From fcb74112105e45ffc0a26aca7d952e84b05c782c Mon Sep 17 00:00:00 2001 From: Leo Tenenbaum Date: Tue, 16 Feb 2021 11:07:46 -0500 Subject: got WNOHANG to work --- main.c | 17 ++++++----- process-posix.c | 88 ++++++++++++++++++++------------------------------------- process.h | 4 +-- 3 files changed, 41 insertions(+), 68 deletions(-) diff --git a/main.c b/main.c index 8c6308b..d879cb7 100644 --- a/main.c +++ b/main.c @@ -146,14 +146,13 @@ int main(int argc, char **argv) { #endif setlocale(LC_ALL, ""); // allow unicode - process_init(); + char *program = "/usr/bin/sleep"; + char *args[] = {program, "5", NULL}; + Process process = {0}, *proc = &process; - char *program = "/usr/bin/make"; - char *args[] = {program, NULL}; - Process *process = process_exec(program, args); - if (!process) { - printf("Error: %s\n", process_geterr()); + if (!process_exec(proc, program, args)) { + printf("Error: %s\n", process_geterr(proc)); return EXIT_FAILURE; } #if 1 @@ -161,9 +160,9 @@ int main(int argc, char **argv) { i64 bytes = 0; char buf[256]; while (1) { - bytes = process_read(process, buf, sizeof buf); + bytes = process_read(proc, buf, sizeof buf); if (bytes == -2) { - printf("Error: %s\n", process_geterr()); + printf("Error: %s\n", process_geterr(proc)); } else if (bytes == -1) { usleep(1000); } else if (bytes == 0) { @@ -176,7 +175,7 @@ int main(int argc, char **argv) { { char message[256]; while (1) { - int status = process_check_status(process, message, sizeof message); + int status = process_check_status(proc, message, sizeof message); if (status == -1) { printf("%s!!!\n",message); break; diff --git a/process-posix.c b/process-posix.c index 53363b6..d683abe 100644 --- a/process-posix.c +++ b/process-posix.c @@ -6,40 +6,11 @@ struct Process { pid_t pid; int pipe; - bool stopped; - int exit_status; // INT_MAX if process was terminated + char error[64]; }; -static char process_error[64]; -static Process *processes; - -static void process_sigaction_sigchld(int signal, siginfo_t *info, void *context) { - (void)context; - if (signal == SIGCHLD) { - pid_t pid = info->si_pid; - arr_foreach_ptr(processes, Process, process) { - if (process->pid == pid) { - process->stopped = true; - if (info->si_code == CLD_EXITED) - process->exit_status = info->si_status; - else - process->exit_status = INT_MAX; - } - } - } -} - -void process_init(void) { - struct sigaction act = {0}; - act.sa_sigaction = process_sigaction_sigchld; - act.sa_flags = SA_SIGINFO | SA_NOCLDSTOP; - sigaction(SIGCHLD, &act, NULL); -} - - - -Process *process_exec(char const *program, char **argv) { - Process *proc = NULL; +bool process_exec(Process *proc, char const *program, char **argv) { + bool success = false; int pipefd[2]; if (pipe(pipefd) == 0) { @@ -56,21 +27,21 @@ Process *process_exec(char const *program, char **argv) { exit(127); } } else if (pid > 0) { - proc = arr_addp(processes); // parent process close(pipefd[1]); fcntl(pipefd[0], F_SETFL, fcntl(pipefd[0], F_GETFL) | O_NONBLOCK); // set pipe to non-blocking proc->pid = pid; proc->pipe = pipefd[0]; + success = true; } } else { - strbuf_printf(process_error, "%s", strerror(errno)); + strbuf_printf(proc->error, "%s", strerror(errno)); } - return proc; + return success; } -char const *process_geterr(void) { - return *process_error ? process_error : NULL; +char const *process_geterr(Process *p) { + return p->error; } long long process_read(Process *proc, char *data, size_t size) { @@ -81,7 +52,7 @@ long long process_read(Process *proc, char *data, size_t size) { } else if (errno == EAGAIN) { return -1; } else { - strbuf_printf(process_error, "%s", strerror(errno)); + strbuf_printf(proc->error, "%s", strerror(errno)); return -2; } @@ -89,31 +60,34 @@ long long process_read(Process *proc, char *data, size_t size) { void process_stop(Process *proc) { kill(proc->pid, SIGKILL); - // get rid of zombie process - waitpid(proc->pid, NULL, 0); close(proc->pipe); - for (u32 i = 0; i < arr_len(processes); ++i) - if (processes[i].pid == proc->pid) - arr_remove(processes, i); + proc->pid = 0; + proc->pipe = 0; } -#include -int process_check_status(Process *proc, char *message, size_t message_size) { - if (proc->stopped) { - int status = proc->exit_status; - process_stop(proc); - switch (status) { - case 0: - if (message) str_printf(message, message_size, "exited successfully"); - return +1; - case INT_MAX: - if (message) str_printf(message, message_size, "terminated by a signal"); - return -1; - default: - if (message) str_printf(message, message_size, "exited with code %d", status); +int process_check_status(Process *proc, char *message, size_t message_size) { + int wait_status = 0; + if (waitpid(proc->pid, &wait_status, WNOHANG) >= 0) { + if (WIFEXITED(wait_status)) { + int code = WEXITSTATUS(wait_status); + if (code == 0) { + str_printf(message, message_size, "exited successfully"); + return +1; + } else { + str_printf(message, message_size, "exited with code %d", code); + return -1; + } + } else if (WIFSIGNALED(wait_status)) { + str_printf(message, message_size, "terminated by signal %d", WTERMSIG(wait_status)); return -1; } + return 0; + } else if (errno == ECHILD) { + // this process is gone or something? + str_printf(message, message_size, "process ended unexpectedly"); + return -1; } else { + // probably shouldn't happen return 0; } } diff --git a/process.h b/process.h index 2b34120..a21fd5b 100644 --- a/process.h +++ b/process.h @@ -5,9 +5,9 @@ typedef struct Process Process; // returns NULL on failure -Process *process_exec(char const *program, char **argv); +bool process_exec(Process *process, char const *program, char **argv); // returns the error last error produced, or NULL if there was no error. -char const *process_geterr(void); +char const *process_geterr(Process *process); // returns: // -2 on error // -1 if no data is available right now -- cgit v1.2.3