From 3e852104105206f1adea2069bf6c9caa6c3d48ef Mon Sep 17 00:00:00 2001
From: Ali Mashtizadeh <mashti@cs.stanford.edu>
Date: Fri, 30 Jan 2015 20:47:32 -0800
Subject: [PATCH] pthread init and implementing pthread_self

---
 lib/libc/amd64/entry.S   |  1 +
 lib/libc/posix/pthread.c | 64 ++++++++++++++++++++++++++++++++++++++--
 2 files changed, 63 insertions(+), 2 deletions(-)

diff --git a/lib/libc/amd64/entry.S b/lib/libc/amd64/entry.S
index 448e144..2279bae 100644
--- a/lib/libc/amd64/entry.S
+++ b/lib/libc/amd64/entry.S
@@ -7,6 +7,7 @@
 
 .globl _start
 _start:
+    call __pthread_init
     call main
     movq %rax, %rdi
     call OSExit
diff --git a/lib/libc/posix/pthread.c b/lib/libc/posix/pthread.c
index 0631ad6..d4dc3e7 100644
--- a/lib/libc/posix/pthread.c
+++ b/lib/libc/posix/pthread.c
@@ -1,5 +1,7 @@
 
+#include <stdbool.h>
 #include <stdint.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
@@ -7,6 +9,8 @@
 #include <errno.h>
 #include <pthread.h>
 
+#include <core/mutex.h>
+
 #include <syscall.h>
 #include <sys/syscall.h>
 
@@ -17,6 +21,7 @@ struct pthread_attr {
 struct pthread {
     uint64_t	tid;
     int		errno;
+    TAILQ_ENTRY(pthread)    threadTable;
 
     // Initialization
     void	*(*entry)(void *);
@@ -24,13 +29,60 @@ struct pthread {
 
     // Termination
     void	*result;
+
+    // Condition Variables
+    TAILQ_ENTRY(pthread)    threadTable;
 };
 
+typedef TAILQ_HEAD(pthreadList, pthread) pthreadList;
+
+#define THREAD_HASH_SLOTS	32
+
+static CoreMutex __threadTableLock;
+static pthreadList __threads[THREAD_HASH_SLOTS];
+
+void
+__pthread_init(void)
+{
+    int i;
+    struct pthread *thr = (struct pthread *)malloc(sizeof(*thr));
+
+    for (i = 0; i < THREAD_HASH_SLOTS; i++) {
+	TAILQ_INIT(&__threads[i]);
+    }
+
+    if (thr == NULL) {
+	abort();
+    }
+
+    thr->tid = OSGetTID();
+    thr->entry = NULL;
+    thr->arg = 0;
+
+    CoreMutex_Init(&__threadTableLock);
+
+    CoreMutex_Lock(&__threadTableLock);
+    TAILQ_INSERT_HEAD(&__threads[thr->tid % THREAD_HASH_SLOTS], thr, threadTable);
+    CoreMutex_Unlock(&__threadTableLock);
+}
+
 pthread_t
 pthread_self(void)
 {
-    // XXX Implement
-    return NULL;
+    int tid = OSGetTID();
+    struct pthread *thr;
+
+    CoreMutex_Lock(&__threadTableLock);
+    TAILQ_FOREACH(thr, &__threads[tid % THREAD_HASH_SLOTS], threadTable) {
+	if (thr->tid == tid) {
+	    CoreMutex_Unlock(&__threadTableLock);
+	    return thr;
+	}
+    }
+    CoreMutex_Unlock(&__threadTableLock);
+
+    printf("pthread_self failed to find current thread!\n");
+    abort();
 }
 
 void
@@ -66,6 +118,10 @@ pthread_create(pthread_t *thread, const pthread_attr_t *attr,
 
     thr->tid = SYSCALL_VALUE(status);
 
+    CoreMutex_Lock(&__threadTableLock);
+    TAILQ_INSERT_HEAD(&__threads[thr->tid % THREAD_HASH_SLOTS], thr, threadTable);
+    CoreMutex_Unlock(&__threadTableLock);
+
     *thread = thr;
 
     return 0;
@@ -92,6 +148,10 @@ pthread_join(pthread_t thread, void **value_ptr)
 
     *value_ptr = (void *)thr->result;
 
+    CoreMutex_Lock(&__threadTableLock);
+    TAILQ_REMOVE(&__threads[thr->tid % THREAD_HASH_SLOTS], thr, threadTable);
+    CoreMutex_Unlock(&__threadTableLock);
+
     // Cleanup
     free(thr);