Made ptty -> stdout be on a seperate thread to we can make stdin/stdout blocking

again for performance reasons

1 files changed, 55 insertions, 38 deletions

diff --git a/ptyim.c b/ptyim.c
index bf84ec7..daf64b7 100644
--- a/ptyim.c
+++ b/ptyim.c
@@ -98,9 +98,9 @@ int main (int argc, char * argv[], char * envp[]) {
 	//resize interrupt handler
 	winchhook(0);
 	//forks for running bash
-	pid_t mypid = fork();
-	if (mypid == 0) {
-		//child process
+	pid_t shell_pid = fork();
+	if (shell_pid == 0) {
+		//shell child process
 		//set self to be session leader
 		if (setsid() <0) {
 			fprintf(stderr, "failed to make new session\n");
@@ -135,47 +135,64 @@ int main (int argc, char * argv[], char * envp[]) {
 		//should automatically close any file descriptors
 		_exit(0);
 	} else {
-		//master process
-		//registers interrupts
-		signal(SIGCHLD, childhook);
-		signal(SIGWINCH, winchhook);
-		//display the im for the first time
-		disp_im(STDIN_FILENO, trows, tcols);
+		//forks for read and write, master process handles im, child
+		//process just handles transfering pty output to stdout
+		pid_t om_pid = fork();
+		if (om_pid == 0) {
+			//output manager child process
+			//runs forever until SIGKILL'd
+			while (true) {
+				//output manager child process
+				//buffer for reading from pty_master and writing to stdout
+				char write_buffer[WRITE_BUFFER_LEN] = {0};
+				//only read/write syscalls work well for this, printfs
+				//etcs do not work
+				// pty_master -> STDOUT
+				int wchars_read = read(pty_master,write_buffer, WRITE_BUFFER_LEN);
+				if (wchars_read >0) {
+					write(STDOUT_FILENO,write_buffer,wchars_read);
+				}
+				// stdin -> pty_master, im logic is also here
+			}
+			//child process exit
+			_exit(0);
+		} else {
+			//master process
+			//registers interrupts
+			signal(SIGCHLD, childhook);
+			signal(SIGWINCH, winchhook);
+			//display the im for the first time
+			disp_im(STDIN_FILENO, trows, tcols);
 
-		//1 char buffer for reading from stdin and writing to pty_master
-		char read_buffer[1] = {0};
+			//1 char buffer for reading from stdin and writing to pty_master
+			char read_buffer[1] = {0};
 
-		//buffer for reading from pty_master and writing to stdout
-		char write_buffer[WRITE_BUFFER_LEN] = {0};
-		//open
-		while (running) {
-			//only read/write syscalls work well for this, printfs
-			//etcs do not work
-			// pty_master -> STDOUT
-			int wchars_read = read(pty_master,write_buffer, WRITE_BUFFER_LEN);
-			if (wchars_read >0) {
-				write(STDOUT_FILENO,write_buffer,wchars_read);
-			}
-			// stdin -> pty_master, im logic is also here
-			int rchars_read = read(STDIN_FILENO, read_buffer, 1);
-			if (rchars_read > 0) {
-				//feeds the input char into the im state machine
-				char input_buffer[IM_TABLE_ENTRY_LEN+1] = {0};
-				int im_chars = update_im_state(read_buffer[0],
-						input_buffer);
-				//just in case it wasn't null terminated right
-				input_buffer[im_chars] = 0;
-				if (im_chars >0) {
-					//writes the input into pty_master if
-					//there was an output from the state
-					//machine
-					write(pty_master,input_buffer,im_chars);
+			//open
+			while (running) {
+				int rchars_read = read(STDIN_FILENO, read_buffer, 1);
+				if (rchars_read > 0) {
+					//feeds the input char into the im state machine
+					char input_buffer[IM_TABLE_ENTRY_LEN+1] = {0};
+					int im_chars = update_im_state(read_buffer[0],
+							input_buffer);
+					//just in case it wasn't null terminated right
+					input_buffer[im_chars] = 0;
+					if (im_chars >0) {
+						//writes the input into pty_master if
+						//there was an output from the state
+						//machine
+						write(pty_master,input_buffer,im_chars);
+					}
+					//any input update will lead to a disp_im update
+					disp_im(STDIN_FILENO, trows, tcols);
 				}
-				//any input update will lead to a disp_im update
-				disp_im(STDIN_FILENO, trows, tcols);
 			}
+			//at the end of the main process, kil lthe om process
+			kill(om_pid, SIGKILL);
 		}
 	}
+	//kill shell , can not be blocked
+	kill(shell_pid, SIGKILL);
 	//exit, only the master process should reach this point
 	close(pty_master);
 	close(pty_slave);