Tweak listener yielding

README.md

@@ -38,8 +38,8 @@ A simple, light-weight C/C++ Redis client.
 
 __RedisX__ is a light-weight [Redis](https://redis.io) client for C/C++. As such, it should also work with Redis forks 
 / clones like [Dragonfly](https://dragonfly.io) or [Valkey](https://valkey.io). It supports both interactive and 
-pipelined Redis queries, managing and processing subscriptions. It also supports atomic execution blocks and LUA 
-scripts loading. It can be used with one or more distinct Redis servers simultaneously.
+pipelined Redis queries, managing and processing subscriptions, atomic execution blocks, and LUA scripts loading. It 
+can be used with multiple Redis servers simultaneously also.
 
 While there are other C/C++ Redis clients available, this one is C90 compatible, and hence can be used on older 
 platforms also. It is also small and fast, but still capable and versatile.
@@ -49,12 +49,6 @@ the pace new commands are being introduced all the time), it provides a basic fr
 asynchronous queries, with some higher-level functions for managing key/value storage types (including hash tables), 
 and PUB/SUB. Future releases may add further higher-level functionality based on demand for such features.
 
-The library maintains up to three separate connections (channels) for each separate Redis server instance used: (1) an 
-interactive client for sequential round-trip transactions, (2) a pipeline client for bulk queries and asynchronous 
-background processing, and (3) a subscription client for PUB/SUB requests and notifications. The interactive client is 
-always connected, the pipeline client is connected only if explicitly requested at the time of establishing the server 
-connection, while the subscription client is connected only as needed.
-
 The __RedisX__ library was created, and is maintained, by Attila Kovács at the Center for Astrophysics \| Harvard 
 & Smithsonian, and it is available through the [Smithsonian/redisx](https://github.com/Smithsonian/redisx) 
 repository on GitHub. 
@@ -97,7 +91,7 @@ prior to invoking `make`. The following build variables can be configured:
 
  - `CFLAGS`: Flags to pass onto the C compiler (default: `-Os -Wall`). Note, `-Iinclude` will be added automatically.
 
- - `LDFLAGS`: Linker flags (default is `-lm`).
+ - `LDFLAGS`: Linker flags (default is `-lm`). Note, `-lxchange` will be added automatically.
 
  - `CHECKEXTRA`: Extra options to pass to `cppcheck` for the `make check` target
 
@@ -117,6 +111,12 @@ desired `make` target(s). (You can use `make help` to get a summary of the avail
  - [Disconnecting](#disconnecting)
  - [Connection hooks](#connection-hooks)
 
+The library maintains up to three separate connections (channels) for each separate Redis server instance used: (1) an 
+interactive client for sequential round-trip transactions, (2) a pipeline client for bulk queries and asynchronous 
+background processing, and (3) a subscription client for PUB/SUB requests and notifications. The interactive client is 
+always connected, the pipeline client is connected only if explicitly requested at the time of establishing the server 
+connection, while the subscription client is connected only as needed.
+
 <a name="initializing"></a>
 ### Initializing
 

config.mk

@@ -29,18 +29,21 @@ CFLAGS ?= -Os -Wall
 # Add include/ directory
 CFLAGS += -I$(INC)
 
+# Extra warnings (not supported on all compilers)
+#CFLAGS += -Wextra
+
 # Link against math libs (for e.g. isnan())
 LDFLAGS ?= -lm
 
 # Compile and link against a specific xchange library (if defined)
 ifdef XCHANGE
   CFLAGS += -I$(XCHANGE)/include
-  LDFLAGS += -L$(XCHANGE)/lib -lxchange
+  LDFLAGS = -L$(XCHANGE)/lib
   LD_LIBRARY_PATH = $(XCHANGE)/lib:$(LD_LIBRARY_PATH)
 endif
 
-# Extra warnings (not supported on all compilers)
-#CFLAGS += -Wextra
+# Always link against the xchange lib.
+LDFLAGS += -lxchange
 
 # cppcheck options for 'check' target
 CHECKOPTS ?= --enable=performance,warning,portability,style --language=c \

include/redisx.h

@@ -37,7 +37,7 @@
 #ifndef REDISX_LISTENER_REL_PRIORITY
 /// [0.0:1.0] Listener priority as fraction of available range
 /// You may want to set it quite high to ensure that the receive buffer is promptly cleared.
-#  define REDISX_LISTENER_REL_PRIORITY       (0.9)
+#  define REDISX_LISTENER_REL_PRIORITY       (0.5)
 #endif
 
 // Various exposed constants ----------------------------------------------------->
@@ -199,7 +199,7 @@ typedef struct Redis {
  *                 be binary a '\0' termination should no be assumed. Instead, the
  *                 length of the message is specified explicitly.
  */
-typedef void (*RedisSubscriberCall)(const char *pattern, const char *channel, const char *msg, int length);
+typedef void (*RedisSubscriberCall)(const char *pattern, const char *channel, const char *msg, long length);
 
 
 /**

resources/header.html

@@ -6,7 +6,7 @@
 <meta http-equiv="X-UA-Compatible" content="IE=11"/>
 <meta charset="utf-8"/>
 <meta name="description" content="A light-weight Redis client library for C/C++"/>
-<meta name="keywords" content="redis client, C, C++, library"/>
+<meta name="keywords" content="Redis client library, C, C++, C90, software library, open source"/>
 <meta name="author" content="Attila Kovacs"/>
 <meta name="copyright" content="(C)2024 Attila Kovacs" />
 <meta name="robots" content="index,follow"/>

src/redisx-sub.c

@@ -480,10 +480,6 @@ void redisxEndSubscription(Redis *redis) {
 }
 
 static void rNotifyConsumers(Redis *redis, char *pattern, char *channel, char *msg, int length) {
-#if REDISX_LISTENER_YIELD_COUNT > 0
-  static int count;
-#endif
-
   MessageConsumer *c;
   RedisPrivate *p;
   RedisSubscriberCall *f = NULL;
@@ -519,11 +515,6 @@ static void rNotifyConsumers(Redis *redis, char *pattern, char *channel, char *m
     for(i=0; i<n; i++) f[i](pattern, channel, msg, length);
     free(f);
   }
-
-#if REDISX_LISTENER_YIELD_COUNT > 0
-  // Allow the waiting processes to take control...
-  if(++count % REDISX_LISTENER_YIELD_COUNT == 0) sched_yield();
-#endif
 }
 
 /// \cond PRIVATE

src/redisx.c

@@ -31,7 +31,7 @@
 #define XPRIO_MAX                   (sched_get_priority_max(SCHED_RR))
 #define XPRIO_RANGE                 (XPRIO_MAX - XPRIO_MIN)
 
-#define REDISX_LISTENER_PRIORITY           (XPRIO_MIN + (int) (REDISX_LISTENER_REL_PRIORITY * XPRIO_RANGE))
+#define REDISX_LISTENER_PRIORITY    (XPRIO_MIN + (int) (REDISX_LISTENER_REL_PRIORITY * XPRIO_RANGE))
 
 typedef struct ServerLink {
   Redis *redis;