Windows: Always set the system timer resolution to 1ms by default.

An existing hint lets apps that don't need the timer resolution changed avoid
this, to save battery, etc, but this fixes several problems in timing, audio
callbacks not firing fast enough, etc.

Fixes Bugzilla #2944.

visualtest/src/linux/linux_process.c

@@ -0,0 +1,199 @@
+/* See COPYING.txt for the full license governing this code. */
+/**
+ *  \file linux_process.c
+ * 
+ *  Source file for the process API on linux.
+ */
+
+
+#include <SDL.h>
+#include <SDL_test.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include "SDL_visualtest_process.h"
+#include "SDL_visualtest_harness_argparser.h"
+#include "SDL_visualtest_parsehelper.h"
+
+#if defined(__LINUX__)
+
+static void
+LogLastError(char* str)
+{
+    char* error = (char*)strerror(errno);
+    if(!str || !error)
+    	return;
+    SDLTest_LogError("%s: %s", str, error);
+}
+
+int
+SDL_LaunchProcess(char* file, char* args, SDL_ProcessInfo* pinfo)
+{
+    pid_t pid;
+    char** argv;
+
+    if(!file)
+    {
+        SDLTest_LogError("file argument cannot be NULL");
+        return 0;
+    }
+    if(!pinfo)
+    {
+        SDLTest_LogError("pinfo cannot be NULL");
+        return 0;
+    }
+    pid = fork();
+    if(pid == -1)
+    {
+        LogLastError("fork() failed");
+        return 0;
+    }
+    else if(pid == 0)
+    {
+        /* parse the arguments string */
+        argv = SDLVisualTest_ParseArgsToArgv(args);
+        argv[0] = file;
+        execv(file, argv);
+        LogLastError("execv() failed");
+        return 0;
+    }
+    else
+    {
+        pinfo->pid = pid;
+        return 1;
+    }
+
+    /* never executed */
+    return 0;
+}
+
+int
+SDL_GetProcessExitStatus(SDL_ProcessInfo* pinfo, SDL_ProcessExitStatus* ps)
+{
+    int success, status;
+    if(!pinfo)
+    {
+        SDLTest_LogError("pinfo argument cannot be NULL");
+        return 0;
+    }
+    if(!ps)
+    {
+        SDLTest_LogError("ps argument cannot be NULL");
+        return 0;
+    }
+    success = waitpid(pinfo->pid, &status, WNOHANG);
+    if(success == -1)
+    {
+        LogLastError("waitpid() failed");
+        return 0;
+    }
+    else if(success == 0)
+    {
+        ps->exit_status = -1;
+        ps->exit_success = 1;
+    }
+    else
+    {
+        ps->exit_success = WIFEXITED(status);
+        ps->exit_status = WEXITSTATUS(status);
+    }
+    return 1;
+}
+
+int
+SDL_IsProcessRunning(SDL_ProcessInfo* pinfo)
+{
+    int success;
+
+    if(!pinfo)
+    {
+        SDLTest_LogError("pinfo cannot be NULL");
+        return -1;
+    }
+
+    success = kill(pinfo->pid, 0);
+    if(success == -1)
+    {
+        if(errno == ESRCH) /* process is not running */
+            return 0;
+        else
+        {
+            LogLastError("kill() failed");
+            return -1;
+        }
+    }
+    return 1;
+}
+
+int
+SDL_QuitProcess(SDL_ProcessInfo* pinfo, SDL_ProcessExitStatus* ps)
+{
+    int success, status;
+
+    if(!pinfo)
+    {
+        SDLTest_LogError("pinfo argument cannot be NULL");
+        return 0;
+    }
+    if(!ps)
+    {
+        SDLTest_LogError("ps argument cannot be NULL");
+        return 0;
+    }
+
+    success = kill(pinfo->pid, SIGQUIT);
+    if(success == -1)
+    {
+        LogLastError("kill() failed");
+        return 0;
+    }
+
+    success = waitpid(pinfo->pid, &status, 0);
+    if(success == -1)
+    {
+        LogLastError("waitpid() failed");
+        return 0;
+    }
+
+    ps->exit_success = WIFEXITED(status);
+    ps->exit_status = WEXITSTATUS(status);
+    return 1;
+}
+
+int
+SDL_KillProcess(SDL_ProcessInfo* pinfo, SDL_ProcessExitStatus* ps)
+{
+    int success, status;
+
+    if(!pinfo)
+    {
+        SDLTest_LogError("pinfo argument cannot be NULL");
+        return 0;
+    }
+    if(!ps)
+    {
+        SDLTest_LogError("ps argument cannot be NULL");
+        return 0;
+    }
+
+    success = kill(pinfo->pid, SIGKILL);
+    if(success == -1)
+    {
+        LogLastError("kill() failed");
+        return 0;
+    }
+    success = waitpid(pinfo->pid, &status, 0);
+    if(success == -1)
+    {
+        LogLastError("waitpid() failed");
+        return 0;
+    }
+
+    ps->exit_success = WIFEXITED(status);
+    ps->exit_status = WEXITSTATUS(status);
+    return 1;
+}
+
+#endif