X-Git-Url: http://git.silcnet.org/gitweb/?a=blobdiff_plain;f=lib%2Fsilcutil%2Fsilcmutex.h;h=6e8efeb2b7dfd807ed63d9696f005351bb23d3bf;hb=e7b6c157b80152bf9fb9266e6bdd93f9fb0db776;hp=52407855d648726701c08bda6cb032282fd3230d;hpb=cb7c2ffa5dbe4332ca22ddb46b0517aadbf49714;p=silc.git

diff --git a/lib/silcutil/silcmutex.h b/lib/silcutil/silcmutex.h
index 52407855..6e8efeb2 100644
--- a/lib/silcutil/silcmutex.h
+++ b/lib/silcutil/silcmutex.h
@@ -4,7 +4,7 @@
 
   Author: Pekka Riikonen <priikone@silcnet.org>
 
-  Copyright (C) 2001 - 2005 Pekka Riikonen
+  Copyright (C) 2001 - 2007 Pekka Riikonen
 
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -21,9 +21,9 @@
  *
  * DESCRIPTION
  *
- * Interface for the SILC Mutex locking implementation. This is platform
- * independent mutual exclusion interface for applications that need
- * concurrency control.
+ * Interface for mutual exclusion locks and read/write locks.  This is
+ * platform independent interface for applications that need concurrency
+ * control.
  *
  ***/
 
@@ -45,6 +45,21 @@
  ***/
 typedef struct SilcMutexStruct *SilcMutex;
 
+/****s* silcutil/SilcMutexAPI/SilcRwLock
+ *
+ * NAME
+ *
+ *    typedef struct SilcRwLockStruct *SilcRwLock;
+ *
+ * DESCRIPTION
+ *
+ *    This context is the actual SILC read/write lock and is allocated
+ *    by silc_rwlock_alloc and given as argument to all silc_rwlock_*
+ *    functions.  It is freed by the silc_rwlock_free function.
+ *
+ ***/
+typedef struct SilcRwLockStruct *SilcRwLock;
+
 /****f* silcutil/SilcMutexAPI/silc_mutex_alloc
  *
  * SYNOPSIS
@@ -56,7 +71,8 @@ typedef struct SilcMutexStruct *SilcMutex;
  *    Allocates SILC Mutex object.  The mutex object must be allocated
  *    before it can be used.  It is freed by the silc_mutex_free function.
  *    This returns TRUE and allocated mutex in to the `mutex' and FALSE
- *    on error.
+ *    on error.  If threads support is not compiled in this returns FALSE,
+ *    but should not be considered as an error.
  *
  ***/
 SilcBool silc_mutex_alloc(SilcMutex *mutex);
@@ -112,10 +128,106 @@ void silc_mutex_lock(SilcMutex mutex);
  * NOTES
  *
  *    The caller must not call the silc_mutex_unlock for an unlocked
- *    mutex or mutex not locked by the current thread.  It is fatal
- *    error if this occurs.
+ *    mutex or mutex not locked by the current thread.
  *
  ***/
 void silc_mutex_unlock(SilcMutex mutex);
 
+/****f* silcutil/SilcMutexAPI/silc_mutex_assert_locked
+ *
+ * SYNOPSIS
+ *
+ *    void silc_mutex_assert_locked(SilcMutex mutex);
+ *
+ * DESCRIPTION
+ *
+ *    Asserts that the `mutex' is locked.  It is fatal error if the mutex
+ *    is not locked.  If debugging is not compiled in this function has
+ *    no effect (SILC_DEBUG define).
+ *
+ ***/
+void silc_mutex_assert_locked(SilcMutex mutex);
+
+/****f* silcutil/SilcMutexAPI/silc_rwlock_alloc
+ *
+ * SYNOPSIS
+ *
+ *    SilcBool silc_rwlock_alloc(SilcRwLock *rwlock);
+ *
+ * DESCRIPTION
+ *
+ *    Allocates SILC read/write lock.  The read/write lock must be allocated
+ *    before it can be used.  It is freed by the silc_rwlock_free function.
+ *    This returns TRUE and allocated read/write lock in to the `rwlock' and
+ *    FALSE on error.
+ *
+ ***/
+SilcBool silc_rwlock_alloc(SilcRwLock *rwlock);
+
+/****f* silcutil/SilcRwLockAPI/silc_rwlock_free
+ *
+ * SYNOPSIS
+ *
+ *    void silc_rwlock_free(SilcRwLock rwlock);
+ *
+ * DESCRIPTION
+ *
+ *    Free SILC Rwlock object and frees all allocated memory.  If `rwlock'
+ *    is NULL this function has no effect.
+ *
+ ***/
+void silc_rwlock_free(SilcRwLock rwlock);
+
+/****f* silcutil/SilcRwLockAPI/silc_rwlock_rdlock
+ *
+ * SYNOPSIS
+ *
+ *    void silc_rwlock_rdlock(SilcRwLock rwlock);
+ *
+ * DESCRIPTION
+ *
+ *    Acquires read lock of the read/write lock `rwlock'.  If the `rwlock'
+ *    is locked by a writer the current thread will block until the other
+ *    thread has issued silc_rwlock_unlock for the `rwlock'.  This function
+ *    may be called multiple times to acquire the read lock.  There must be
+ *    same number of silc_rwlock_unlock calls.  If `rwlock' is NULL this
+ *    function has no effect.
+ *
+ ***/
+void silc_rwlock_rdlock(SilcRwLock rwlock);
+
+/****f* silcutil/SilcRwLockAPI/silc_rwlock_wrlock
+ *
+ * SYNOPSIS
+ *
+ *    void silc_rwlock_wrlock(SilcRwLock rwlock);
+ *
+ * DESCRIPTION
+ *
+ *    Acquires write lock of the read/write lock `rwlock'.  If the `rwlock'
+ *    is locked by a writer or a reader the current thread will block until
+ *    the other thread(s) have issued silc_rwlock_unlock for the `rwlock'.
+ *    A thread may acquire the write lock only once.  A deadlock may occur
+ *    if thread attempts to acquire the write lock when it has already done
+ *    so.  If `rwlock' is NULL this function has no effect.
+ *
+ ***/
+void silc_rwlock_wrlock(SilcRwLock rwlock);
+
+/****f* silcutil/SilcRwLockAPI/silc_rwlock_unlock
+ *
+ * SYNOPSIS
+ *
+ *    void silc_rwlock_unlock(SilcRwLock rwlock);
+ *
+ * DESCRIPTION
+ *
+ *    Releases the lock of the read/write lock `rwlock'.  If `rwlock' was
+ *    locked by a writer this will release the writer lock.  Otherwise this
+ *    releases the reader lock.  If `rwlock' is NULL this function has no
+ *    effect.
+ *
+ ***/
+void silc_rwlock_unlock(SilcRwLock rwlock);
+
 #endif