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HH snippet
#include <pthread.h>
struct osx_thread_control
{
pthread_mutex_t *SuspendMutex;
pthread_cond_t *ResumeCond;
};
struct work_queue_entry_storage
{
void *UserPointer;
};
struct work_queue
{
uint32 volatile EntryCompletionCount;
uint32 volatile NextEntryToDo;
uint32 volatile EntryCount;
work_queue_entry_storage Entries[256];
};
struct work_queue_entry
{
void *Data;
bool32 IsValid;
};
inline uint32
InterlockedIncrement(uint32 volatile *p)
{
return __atomic_add_fetch(p, 1, __ATOMIC_SEQ_CST);
}
internal void
AddWorkQueueEntry(work_queue *Queue, osx_thread_control *Control, void *Pointer)
{
Assert(Queue->EntryCount < ArrayCount(Queue->Entries));
Queue->Entries[Queue->EntryCount].UserPointer = Pointer;
asm volatile("" ::: "memory");
_mm_sfence();
++Queue->EntryCount;
pthread_mutex_lock(Control->SuspendMutex);
pthread_cond_broadcast(Control->ResumeCond);
pthread_mutex_unlock(Control->SuspendMutex);
}
internal work_queue_entry
CompleteAndGetNextWorkQueueEntry(work_queue *Queue, work_queue_entry Completed)
{
work_queue_entry Result;
Result.IsValid = false;
if (Completed.IsValid)
{
InterlockedIncrement(&Queue->EntryCompletionCount);
}
if (Queue->NextEntryToDo < Queue->EntryCount)
{
uint32 Index = InterlockedIncrement(&Queue->NextEntryToDo) - 1;
Result.Data = Queue->Entries[Index].UserPointer;
Result.IsValid = true;
asm volatile("" ::: "memory");
}
return Result;
}
internal bool32
QueueWorkStillInProgress(work_queue *Queue)
{
bool32 Result = (Queue->EntryCount != Queue->EntryCompletionCount);
return Result;
}
inline void
DoWorkerWork(work_queue_entry Entry, int LogicalThreadIndex)
{
Assert(Entry.IsValid);
printf("Thread %u: %s\n", LogicalThreadIndex, (char *)Entry.Data);
}
struct osx_thread_info
{
int LogicalThreadIndex;
pthread_t ThreadID;
work_queue *Queue;
osx_thread_control *Control;
};
void *
ThreadProc(void *lpParameter)
{
osx_thread_info *ThreadInfo = (osx_thread_info *)lpParameter;
work_queue_entry Entry = {};
for(;;)
{
Entry = CompleteAndGetNextWorkQueueEntry(ThreadInfo->Queue, Entry);
if (Entry.IsValid)
{
DoWorkerWork(Entry, ThreadInfo->LogicalThreadIndex);
} else {
pthread_mutex_lock(ThreadInfo->Control->SuspendMutex);
pthread_cond_wait(ThreadInfo->Control->ResumeCond, ThreadInfo->Control->SuspendMutex);
pthread_mutex_unlock(ThreadInfo->Control->SuspendMutex);
}
}
}
internal void
PushString(work_queue *Queue, osx_thread_control *Control, char *String)
{
AddWorkQueueEntry(Queue, Control, String);
}
int main() {
/* init hi-res time */
osxInitHrtime();
/* multithreading */
pthread_mutex_t SuspendMutex;
pthread_cond_t ResumeCond;
pthread_mutex_init(&SuspendMutex, NULL);
pthread_cond_init(&ResumeCond, NULL);
osx_thread_control ThreadControl = {};
ThreadControl.SuspendMutex = &SuspendMutex;
ThreadControl.ResumeCond = &ResumeCond;
osx_thread_info ThreadInfo[7];
work_queue Queue = {};
uint32 InitialCount = 1;
uint32 ThreadCount = ArrayCount(ThreadInfo);
for(uint32 ThreadIndex = 0;
ThreadIndex < ThreadCount;
++ThreadIndex)
{
osx_thread_info *Info = ThreadInfo + ThreadIndex;
Info->Queue = &Queue;
Info->Control = &ThreadControl;
Info->LogicalThreadIndex = ThreadIndex;
pthread_create(&Info->ThreadID, NULL, &ThreadProc, Info);
}
PushString(&Queue, &ThreadControl, (char *)"String A0");
PushString(&Queue, &ThreadControl, (char *)"String A1");
PushString(&Queue, &ThreadControl, (char *)"String A2");
PushString(&Queue, &ThreadControl, (char *)"String A3");
PushString(&Queue, &ThreadControl, (char *)"String A4");
PushString(&Queue, &ThreadControl, (char *)"String A5");
PushString(&Queue, &ThreadControl, (char *)"String A6");
PushString(&Queue, &ThreadControl, (char *)"String A7");
PushString(&Queue, &ThreadControl, (char *)"String A8");
PushString(&Queue, &ThreadControl, (char *)"String A9");
PushString(&Queue, &ThreadControl, (char *)"String B0");
PushString(&Queue, &ThreadControl, (char *)"String B1");
PushString(&Queue, &ThreadControl, (char *)"String B2");
PushString(&Queue, &ThreadControl, (char *)"String B3");
PushString(&Queue, &ThreadControl, (char *)"String B4");
PushString(&Queue, &ThreadControl, (char *)"String B5");
PushString(&Queue, &ThreadControl, (char *)"String B6");
PushString(&Queue, &ThreadControl, (char *)"String B7");
PushString(&Queue, &ThreadControl, (char *)"String B8");
PushString(&Queue, &ThreadControl, (char *)"String B9");
work_queue_entry Entry = {};
while (QueueWorkStillInProgress(&Queue))
{
Entry = CompleteAndGetNextWorkQueueEntry(&Queue, Entry);
if (Entry.IsValid)
{
DoWorkerWork(Entry, 7);
}
}
// ...
for(uint ThreadIndex = 0;
ThreadIndex < ThreadCount;
++ThreadIndex)
{
osx_thread_info *Info = ThreadInfo + ThreadIndex;
pthread_cancel(Info->ThreadID);
}
pthread_mutex_destroy(&SuspendMutex);
pthread_cond_destroy(&ResumeCond);
mainWindow.close();
return 0;
}
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