dhewm/dhewm3
0
0
Fork 0
mirror of https://github.com/dhewm/dhewm3.git synced 2025-03-21 18:21:08 +00:00
Code Issues Projects Releases Packages Wiki Activity

Implement Mem_MallocA()+Mem_FreeA(): alloca() but might use Heap

Browse source 
When requesting < 1 MB, _alloca16() is used, otherwise Mem_Alloc16().
Furthermore you must pass a bool that will get true assigned if the
memory has been allocated on the stack, else false.
At the end of the function you must call Mem_FreeA( ptr, onStack )
(where onStack is the aforementioned bool), so Mem_Free16() can be
called if it was allocated on the heap.
This commit is contained in:
Daniel Gibson 2024-10-31 18:13:40 +01:00
parent 81cab591da
commit 5c9d9ff53c
2 changed files with 23 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

18
neo/idlib/Heap.h
View file

@ -142,6 +142,24 @@ __inline void operator delete[]( void *p ) {
#endif /* ID_DEBUG_MEMORY */
// allocate SIZE bytes, aligned to 16 bytes - possibly on the stack (like _alloca16())
// if it's too big (> ID_MAX_ALLOCA_SIZE, 1MB), it gets allocated on the Heap instead.
// ON_STACK should be a bool and will be set to true if it was allocated on the stack
// and false if it was allocated on the heap.
// if ON_STACK is false, you must free this with Mem_FreeA() or Mem_Free16()!
// (just pass your ON_STACK bool to Mem_FreeA() and it will do the right thing)
#define Mem_MallocA( SIZE, ON_STACK ) \
( (SIZE) < ID_MAX_ALLOCA_SIZE ? ( ON_STACK=true, _alloca16(SIZE) ) : ( ON_STACK=false, Mem_Alloc16(SIZE) ) )
// free memory allocated with Mem_MallocA()
ID_INLINE void Mem_FreeA( void* ptr, bool onStack )
{
if( !onStack ) {
Mem_Free16( ptr );
}
}
/*
===============================================================================

8
neo/sys/platform.h
View file

@ -38,9 +38,11 @@ If you have questions concerning this license or the applicable additional terms
// NOTE: By default Win32 uses a 1MB stack. Doom3 1.3.1 uses 4MB (probably set after compiling with EDITBIN /STACK
// dhewm3 now uses a 8MB stack, set with a linker flag in CMakeLists.txt (/STACK:8388608 for MSVC, -Wl,--stack,8388608 for mingw)
// Linux has a 8MB stack by default, and so does macOS, at least for the main thread
// anyway, a 2MB limit alloca should be safe even when using it multiple times in the same function
#define ID_MAX_ALLOCA_SIZE 2097152 // 2MB
// Linux has a 8MB stack by default, and so does macOS, at least for the main thread.
// Anyway, a 1MB limit for _alloca() should be safe even when using it multiple times
// in the same function or callstack.
// If there's a risk of bigger stack allocations, Mem_MallocA() should be used instead.
#define ID_MAX_ALLOCA_SIZE 1048576 // 1MB
/*
===============================================================================