/// <summary>
/// Attempts to acquire the specified resources
/// </summary>
/// <param name="resources">the resources to acquire</param>
/// <param name="limitingResourceIndex">the first encountered semaphore limiting resource acquisition if any</param>
/// <param name="force">true to force acquisition of the resources even acquisition would exceed limits for the semaphores</param>
/// <returns>true if the resources where successfully acquired. False, otherwise.</returns>
public bool TryAcquireResources(ItemResources resources, out int?limitingResourceIndex, bool force = false)
{
if (!resources.IsValid || resources.SemaphoreIncrements.Length == 0)
{
limitingResourceIndex = null;
return(true);
}
lock (SyncLock)
{
if (!HasAvailableResourcesCore(resources, out limitingResourceIndex, force))
{
return(false);
}
for (int i = 0; i < resources.SemaphoreIncrements.Length; i++)
{
int usageCount = resources.SemaphoreIncrements[i];
if (usageCount == 0)
{
continue;
}
m_semaphoreUsages[i] += usageCount;
Contract.Assume(force || m_semaphoreUsages[i] <= SemaphoreLimits[i]);
}
}
limitingResourceIndex = null;
return(true);
}
private bool HasAvailableResourcesCore(ItemResources resources, out int?limitingResourceIndex, bool force = false)
{
Contract.Assume(
resources.SemaphoreIncrements.Length <= SemaphoreLimits.Count,
"ItemResources uses unknown semaphore indices.");
Array.Resize(ref m_semaphoreUsages, SemaphoreLimits.Count);
if (!force)
{
for (int i = 0; i < resources.SemaphoreIncrements.Length; i++)
{
int usageCount = resources.SemaphoreIncrements[i];
if (usageCount == 0)
{
continue;
}
if ((m_semaphoreUsages[i] + usageCount) > SemaphoreLimits[i])
{
limitingResourceIndex = i;
return(false);
}
}
}
limitingResourceIndex = null;
return(true);
}
/// <summary>
/// Gets whether the semaphore set currently can acquire the given resources
/// </summary>
/// <param name="resources">the resources to acquire</param>
/// <returns>true if the resources where available. False, otherwise.</returns>
public bool HasAvailableResources(ItemResources resources)
{
if (!resources.IsValid || resources.SemaphoreIncrements.Length == 0)
{
return(true);
}
lock (SyncLock)
{
return(HasAvailableResourcesCore(resources, out int?limitingResourceIndex));
}
}
/// <summary>
/// Releases the resources
/// </summary>
public void ReleaseResources(ItemResources resources)
{
if (!resources.IsValid || resources.SemaphoreIncrements.Length == 0)
{
return;
}
lock (SyncLock)
{
Array.Resize(ref m_semaphoreUsages, SemaphoreLimits.Count);
for (int i = 0; i < resources.SemaphoreIncrements.Length; i++)
{
int usageCount = resources.SemaphoreIncrements[i];
m_semaphoreUsages[i] -= usageCount;
Contract.Assume(m_semaphoreUsages[i] >= 0);
}
}
}
/// <summary>
/// Attempts to acquire the specified resources
/// </summary>
/// <param name="resources">the resources to acquire</param>
/// <param name="force">true to force acquisition of the resources even acquisition would exceed limits for the semaphores</param>
/// <returns>true if the resources where successfully acquired. False, otherwise.</returns>
public bool TryAcquireResources(ItemResources resources, bool force = false)
{
int?limitingResourceIndex;
return(TryAcquireResources(resources, out limitingResourceIndex, force));
}
/// <summary>
/// Creates an instance
/// </summary>
public ItemSemaphoreQueuedEventArgs(bool queued, TItem item, ItemResources itemResources)
{
Queued = queued;
Item = item;
ItemResources = itemResources;
}