X-Git-Url: http://mj.ucw.cz/gitweb/?a=blobdiff_plain;f=ucw%2Ftrans.h;h=3d52172f4e7bac038bf122e6b2e4101a779df7e4;hb=a6368763d08042207963c941b1c52b5fafcb0cb3;hp=95d9ce116700456fde15ee645d46b1322a509e8b;hpb=2eccc3083bc077da6ee2623e9c4bf4ded58941ac;p=libucw.git

diff --git a/ucw/trans.h b/ucw/trans.h
index 95d9ce11..3d52172f 100644
--- a/ucw/trans.h
+++ b/ucw/trans.h
@@ -1,7 +1,7 @@
 /*
  *	The UCW Library -- Transactions
  *
- *	(c) 2008 Martin Mares <mj@ucw.cz>
+ *	(c) 2008--2011 Martin Mares <mj@ucw.cz>
  *
  *	This software may be freely distributed and used according to the terms
  *	of the GNU Lesser General Public License.
@@ -10,51 +10,74 @@
 #ifndef _UCW_TRANS_H
 #define _UCW_TRANS_H
 
-#include "ucw/mempool.h"
+#include <ucw/mempool.h>
 
 #include <setjmp.h>
 
-/* Transactions */
+#ifdef CONFIG_UCW_CLEAN_ABI
+#define trans_caught ucw_trans_caught
+#define trans_cleanup ucw_trans_cleanup
+#define trans_commit ucw_trans_commit
+#define trans_current_exc ucw_trans_current_exc
+#define trans_dump ucw_trans_dump
+#define trans_fold ucw_trans_fold
+#define trans_get_current ucw_trans_get_current
+#define trans_get_pool ucw_trans_get_pool
+#define trans_init ucw_trans_init
+#define trans_open ucw_trans_open
+#define trans_rollback ucw_trans_rollback
+#define trans_throw ucw_trans_throw
+#define trans_throw_exc ucw_trans_throw_exc
+#define trans_vthrow ucw_trans_vthrow
+#endif
 
+/** A structure describing a transaction. All fields are for internal use only. **/
 struct trans {
   struct trans *prev_trans;
   struct mempool_state *trans_pool_state;
   struct respool *rpool;
   struct respool *prev_rpool;
+  struct exception *thrown_exc;
   jmp_buf jmp;
 };
 
-void trans_init(void);		// Called automatically on trans_open() if needed
-void trans_cleanup(void);	// Free memory occupied by the transaction system pools
+void trans_init(void);		/** Initializes the transaction system for the current thread. Called automatically as needed. **/
+void trans_cleanup(void);	/** Frees memory occupied by the transaction system pools for the current thread. **/
 
-struct trans *trans_open_rp(struct respool *rp);
-static inline struct trans *trans_open(void)
-{
-  return trans_open_rp(NULL);
-}
-struct trans *trans_get_current(void);
-void trans_commit(void);
-void trans_rollback(void);
-void trans_dump(void);
+struct trans *trans_open(void);	/** Creates a new transaction. Used inside `TRANS_TRY`. **/
+struct trans *trans_get_current(void);	/** Get a pointer to the currently running transaction, or NULL if there is none. **/
+void trans_commit(void);	/** Commits the current transaction. **/
+void trans_rollback(void);	/** Rolls back the current transaction. **/
+void trans_fold(void);		/** Folds the current transaction to its parent. **/
+void trans_dump(void);		/** Prints out a debugging dump of the transaction stack to stdout. **/
 
 struct mempool *trans_get_pool(void);
-struct mempool *trans_get_exc_pool(void);
-
-/* Exceptions */
 
+/**
+ * Data associated with an exception. Usually, this structure is created
+ * by calling @trans_throw(), but if you want to pass more data, you can
+ * create your own exception and throw it using @trans_throw_exc().
+ **/
 struct exception {
-  const char *id;		// Hierarchic identifier of the exception
+  const char *id;		// Hierarchical identifier of the exception
   const char *msg;		// Error message to present to the user
   void *object;			// Object on which the exception happened
-  struct trans *trans;		// Transaction in which it happened (set by trans_throw*)
   // More data specific for the particular `id' can follow
 };
 
-void trans_throw_exc(struct exception *x) NONRET;
+/** Creates an exception and throws it. The error message can contain `printf`-like formatting. **/
 void trans_throw(const char *id, void *object, const char *fmt, ...) FORMAT_CHECK(printf,3,4) NONRET;
+
+/** A `va_list` variant of @trans_throw(). **/
 void trans_vthrow(const char *id, void *object, const char *fmt, va_list args) NONRET;
 
-struct exception *trans_current_exc(void);
+/** Throw an already constructed exception (or re-throw an exception you have caught). **/
+void trans_throw_exc(struct exception *x) NONRET;
+
+/** Declare the current exception caught and roll back the current transaction. Called from `TRANS_END`. **/
+void trans_caught(void);
+
+struct exception *trans_current_exc(void);	/** Return the exception in flight, or NULL if there is none. **/
 
 #define TRANS_TRY do {				\
   struct trans *_t = trans_open();		\
@@ -69,7 +92,7 @@ struct exception *trans_current_exc(void);
       struct exception *x UNUSED = trans_current_exc();
 
 #define TRANS_END				\
-      trans_rollback();				\
+      trans_caught();				\
     }						\
   } while(0)