AK: Use get_random() in IDAllocator

Also generate a new random ID on collision, instead of using
the old ID + 1. :^)

SonarCloud: https://sonarcloud.io/project/security_hotspots?id=SerenityOS_serenity&hotspots=AXuVPBMNk92xXUF3qWZd
This commit is contained in:
Andreas Kling 2021-08-30 13:50:01 +02:00
parent eaf904000f
commit 9fd58fd6d8

View file

@ -8,9 +8,11 @@
#include <AK/Forward.h>
#include <AK/HashTable.h>
#include <AK/Random.h>
namespace AK {
// This class manages a pool of random ID's in the range 1..INT32_MAX
class IDAllocator {
public:
@ -19,18 +21,16 @@ public:
int allocate()
{
int r = rand();
for (int i = 0; i < 100000; ++i) {
int allocated_id = r + i;
// Make sure we never vend ID 0, as some code may interpret that as "no ID"
if (allocated_id == 0)
++allocated_id;
if (!m_allocated_ids.contains(allocated_id)) {
m_allocated_ids.set(allocated_id);
return allocated_id;
}
VERIFY(m_allocated_ids.size() < (INT32_MAX - 2));
int id = 0;
for (;;) {
id = static_cast<int>(get_random_uniform(NumericLimits<int>::max()));
if (id == 0)
continue;
if (m_allocated_ids.set(id) == AK::HashSetResult::InsertedNewEntry)
break;
}
VERIFY_NOT_REACHED();
return id;
}
void deallocate(int id)