Allow starting test-platform as a Daemon

BZ: 151780

Currently, test-platform does not return when it is launched. In
particular, one has to try to connect to it in order to know if it
has correctly been initialized.

Added a new '-d' option to test-platform to start it as a daemon:

    test-platform [-d] <file path> [port number, default 5001]

When test-platform is started as a daemon, a child process is created
and the main process immediatly returns its status.

Change-Id: I70a33691909c958904cf50d156a563b998f92657
Signed-off-by: Frédéric Boisnard <fredericx.boisnard@intel.com>

3 files changed, 163 insertions, 16 deletions

diff --git a/test/test-platform/TestPlatform.cpp b/test/test-platform/TestPlatform.cpp
index b69a10e..1b9951e 100644
--- a/test/test-platform/TestPlatform.cpp
+++ b/test/test-platform/TestPlatform.cpp
@@ -29,6 +29,7 @@
 #include <assert.h>
 #include <errno.h>
 #include <convert.hpp>
+#include <sstream>
 #include "TestPlatform.h"
 #include "ParameterMgrPlatformConnector.h"
 #include "RemoteProcessorServer.h"
@@ -53,6 +54,7 @@ public:
 CTestPlatform::CTestPlatform(const string& strClass, int iPortNumber, sem_t& exitSemaphore) :
     _pParameterMgrPlatformConnector(new CParameterMgrPlatformConnector(strClass)),
     _pParameterMgrPlatformConnectorLogger(new CParameterMgrPlatformConnectorLogger),
+    _portNumber(iPortNumber),
     _exitSemaphore(exitSemaphore)
 {
     _pCommandHandler = new CCommandHandler(this);
@@ -146,7 +148,9 @@ bool CTestPlatform::load(std::string& strError)
     // Start remote processor server
     if (!_pRemoteProcessorServer->start()) {
 
-        strError = "Unable to start remote processor server";
+        ostringstream oss;
+        oss << "TestPlatform: Unable to start remote processor server on port " << _portNumber;
+        strError = oss.str();
 
         return false;
     }
diff --git a/test/test-platform/TestPlatform.h b/test/test-platform/TestPlatform.h
index 8673e9d..9198ef8 100644
--- a/test/test-platform/TestPlatform.h
+++ b/test/test-platform/TestPlatform.h
@@ -150,6 +150,9 @@ private:
     // Remote Processor Server
     CRemoteProcessorServer* _pRemoteProcessorServer;
 
+    // Port number for the server socket
+    int _portNumber;
+
     // Semaphore used by calling thread to avoid exiting
     sem_t& _exitSemaphore;
 };
diff --git a/test/test-platform/main.cpp b/test/test-platform/main.cpp
index d97a449..6ed5a38 100644
--- a/test/test-platform/main.cpp
+++ b/test/test-platform/main.cpp
@@ -28,21 +28,16 @@
 #include <iostream>
 #include <cstdlib>
 #include <semaphore.h>
+#include <string.h>
+#include <unistd.h>
 
 using namespace std;
 
 const int iDefaultPortNumber = 5001;
 
-int main(int argc, char *argv[])
+// Starts test-platform in blocking mode
+static bool startBlockingTestPlatform(const char *filePath, int portNumber, string &strError)
 {
-    if (argc < 2) {
-
-        cerr << "Missing arguments: test-platform <file path> [port number, default " << iDefaultPortNumber << "]" << endl;
-
-        return -1;
-    }
-
-    string strError;
 
     // Init semaphore
     sem_t sem;
@@ -50,24 +45,169 @@ int main(int argc, char *argv[])
     sem_init(&sem, false, 0);
 
     // Create param mgr
-    CTestPlatform testPlatform(argv[1], argc > 2 ? atoi(argv[2]) : iDefaultPortNumber, sem);
+    CTestPlatform testPlatform(filePath, portNumber, sem);
 
     // Start platformmgr
     if (!testPlatform.load(strError)) {
 
-        cerr << strError << endl;
-
         sem_destroy(&sem);
 
-        return -1;
+        return false;
     }
 
-    // Change criteria
-
     // Block here
     sem_wait(&sem);
 
     sem_destroy(&sem);
 
+    return true;
+}
+
+// Starts test-platform in daemon mode
+static bool startDaemonTestPlatform(const char *filePath, int portNumber, string &strError)
+{
+    // Pipe used for communication between the child and the parent processes
+    int pipefd[2];
+
+    if (pipe(pipefd) == -1) {
+
+        strError = "pipe failed";
+        return false;
+    }
+
+    // Fork the current process:
+    // - Child process is used to start test-platform
+    // - Parent process is killed in order to turn its child into a daemon
+    pid_t pid = fork();
+
+    if (pid < 0) {
+
+        strError = "fork failed!";
+        return false;
+
+    } else if (pid == 0) {
+
+        // Child process : starts test-platform and notify the parent if it succeeds.
+
+        // Close read side of the pipe
+        close(pipefd[0]);
+
+        // Init semaphore
+        sem_t sem;
+
+        sem_init(&sem, false, 0);
+
+        // Create param mgr
+        CTestPlatform testPlatform(filePath, portNumber, sem);
+
+        // Message to send to parent process
+        bool msgToParent;
+
+        // Start platformmgr
+        if (!testPlatform.load(strError)) {
+
+            cerr << strError << endl;
+
+            // Notify parent of failure;
+            msgToParent = false;
+            write(pipefd[1], &msgToParent, sizeof(msgToParent));
+
+            sem_destroy(&sem);
+        } else {
+
+            // Notify parent of success
+            msgToParent = true;
+            write(pipefd[1], &msgToParent, sizeof(msgToParent));
+
+            // Block here
+            sem_wait(&sem);
+
+            sem_destroy(&sem);
+        }
+
+        return msgToParent;
+
+    } else {
+
+        // Parent process : need to kill it once the child notifies the successs/failure to start
+        // test-platform (this status is used as exit value of the program).
+
+        // Close write side of the pipe
+        close(pipefd[1]);
+
+        // Message received from the child process
+        bool msgFromChild = false;
+
+        if (read(pipefd[0], &msgFromChild, sizeof(msgFromChild)) <= 0) {
+
+            strError = "Read pipe failed";
+        }
+
+        // return success/failure in exit status
+        return msgFromChild;
+    }
+}
+
+static void usage()
+{
+    cerr << "Invalid arguments: test-platform [-d] <file path> [port number, default "
+         << iDefaultPortNumber << "]" << endl;
+}
+
+int main(int argc, char *argv[])
+{
+    // Option found by call to getopt()
+    int opt;
+
+    // Port number to be used by test-platform
+    int portNumber;
+
+    // Daemon flag
+    bool isDaemon = false;
+
+    // Index of the <file path> argument in the arguments list provided
+    int indexFilePath = 1;
+
+    // Handle the -d option
+    while ((opt = getopt(argc, argv, "d")) != -1) {
+        switch (opt) {
+        case 'd':
+            isDaemon = true;
+            indexFilePath = 2;
+            break;
+
+        default:
+            usage();
+            return -1;
+        }
+    }
+
+    // Check the number of arguments
+    if ((argc < indexFilePath + 1) || (argc > indexFilePath + 2)) {
+
+        usage();
+        return -1;
+    }
+
+    char *filePath = argv[indexFilePath];
+    portNumber = argc > indexFilePath + 1 ? atoi(argv[indexFilePath + 1]) : iDefaultPortNumber;
+
+    // Choose either blocking or daemon test-platform
+    bool startError;
+    string strError;
+
+    if (isDaemon) {
+
+        startError = startDaemonTestPlatform(filePath, portNumber, strError);
+    } else {
+
+        startError = startBlockingTestPlatform(filePath, portNumber, strError);
+    }
+
+    if (!startError) {
+
+        cerr << "Test-platform error:" << strError.c_str() << endl;
+        return -1;
+    }
     return 0;
 }