const StackState& current) noexcept +{ + /* must free all the C stack up to target_stop */ + const char* const target_stop = this->stack_stop; + + StackState* owner = const_cast<StackState*>(¤t); + assert(owner->_stack_saved == 0); // everything is present on the stack + if (!owner->_stack_start) { + owner = owner->stack_prev; /* not saved if dying */ + } + else { + owner->_stack_start = stackref; + } + + while (owner->stack_stop < target_stop) { + /* ts_current is entierely within the area to free */ + if (owner->copy_stack_to_heap_up_to(owner->stack_stop)) { + return -1; /* XXX */ + } + owner = owner->stack_prev; + } + if (owner != this) { + if (owner->copy_stack_to_heap_up_to(target_stop)) { + return -1; /* XXX */ + } + } + return 0; +} + +inline bool StackState::started() const noexcept +{ + return this->stack_stop != nullptr; +} + +inline bool StackState::main() const noexcept +{ + return this->stack_stop == (char*)-1; +} + +inline bool StackState::active() const noexcept +{ + return this->_stack_start != nullptr; +} + +inline void StackState::set_active() noexcept +{ + assert(this->_stack_start == nullptr); + this->_stack_start = (char*)1; +} + +inline void StackState::set_inactive() noexcept +{ + this->_stack_start = nullptr; + // XXX: What if we still have memory out there? + // That case is actually triggered by + // test_issue251_issue252_explicit_reference_not_collectable (greenlet.tests.test_leaks.TestLeaks) + // and + // test_issue251_issue252_need_to_collect_in_background + // (greenlet.tests.test_leaks.TestLeaks) + // + // Those objects never get deallocated, so the destructor never + // runs. + // It *seems* safe to clean up the memory here? + if (this->_stack_saved) { + this->free_stack_copy(); + } +} + +inline intptr_t StackState::stack_saved() const noexcept +{ + return this->_stack_saved; +} + +inline char* StackState::stack_start() const noexcept +{ + return this->_stack_start; +} + + +inline StackState StackState::make_main() noexcept +{ + StackState s; + s._stack_start = (char*)1; + s.stack_stop = (char*)-1; + return s; +} + +StackState::~StackState() +{ + if (this->_stack_saved != 0) { + this->free_stack_copy(); + } +} + +void StackState::copy_from_stack(void* vdest, const void* vsrc, size_t n) const +{ + char* dest = static_cast<char*>(vdest); + const char* src = static_cast<const char*>(vsrc); + if (src + n <= this->_stack_start + || src >= this->_stack_start + this->_stack_saved + || this->_stack_saved == 0) { + // Nothing we're copying was spilled from the stack + memcpy(dest, src, n); + return; + } + + if (src < this->_stack_start) { + // Copy the part before the saved stack. + // We know src + n > _stack_start due to the test above. + const size_t nbefore = this->_stack_start - src; + memcpy(dest, src, nbefore); + dest += nbefore; + src += nbefore; + n -= nbefore; + } + // We know src >= _stack_start after the before-copy, and + // src < _stack_start + _stack_saved due to the first if condition + size_t nspilled = std::min<size_t>(n, this->_stack_start + this->_stack_saved - src); + memcpy(dest, this->stack_copy + (src - this->_stack_start), nspilled); + dest += nspilled; + src += nspilled; + n -= nspilled; + if (n > 0) { + // Copy the part after the saved stack + memcpy(dest, src, n); + } +} + +}; // namespace greenlet + +#endif // GREENLET_STACK_STATE_CPP |