pthread: add pthread_{getspecific,setspecific,key_create}

Makefile

@@ -22,6 +22,7 @@ drivers += elf.o
 objects = exceptions.o
 objects += entry.o
 objects += mutex.o
+objects += pthread.o
 
 libc = libc/string/strcmp.o
 

pthread.cc

+#include "mutex.hh"
+#include <pthread.h>
+#include <errno.h>
+#include <mutex>
+#include <vector>
+#include <algorithm>
+
+namespace pthread_private {
+
+    const unsigned tsd_nkeys = 100;
+
+    __thread void* tsd[tsd_nkeys];
+
+    mutex tsd_key_mutex;
+    std::vector<bool> tsd_used_keys(tsd_nkeys);
+}
+
+using namespace pthread_private;
+
+pthread_key_t pthread_key_create()
+{
+    std::lock_guard<mutex> guard(tsd_key_mutex);
+    auto p = std::find(tsd_used_keys.begin(), tsd_used_keys.end(), false);
+    if (p == tsd_used_keys.end()) {
+        return ENOMEM;
+    }
+    *p = true;
+}
+
+void* pthread_getspecific(pthread_key_t key)
+{
+    return tsd[key];
+}
+
+int pthread_setspecific(pthread_key_t key, void* value)
+{
+    tsd[key] = value;
+    return 0;
+}