Synchronization in system calls without global locks across all syste…

…m calls?
xomboverlord · Jan 19, 2010 · aedacc5 · aedacc5
1 parent ef4f99c
commit aedacc5
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Showing 2 changed files with 53 additions and 34 deletions.
diff --git a/kernel/core/syscall.d b/kernel/core/syscall.d
@@ -39,18 +39,20 @@ public:
 		return SyscallError.OK;
 	}
 
-	synchronized SyscallError allocPage(out int ret, AllocPageArgs* params) {
-		Environment* current = Scheduler.current();
+	SyscallError allocPage(out int ret, AllocPageArgs* params) {
+		synchronized {
+			Environment* current = Scheduler.current();
 
-		if (current.alloc(params.virtualAddress, 4096, true) == ErrorVal.Fail) {
-			ret = -1;
-			kprintfln!("allocPage({}): FAIL")(params.virtualAddress);
-			return SyscallError.Failcopter;
-		}	
+			if (current.alloc(params.virtualAddress, 4096, true) == ErrorVal.Fail) {
+				ret = -1;
+				kprintfln!("allocPage({}): FAIL")(params.virtualAddress);
+				return SyscallError.Failcopter;
+			}	
 
-		ret = 0;
+			ret = 0;
 
-		return SyscallError.OK;
+			return SyscallError.OK;
+		}
 	}
 
 	// void exit(ulong retval)
@@ -83,32 +85,34 @@ public:
 //		return SyscallError.OK;
 //	}
 
-	synchronized SyscallError perfPoll(PerfPollArgs* params) {
-		static ulong[256] value;
-		static ulong numTimes = 0;
-		static ulong overall;
-
-		numTimes++;
-		bool firstTime = false;
-
-		//params.value = PerfMon.pollEvent(params.event) - params.value;
-		if (numTimes == 1) {
-			firstTime = true;
+	SyscallError perfPoll(PerfPollArgs* params) {
+		synchronized {
+			static ulong[256] value;
+			static ulong numTimes = 0;
+			static ulong overall;
+
+			numTimes++;
+			bool firstTime = false;
+
+			//params.value = PerfMon.pollEvent(params.event) - params.value;
+			if (numTimes == 1) {
+				firstTime = true;
+			}
+
+			value[Cpu.identifier] = PerfMon.pollEvent(params.event) - value[Cpu.identifier];
+
+			if (numTimes == 1) {
+				overall = PerfMon.pollEvent(params.event);
+			}
+			else if (numTimes == 8) {
+				overall = value[0];
+				overall += value[1];
+				overall += value[2];
+				overall += value[3];
+			}
+
+			return SyscallError.OK;
 		}
-
-		value[Cpu.identifier] = PerfMon.pollEvent(params.event) - value[Cpu.identifier];
-
-		if (numTimes == 1) {
-			overall = PerfMon.pollEvent(params.event);
-		}
-		else if (numTimes == 8) {
-			overall = value[0];
-			overall += value[1];
-			overall += value[2];
-			overall += value[3];
-		}
-
-		return SyscallError.OK;
 	}
 
 }

diff --git a/kernel/runtime/dstubs.d b/kernel/runtime/dstubs.d
@@ -95,6 +95,21 @@ void _d_monitorexit(Object h){
 	mon.unlock();
 }
 
+// XXX: Also magical.
+
+struct D_CRITICAL_SECTION {
+	D_CRITICAL_SECTION* next;
+	Mutex mtx;
+}
+
+void _d_criticalenter(D_CRITICAL_SECTION* dcs) {
+	dcs.mtx.lock();
+}
+
+void _d_criticalexit(D_CRITICAL_SECTION* dcs) {
+	dcs.mtx.unlock();
+}
+
 /**************************************************
  Random stubs (they'll go somewhere eventually)
 **************************************************/