Modules API: blocked client free callback modified to get a context.

Note that this was an experimental API that can only be enabled with
REIDSMODULE_EXPERIMENTAL_API, so it is subject to change until its
promoted to stable API. Sorry for the breakage, it is trivial to
resolve btw. This change will not be back ported to Redis 4.0.

4 files changed, 51 insertions, 31 deletions

diff --git a/src/module.c b/src/module.c
index 7cf1a24bd..3a494a203 100644
--- a/src/module.c
+++ b/src/module.c
@@ -127,6 +127,7 @@ typedef struct RedisModuleCtx RedisModuleCtx;
 #define REDISMODULE_CTX_BLOCKED_REPLY (1<<3)
 #define REDISMODULE_CTX_BLOCKED_TIMEOUT (1<<4)
 #define REDISMODULE_CTX_THREAD_SAFE (1<<5)
+#define REDISMODULE_CTX_BLOCKED_DISCONNECTED (1<<6)
 
 /* This represents a Redis key opened with RM_OpenKey(). */
 struct RedisModuleKey {
@@ -200,7 +201,7 @@ typedef struct RedisModuleBlockedClient {
     RedisModule *module;    /* Module blocking the client. */
     RedisModuleCmdFunc reply_callback; /* Reply callback on normal completion.*/
     RedisModuleCmdFunc timeout_callback; /* Reply callback on timeout. */
-    void (*free_privdata)(void *);       /* privdata cleanup callback. */
+    void (*free_privdata)(RedisModuleCtx*,void*);/* privdata cleanup callback.*/
     void *privdata;     /* Module private data that may be used by the reply
                            or timeout callback. It is set via the
                            RedisModule_UnblockClient() API. */
@@ -3449,7 +3450,7 @@ void unblockClientFromModule(client *c) {
  *     free_privdata:   called in order to free the privata data that is passed
  *                      by RedisModule_UnblockClient() call.
  */
-RedisModuleBlockedClient *RM_BlockClient(RedisModuleCtx *ctx, RedisModuleCmdFunc reply_callback, RedisModuleCmdFunc timeout_callback, void (*free_privdata)(void*), long long timeout_ms) {
+RedisModuleBlockedClient *RM_BlockClient(RedisModuleCtx *ctx, RedisModuleCmdFunc reply_callback, RedisModuleCmdFunc timeout_callback, void (*free_privdata)(RedisModuleCtx*,void*), long long timeout_ms) {
     client *c = ctx->client;
     int islua = c->flags & CLIENT_LUA;
     int ismulti = c->flags & CLIENT_MULTI;
@@ -3553,8 +3554,16 @@ void moduleHandleBlockedClients(void) {
         }
 
         /* Free privdata if any. */
-        if (bc->privdata && bc->free_privdata)
-            bc->free_privdata(bc->privdata);
+        if (bc->privdata && bc->free_privdata) {
+            RedisModuleCtx ctx = REDISMODULE_CTX_INIT;
+            if (c == NULL)
+                ctx.flags |= REDISMODULE_CTX_BLOCKED_DISCONNECTED;
+            ctx.blocked_privdata = bc->privdata;
+            ctx.module = bc->module;
+            ctx.client = bc->client;
+            bc->free_privdata(&ctx,bc->privdata);
+            moduleFreeContext(&ctx);
+        }
 
         /* It is possible that this blocked client object accumulated
          * replies to send to the client in a thread safe context.
@@ -3625,6 +3634,13 @@ void *RM_GetBlockedClientPrivateData(RedisModuleCtx *ctx) {
     return ctx->blocked_privdata;
 }
 
+/* Return true if when the free callback of a blocked client is called,
+ * the reason for the client to be unblocked is that it disconnected
+ * while it was blocked. */
+int RM_BlockedClientDisconnected(RedisModuleCtx *ctx) {
+    return (ctx->flags & REDISMODULE_CTX_BLOCKED_DISCONNECTED) != 0;
+}
+
 /* --------------------------------------------------------------------------
  * Thread Safe Contexts
  * -------------------------------------------------------------------------- */
@@ -4596,4 +4612,5 @@ void moduleRegisterCoreAPI(void) {
     REGISTER_API(GetClusterSize);
     REGISTER_API(GetRandomBytes);
     REGISTER_API(GetRandomHexChars);
+    REGISTER_API(BlockedClientDisconnected);
 }
diff --git a/src/modules/helloblock.c b/src/modules/helloblock.c
index c74fcd30f..cabaeff6c 100644
--- a/src/modules/helloblock.c
+++ b/src/modules/helloblock.c
@@ -54,7 +54,8 @@ int HelloBlock_Timeout(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
 }
 
 /* Private data freeing callback for HELLO.BLOCK command. */
-void HelloBlock_FreeData(void *privdata) {
+void HelloBlock_FreeData(RedisModuleCtx *ctx, void *privdata) {
+    REDISMODULE_NOT_USED(ctx);
     RedisModule_Free(privdata);
 }
 
diff --git a/src/modules/hellocluster.c b/src/modules/hellocluster.c
index 4cc40a17f..75d18f3e2 100644
--- a/src/modules/hellocluster.c
+++ b/src/modules/hellocluster.c
@@ -30,6 +30,7 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
+#define REDISMODULE_EXPERIMENTAL_API
 #include "../redismodule.h"
 #include <stdio.h>
 #include <stdlib.h>
diff --git a/src/redismodule.h b/src/redismodule.h
index f663006ab..4ba4be3b9 100644
--- a/src/redismodule.h
+++ b/src/redismodule.h
@@ -268,23 +268,10 @@ long long REDISMODULE_API_FUNC(RedisModule_Milliseconds)(void);
 void REDISMODULE_API_FUNC(RedisModule_DigestAddStringBuffer)(RedisModuleDigest *md, unsigned char *ele, size_t len);
 void REDISMODULE_API_FUNC(RedisModule_DigestAddLongLong)(RedisModuleDigest *md, long long ele);
 void REDISMODULE_API_FUNC(RedisModule_DigestEndSequence)(RedisModuleDigest *md);
-void REDISMODULE_API_FUNC(RedisModule_RegisterClusterMessageReceiver)(RedisModuleCtx *ctx, uint8_t type, RedisModuleClusterMessageReceiver callback);
-int REDISMODULE_API_FUNC(RedisModule_SendClusterMessage)(RedisModuleCtx *ctx, char *target_id, uint8_t type, unsigned char *msg, uint32_t len);
-int REDISMODULE_API_FUNC(RedisModule_GetClusterNodeInfo)(RedisModuleCtx *ctx, const char *id, char *ip, char *master_id, int *port, int *flags);
-char **REDISMODULE_API_FUNC(RedisModule_GetClusterNodesList)(RedisModuleCtx *ctx, size_t *numnodes);
-void REDISMODULE_API_FUNC(RedisModule_FreeClusterNodesList)(char **ids);
-RedisModuleTimerID REDISMODULE_API_FUNC(RedisModule_CreateTimer)(RedisModuleCtx *ctx, mstime_t period, RedisModuleTimerProc callback, void *data);
-int REDISMODULE_API_FUNC(RedisModule_StopTimer)(RedisModuleCtx *ctx, RedisModuleTimerID id, void **data);
-int REDISMODULE_API_FUNC(RedisModule_GetTimerInfo)(RedisModuleCtx *ctx, RedisModuleTimerID id, uint64_t *remaining, void **data);
-const char *REDISMODULE_API_FUNC(RedisModule_GetMyClusterID)(void);
-size_t REDISMODULE_API_FUNC(RedisModule_GetClusterSize)(void);
-void REDISMODULE_API_FUNC(RedisModule_GetRandomBytes)(unsigned char *dst, size_t len);
-void REDISMODULE_API_FUNC(RedisModule_GetRandomHexChars)(char *dst, size_t len);
-
 
 /* Experimental APIs */
 #ifdef REDISMODULE_EXPERIMENTAL_API
-RedisModuleBlockedClient *REDISMODULE_API_FUNC(RedisModule_BlockClient)(RedisModuleCtx *ctx, RedisModuleCmdFunc reply_callback, RedisModuleCmdFunc timeout_callback, void (*free_privdata)(void*), long long timeout_ms);
+RedisModuleBlockedClient *REDISMODULE_API_FUNC(RedisModule_BlockClient)(RedisModuleCtx *ctx, RedisModuleCmdFunc reply_callback, RedisModuleCmdFunc timeout_callback, void (*free_privdata)(RedisModuleCtx*,void*), long long timeout_ms);
 int REDISMODULE_API_FUNC(RedisModule_UnblockClient)(RedisModuleBlockedClient *bc, void *privdata);
 int REDISMODULE_API_FUNC(RedisModule_IsBlockedReplyRequest)(RedisModuleCtx *ctx);
 int REDISMODULE_API_FUNC(RedisModule_IsBlockedTimeoutRequest)(RedisModuleCtx *ctx);
@@ -295,6 +282,19 @@ void REDISMODULE_API_FUNC(RedisModule_FreeThreadSafeContext)(RedisModuleCtx *ctx
 void REDISMODULE_API_FUNC(RedisModule_ThreadSafeContextLock)(RedisModuleCtx *ctx);
 void REDISMODULE_API_FUNC(RedisModule_ThreadSafeContextUnlock)(RedisModuleCtx *ctx);
 int REDISMODULE_API_FUNC(RedisModule_SubscribeToKeyspaceEvents)(RedisModuleCtx *ctx, int types, RedisModuleNotificationFunc cb);
+int REDISMODULE_API_FUNC(RedisModule_BlockedClientDisconnected)(RedisModuleCtx *ctx);
+void REDISMODULE_API_FUNC(RedisModule_RegisterClusterMessageReceiver)(RedisModuleCtx *ctx, uint8_t type, RedisModuleClusterMessageReceiver callback);
+int REDISMODULE_API_FUNC(RedisModule_SendClusterMessage)(RedisModuleCtx *ctx, char *target_id, uint8_t type, unsigned char *msg, uint32_t len);
+int REDISMODULE_API_FUNC(RedisModule_GetClusterNodeInfo)(RedisModuleCtx *ctx, const char *id, char *ip, char *master_id, int *port, int *flags);
+char **REDISMODULE_API_FUNC(RedisModule_GetClusterNodesList)(RedisModuleCtx *ctx, size_t *numnodes);
+void REDISMODULE_API_FUNC(RedisModule_FreeClusterNodesList)(char **ids);
+RedisModuleTimerID REDISMODULE_API_FUNC(RedisModule_CreateTimer)(RedisModuleCtx *ctx, mstime_t period, RedisModuleTimerProc callback, void *data);
+int REDISMODULE_API_FUNC(RedisModule_StopTimer)(RedisModuleCtx *ctx, RedisModuleTimerID id, void **data);
+int REDISMODULE_API_FUNC(RedisModule_GetTimerInfo)(RedisModuleCtx *ctx, RedisModuleTimerID id, uint64_t *remaining, void **data);
+const char *REDISMODULE_API_FUNC(RedisModule_GetMyClusterID)(void);
+size_t REDISMODULE_API_FUNC(RedisModule_GetClusterSize)(void);
+void REDISMODULE_API_FUNC(RedisModule_GetRandomBytes)(unsigned char *dst, size_t len);
+void REDISMODULE_API_FUNC(RedisModule_GetRandomHexChars)(char *dst, size_t len);
 #endif
 
 /* This is included inline inside each Redis module. */
@@ -404,18 +404,6 @@ static int RedisModule_Init(RedisModuleCtx *ctx, const char *name, int ver, int
     REDISMODULE_GET_API(DigestAddStringBuffer);
     REDISMODULE_GET_API(DigestAddLongLong);
     REDISMODULE_GET_API(DigestEndSequence);
-    REDISMODULE_GET_API(RegisterClusterMessageReceiver);
-    REDISMODULE_GET_API(SendClusterMessage);
-    REDISMODULE_GET_API(GetClusterNodeInfo);
-    REDISMODULE_GET_API(GetClusterNodesList);
-    REDISMODULE_GET_API(FreeClusterNodesList);
-    REDISMODULE_GET_API(CreateTimer);
-    REDISMODULE_GET_API(StopTimer);
-    REDISMODULE_GET_API(GetTimerInfo);
-    REDISMODULE_GET_API(GetMyClusterID);
-    REDISMODULE_GET_API(GetClusterSize);
-    REDISMODULE_GET_API(GetRandomBytes);
-    REDISMODULE_GET_API(GetRandomHexChars);
 
 #ifdef REDISMODULE_EXPERIMENTAL_API
     REDISMODULE_GET_API(GetThreadSafeContext);
@@ -429,6 +417,19 @@ static int RedisModule_Init(RedisModuleCtx *ctx, const char *name, int ver, int
     REDISMODULE_GET_API(GetBlockedClientPrivateData);
     REDISMODULE_GET_API(AbortBlock);
     REDISMODULE_GET_API(SubscribeToKeyspaceEvents);
+    REDISMODULE_GET_API(BlockedClientDisconnected);
+    REDISMODULE_GET_API(RegisterClusterMessageReceiver);
+    REDISMODULE_GET_API(SendClusterMessage);
+    REDISMODULE_GET_API(GetClusterNodeInfo);
+    REDISMODULE_GET_API(GetClusterNodesList);
+    REDISMODULE_GET_API(FreeClusterNodesList);
+    REDISMODULE_GET_API(CreateTimer);
+    REDISMODULE_GET_API(StopTimer);
+    REDISMODULE_GET_API(GetTimerInfo);
+    REDISMODULE_GET_API(GetMyClusterID);
+    REDISMODULE_GET_API(GetClusterSize);
+    REDISMODULE_GET_API(GetRandomBytes);
+    REDISMODULE_GET_API(GetRandomHexChars);
 #endif
 
     if (RedisModule_IsModuleNameBusy && RedisModule_IsModuleNameBusy(name)) return REDISMODULE_ERR;