emulator opengl: add OpenglOsUtils library, a set of OS utils.

This is just a set of OS dependant functionality needed by the
emulator OpenGL host renderer. It currently has implementation for
Linux and Windows only.

osDynLibrary - dlopen/dlsym abstraction
osProcess    - interface to launch a new process, wait and kill it.
osThread     - abstraction interface for creating a thread.

Change-Id: Ib0264592d8c87e865da87acf5c94e2b331801ca4

tools/emulator/opengl/shared/OpenglOsUtils/osProcessUnix.cpp

@@ -0,0 +1,210 @@
+/*
+* Copyright (C) 2011 The Android Open Source Project
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+* http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+#include "osProcess.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/wait.h>
+#include <sys/types.h>
+#include <poll.h>
+#include <pthread.h>
+#include <string.h>
+#include <pwd.h>
+#include <paths.h>
+#include <errno.h>
+#include <signal.h>
+#include <unistd.h>
+#include <assert.h>
+
+namespace osUtils {
+
+//
+// buildArgList converts a command line into null terminated argument list.
+// to be used with execv or execvp.
+// each argument is seperated by space or tab, to specify multiple words
+// at the same argument place it inside single-quoted or double-quoted string.
+//
+static char **buildArgList(const char *command)
+{
+    char **argv = NULL;
+    int argvSize = 0;
+    int nArgs = 0;
+    char *tmpcmd = strdup(command);
+    char *t = tmpcmd;
+    char *strStart = NULL;
+    int i = 0;
+
+    #define ADD_ARG \
+        { \
+            nArgs++; \
+            if (!argv) { \
+                argvSize = 12; \
+                argv = (char **)malloc(argvSize * sizeof(char *)); \
+            } \
+            else if (nArgs > argvSize) { \
+                argvSize += 12; \
+                argv = (char **)realloc(argv, argvSize * sizeof(char *)); \
+            } \
+            argv[nArgs-1] = t; \
+            t = NULL; \
+        }
+
+    while( tmpcmd[i] != '\0' ) {
+        if (!strStart) {
+            if (tmpcmd[i] == '"' || tmpcmd[i] == '\'') {
+                strStart = &tmpcmd[i];
+            }
+            else if (tmpcmd[i] == ' ' || tmpcmd[i] == '\t') {
+                tmpcmd[i] = '\0';
+                if (t) ADD_ARG;
+            }
+            else if (!t) {
+                t = &tmpcmd[i];
+            }
+        }
+        else if (tmpcmd[i] == *strStart) {
+            t = strStart;
+            strStart = NULL;
+        }
+
+        i++;
+    }
+    if (t) {
+        ADD_ARG;
+    }
+    if (nArgs > 0) {
+        ADD_ARG; // for NULL terminating list
+    }
+
+    return argv;
+}
+
+static pid_t start_process(const char *command,const char *startDir)
+{
+    pid_t pid;
+
+    pid = fork();
+
+    if (pid < 0) {
+        return pid;
+    }
+    else if (pid == 0) {
+        //
+        // Close all opened file descriptors
+        //
+        for (int i=3; i<256; i++) {
+            close(i);
+        }
+
+        if (startDir) {
+            chdir(startDir);
+        }
+
+        char **argv = buildArgList(command);
+        if (!argv) {
+            return -1;
+        }
+        execvp(argv[0], argv);
+
+        perror("execl");
+        exit(-101);
+    }
+
+    return pid;
+}
+
+childProcess *
+childProcess::create(const char *p_cmdLine, const char *p_startdir)
+{
+    childProcess *child = new childProcess();
+    if (!child) {
+        return NULL;
+    }
+
+    child->m_pid = start_process(p_cmdLine, p_startdir);
+    if (child->m_pid < 0) {
+        delete child;
+        return NULL;
+    }
+
+    return child;
+}
+
+childProcess::~childProcess()
+{
+}
+
+bool
+childProcess::wait(int *exitStatus)
+{
+    int ret=0;
+    if (m_pid>0) {
+        pid_t pid = waitpid(m_pid,&ret,0);
+        if (pid != -1) {
+            m_pid=-1;
+            if (exitStatus) {
+                *exitStatus = ret;
+            }
+            return true;
+        }
+    }
+    return false;
+}
+
+int
+childProcess::tryWait(bool &isAlive)
+{
+    int ret=0;
+    isAlive = false;
+    if (m_pid>0) {
+        pid_t pid = waitpid(m_pid,&ret,WNOHANG);
+        if (pid == 0) {
+            isAlive = true;
+        }
+    }
+
+    return ((char)WEXITSTATUS(ret));
+}
+
+int ProcessGetPID()
+{
+    return getpid();
+}
+
+int KillProcess(int pid, bool wait)
+{
+    if (pid<1) {
+        return false;
+    }
+
+    if (0!=kill(pid,SIGTERM)) {
+        return false;
+    }
+
+    if (wait) {
+        if (waitpid(pid,NULL,0)<0) {
+            return false;
+        }
+    }
+
+    return true;
+}
+
+bool isProcessRunning(int pid)
+{
+    return (kill(pid,0) == 0);
+}
+
+} // of namespace osUtils