Initial revision

4 files changed, 288 insertions, 0 deletions

diff --git a/quickexec/johns/README b/quickexec/johns/README
new file mode 100644
index 0000000..1af84dc
--- a/dev/null
+++ b/quickexec/johns/README
@@ -0,0 +1,21 @@
+
+Compile qinit_srv.c to qinit_srv as usual
+Compile your applications at shared libraries instead of as executables:
+    eg: gcc test.c -o test.so -shared
+Make a symbolic link from qinit_srv to the name of the application:
+    eg: ln -s qinit_srv test
+Now make sure 'test' (The symlink) and 'test.so' (the shared library version of the app) are together.
+When you run ./test it will load test.so and run it just like you were running the application for real.
+There will be a qinit_srv process created the first time you run a program this way.
+
+How it works:
+
+qinit_srv checks to see if there is already a server, if not it starts as a server which runs in the background as a deamon.
+If it's a server it loads all the libraries listed in the library.lst file.
+It then waits for signals to be sent to it which tell it to fork itself and load shared libraries and run them.
+If it decides it's not the server, it sends a signal to the server to run the given command.
+The server then executes a shared object file of whatever name the original process is invoked as (argv[0], the symlink trick)
+The other process waits until the forked server finishes and signals the original process that it as finished and to return
+
+
+
diff --git a/quickexec/johns/library.lst b/quickexec/johns/library.lst
new file mode 100644
index 0000000..42f310b
--- a/dev/null
+++ b/quickexec/johns/library.lst
@@ -0,0 +1,2 @@
+libqte.so
+libqpe.so
diff --git a/quickexec/johns/qinit_srv.c b/quickexec/johns/qinit_srv.c
new file mode 100644
index 0000000..03c6cd3
--- a/dev/null
+++ b/quickexec/johns/qinit_srv.c
@@ -0,0 +1,242 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <signal.h>
+#include <unistd.h>
+#include <dlfcn.h>
+
+
+#define PID_FILE    "/tmp/qinit1.pid"
+#define CMD_FILE    "/tmp/qinit1.cmd"
+#define RET_FILE    "/tmp/qinit1.ret"
+
+
+static int librariesFinishedLoading = 0; 
+static void **handles = NULL;
+static int handleCount = 0;
+
+
+static void savePid( void );
+static int loadPid( void );
+void saveRetVal( int retVal );
+int loadRetVal( void );
+static void saveCmd( int callingPid, int argc, char *argv[] );
+static int execCmd( void );
+static void loadLibraries( char *listFile );
+static void signalHandler( int signal );
+static void finishedHandler( int signal );
+static void cleanUpHandler( int signal );
+static void cleanUp( void );
+
+
+int main( int argc, char *argv[] ) {
+    FILE *fh;
+
+    // See if there is already a server running
+    if ( ( fh = fopen( PID_FILE, "r" ) ) != NULL ) {
+	// There appears to already be a server running
+	fclose( fh );
+	// Install handler that tells us when the process created by the server has finished
+	signal( SIGUSR2, finishedHandler );
+	// Send our command to the server (saved to a file)
+	saveCmd( getpid(), argc, argv );
+	// Send a signal to the server to run our command 
+	kill( loadPid(), SIGUSR1 );
+	// Wait for the process created by the server to terminate
+	for (;;)
+	    sleep( 1 ); // Will eventually terminate when the SIGUSER2 signal is sent to us by the server
+    }
+
+    // Send the server to the background
+    daemon( 1, 1 );
+
+    // Save the process number of this process somewhere (in a file)
+    savePid();
+
+    // Wait for signal used to let us know when to fork to run commands
+    signal( SIGUSR1, signalHandler );
+    signal( SIGTERM, cleanUpHandler );
+    signal( SIGINT,  cleanUpHandler );
+    signal( SIGABRT, cleanUpHandler );
+    signal( SIGQUIT, cleanUpHandler );
+
+    // Iterate library list file and dynamically load at runtime
+    // the library files from the list
+    if ( argc > 1 )
+	loadLibraries( argv[1] ); // Use a library list file specified from command line
+    else
+	loadLibraries( "library.lst" ); // Use the default library list file
+
+    // Run the given command
+    signalHandler( SIGUSR1 );
+ 
+    // Keep waiting for signals infinitely that tell us to fork
+    for (;;)
+	wait( NULL ); // Wait for child processes to die or signals to be sent to us
+
+    cleanUp();
+
+    return 0;
+}
+
+
+void cleanUp( void ) {
+    int i;
+
+    // Close the shared libraries we opened
+    for ( i = 0; i < handleCount; i++ )
+	dlclose( handles[ i ] );
+    free( handles );
+
+    // Unlink the PID_FILE file
+    remove( PID_FILE );
+}
+
+
+void savePid( void ) {
+    int pid = getpid();
+    FILE *fh = fopen( PID_FILE, "w");
+    if ( !fh )
+	fputs("error writing pid to file " PID_FILE, stderr), exit(1);
+    fprintf( fh, "%i", pid );
+    fclose( fh );
+}
+
+
+int loadPid( void ) {
+    int pid;
+    FILE *fh = fopen( PID_FILE, "r" );
+    if ( !fh )
+	fputs("error loading pid from file " PID_FILE, stderr), exit(1);
+    fscanf( fh, "%i", &pid );
+    fclose( fh );
+    return pid;
+}
+
+
+void saveRetVal( int retVal ) {
+    FILE *fh = fopen( RET_FILE, "w");
+    if ( !fh )
+	fputs("error writing retVal to file " RET_FILE, stderr), exit(1);
+    fprintf( fh, "%i", retVal );
+    fclose( fh );
+}
+
+
+int loadRetVal( void ) {
+    int retVal;
+    FILE *fh = fopen( RET_FILE, "r" );
+    if ( !fh )
+	fputs("error loading retVal from file " RET_FILE, stderr), exit(1);
+    fscanf( fh, "%i", &retVal );
+    fclose( fh );
+    return retVal;
+}
+
+
+void saveCmd( int callingPid, int argc, char *argv[] ) {
+    int i;
+    FILE *fh = fopen( CMD_FILE, "w" );
+    if ( !fh )
+	fputs("error saving arg list to file " CMD_FILE, stderr), exit(1);
+    fprintf( fh, "%i\n", callingPid );
+    fprintf( fh, "%s.so", argv[0] );
+    for ( i = 0; i < argc; i++ )
+	fprintf( fh, "\n%s", argv[i] );
+    fclose( fh ); 
+}
+
+
+int execCmd( void ) {
+    int callingPid;
+    char sharedObject[128];
+    int argc;
+    char argv[128][128];
+    int (*childMain)( int argc, char *argv[] );
+    char *error;
+    void *handle;
+    int retVal = 0;
+
+    // Get the name of the file to dlopen and the arguments to pass (from a file)
+    FILE *fh = fopen( CMD_FILE, "r" );
+    fscanf( fh, "%i\n", &callingPid );
+    fgets( sharedObject, 128, fh );
+    sharedObject[strlen( sharedObject ) - 1] = '\0';	
+    for ( argc = 0; fgets( argv[argc], 128, fh ); argc++)
+	argv[argc][strlen( argv[argc] ) - 1] = '\0';	
+    fclose( fh );
+
+    // Open the shared object of what we want to execute
+    handle = dlopen( sharedObject, RTLD_LAZY );
+    if ( !handle )
+	fputs( dlerror(), stderr ), kill( callingPid, SIGUSR2 ), exit( 1 );
+
+    // Find main symbol and jump to it
+    childMain = dlsym( handle, "main" );
+    if ( ( error = dlerror() ) != NULL )
+	fputs( error, stderr ), kill( callingPid, SIGUSR2 ), exit( 1 );
+    retVal = (*childMain)( argc, (char**)argv );
+
+    // Notify caller that we have finished
+    saveRetVal( retVal );
+    kill( callingPid, SIGUSR2 );
+
+    // When we are done, close the shared object
+    dlclose( handle );
+    return retVal;
+}
+
+
+void finishedHandler( int signal ) {
+    // We have been notified of the completion of the task
+    exit( loadRetVal() );
+}
+
+
+void cleanUpHandler( int signal ) {
+    // Cleanup and exit if we have been told to quit
+    cleanUp();
+    exit(1);
+}
+
+
+void signalHandler( int signal ) {
+    //printf("got a signal of %i\n", signal );
+
+    if ( fork() == 0 ) {
+	// We are the child process
+
+/*
+	while ( librariesFinishedLoading != 1 ) {
+	    printf("waiting for libraries to load\n");
+	    sleep(1);
+	}
+*/
+	// Close file handles and open others etc
+
+	// Execute the command and return when done
+	exit( execCmd() );
+    }
+ 
+    // Parent process, just continue
+    sleep( 1 ); // Need to yield to child process
+}
+
+
+void loadLibraries( char *listFile ) {
+    FILE *fh = fopen( listFile, "r" );
+    char line[1024];
+    if ( !fh )
+	fputs("error opening library list file", stderr), exit(1);
+    while ( fgets( line, 1024, fh ) ) {
+	line[strlen( line ) - 1] = '\0';
+	printf("loading library: --%s--\n", line);
+	handleCount++;
+	handles = realloc( handles, handleCount * sizeof( void * ) );
+	handles[ handleCount - 1 ] = dlopen( line, RTLD_NOW );
+	if ( !handles[ handleCount - 1 ] )
+	    fputs( dlerror(), stderr ), exit( 1 );
+    }
+    fclose( fh );
+    librariesFinishedLoading = 1;
+}
+
diff --git a/quickexec/johns/so_stub.c b/quickexec/johns/so_stub.c
new file mode 100644
index 0000000..fe71f9c
--- a/dev/null
+++ b/quickexec/johns/so_stub.c
@@ -0,0 +1,23 @@
+#include <stdio.h>
+#include <string.h>
+#include <dlfcn.h>
+
+
+int main( int argc, char *argv[] ) {
+    char module[1024];
+    int (*loadedMain)( int argc, char *argv[] );
+    char *error;
+    int retVal = 0;
+    void *handle;
+    strcpy( module, argv[0] );
+    strcat( module, ".so" );
+    if ( !(handle  = dlopen( module, RTLD_LAZY ) ) )
+	fputs( dlerror(), stderr ), exit( 1 );
+    loadedMain = dlsym( handle, "main" );
+    if ( ( error = dlerror() ) != NULL )
+	fputs( error, stderr ), exit( 1 );
+    retVal = (*loadedMain)( argc, argv );
+    dlclose( handle );
+    return retVal;
+}
+