I broke the Windows error handling code with the WT_SESSION.strerror

rework, take another run at it.

6 files changed, 78 insertions, 100 deletions

diff --git a/dist/api_err.py b/dist/api_err.py
index a35b3f931e6..d39f076656f 100644
--- a/dist/api_err.py
+++ b/dist/api_err.py
@@ -94,26 +94,39 @@ tfile.write('''/* DO NOT EDIT: automatically built by dist/api_err.py. */
  * port didn't need anything more complex; Windows requires memory allocation
  * of error strings, so we added the WT_SESSION.strerror method. Because we
  * want wiredtiger_strerror to continue to be as thread-safe as possible, errors
- * are split into three categories: WiredTiger constant strings, system constant
- * strings and Everything Else, and we check constant strings before Everything
- * Else.
+ * are split into two categories: WiredTiger's or the system's constant strings
+ * and Everything Else, and we check constant strings before Everything Else.
  */
 
 /*
- * __wiredtiger_error --
- *\tReturn a constant string for the WiredTiger errors.
+ * __wt_wiredtiger_error --
+ *\tReturn a constant string for WiredTiger POSIX-standard and errors.
  */
 const char *
 __wt_wiredtiger_error(int error)
 {
+\tconst char *p;
+
+\t/*
+\t * Check for WiredTiger specific errors.
+\t */
 \tswitch (error) {
 ''')
 
 for err in errors:
     tfile.write('\tcase ' + err.name + ':\n')
     tfile.write('\t\treturn ("' + err.name + ': ' + err.desc + '");\n')
-
 tfile.write('''\t}
+
+\t/*
+\t * POSIX errors are non-negative integers; check for 0 explicitly
+\t * in-case the underlying strerror doesn't handle 0, some don't.
+\t */
+\tif (error == 0)
+\t\treturn ("Successful return: 0");
+\tif (error > 0 && (p = strerror(error)) != NULL)
+\t\treturn (p);
+
 \treturn (NULL);
 }
 
@@ -125,20 +138,8 @@ const char *
 wiredtiger_strerror(int error)
 {
 \tstatic char buf[128];
-\tconst char *p;
-
-\t/* Check for a constant string. */
-\tif ((p = __wt_wiredtiger_error(error)) != NULL)
-\t\treturn (p);
-\tif ((p = __wt_strerror(error)) != NULL)
-\t\treturn (p);
-
-\t/* Else, fill in the non-thread-safe static buffer. */
-\tif (snprintf(buf, sizeof(buf), "error return: %d", error) > 0)
-\t\treturn (buf);
 
-\t/* OK, we're done. */
-\treturn ("Unable to return error string");
+\treturn (__wt_strerror(NULL, error, buf, sizeof(buf)));
 }
 ''')
 tfile.close()
diff --git a/src/conn/api_strerror.c b/src/conn/api_strerror.c
index f08d70969dd..e41e402a1fd 100644
--- a/src/conn/api_strerror.c
+++ b/src/conn/api_strerror.c
@@ -7,18 +7,22 @@
  * port didn't need anything more complex; Windows requires memory allocation
  * of error strings, so we added the WT_SESSION.strerror method. Because we
  * want wiredtiger_strerror to continue to be as thread-safe as possible, errors
- * are split into three categories: WiredTiger constant strings, system constant
- * strings and Everything Else, and we check constant strings before Everything
- * Else.
+ * are split into two categories: WiredTiger's or the system's constant strings
+ * and Everything Else, and we check constant strings before Everything Else.
  */
 
 /*
- * __wiredtiger_error --
- *	Return a constant string for the WiredTiger errors.
+ * __wt_wiredtiger_error --
+ *	Return a constant string for WiredTiger POSIX-standard and errors.
  */
 const char *
 __wt_wiredtiger_error(int error)
 {
+	const char *p;
+
+	/*
+	 * Check for WiredTiger specific errors.
+	 */
 	switch (error) {
 	case WT_ROLLBACK:
 		return ("WT_ROLLBACK: conflict between concurrent operations");
@@ -35,6 +39,16 @@ __wt_wiredtiger_error(int error)
 	case WT_RUN_RECOVERY:
 		return ("WT_RUN_RECOVERY: recovery must be run to continue");
 	}
+
+	/*
+	 * POSIX errors are non-negative integers; check for 0 explicitly
+	 * in-case the underlying strerror doesn't handle 0, some don't.
+	 */
+	if (error == 0)
+		return ("Successful return: 0");
+	if (error > 0 && (p = strerror(error)) != NULL)
+		return (p);
+
 	return (NULL);
 }
 
@@ -46,18 +60,6 @@ const char *
 wiredtiger_strerror(int error)
 {
 	static char buf[128];
-	const char *p;
-
-	/* Check for a constant string. */
-	if ((p = __wt_wiredtiger_error(error)) != NULL)
-		return (p);
-	if ((p = __wt_strerror(error)) != NULL)
-		return (p);
-
-	/* Else, fill in the non-thread-safe static buffer. */
-	if (snprintf(buf, sizeof(buf), "error return: %d", error) > 0)
-		return (buf);
 
-	/* OK, we're done. */
-	return ("Unable to return error string");
+	return (__wt_strerror(NULL, error, buf, sizeof(buf)));
 }
diff --git a/src/include/extern.h b/src/include/extern.h
index 3b08d79e842..af1ea057ca7 100644
--- a/src/include/extern.h
+++ b/src/include/extern.h
@@ -438,8 +438,7 @@ extern int __wt_dlopen(WT_SESSION_IMPL *session, const char *path, WT_DLH **dlhp
 extern int __wt_dlsym(WT_SESSION_IMPL *session, WT_DLH *dlh, const char *name, int fail, void *sym_ret);
 extern int __wt_dlclose(WT_SESSION_IMPL *session, WT_DLH *dlh);
 extern int __wt_errno(void);
-extern const char *__wt_strerror(int error);
-extern const char *__wt_session_strerror(WT_SESSION_IMPL *session, int error);
+extern const char *__wt_strerror(WT_SESSION_IMPL *session, int error, char *errbuf, size_t errlen);
 extern int __wt_exist(WT_SESSION_IMPL *session, const char *filename, int *existp);
 extern void __wt_fallocate_config(WT_SESSION_IMPL *session, WT_FH *fh);
 extern int __wt_fallocate( WT_SESSION_IMPL *session, WT_FH *fh, wt_off_t offset, wt_off_t len);
diff --git a/src/os_posix/os_errno.c b/src/os_posix/os_errno.c
index c022cfda6bc..229b68e0008 100644
--- a/src/os_posix/os_errno.c
+++ b/src/os_posix/os_errno.c
@@ -24,39 +24,29 @@ __wt_errno(void)
 
 /*
  * __wt_strerror --
- *	POSIX implementation of wiredtiger_strerror.
+ *	POSIX implementation of WT_SESSION.strerror and wiredtiger_strerror.
  */
 const char *
-__wt_strerror(int error)
+__wt_strerror(WT_SESSION_IMPL *session, int error, char *errbuf, size_t errlen)
 {
 	const char *p;
 
 	/*
-	 * POSIX errors are non-negative integers; check for 0 explicitly
-	 * in-case the underlying strerror doesn't handle 0, some don't.
+	 * Check for a WiredTiger or POSIX constant string, no buffer needed.
 	 */
-	if (error == 0)
-		return ("Successful return: 0");
-	if (error > 0 && (p = strerror(error)) != NULL)
+	if ((p = __wt_wiredtiger_error(error)) != NULL)
 		return (p);
-	return (NULL);
-}
 
-/*
- * __wt_session_strerror --
- *	POSIX implementation of WT_SESSION.strerror.
- */
-const char *
-__wt_session_strerror(WT_SESSION_IMPL *session, int error)
-{
-	const char *p;
-
-	/* Check for POSIX errors. */
-	if ((p = __wt_strerror(error)) != NULL)
-		return (p);
-
-	/* Fallback to a generic message. */
-	if (__wt_buf_fmt(
+	/*
+	 * When called from wiredtiger_strerror, write a passed-in buffer.
+	 * When called from WT_SESSION.strerror, write the session's buffer.
+	 *
+	 * Fallback to a generic message.
+	 */
+	if (session == NULL &&
+	    snprintf(errbuf, errlen, "error return: %d", error) > 0)
+		return (errbuf);
+	if (session != NULL && __wt_buf_fmt(
 	    session, &session->err, "error return: %d", error) == 0)
 		return (session->err.data);
 
diff --git a/src/os_win/os_errno.c b/src/os_win/os_errno.c
index c81432299a3..81bcdf9089e 100644
--- a/src/os_win/os_errno.c
+++ b/src/os_win/os_errno.c
@@ -58,43 +58,27 @@ __wt_errno(void)
 
 /*
  * __wt_strerror --
- *	Windows implementation of wiredtiger_strerror.
+ *	Windows implementation of WT_SESSION.strerror and wiredtiger_strerror.
  */
 const char *
-__wt_strerror(int error)
+__wt_strerror(WT_SESSION_IMPL *session, int error, char *errbuf, size_t errlen)
 {
+	DWORD lasterror;
 	const char *p;
+	char buf[512];
 
 	/*
-	 * POSIX errors are non-negative integers; check for 0 explicitly
-	 * in-case the underlying strerror doesn't handle 0, some don't.
+	 * Check for a WiredTiger or POSIX constant string, no buffer needed.
 	 */
-	if (error == 0)
-		return ("Successful return: 0");
-	if (error > 0 && (p = strerror(error)) != NULL)
+	if ((p = __wt_wiredtiger_error(error)) != NULL)
 		return (p);
-	return (NULL);
-}
-
-/*
- * __wt_session_strerror --
- *	Windows implementation of WT_SESSION.strerror.
- */
-const char *
-__wt_session_strerror(WT_SESSION_IMPL *session, int error)
-{
-	DWORD lasterror;
-	const char *p;
-	char buf[256];
 
 	/*
-	 * Check for POSIX errors, Windows errors, then fallback to something
-	 * generic.  Copy the string into the user's buffer, return success if
-	 * anything printed.
+	 * When called from wiredtiger_strerror, write a passed-in buffer.
+	 * When called from WT_SESSION.strerror, write the session's buffer.
+	 *
+	 * Check for Windows errors.
 	 */
-	if ((p = __wt_strerror(error)) != NULL)
-		return (p);
-
 	if (error < 0) {
 		error = __wt_map_error_to_windows_error(error);
 
@@ -108,13 +92,22 @@ __wt_session_strerror(WT_SESSION_IMPL *session, int error)
 			sizeof(buf),
 			NULL);
 
-		if (lasterror != 0 &&
+		if (lasterror != 0 && session == NULL &&
+		    snprintf(errbuf, errlen, "%s", buf) > 0)
+			return (errbuf);
+		if (lasterror != 0 && session != NULL &&
 		    __wt_buf_set(session, &session->err, buf, strlen(buf)) == 0)
 			return (session->err.data);
-
-		/* Fall through to the fallback error code */
 	}
 
+	/* Fallback to a generic message. */
+	if (session == NULL &&
+	    snprintf(errbuf, errlen, "error return: %d", error) > 0)
+		return (errbuf);
+	if (session != NULL && __wt_buf_fmt(
+	    session, &session->err, "error return: %d", error) == 0)
+		return (session->err.data);
+
 	/* Defeated. */
 	return ("Unable to return error string");
 }
diff --git a/src/session/session_api.c b/src/session/session_api.c
index 986473ae1cc..e54553aa071 100644
--- a/src/session/session_api.c
+++ b/src/session/session_api.c
@@ -910,17 +910,10 @@ static const char *
 __session_strerror(WT_SESSION *wt_session, int error)
 {
 	WT_SESSION_IMPL *session;
-	const char *p;
 
 	session = (WT_SESSION_IMPL *)wt_session;
 
-	/* Check for a constant string. */
-	if ((p = __wt_wiredtiger_error(error)) != NULL)
-		return (p);
-	if ((p = __wt_strerror(error)) != NULL)
-		return (p);
-
-	return (__wt_session_strerror(session, error));
+	return (__wt_strerror(session, error, NULL, 0));
 }
 
 /*