Fail fast when systemic error occurs in poll (#8749)

Most of the ae.c backends didn't explicitly handle errors, and instead
ignored all errors and did an implicit retry.
This is desired for EAGAIN and EINTER, but in case of other systematic
errors, we prefer to fail and log the error we got rather than get into a busy loop.

1 files changed, 52 insertions, 0 deletions

diff --git a/src/redisassert.c b/src/redisassert.c
new file mode 100644
index 000000000..0e2da18ca
--- /dev/null
+++ b/src/redisassert.c
@@ -0,0 +1,52 @@
+/* redisassert.c -- Implement the default _serverAssert and _serverPanic which 
+ * simply print stack trace to standard error stream.
+ * 
+ * This file is shared by those modules that try to print some logs about stack trace 
+ * but don't have their own implementations of functions in redisassert.h.
+ *
+ * ----------------------------------------------------------------------------
+ *
+ * Copyright (c) 2021, Andy Pan <panjf2000@gmail.com> and Redis Labs
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+
+#include <stdio.h> 
+#include <stdlib.h>
+
+void _serverAssert(const char *estr, const char *file, int line) {
+    fprintf(stderr, "=== ASSERTION FAILED ===");
+    fprintf(stderr, "==> %s:%d '%s' is not true",file,line,estr);
+    *((char*)-1) = 'x';
+}
+
+void _serverPanic(const char *file, int line, const char *msg, ...) {
+    fprintf(stderr, "------------------------------------------------");
+    fprintf(stderr, "!!! Software Failure. Press left mouse button to continue");
+    fprintf(stderr, "Guru Meditation: %s #%s:%d",msg,file,line);
+    abort();
+}