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#include <util/mutex.h>
#include <globals.h>
void mutex_init(void)
{
for (unsigned long m = 0; m < MAX_MUTEXS; m++) {
mutexs[m].pid = 0;
mutexs[m].addr = 0;
mutex_entries[m].value = &mutexs[m];
mutex_entries[m].entry_type = VALUE_ENTRY;
mutex_entries[m].next = &mutex_entries[(m+1)%MAX_MUTEXS];
}
// Initialize Free Mutexs
mutex_manager.free.start.value = 0;
mutex_manager.free.start.next = &mutex_entries[0];
mutex_manager.free.start.entry_type = START_ENTRY;
mutex_manager.free.end.value = 0;
mutex_manager.free.end.next = &mutex_entries[MAX_MUTEXS-1];
mutex_entries[MAX_MUTEXS-1].next = &mutex_manager.free.end;
mutex_manager.free.end.entry_type = END_ENTRY;
// Initialize In-use Mutexs
mutex_manager.used.start.value = 0;
mutex_manager.used.start.next = &mutex_manager.used.end;
mutex_manager.used.start.entry_type = START_ENTRY;
mutex_manager.used.end.value = 0;
mutex_manager.used.end.next = &mutex_manager.used.start;
mutex_manager.used.end.entry_type = END_ENTRY;
}
struct Mutex* create_mutex(void* addr)
{
struct Entry* e = pop_from_queue(&mutex_manager.free);
if (e == 0)
return 0;
struct Mutex* m = e->value;
m->pid = 0;
m->addr = addr;
push_to_queue(e, &mutex_manager.used);
return e->value;
}
unsigned char delete_mutex(struct Mutex* m)
{
struct Entry* entry = find_value(m, &mutex_manager.used);
if (entry == 0)
return 1;
// Remove it from the queue
remove_next_from_queue(entry);
// Add it to the free queue
prepend_to_queue(entry, &mutex_manager.free);
return 0;
}
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