Kernel/Semaphores: Addressed some issues.

This commit is contained in:
Subv 2014-12-12 20:46:52 -05:00
parent cc81a510e3
commit 5e25986235
2 changed files with 20 additions and 34 deletions

View File

@ -27,11 +27,11 @@ public:
std::string name; ///< Name of semaphore (optional) std::string name; ///< Name of semaphore (optional)
/** /**
* Tests whether a semaphore is at its peak capacity * Tests whether a semaphore still has free slots
* @return Whether the semaphore is full * @return Whether the semaphore is available
*/ */
bool IsFull() const { bool IsAvailable() const {
return current_usage == max_count; return current_usage < max_count;
} }
ResultVal<bool> WaitSynchronization() override { ResultVal<bool> WaitSynchronization() override {
@ -50,42 +50,27 @@ public:
//////////////////////////////////////////////////////////////////////////////////////////////////// ////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* Creates a semaphore
* @param initial_count number of slots reserved for other threads
* @param max_count maximum number of holders the semaphore can have
* @param name Optional name of semaphore
* @return Handle for the newly created semaphore
*/
Handle CreateSemaphore(u32 initial_count,
u32 max_count, const std::string& name) {
Semaphore* semaphore = new Semaphore;
Handle handle = g_object_pool.Create(semaphore);
semaphore->initial_count = initial_count;
// When the semaphore is created, some slots are reserved for other threads,
// and the rest is reserved for the caller thread
semaphore->max_count = semaphore->current_usage = max_count;
semaphore->current_usage -= initial_count;
semaphore->name = name;
return handle;
}
ResultCode CreateSemaphore(Handle* handle, u32 initial_count, ResultCode CreateSemaphore(Handle* handle, u32 initial_count,
u32 max_count, const std::string& name) { u32 max_count, const std::string& name) {
if (initial_count > max_count) if (initial_count > max_count)
return ResultCode(ErrorDescription::InvalidCombination, ErrorModule::Kernel, return ResultCode(ErrorDescription::InvalidCombination, ErrorModule::Kernel,
ErrorSummary::WrongArgument, ErrorLevel::Permanent); ErrorSummary::WrongArgument, ErrorLevel::Permanent);
*handle = CreateSemaphore(initial_count, max_count, name);
Semaphore* semaphore = new Semaphore;
*handle = g_object_pool.Create(semaphore);
semaphore->initial_count = initial_count;
// When the semaphore is created, some slots are reserved for other threads,
// and the rest is reserved for the caller thread
semaphore->max_count = max_count;
semaphore->current_usage = max_count - initial_count;
semaphore->name = name;
return RESULT_SUCCESS; return RESULT_SUCCESS;
} }
ResultCode ReleaseSemaphore(s32* count, Handle handle, s32 release_count) { ResultCode ReleaseSemaphore(s32* count, Handle handle, s32 release_count) {
Semaphore* semaphore = g_object_pool.Get<Semaphore>(handle); Semaphore* semaphore = g_object_pool.Get<Semaphore>(handle);
if (semaphore == nullptr) if (semaphore == nullptr)
return InvalidHandle(ErrorModule::Kernel); return InvalidHandle(ErrorModule::Kernel);
@ -99,7 +84,7 @@ ResultCode ReleaseSemaphore(s32* count, Handle handle, s32 release_count) {
// Notify some of the threads that the semaphore has been released // Notify some of the threads that the semaphore has been released
// stop once the semaphore is full again or there are no more waiting threads // stop once the semaphore is full again or there are no more waiting threads
while (!semaphore->waiting_threads.empty() && !semaphore->IsFull()) { while (!semaphore->waiting_threads.empty() && semaphore->IsAvailable()) {
Kernel::ResumeThreadFromWait(semaphore->waiting_threads.front()); Kernel::ResumeThreadFromWait(semaphore->waiting_threads.front());
semaphore->waiting_threads.pop(); semaphore->waiting_threads.pop();
semaphore->current_usage++; semaphore->current_usage++;

View File

@ -11,21 +11,22 @@
namespace Kernel { namespace Kernel {
/** /**
* Creates a semaphore * Creates a semaphore.
* @param handle Pointer to the handle of the newly created object * @param handle Pointer to the handle of the newly created object
* @param initial_count number of slots reserved for other threads * @param initial_count Number of slots reserved for other threads
* @param max_count maximum number of slots the semaphore can have * @param max_count Maximum number of slots the semaphore can have
* @param name Optional name of semaphore * @param name Optional name of semaphore
* @return ResultCode of the error * @return ResultCode of the error
*/ */
ResultCode CreateSemaphore(Handle* handle, u32 initial_count, u32 max_count, const std::string& name = "Unknown"); ResultCode CreateSemaphore(Handle* handle, u32 initial_count, u32 max_count, const std::string& name = "Unknown");
/** /**
* Releases a certain number of slots from a semaphore * Releases a certain number of slots from a semaphore.
* @param count The number of free slots the semaphore had before this call * @param count The number of free slots the semaphore had before this call
* @param handle The handle of the semaphore to release * @param handle The handle of the semaphore to release
* @param release_count The number of slots to release * @param release_count The number of slots to release
* @return ResultCode of the error * @return ResultCode of the error
*/ */
ResultCode ReleaseSemaphore(s32* count, Handle handle, s32 release_count); ResultCode ReleaseSemaphore(s32* count, Handle handle, s32 release_count);
} // namespace } // namespace