autocommit for file dated 1995-01-21 07:59:46

diff --git a/msamples/service/service.c b/msamples/service/service.c
new file mode 100644 (file)
index 0000000..a5f48b5
--- /dev/null
+++ b/msamples/service/service.c
@@ -0,0 +1,95 @@
+/* Super Simple System Service.\r
+   This is expanded from the sample in the Systems Programming\r
+   chapter to show how to properly deinstall a system service.\r
+   The steps to deinstall are:\r
+   1) UnRegister the Service\r
+   2) Serve all remaining requests at service exchange\r
+   3) Deallocate all resources\r
+   4) Exit\r
+*/\r
+\r
+#include <stdio.h>\r
+#include "\OSSource\MKernel.h"\r
+#include "\OSSource\MJob.h"\r
+#include "\OSSource\MVid.h"\r
+\r
+#define ErcOK         0\r
+#define ErcOpCancel   4\r
+#define ErcNoSuchSvc  30\r
+#define ErcBadSvcCode 32\r
+\r
+struct RqBlkType *pRqBlk;        /* A pointer to a Reqeust Block */\r
+unsigned long NextNumber = 0;    /* The number to return */\r
+unsigned long MainExch;          /* Where we wait for Requests */\r
+unsigned long Message[2];        /* The Message with the Request */\r
+long rqHndl;                            /* Used for keyboard request */\r
+\r
+void main(void)\r
+{\r
+unsigned long OSError, ErrorToUser, keycode;\r
+long *pDataRet;\r
+\r
+  OSError = AllocExch(&MainExch);        /* get an exchange */\r
+\r
+  if (OSError)                      /* look for a kernel error */\r
+    ExitJob(OSError);\r
+\r
+  OSError = RegisterSvc("NUMBERS ", MainExch);\r
+\r
+  if (OSError)                      /* look for a system error */\r
+    ExitJob(OSError);\r
+\r
+  SetNormVid(WHITE|BGBLACK);\r
+  ClrScr();\r
+\r
+  printf("NUMBERS Service Installed.\r\n");\r
+  printf("ANY valid keystroke will terminate the service.\r\n");\r
+\r
+  OSError = Request("KEYBOARD", 1, MainExch, &rqHndl, 0, &keycode,\r
+                                         4, 0, 0, 1, 0, 0);  /* 1 in dData0 = WAIT for key */\r
+  if (OSError)\r
+         printf("Error on Keyboard Request:\r\n", OSError);\r
+\r
+  while (1)            /* WHILE forever (almost...) */\r
+  {\r
+\r
+       /* Now we wait for a client or for a keystroke to come back */\r
+\r
+    OSError = WaitMsg(MainExch, Message); /* Exch & pointer */\r
+\r
+    if (!OSError)\r
+    {\r
+\r
+         if (Message[0] == rqHndl)  /* it was a keystroke and NOT a client */\r
+         {\r
+               UnRegisterSvc("NUMBERS ");\r
+               while (!CheckMsg(MainExch, Message))\r
+               {\r
+            pRqBlk = Message[0];\r
+                       Respond(pRqBlk, ErcNoSuchSvc);\r
+               }\r
+               DeAllocExch(MainExch);\r
+               ExitJob(ErcOpCancel);\r
+         }\r
+\r
+      pRqBlk = Message[0];   /* First DWORD contains ptr to RqBlk */\r
+\r
+         if (pRqBlk->ServiceCode == 0)          /* Abort request from OS */\r
+          ErrorToUser = ErcOK;\r
+\r
+      else if (pRqBlk->ServiceCode == 1)     /* User Asking for Number */\r
+      {\r
+                pDataRet = pRqBlk->pData1;\r
+         *pDataRet = NextNumber++;       /* Give them a number */\r
+         ErrorToUser = ErcOK;                 /* Respond with No error */\r
+\r
+               printf("NUMBERS Service gave out number: %d.\r\n", NextNumber-1);\r
+\r
+      }\r
+      else ErrorToUser = ErcBadSvcCode;       /* Unknown Service code! */\r
+\r
+      OSError = Respond(pRqBlk, ErrorToUser); /* Respond to Request */\r
+\r
+    }\r
+  }  /* Loop while(1) */\r
+}\r