From 7ca1a339cb488fd97015e959e2a17e91e9b56409 Mon Sep 17 00:00:00 2001
From: Jeffrey Altman <jaltman@secure-endpoints.com>
Date: Fri, 26 May 2006 07:35:34 +0000
Subject: [PATCH] windows-dynamic-thread-priority-20060525

Dynamically adjust the priority of server threads based upon the age
of the cifs request that is being processed.  Bump the priority one
level for each 15 seconds of age.
---
 src/WINNT/afsd/cm_buf.c    |  3 +++
 src/WINNT/afsd/cm_scache.c |  3 +++
 src/WINNT/afsd/smb.c       | 45 ++++++++++++++++++++++++++++++++++++++
 src/WINNT/afsd/smb.h       |  4 ++++
 4 files changed, 55 insertions(+)

diff --git a/src/WINNT/afsd/cm_buf.c b/src/WINNT/afsd/cm_buf.c
index cdfe13969..aa6610b39 100644
--- a/src/WINNT/afsd/cm_buf.c
+++ b/src/WINNT/afsd/cm_buf.c
@@ -462,6 +462,9 @@ void buf_WaitIO(cm_scache_t * scp, cm_buf_t *bp)
             bp->waitCount = bp->waitRequests = 1;
         }
         osi_SleepM((LONG_PTR)bp, &bp->mx);
+
+	smb_UpdateServerPriority();
+
         lock_ObtainMutex(&bp->mx);
         osi_Log1(afsd_logp, "buf_WaitIO conflict wait done for 0x%p", bp);
         bp->waitCount--;
diff --git a/src/WINNT/afsd/cm_scache.c b/src/WINNT/afsd/cm_scache.c
index 80d49aced..826b26976 100644
--- a/src/WINNT/afsd/cm_scache.c
+++ b/src/WINNT/afsd/cm_scache.c
@@ -917,6 +917,9 @@ long cm_SyncOp(cm_scache_t *scp, cm_buf_t *bufp, cm_user_t *up, cm_req_t *reqp,
         if (bufLocked) 
             lock_ReleaseMutex(&bufp->mx);
         osi_SleepM((LONG_PTR) &scp->flags, &scp->mx);
+
+	smb_UpdateServerPriority();
+
         if (bufLocked) 
             lock_ObtainMutex(&bufp->mx);
         lock_ObtainMutex(&scp->mx);
diff --git a/src/WINNT/afsd/smb.c b/src/WINNT/afsd/smb.c
index 89ab3def2..4b62388a4 100644
--- a/src/WINNT/afsd/smb.c
+++ b/src/WINNT/afsd/smb.c
@@ -170,6 +170,8 @@ smb_username_t *usernamesp = NULL;
 
 smb_waitingLockRequest_t *smb_allWaitingLocks;
 
+DWORD smb_TlsRequestSlot = -1;
+
 /* forward decl */
 void smb_DispatchPacket(smb_vc_t *vcp, smb_packet_t *inp, smb_packet_t *outp,
 			NCB *ncbp, raw_write_cont_t *rwcp);
@@ -204,6 +206,40 @@ int smb_ServerLanManagerLength = sizeof(smb_ServerLanManager);
 /* Faux server GUID. This is never checked. */
 GUID smb_ServerGUID = { 0x40015cb8, 0x058a, 0x44fc, { 0xae, 0x7e, 0xbb, 0x29, 0x52, 0xee, 0x7e, 0xff }};
 
+void smb_ResetServerPriority()
+{
+    void * p = TlsGetValue(smb_TlsRequestSlot);
+    if (p) {
+	free(p);
+	TlsSetValue(smb_TlsRequestSlot, NULL);
+	SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_NORMAL);
+    }
+}
+
+void smb_SetRequestStartTime()
+{
+    time_t * tp = malloc(sizeof(time_t));
+    if (tp) {
+	*tp = osi_Time();
+
+	if (!TlsSetValue(smb_TlsRequestSlot, tp))
+	    free(tp);
+    }	
+}
+
+void smb_UpdateServerPriority()
+{	
+    time_t *tp = TlsGetValue(smb_TlsRequestSlot);
+
+    if (tp) {
+	time_t now = osi_Time();
+
+	/* Give one priority boost for each 15 seconds */
+	SetThreadPriority(GetCurrentThread(), (now - *tp) / 15);
+    }
+}
+
+
 const char * ncb_error_string(int code)
 {
     const char * s;
@@ -7570,6 +7606,9 @@ void smb_Server(VOID *parmp)
 	    smb_ReleaseVC(vcp);
 	    vcp = NULL;
 	}
+
+	smb_ResetServerPriority();
+
         code = thrd_WaitForMultipleObjects_Event(numNCBs, NCBreturns[myIdx],
                                                  FALSE, INFINITE);
 
@@ -7760,6 +7799,8 @@ void smb_Server(VOID *parmp)
             continue;
         }
 
+	smb_SetRequestStartTime();
+
         vcp->errorCount = 0;
         bufp = (struct smb_packet *) ncbp->ncb_buffer;
 #ifdef DJGPP
@@ -8363,6 +8404,8 @@ void smb_Init(osi_log_t *logp, char *snamep, int useV3, int LANadapt,
     EVENT_HANDLE retHandle;
     char eventName[MAX_PATH];
 
+    smb_TlsRequestSlot = TlsAlloc();
+
 #ifndef DJGPP
     smb_MBfunc = aMBfunc;
 #endif /* DJGPP */
@@ -8886,6 +8929,8 @@ void smb_Shutdown(void)
         }
     }
     lock_ReleaseWrite(&smb_rctLock);
+
+    TlsFree(smb_TlsRequestSlot);
 }
 
 /* Get the UNC \\<servername>\<sharename> prefix. */
diff --git a/src/WINNT/afsd/smb.h b/src/WINNT/afsd/smb.h
index 6cf67ed86..856324509 100644
--- a/src/WINNT/afsd/smb.h
+++ b/src/WINNT/afsd/smb.h
@@ -698,6 +698,10 @@ extern char *smb_GetSharename(void);
 
 extern DWORD smb_ServerExceptionFilter(void);
 
+extern void smb_UpdateServerPriority(void);
+extern void smb_SetRequestStartTime(void);
+extern void smb_ResetServerPriority(void);
+
 /* include other include files */
 #include "smb3.h"
 #include "smb_ioctl.h"
-- 
2.39.5