diff options
Diffstat (limited to 'Kernel/Source/UserHeap.cxx')
| -rw-r--r-- | Kernel/Source/UserHeap.cxx | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/Kernel/Source/UserHeap.cxx b/Kernel/Source/UserHeap.cxx new file mode 100644 index 00000000..9d9cd627 --- /dev/null +++ b/Kernel/Source/UserHeap.cxx @@ -0,0 +1,252 @@ +/* ------------------------------------------- + + Copyright SoftwareLabs + +------------------------------------------- */ + +#include <KernelKit/ProcessScheduler.hpp> +#include <KernelKit/UserHeap.hpp> +#include <NewKit/PageManager.hpp> + +#define kHeapHeaderPaddingSz (16U) + +/// @file UserHeap.cxx +/// @brief User Heap Manager, Process heap allocator. +/// @note if you want to look at the kernel allocator, please look for +/// KernelHeap.cxx +/// BUGS: 0 + +namespace NewOS +{ + /** + * @brief Process Heap Header + * @note Allocated per process, it denotes the user's heap. + */ + struct UserHeapHeader final + { + UInt32 fMagic; + Int32 fFlags; + Boolean fFree; + UInt8 fPadding[kHeapHeaderPaddingSz]; + }; + + /** + * @brief User Heap Manager class, takes care of allocating the process pools. + * @note This rely on Virtual Memory! Consider adding good vmem support when + * @note porting to a new arch. + */ + class UserHeapManager final + { + public: + UserHeapManager() = delete; + ~UserHeapManager() = default; + + public: + STATIC SizeT& Count() + { + return s_NumPools; + } + STATIC Ref<Pmm>& Leak() + { + return s_Pmm; + } + STATIC Boolean& IsEnabled() + { + return s_PoolsAreEnabled; + } + STATIC MutableArray<Ref<PTEWrapper>>& The() + { + return s_Pool; + } + + private: + STATIC Size s_NumPools; + STATIC Ref<Pmm> s_Pmm; + + private: + STATIC Boolean s_PoolsAreEnabled; + STATIC MutableArray<Ref<PTEWrapper>> s_Pool; + }; + + //! declare fields + + SizeT UserHeapManager::s_NumPools = 0UL; + Ref<Pmm> UserHeapManager::s_Pmm; + Boolean UserHeapManager::s_PoolsAreEnabled = true; + MutableArray<Ref<PTEWrapper>> UserHeapManager::s_Pool; + + STATIC VoidPtr ke_find_unused_heap(Int32 flags); + STATIC Void ke_free_heap_internal(VoidPtr vaddr); + STATIC VoidPtr ke_make_heap_internal(VoidPtr vaddr, Int32 flags); + STATIC Boolean ke_check_and_free_heap(const SizeT& index, VoidPtr ptr); + + /// @brief Find an unused heap header to allocate on. + /// @param flags the flags to use. + /// @return VoidPtr the heap pointer. + STATIC VoidPtr ke_find_unused_heap(Int32 flags) + { + for (SizeT index = 0; index < kUserHeapMaxSz; ++index) + { + if (UserHeapManager::The()[index] && + !UserHeapManager::The()[index].Leak().Leak().Present()) + { + UserHeapManager::Leak().Leak().TogglePresent( + UserHeapManager::The()[index].Leak().Leak(), true); + kcout << "[ke_find_unused_heap] Done, trying to make a pool now...\r"; + + return ke_make_heap_internal( + (VoidPtr)UserHeapManager::The()[index].Leak().Leak().VirtualAddress(), + flags); + } + } + + return nullptr; + } + + /// @brief Makes a new heap for the process to use. + /// @param virtualAddress the virtual address of the process. + /// @param flags the flags. + /// @return + STATIC VoidPtr ke_make_heap_internal(VoidPtr virtualAddress, Int32 flags) + { + if (virtualAddress) + { + UserHeapHeader* poolHdr = reinterpret_cast<UserHeapHeader*>(virtualAddress); + + if (!poolHdr->fFree) + { + kcout + << "[ke_make_heap_internal] poolHdr->fFree, HeapPtr already exists\n"; + return nullptr; + } + + poolHdr->fFlags = flags; + poolHdr->fMagic = kUserHeapMag; + poolHdr->fFree = false; + + kcout << "[ke_make_heap_internal] New allocation has been done.\n"; + return reinterpret_cast<VoidPtr>( + (reinterpret_cast<UIntPtr>(virtualAddress) + sizeof(UserHeapHeader))); + } + + kcout << "[ke_make_heap_internal] Address is invalid"; + return nullptr; + } + + /// @brief Internally makrs the heap as free. + /// This is done by setting the fFree bit to true + /// @param virtualAddress + /// @return + STATIC Void ke_free_heap_internal(VoidPtr virtualAddress) + { + UserHeapHeader* poolHdr = reinterpret_cast<UserHeapHeader*>( + reinterpret_cast<UIntPtr>(virtualAddress) - sizeof(UserHeapHeader)); + + if (poolHdr->fMagic == kUserHeapMag) + { + if (!poolHdr->fFree) + { + ProcessScheduler::Shared().Leak().GetCurrent().Leak().Crash(); + return; + } + + poolHdr->fFree = true; + poolHdr->fFlags = 0; + + kcout << "[ke_free_heap_internal] Successfully marked header as free!\r"; + } + } + + /** + * @brief Check for the ptr and frees it. + * + * @param index Where to look at. + * @param ptr The ptr to check. + * @return Boolean true if successful. + */ + STATIC Boolean ke_check_and_free_heap(const SizeT& index, VoidPtr ptr) + { + if (UserHeapManager::The()[index]) + { + // ErrorOr<>::operator Boolean + /// if (address matches) + /// -> Free heap. + if (UserHeapManager::The()[index].Leak().Leak().VirtualAddress() == + (UIntPtr)ptr) + { + UserHeapManager::Leak().Leak().FreePage( + UserHeapManager::The()[index].Leak().Leak()); + + --UserHeapManager::Count(); + + ke_free_heap_internal(ptr); + ptr = nullptr; + + return true; + } + } + + return false; + } + + /// @brief Creates a new pool pointer. + /// @param flags the flags attached to it. + /// @return a pool pointer with selected permissions. + VoidPtr rt_new_heap(Int32 flags) + { + if (!UserHeapManager::IsEnabled()) + return nullptr; + + if (UserHeapManager::Count() > kUserHeapMaxSz) + return nullptr; + + if (VoidPtr ret = ke_find_unused_heap(flags)) + return ret; + + // this wasn't set to true + auto ref_page = UserHeapManager::Leak().Leak().RequestPage( + ((flags & kUserHeapUser)), (flags & kUserHeapRw)); + + if (ref_page) + { + ///! reserve page. + UserHeapManager::The()[UserHeapManager::Count()].Leak() = ref_page; + auto& ref = UserHeapManager::Count(); + + ++ref; // increment the number of addresses we have now. + + // finally make the pool address. + return ke_make_heap_internal( + reinterpret_cast<VoidPtr>(ref_page.Leak().VirtualAddress()), flags); + } + + return nullptr; + } + + /// @brief free a pool pointer. + /// @param ptr The pool pointer to free. + /// @return status code + Int32 rt_free_heap(VoidPtr ptr) + { + if (!UserHeapManager::IsEnabled()) + return -1; + + if (ptr) + { + SizeT base = UserHeapManager::Count(); + + if (ke_check_and_free_heap(base, ptr)) + return 0; + + for (SizeT index = 0; index < kUserHeapMaxSz; ++index) + { + if (ke_check_and_free_heap(index, ptr)) + return 0; + + --base; + } + } + + return -1; + } +} // namespace NewOS |