New synchronization mechanism for qcom

src/lib/rt/src/os_linux/rt_futex.c

+/* rt_futex.c -- Futex operations
+
+   PROVIEW/R
+   Contains functions that are heavily os-dependant.  
+   
+   Author: Robert Karlsson 21 Apr 2004 
+   
+   Description:
+   This module provides an interface to futexes - "fast user level
+   locking in Linux". This is achieved through the multiplexing
+   system call sys_futex(). As implemented below this interface provides
+   a synchronization mechanism that can be used both between threads
+   in one process as well as between threads in different processes */
+
+#if !defined(OS_LINUX)
+# error "This file is valid only for OS_LINUX"
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+#define FUTEX_WAIT (0)
+#define FUTEX_WAKE (1)
+#define FUTEX_FD (2)
+#define FUTEX_REQUEUE (3)
+
+
+int 
+futex_wait (
+      int *futex, 
+      int val
+)
+{
+  int  ok;
+  ok = syscall(SYS_futex, futex, FUTEX_WAIT, val, NULL);
+  if (ok == -1) {
+    return errno;
+  }
+  else {
+    return ok;
+  }
+}
+
+int 
+futex_timed_wait (
+      int *futex, 
+      int val, 
+      const struct timespec * timespec
+)
+{
+  int  ok;
+  ok = syscall(SYS_futex, futex, FUTEX_WAIT, val, timespec);
+  if (ok == -1) {
+    return errno;
+  }
+  else {
+    return ok;
+  }
+}
+
+int 
+futex_wake (
+      int *futex,
+      int nr
+)
+{
+  int  ok;
+  ok = syscall(SYS_futex, futex, FUTEX_WAKE, nr, NULL);
+  if (ok == -1) {
+    return errno;
+  }
+  else {
+    return ok;
+  }
+}

src/lib/rt/src/os_linux/rt_futex.h

+/* rt_futex.h */
+
+#ifndef rt_futex_h
+#define rt_futex_h
+
+#ifdef __cplusplus
+extern "C" { 
+#endif
+    int futex_wait(int *futex, int val);
+    
+    int futex_timed_wait(int *futex, int val, const struct timespec * timespec);
+    
+    int futex_wake(int *futex,int nr);
+
+#ifdef __cplusplus
+} 
+#endif
+
+#endif

src/lib/rt/src/os_linux/rt_qos.c

@@ -26,10 +26,11 @@
 #include "rt_qdb.h"
 #include "rt_pool.h"
 #include "rt_hash.h"
+#include "rt_futex.h"
 
 
 pwr_tBoolean
-qos_WaitQue (
+qos_WaitQueOld (
   pwr_tStatus		*status,
   qdb_sQue		*qp,
   int			tmo
@@ -88,8 +89,57 @@ qos_WaitQue (
   return signal;
 }
 
+pwr_tBoolean
+qos_WaitQue (
+  pwr_tStatus		*status,
+  qdb_sQue		*qp,
+  int			tmo
+)
+{
+  pwr_tDeltaTime	dtime;
+  int			ok;
+  pwr_tBoolean		signal = FALSE;
+  pwr_dStatus		(sts, status, QCOM__SUCCESS);
+
+  qdb_AssumeLocked;
+
+  if (tmo == qcom_cTmoNone)
+    return FALSE;
+
+  qp->lock.waiting = TRUE;
+  qp->lock.pid     = 0;
+
+  qdb_Unlock;
+
+    if (tmo != qcom_cTmoEternal) {
+      ok = futex_timed_wait(&(qp->lock.pid), 0, (struct timespec *) time_MsToD(&dtime, tmo));
+    } else {
+      for (;;) {
+        ok = futex_wait(&(qp->lock.pid), 0);
+        if (ok == EINTR)
+          continue;
+        break;
+      }
+    }
+    
+    if (ok == EWOULDBLOCK) {
+      errh_Error("waitQue - Deadlock would occur");
+    }
+
+  qdb_Lock;
+
+  if ((qp->lock.waiting) || (ok == ETIMEDOUT)) {
+    *sts = QCOM__TMO;
+    qp->lock.waiting = FALSE;
+  } else {
+    signal = TRUE;
+  }
+
+  return signal;
+}
+
 pwr_tStatus
-qos_SignalQue (
+qos_SignalQueOld (
   pwr_tStatus	*status,
   qdb_sQue	*qp
 )
@@ -114,7 +164,27 @@ qos_SignalQue (
 
   return TRUE;
 }
+
+pwr_tStatus
+qos_SignalQue (
+  pwr_tStatus	*status,
+  qdb_sQue	*qp
+)
+{
+  int		ok;
+  pwr_dStatus	(sts, status, QCOM__SUCCESS);
+
+  qdb_AssumeLocked;
 
+  if (qp->lock.waiting) {
+    qp->lock.waiting = FALSE;
+
+    ok = futex_wake(&(qp->lock.pid), INT_MAX);
+
+  }
+
+  return TRUE;
+}
 
 qdb_sQlock *
 qos_CreateQlock (