@@ -21,7 +21,13 @@
#include <../squirrel/sqvm.h>
#include "../core/alloc_func.hpp"
#include "../safeguards.h"
/**
* In the memory allocator for Squirrel we want to directly use malloc/realloc, so when the OS
* does not have enough memory the game does not go into unrecoverable error mode and kill the
* whole game, but rather let the AI die though then we need to circumvent MallocT/ReallocT.
*
* So no #include "../safeguards.h" here as is required, but after the allocator's implementation.
*/
/*
* If changing the call paths into the scripting engine, define this symbol to enable full debugging of allocations.
@@ -32,6 +38,13 @@
struct ScriptAllocator {
size_t allocated_size; ///< Sum of allocated data size
size_t allocation_limit; ///< Maximum this allocator may use before allocations fail
* Whether the error has already been thrown, so to not throw secondary errors in
* the handling of the allocation error. This as the handling of the error will
* throw a Squirrel error so the Squirrel stack can be dumped, however that gets
* allocated by this allocator and then you might end up in an infinite loop.
bool error_thrown;
static const size_t SAFE_LIMIT = 0x8000000; ///< 128 MiB, a safe choice for almost any situation
@@ -44,11 +57,52 @@ struct ScriptAllocator {
if (this->allocated_size > this->allocation_limit) throw Script_FatalError("Maximum memory allocation exceeded");
}
* Catch all validation for the allocation; did it allocate too much memory according
* to the allocation limit or did the allocation at the OS level maybe fail? In those
* error situations a Script_FatalError is thrown, but once that has been done further
* allocations are allowed to make it possible for Squirrel to throw the error and
* clean everything up.
* @param requested_size The requested size that was requested to be allocated.
* @param p The pointer to the allocated object, or null if allocation failed.
void CheckAllocation(size_t requested_size, const void *p)
{
if (this->allocated_size > this->allocation_limit && !this->error_thrown) {
/* Do not allow allocating more than the allocation limit, except when an error is
* already as then the allocation is for throwing that error in Squirrel, the
* associated stack trace information and while cleaning up the AI. */
this->error_thrown = true;
char buff[128];
seprintf(buff, lastof(buff), "Maximum memory allocation exceeded by " PRINTF_SIZE " bytes when allocating " PRINTF_SIZE " bytes",
this->allocated_size - this->allocation_limit, requested_size);
throw Script_FatalError(buff);
if (p == nullptr) {
/* The OS did not have enough memory to allocate the object, regardless of the
* limit imposed by OpenTTD on the amount of memory that may be allocated. */
if (this->error_thrown) {
/* The allocation is called in the error handling of a memory allocation
* failure, then not being able to allocate that small amount of memory
* means there is no other choice than to bug out completely. */
MallocError(requested_size);
char buff[64];
seprintf(buff, lastof(buff), "Out of memory. Cannot allocate " PRINTF_SIZE " bytes", requested_size);
void *Malloc(SQUnsignedInteger size)
void *p = MallocT<char>(size);
void *p = malloc(size);
this->allocated_size += size;
this->CheckAllocation(size, p);
#ifdef SCRIPT_DEBUG_ALLOCATIONS
assert(p != nullptr);
assert(this->allocations.find(p) == this->allocations.end());
@@ -73,11 +127,13 @@ struct ScriptAllocator {
this->allocations.erase(p);
#endif
void *new_p = ReallocT<char>(static_cast<char *>(p), size);
void *new_p = realloc(p, size);
this->allocated_size -= oldsize;
assert(new_p != nullptr);
@@ -104,6 +160,7 @@ struct ScriptAllocator {
this->allocated_size = 0;
this->allocation_limit = static_cast<size_t>(_settings_game.script.script_max_memory_megabytes) << 20;
if (this->allocation_limit == 0) this->allocation_limit = SAFE_LIMIT; // in case the setting is somehow zero
this->error_thrown = false;
~ScriptAllocator()
@@ -114,6 +171,14 @@ struct ScriptAllocator {
};
* For the rest of this code, the safeguards should be in place though!
ScriptAllocator *_squirrel_allocator = nullptr;
/* See 3rdparty/squirrel/squirrel/sqmem.cpp for the default allocator implementation, which this overrides */
Status change: