Improved usercontext test with threading

tests/CMakeLists.txt

@@ -28,7 +28,7 @@ add_executable(iconify iconify.c ${GETOPT} ${GLAD_GL})
 add_executable(monitors monitors.c ${GETOPT} ${GLAD_GL})
 add_executable(reopen reopen.c ${GLAD_GL})
 add_executable(cursor cursor.c ${GLAD_GL})
-add_executable(usercontext usercontext.c  ${GLAD_GL})
+add_executable(usercontext usercontext.c  ${TINYCTHREAD} ${GLAD_GL})
 
 add_executable(empty WIN32 MACOSX_BUNDLE empty.c ${TINYCTHREAD} ${GLAD_GL})
 add_executable(gamma WIN32 MACOSX_BUNDLE gamma.c ${GLAD_GL})

tests/usercontext.c

+//========================================================================
+// User context test
+// Copyright (c) Camilla Löwy <elmindreda@glfw.org>
+//
+// This software is provided 'as-is', without any express or implied
+// warranty. In no event will the authors be held liable for any damages
+// arising from the use of this software.
+//
+// Permission is granted to anyone to use this software for any purpose,
+// including commercial applications, and to alter it and redistribute it
+// freely, subject to the following restrictions:
+//
+// 1. The origin of this software must not be misrepresented; you must not
+//    claim that you wrote the original software. If you use this software
+//    in a product, an acknowledgment in the product documentation would
+//    be appreciated but is not required.
+//
+// 2. Altered source versions must be plainly marked as such, and must not
+//    be misrepresented as being the original software.
+//
+// 3. This notice may not be removed or altered from any source
+//    distribution.
+//
+//========================================================================
+//
+// This test is intended to verify whether the OpenGL user context part of
+// the GLFW API is able to be used from multiple threads
+//
+//========================================================================
+
+#include "tinycthread.h"
+
 #define GLAD_GL_IMPLEMENTATION
 #include <glad/gl.h>
 #define GLFW_INCLUDE_NONE
@@ -9,10 +41,44 @@ static void error_callback(int error, const char* description)
     fprintf(stderr, "Error: %s\n", description);
 }
 
+static int thread_main(void* data)
+{
+    GLFWusercontext* usercontext = (GLFWusercontext*)data;
+
+    /* set the user context current */
+    glfwMakeUserContextCurrent(usercontext);
+
+    if (glfwGetCurrentContext() != NULL)
+    {
+        fprintf(stderr, "Current glfw window context not NULL after glfwMakeUserContextCurrent\n");
+        glfwTerminate();
+        return -1;
+    }
+    if (glfwGetCurrentUserContext() != usercontext)
+    {
+        fprintf(stderr, "Current user context not correct after glfwMakeUserContextCurrent\n");
+        glfwTerminate();
+        return -1;
+    }
+
+    /* set the user context to NULL */
+    glfwMakeUserContextCurrent(NULL);
+    if (glfwGetCurrentUserContext() != NULL)
+    {
+        fprintf(stderr, "Current user context not NULL after glfwMakeContextCurrent\n");
+        glfwTerminate();
+        return -1;
+    }
+
+    return 0;
+}
+
 int main(void)
 {
     GLFWwindow* window;
     GLFWusercontext* usercontext;
+    thrd_t thread_id;
+    int result, count;
 
     glfwSetErrorCallback(error_callback);
 
@@ -41,7 +107,6 @@ int main(void)
         return -1;
     }
 
-
     /* set the user context current */
     glfwMakeUserContextCurrent(usercontext);
 
@@ -76,9 +141,19 @@ int main(void)
 
     glClearColor( 0.4f, 0.3f, 0.4f, 1.0f );
 
+    // Launch a thread which should create and use the usercontext
+    if (thrd_create(&thread_id, thread_main, usercontext ) !=
+            thrd_success)
+    {
+        fprintf(stderr, "Failed to create secondary thread\n");
+
+        glfwTerminate();
+        exit(EXIT_FAILURE);
+    }
 
-    /* Loop until the user closes the window */
-    while (!glfwWindowShouldClose(window))
+    /* Loop 60 times or until the user closes the window */
+    count = 0;
+    while (!glfwWindowShouldClose(window) && count++ < 60)
     {
         /* Render here */
         glClear(GL_COLOR_BUFFER_BIT);
@@ -90,6 +165,35 @@ int main(void)
         glfwPollEvents();
     }
 
+    thrd_join(thread_id, &result);
+
+    /* One more test now the thread has joined */
+
+    /* set the user context current */
+    glfwMakeUserContextCurrent(usercontext);
+
+    if (glfwGetCurrentContext() != NULL)
+    {
+        fprintf(stderr, "Current glfw window context not NULL after glfwMakeUserContextCurrent\n");
+        glfwTerminate();
+        return -1;
+    }
+    if (glfwGetCurrentUserContext() != usercontext)
+    {
+        fprintf(stderr, "Current user context not correct after glfwMakeUserContextCurrent\n");
+        glfwTerminate();
+        return -1;
+    }
+
+    /* set the user context to NULL */
+    glfwMakeUserContextCurrent(NULL);
+    if (glfwGetCurrentUserContext() != NULL)
+    {
+        fprintf(stderr, "Current user context not NULL after glfwMakeContextCurrent\n");
+        glfwTerminate();
+        return -1;
+    }
+
     glfwDestroyUserContext(usercontext);
     glfwTerminate();
     return 0;