Provide a libsmbclient interface for programs requiring threads

- This adds two functions: smbc_thread_posix() which provides access to the
  internal threading implementation using pthread; and smbc_thread_impl()
  where the user provides each of the functions required by Samba, to give
  access to the thread implementation's native capabilities.

Derrell

1 files changed, 109 insertions, 0 deletions

diff --git a/source3/include/libsmbclient.h b/source3/include/libsmbclient.h
index 869aeb6a03..3b38b30c32 100644
--- a/source3/include/libsmbclient.h
+++ b/source3/include/libsmbclient.h
@@ -2696,6 +2696,115 @@ smbc_set_credentials_with_fallback(SMBCCTX *ctx,
 			     	   const char *user,
 			    	   const char *password);
 
+
+/**
+ * @ingroup threads
+ *
+ * Initialize for threads using the Posix Threads (pthread)
+ * implementation. This is a built-in implementation, avoiding the need to
+ * implement the component functions of the thread interface. If this function
+ * is used, it is not necessary to call smbc_thread_impl().
+ *
+ * @return {void}
+ */
+void
+smbc_thread_posix(void);
+
+/**
+ * @ingroup threads
+ *
+ * Initialize for an arbitrary thread implementation. The caller should
+ * provide, as parameters, pointers to functions to implement the requisite
+ * low-level thread functionality. A function must be provided for each
+ * parameter; none may be null.
+ *
+ * If the thread implementation is POSIX Threads (pthreads), then the much
+ * simpler smbc_thread_pthread() function may be used instead of this one.
+ *
+ * @param create_mutex
+ *   Create a mutex. This function should expect three parameters: lockname,
+ *   pplock, and location. It should create a unique mutex for each unique
+ *   lockname it is provided, and return the mutex identifier in *pplock. The
+ *   location parameter can be used for debugging, as it contains the
+ *   compiler-provided __location__ of the call.
+ *
+ * @param destroy_mutex
+ *   Destroy a mutex. This function should expect two parameters: plock and
+ *   location. It should destroy the mutex associated with the identifier
+ *   plock. The location parameter can be used for debugging, as it contains
+ *   the compiler-provided __location__ of the call.
+ *
+ * @param lock_mutex
+ *   Lock a mutex. This function should expect three parameters: plock,
+ *   lock_type, and location. The mutex aassociated with identifier plock
+ *   should be locked if lock_type is 1, and unlocked if lock_type is 2. The
+ *   location parameter can be used for debugging, as it contains the
+ *   compiler-provided __location__ of the call.
+ *
+ * @param create_tls
+ *   Create thread local storage. This function should expect three
+ *   parameters: keyname, ppkey, and location. It should allocate an
+ *   implementation-specific amount of memory and assign the pointer to that
+ *   allocated memory to *ppkey. The location parameter can be used for
+ *   debugging, as it contains the compiler-provided __location__ of the
+ *   call. This function should return 0 upon success, non-zero upon failure.
+ *
+ * @param destroy_tls
+ *   Destroy thread local storage. This function should expect two parameters:
+ *   ppkey and location. The ppkey parameter points to a variable containing a
+ *   thread local storage key previously provided by the create_tls
+ *   function. The location parameter can be used for debugging, as it
+ *   contains the compiler-provided __location__ of the call.
+ *
+ * @param set_tls
+ *   Set a thread local storage variable's value. This function should expect
+ *   three parameters: pkey, pval, and location. The pkey parameter is a
+ *   thread local storage key previously provided by the create_tls
+ *   function. The (void *) pval parameter contains the value to be placed in
+ *   the thread local storage variable identified by pkey. The location
+ *   parameter can be used for debugging, as it contains the compiler-provided
+ *   __location__ of the call. This function should return 0 upon success;
+ *   non-zero otherwise.
+ *
+ * @param get_tls
+ *   Retrieve a thread local storage variable's value. This function should
+ *   expect two parameters: pkey and location. The pkey parameter is a thread
+ *   local storage key previously provided by the create_tls function, and
+ *   which has previously been used in a call to the set_tls function to
+ *   initialize a thread local storage variable. The location parameter can be
+ *   used for debugging, as it contains the compiler-provided __location__ of
+ *   the call. This function should return the (void *) value stored in the
+ *   variable identified by pkey.
+ *
+ * @return {void}
+ */
+void
+smbc_thread_impl(
+        /* Mutex functions. */
+        int (*create_mutex)(const char *lockname,
+                            void **pplock,
+                            const char *location);
+        void (*destroy_mutex)(void *plock,
+                              const char *location);
+        int (*lock_mutex)(void *plock,
+                          int lock_type,
+                          const char *location);
+    
+        /* Thread local storage. */
+        int (*create_tls)(const char *keyname,
+                          void **ppkey,
+                          const char *location);
+        void (*destroy_tls)(void **ppkey,
+                            const char *location);
+        int (*set_tls)(void *pkey,
+                       const void *pval,
+                       const char *location);
+        void *(*get_tls)(void *pkey,
+                         const char *location);
+        );
+
+
+
 /**
  * @ingroup structure
  * Structure that contains a client context information