thread-specific storage helper

1 files changed, 77 insertions, 0 deletions

diff --git a/lib/libpthread/thread/thread_storage.c b/lib/libpthread/thread/thread_storage.c
new file mode 100644
index 00000000000..7d4012ecb35
--- /dev/null
+++ b/lib/libpthread/thread/thread_storage.c
@@ -0,0 +1,77 @@
+
+/* libpthread's stronger functions */
+
+#include <stdlib.h>
+#include <pthread.h>
+#include "pthread_private.h"
+
+void
+_libc_private_storage_lock(mutex)
+        pthread_mutex_t *mutex;
+{
+	if (__isthreaded && pthread_mutex_lock(mutex) != 0)
+		PANIC("_libc_private_storage_lock");
+}
+
+void
+_libc_private_storage_unlock(mutex)
+        pthread_mutex_t *mutex;
+{
+	if (__isthreaded && pthread_mutex_unlock(mutex) != 0)
+		PANIC("_libc_private_storage_unlock");
+}
+
+void *
+_libc_private_storage(volkey, init, initsz, error)
+	volatile struct _thread_private_key_struct * volkey;
+	void *	init;
+	size_t	initsz;
+	void *	error;
+{
+	void *result;
+	void (*cleanfn) __P((void *));
+	struct _thread_private_key_struct * key;
+
+	/* Use static storage while not threaded: */
+	if (!__isthreaded)
+		return init;
+
+	key = (struct _thread_private_key_struct *)volkey;	/* for gcc */
+
+	/* Create the key once: */
+	if (volkey->once.state == PTHREAD_NEEDS_INIT) {
+		if (pthread_mutex_lock(&key->once.mutex) != 0)
+			return error;
+		if (volkey->once.state == PTHREAD_NEEDS_INIT) {
+			if (key->cleanfn == NULL)
+				cleanfn = free;
+			else
+				cleanfn = key->cleanfn;
+			if (pthread_key_create(&key->key, cleanfn) != 0) {
+				pthread_mutex_unlock(&key->once.mutex);
+				return error;
+			}
+			key->once.state = PTHREAD_DONE_INIT;
+		}
+		pthread_mutex_unlock(&key->once.mutex);
+	}
+
+	/* XXX signals may cause re-entrancy here? */
+
+	/* Acquire this key's thread-specific storage: */
+	result = pthread_getspecific(key->key);
+
+	/* Allocate and initialise storage if unallocated: */
+	if (result == NULL) {
+		result = malloc(initsz);
+		if (result == NULL)
+			return error;
+		if (pthread_setspecific(key->key, result) != 0) {
+			free(result);
+			return error;
+		}
+		memcpy(result, init, initsz);
+	}
+
+	return result;
+}