[cscore] Change run loop functions to not be mac specific (#4854)

cscore/src/main/java/edu/wpi/first/cscore/CameraServerJNI.java

@@ -391,9 +391,9 @@ public class CameraServerJNI {
 
   public static native void freeRawFrame(long frame);
 
-  public static native void runOsxRunLoop();
+  public static native void runMainRunLoop();
 
-  public static native int runOsxRunLoopTimeout(double timeoutSeconds);
+  public static native int runMainRunLoopTimeout(double timeoutSeconds);
 
-  public static native void stopOsxMainRunLoop();
+  public static native void stopMainRunLoop();
 }

cscore/src/main/native/cpp/jni/CameraServerJNI.cpp

@@ -2229,38 +2229,38 @@ Java_edu_wpi_first_cscore_CameraServerJNI_freeRawFrame
 
 /*
  * Class:     edu_wpi_first_cscore_CameraServerJNI
- * Method:    runOsxRunLoop
+ * Method:    runMainRunLoop
  * Signature: ()V
  */
 JNIEXPORT void JNICALL
-Java_edu_wpi_first_cscore_CameraServerJNI_runOsxRunLoop
+Java_edu_wpi_first_cscore_CameraServerJNI_runMainRunLoop
   (JNIEnv*, jclass)
 {
-  cs::RunOsxRunLoop();
+  cs::RunMainRunLoop();
 }
 
 /*
  * Class:     edu_wpi_first_cscore_CameraServerJNI
- * Method:    runOsxRunLoopTimeout
+ * Method:    runMainRunLoopTimeout
  * Signature: (D)I
  */
 JNIEXPORT jint JNICALL
-Java_edu_wpi_first_cscore_CameraServerJNI_runOsxRunLoopTimeout
+Java_edu_wpi_first_cscore_CameraServerJNI_runMainRunLoopTimeout
   (JNIEnv*, jclass, jdouble timeoutSeconds)
 {
-  return cs::RunOsxRunLoopTimeout(timeoutSeconds);
+  return cs::RunMainRunLoopTimeout(timeoutSeconds);
 }
 
 /*
  * Class:     edu_wpi_first_cscore_CameraServerJNI
- * Method:    stopOsxMainRunLoop
+ * Method:    stopMainRunLoop
  * Signature: ()V
  */
 JNIEXPORT void JNICALL
-Java_edu_wpi_first_cscore_CameraServerJNI_stopOsxMainRunLoop
+Java_edu_wpi_first_cscore_CameraServerJNI_stopMainRunLoop
   (JNIEnv*, jclass)
 {
-  return cs::StopOsxMainRunLoop();
+  return cs::StopMainRunLoop();
 }
 
 }  // extern "C"

cscore/src/main/native/include/cscore_runloop.h

@@ -5,7 +5,7 @@
 #pragma once
 
 namespace cs {
-void RunOsxRunLoop();
-int RunOsxRunLoopTimeout(double timeoutSeconds);
-void StopOsxMainRunLoop();
+void RunMainRunLoop();
+int RunMainRunLoopTimeout(double timeoutSeconds);
+void StopMainRunLoop();
 }  // namespace cs

cscore/src/main/native/linux/RunLoopHelpers.cpp

@@ -2,12 +2,37 @@
 // Open Source Software; you can modify and/or share it under the terms of
 // the WPILib BSD license file in the root directory of this project.
 
+#include <wpi/Synchronization.h>
+
 #include "cscore_runloop.h"
 
-namespace cs {
-void RunOsxRunLoop() {}
-int RunOsxRunLoopTimeout(double timeoutSeconds) {
-  return 0;
+static wpi::Event& GetInstance() {
+  static wpi::Event event;
+  return event;
+}
+
+namespace cs {
+void RunMainRunLoop() {
+  wpi::Event& event = GetInstance();
+  wpi::WaitForObject(event.GetHandle());
+}
+
+int RunMainRunLoopTimeout(double timeoutSeconds) {
+  wpi::Event& event = GetInstance();
+  bool timedOut = false;
+  bool signaled =
+      wpi::WaitForObject(event.GetHandle(), timeoutSeconds, &timedOut);
+  if (timedOut) {
+    return 3;
+  }
+  if (signaled) {
+    return 2;
+  }
+  return 1;
+}
+
+void StopMainRunLoop() {
+  wpi::Event& event = GetInstance();
+  event.Set();
 }
-void StopOsxMainRunLoop() {}
 }  // namespace cs

cscore/src/main/native/objcpp/RunLoopHelpers.mm

@@ -5,17 +5,26 @@
 #include "cscore_runloop.h"
 
 #include <CoreFoundation/CFRunLoop.h>
+#import <Foundation/Foundation.h>
 
 namespace cs {
-void RunOsxRunLoop() {
+void RunMainRunLoop() {
+  if (CFRunLoopGetMain() != CFRunLoopGetCurrent()) {
+    NSLog(@"This method can only be called from the main thread");
+    return;
+  }
   CFRunLoopRun();
 }
 
-int RunOsxRunLoopTimeout(double timeoutSeconds) {
+int RunMainRunLoopTimeout(double timeoutSeconds) {
+  if (CFRunLoopGetMain() != CFRunLoopGetCurrent()) {
+    NSLog(@"This method can only be called from the main thread");
+    return -1;
+  }
   return CFRunLoopRunInMode(kCFRunLoopDefaultMode, timeoutSeconds, false);
 }
 
-void StopOsxMainRunLoop() {
+void StopMainRunLoop() {
   CFRunLoopStop(CFRunLoopGetMain());
 }
 }

cscore/src/main/native/windows/RunLoopHelpers.cpp

@@ -2,12 +2,37 @@
 // Open Source Software; you can modify and/or share it under the terms of
 // the WPILib BSD license file in the root directory of this project.
 
+#include <wpi/Synchronization.h>
+
 #include "cscore_runloop.h"
 
-namespace cs {
-void RunOsxRunLoop() {}
-int RunOsxRunLoopTimeout(double timeoutSeconds) {
-  return 0;
+static wpi::Event& GetInstance() {
+  static wpi::Event event;
+  return event;
+}
+
+namespace cs {
+void RunMainRunLoop() {
+  wpi::Event& event = GetInstance();
+  wpi::WaitForObject(event.GetHandle());
+}
+
+int RunMainRunLoopTimeout(double timeoutSeconds) {
+  wpi::Event& event = GetInstance();
+  bool timedOut = false;
+  bool signaled =
+      wpi::WaitForObject(event.GetHandle(), timeoutSeconds, &timedOut);
+  if (timedOut) {
+    return 3;
+  }
+  if (signaled) {
+    return 2;
+  }
+  return 1;
+}
+
+void StopMainRunLoop() {
+  wpi::Event& event = GetInstance();
+  event.Set();
 }
-void StopOsxMainRunLoop() {}
 }  // namespace cs