lab 4 - ok

phlalx · May 21, 2017 · b401267 · b401267
1 parent 709e34a
commit b401267
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Showing 2 changed files with 37 additions and 30 deletions.
diff --git a/lock_client_cache.cc b/lock_client_cache.cc
@@ -9,6 +9,30 @@
 #include "tprintf.h"
 #include "jsl_log.h"
 
+const char * 
+lock_client_cache::lock_info::to_string() {
+  switch(st){
+    case ACQUIRING: return "ACQUIRING";
+    case RELEASING: return "RELEASING";
+    case FREE: return "FREE";
+    case NONE: return "NONE";
+    case LOCKED: return "LOCKED";
+  }
+  return "--";
+}
+
+void 
+lock_client_cache::lock_info::set(lock_client_cache *lcc, lock_protocol::lockid_t lid, State new_st) {
+    jsl_log(JSL_DBG_ME, "lock_client_cache %s %lud %llu: ", lcc->id.c_str(), pthread_self(), lid);
+    jsl_log(JSL_DBG_ME, "%s -> ", to_string());
+    st = new_st;
+    jsl_log(JSL_DBG_ME, "%s (# = %d)\n", to_string(), number_waiting);
+    if (st == FREE || st == NONE) {
+      is_revoked = false; 
+      is_retried = false; 
+    }
+}
+
 lock_client_cache::lock_client_cache(std::string xdst, 
 				     class lock_release_user *_lu)
   : lock_client(xdst), lu(_lu)
@@ -33,16 +57,15 @@ lock_client_cache::acquire(lock_protocol::lockid_t lid)
     jsl_log(JSL_DBG_ME, "lock_client_cache %s %lud %llu: acquire\n", id.c_str(), pthread_self(), lid);
     lock_info &li = locks[lid];
 
+    while (li.st == ACQUIRING || li.st == RELEASING || li.st == LOCKED) {
+      pthread_cond_wait(&li.waiting_local, &mutex);
+    }
+
     if (li.st == FREE) {
       li.set(this, lid, LOCKED);
       return ret;
     }
-
-    if (li.st != NONE) {
-    // For now, suppose there's only one client thread
-    // meaning li.st == NONE or FREE
-      VERIFY(0);
-    }
+    VERIFY(li.st == NONE);
     li.set(this, lid, ACQUIRING);
   }
 
@@ -83,6 +106,9 @@ lock_client_cache::release(lock_protocol::lockid_t lid)
     ScopedLock ml(&mutex); 
     jsl_log(JSL_DBG_ME, "lock_client_cache %s %lud %llu: release\n", id.c_str(), pthread_self(), lid);
     lock_info &li = locks[lid];
+
+    pthread_cond_signal(&li.waiting_local); // not always necessary
+
     if (li.st == LOCKED) { 
       li.set(this, lid, FREE); 
       return ret;

diff --git a/lock_client_cache.h b/lock_client_cache.h
@@ -26,40 +26,21 @@ class lock_client_cache : public lock_client {
   struct lock_info {
 
     State st;
-    pthread_cond_t waiting_from_server;  // acquire thread
+    pthread_cond_t waiting_local;  // acquire thread
     pthread_cond_t waiting_retry;      // client thread
 
     bool is_revoked;
     bool is_retried;
 
-    const char *to_string() {
-      switch(st){
-        case ACQUIRING: return "ACQUIRING";
-        case RELEASING: return "RELEASING";
-        case FREE: return "FREE";
-        case NONE: return "NONE";
-        case LOCKED: return "LOCKED";
-      }
-      return "--";
-    }
-
-    void set(lock_client_cache *lcc, lock_protocol::lockid_t lid, State new_st) {
-        jsl_log(JSL_DBG_ME, "lock_client_cache %s %lud %llu: ", lcc->id.c_str(), pthread_self(), lid);
-        jsl_log(JSL_DBG_ME, "%s -> ", to_string());
-        st = new_st;
-        jsl_log(JSL_DBG_ME, "%s (# = %d)\n", to_string(), number_waiting);
-        if (st == FREE || st == NONE) {
-          is_revoked = false; 
-          is_retried = false; 
-        }
-    }
-
     int number_waiting;
 
+    const char * to_string();
+    void set(lock_client_cache *lcc, lock_protocol::lockid_t lid, State new_st);
+
     lock_info() {
       number_waiting = 0;
       st = NONE;
-      waiting_from_server = PTHREAD_COND_INITIALIZER; 
+      waiting_local = PTHREAD_COND_INITIALIZER; 
       waiting_retry = PTHREAD_COND_INITIALIZER; 
       is_revoked = false;
       is_retried = false;