From b50c8667e5853b519b043926e3f109e4338f9a57 Mon Sep 17 00:00:00 2001
From: Irek Fakhrutdinov <ifakhrutdinov@rocketsoftware.com>
Date: Tue, 30 Jun 2020 20:03:25 +0200
Subject: [PATCH] Check if XMEM runs as a reusable address space

The use of a cross-memory server without REUSASID=YES may result in an
ASID shortage. This commit adds a check and prints a warning message
informing the user about that.

Signed-off-by: Irek Fakhrutdinov <ifakhrutdinov@rocketsoftware.com>
---
 c/crossmemory.c | 31 +++++++++++++++++++++++++++----
 h/crossmemory.h |  6 ++++++
 2 files changed, 33 insertions(+), 4 deletions(-)

diff --git a/c/crossmemory.c b/c/crossmemory.c
index 014dd3db5..fb3fd239c 100644
--- a/c/crossmemory.c
+++ b/c/crossmemory.c
@@ -4004,11 +4004,16 @@ static int verifySTEPLIB(CrossMemoryServer *srv) {
   return RC_CMS_OK;
 }
 
-#define MAIN_WAIT_MILLIS 10000
-#define START_COMMAND_HANDLING_DELAY_IN_SEC 5
-#define STCBASE_SHUTDOWN_DELAY_IN_SEC       5
+static bool isReusableASID(void) {
 
-int cmsStartMainLoop(CrossMemoryServer *srv) {
+  const char ascbreus = 0x40;
+
+  ASCB *ascb = getASCB();
+
+  return ascb->ascbflg3 & ascbreus;
+}
+
+static int testEnvironment(void) {
 
   int authStatus = testAuth();
   if (authStatus != 0) {
@@ -4023,6 +4028,24 @@ int cmsStartMainLoop(CrossMemoryServer *srv) {
     return RC_CMS_BAD_SERVER_KEY;
   }
 
+  if (!isReusableASID()) {
+    zowelog(NULL, LOG_COMP_ID_CMS, ZOWE_LOG_WARNING, CMS_LOG_REUSASID_NO_MSG);
+  }
+
+  return RC_CMS_OK;
+}
+
+#define MAIN_WAIT_MILLIS 10000
+#define START_COMMAND_HANDLING_DELAY_IN_SEC 5
+#define STCBASE_SHUTDOWN_DELAY_IN_SEC       5
+
+int cmsStartMainLoop(CrossMemoryServer *srv) {
+
+  int envStatus = testEnvironment();
+  if (envStatus != 0) {
+    return envStatus;
+  }
+
   int rcvrPushRC = recoveryPush(
       "cmsStartMainLoop",
       RCVR_FLAG_RETRY | RCVR_FLAG_DELETE_ON_RETRY | RCVR_FLAG_PRODUCE_DUMP,
diff --git a/h/crossmemory.h b/h/crossmemory.h
index 45fad34c9..c9797bc40 100644
--- a/h/crossmemory.h
+++ b/h/crossmemory.h
@@ -857,6 +857,12 @@ CrossMemoryServerName cmsMakeServerName(const char *nameNullTerm);
 #define CMS_LOG_DEV_MODE_ON_MSG_TEXT            "Development mode is enabled"
 #define CMS_LOG_DEV_MODE_ON_MSG                 CMS_LOG_DEV_MODE_ON_MSG_ID" "CMS_LOG_DEV_MODE_ON_MSG_TEXT
 
+#ifndef CMS_LOG_REUSASID_NO_MSG_ID
+#define CMS_LOG_REUSASID_NO_MSG_ID              CMS_MSG_PRFX"0248W"
+#endif
+#define CMS_LOG_REUSASID_NO_MSG_TEXT            "Address space is not reusable, start with REUSASID=YES to prevent an ASID shortage"
+#define CMS_LOG_REUSASID_NO_MSG                 CMS_LOG_REUSASID_NO_MSG_ID" "CMS_LOG_REUSASID_NO_MSG_TEXT
+
 #endif /* H_CROSSMEMORY_H_ */