Silence automake portability warnings caused by multiple inference rules. -- kevin...

[rrdtool.git] / src / rrd_thread_safe.c

diff --git a/src/rrd_thread_safe.c b/src/rrd_thread_safe.c
index 074a873..e1e3cbe 100644 (file)
--- a/src/rrd_thread_safe.c
+++ b/src/rrd_thread_safe.c
@@ -1,5 +1,5 @@
 /*****************************************************************************
- * RRDtool 1.2.23  Copyright by Tobi Oetiker, 1997-2007
+ * RRDtool 1.3.2  Copyright by Tobi Oetiker, 1997-2008
  * This file:     Copyright 2003 Peter Stamfest <peter@stamfest.at> 
  *                             & Tobias Oetiker
  * Distributed under the GPL
@@ -27,7 +27,7 @@ static pthread_once_t context_key_once = PTHREAD_ONCE_INIT;
 static void context_destroy_context(
     void *ctx_)
 {
-    struct rrd_context *ctx = ctx_;
+    rrd_context_t *ctx = ctx_;
 
     if (ctx)
         rrd_free_context(ctx);
@@ -35,15 +35,15 @@ static void context_destroy_context(
 
 /* Allocate the key */
 static void context_get_key(
-    )
+    void)
 {
     pthread_key_create(&context_key, context_destroy_context);
 }
 
-struct rrd_context *rrd_get_context(
+rrd_context_t *rrd_get_context(
     void)
 {
-    struct rrd_context *ctx;
+    rrd_context_t *ctx;
 
     pthread_once(&context_key_once, context_get_key);
     ctx = pthread_getspecific(context_key);
@@ -58,12 +58,39 @@ struct rrd_context *rrd_get_context(
 const char *rrd_strerror(
     int err)
 {
-    struct rrd_context *ctx = rrd_get_context();
+    rrd_context_t *ctx = rrd_get_context();
+    char *ret = "unknown error";
+
+    *ctx->lib_errstr = '\0';
 
-    if (strerror_r(err, ctx->lib_errstr, ctx->errlen))
-        return "strerror_r failed. sorry!";
-    else
-        return ctx->lib_errstr;
+    /* Even though POSIX/XSI requires "strerror_r" to return an "int", some
+     * systems (e.g. the GNU libc) return a "char *" _and_ ignore the second
+     * argument ... -tokkee */
+#ifdef STRERROR_R_CHAR_P
+    ret = strerror_r(err, ctx->lib_errstr, sizeof(ctx->lib_errstr));
+    if ((! ret) || (*ret == '\0')) {
+        if (*ctx->lib_errstr != '\0')
+            ret = ctx->lib_errstr;
+        else {
+            /* according to the manpage this should not happen -
+               let's handle it somehow sanely anyway */
+            snprintf(ctx->lib_errstr, sizeof(ctx->lib_errstr),
+                    "unknown error %i - strerror_r did not return anything",
+                    err);
+            ctx->lib_errstr[sizeof(ctx->lib_errstr) - 1] = '\0';
+            ret = ctx->lib_errstr;
+        }
+    }
+#else /* ! STRERROR_R_CHAR_P */
+    if (strerror_r(err, ctx->lib_errstr, sizeof(ctx->lib_errstr))) {
+        snprintf(ctx->lib_errstr, sizeof(ctx->lib_errstr),
+                "unknown error %i - strerror_r returned with errno = %i",
+                err, errno);
+        ctx->lib_errstr[sizeof(ctx->lib_errstr) - 1] = '\0';
+    }
+    ret = ctx->lib_errstr;
+#endif
+    return ret;
 }
 #else
 #undef strerror
@@ -71,12 +98,12 @@ const char *rrd_strerror(
     int err)
 {
     static pthread_mutex_t mtx = PTHREAD_MUTEX_INITIALIZER;
-    struct rrd_context *ctx;
+    rrd_context_t *ctx;
 
     ctx = rrd_get_context();
     pthread_mutex_lock(&mtx);
-    strncpy(ctx->lib_errstr, strerror(err), ctx->errlen);
-    ctx->lib_errstr[ctx->errlen] = '\0';
+    strncpy(ctx->lib_errstr, strerror(err), sizeof(ctx->lib_errstr));
+    ctx->lib_errstr[sizeof(ctx->lib_errstr) - 1] = '\0';
     pthread_mutex_unlock(&mtx);
     return ctx->lib_errstr;
 }