big s/polyp/pulse/g

git-svn-id: file:///home/lennart/svn/public/pulseaudio/trunk@1033 fefdeb5f-60dc-0310-8127-8f9354f1896f

src/pulsecore/pid.c

@@ -0,0 +1,304 @@
+/* $Id$ */
+
+/***
+  This file is part of PulseAudio.
+ 
+  PulseAudio is free software; you can redistribute it and/or modify
+  it under the terms of the GNU Lesser General Public License as
+  published by the Free Software Foundation; either version 2 of the
+  License, or (at your option) any later version.
+ 
+  PulseAudio is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  General Public License for more details.
+ 
+  You should have received a copy of the GNU Lesser General Public
+  License along with PulseAudio; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <string.h>
+#include <stdio.h>
+#include <assert.h>
+#include <stdlib.h>
+#include <limits.h>
+#include <signal.h>
+
+#ifdef HAVE_WINDOWS_H
+#include <windows.h>
+#endif
+
+#include <pulse/xmalloc.h>
+
+#include <pulsecore/core-error.h>
+#include <pulsecore/core-util.h>
+#include <pulsecore/log.h>
+
+#include "pid.h"
+
+/* Read the PID data from the file descriptor fd, and return it. If no
+ * pid could be read, return 0, on failure (pid_t) -1 */
+static pid_t read_pid(const char *fn, int fd) {
+    ssize_t r;
+    char t[20], *e;
+    uint32_t pid;
+
+    assert(fn && fd >= 0);
+
+    if ((r = pa_loop_read(fd, t, sizeof(t)-1)) < 0) {
+        pa_log_warn(__FILE__": WARNING: failed to read PID file '%s': %s",
+            fn, pa_cstrerror(errno));
+        return (pid_t) -1;
+    }
+
+    if (r == 0)
+        return (pid_t) 0;
+    
+    t[r] = 0;
+    if ((e = strchr(t, '\n')))
+        *e = 0;
+
+    if (pa_atou(t, &pid) < 0) {
+        pa_log(__FILE__": WARNING: failed to parse PID file '%s'", fn);
+        return (pid_t) -1;
+    }
+
+    return (pid_t) pid;
+}
+
+static int open_pid_file(const char *fn, int mode) {
+    int fd = -1;
+    int lock = -1;
+    
+    for (;;) {
+        struct stat st;
+        
+        pa_make_secure_parent_dir(fn);
+        
+        if ((fd = open(fn, mode, S_IRUSR|S_IWUSR)) < 0) {
+            if (mode != O_RDONLY || errno != ENOENT)
+                pa_log_warn(__FILE__": WARNING: failed to open PID file '%s': %s",
+                    fn, pa_cstrerror(errno));
+            goto fail;
+        }
+
+        /* Try to lock the file. If that fails, go without */
+        if (pa_lock_fd(fd, 1) < 0)
+            goto fail;
+        
+        if (fstat(fd, &st) < 0) {
+            pa_log_warn(__FILE__": WARNING: failed to fstat() PID file '%s': %s",
+                fn, pa_cstrerror(errno));
+            goto fail;
+        }
+
+        /* Does the file still exist in the file system? When ye, w're done, otherwise restart */
+        if (st.st_nlink >= 1)
+            break;
+
+        if (pa_lock_fd(fd, 0) < 0)
+            goto fail;
+
+        if (close(fd) < 0) {
+            pa_log_warn(__FILE__": WARNING: failed to close file '%s': %s",
+                fn, pa_cstrerror(errno));
+            goto fail;
+        }
+
+        fd = -1;
+    }
+
+    return fd;
+
+fail:
+
+    if (fd < 0) {
+        if (lock >= 0)
+            pa_lock_fd(fd, 0);
+        
+        close(fd);
+    }
+
+    return -1;
+}
+
+/* Create a new PID file for the current process. */
+int pa_pid_file_create(void) {
+    int fd = -1;
+    int ret = -1;
+    char fn[PATH_MAX];
+    char t[20];
+    pid_t pid;
+    size_t l;
+
+#ifdef OS_IS_WIN32
+    HANDLE process;
+#endif
+
+    pa_runtime_path("pid", fn, sizeof(fn));
+
+    if ((fd = open_pid_file(fn, O_CREAT|O_RDWR)) < 0)
+        goto fail;
+
+    if ((pid = read_pid(fn, fd)) == (pid_t) -1)
+        pa_log(__FILE__": corrupt PID file, overwriting.");
+    else if (pid > 0) {
+#ifdef OS_IS_WIN32
+        if ((process = OpenProcess(PROCESS_QUERY_INFORMATION, FALSE, pid)) != NULL) {
+            CloseHandle(process);
+#else
+        if (kill(pid, 0) >= 0 || errno != ESRCH) {
+#endif
+            pa_log(__FILE__": daemon already running.");
+            goto fail;
+        }
+
+        pa_log(__FILE__": stale PID file, overwriting.");
+    }
+
+    /* Overwrite the current PID file */
+    if (lseek(fd, 0, SEEK_SET) == (off_t) -1 || ftruncate(fd, 0) < 0) {
+        pa_log(__FILE__": failed to truncate PID file '%s': %s",
+            fn, pa_cstrerror(errno));
+        goto fail;
+    }
+    
+    snprintf(t, sizeof(t), "%lu\n", (unsigned long) getpid());
+    l = strlen(t);
+    
+    if (pa_loop_write(fd, t, l) != (ssize_t) l) {
+        pa_log(__FILE__": failed to write PID file.");
+        goto fail;
+    }
+
+    ret = 0;
+    
+fail:
+    if (fd >= 0) {
+        pa_lock_fd(fd, 0);
+        close(fd);
+    }
+    
+    return ret;
+}
+
+/* Remove the PID file, if it is ours */
+int pa_pid_file_remove(void) {
+    int fd = -1;
+    char fn[PATH_MAX];
+    int ret = -1;
+    pid_t pid;
+    char *p;
+
+    pa_runtime_path("pid", fn, sizeof(fn));
+
+    if ((fd = open_pid_file(fn, O_RDWR)) < 0) {
+        pa_log_warn(__FILE__": WARNING: failed to open PID file '%s': %s",
+            fn, pa_cstrerror(errno));
+        goto fail;
+    }
+
+    if ((pid = read_pid(fn, fd)) == (pid_t) -1)
+        goto fail;
+
+    if (pid != getpid()) {
+        pa_log(__FILE__": WARNING: PID file '%s' not mine!", fn);
+        goto fail;
+    }
+
+    if (ftruncate(fd, 0) < 0) {
+        pa_log_warn(__FILE__": WARNING: failed to truncate PID file '%s': %s",
+            fn, pa_cstrerror(errno));
+        goto fail;
+    }
+
+#ifdef OS_IS_WIN32
+    pa_lock_fd(fd, 0);
+    close(fd);
+    fd = -1;
+#endif
+
+    if (unlink(fn) < 0) {
+        pa_log_warn(__FILE__": WARNING: failed to remove PID file '%s': %s",
+            fn, pa_cstrerror(errno));
+        goto fail;
+    }
+
+    if ((p = pa_parent_dir(fn))) {
+        rmdir(p);
+        pa_xfree(p);
+    }
+    
+    ret = 0;
+    
+fail:
+
+    if (fd >= 0) {
+        pa_lock_fd(fd, 0);
+        close(fd);
+    }
+
+    return ret;
+}
+
+/* Check whether the daemon is currently running, i.e. if a PID file
+ * exists and the PID therein too. Returns 0 on succcess, -1
+ * otherwise. If pid is non-NULL and a running daemon was found,
+ * return its PID therein */
+int pa_pid_file_check_running(pid_t *pid) {
+    return pa_pid_file_kill(0, pid);
+}
+
+#ifndef OS_IS_WIN32
+
+/* Kill a current running daemon. Return non-zero on success, -1
+ * otherwise. If successful *pid contains the PID of the daemon
+ * process. */
+int pa_pid_file_kill(int sig, pid_t *pid) {
+    int fd = -1;
+    char fn[PATH_MAX];
+    int ret = -1;
+    pid_t _pid;
+
+    if (!pid)
+        pid = &_pid;
+    
+    pa_runtime_path("pid", fn, sizeof(fn));
+    
+    if ((fd = open_pid_file(fn, O_RDONLY)) < 0)
+        goto fail;
+    
+    if ((*pid = read_pid(fn, fd)) == (pid_t) -1)
+        goto fail;
+
+    ret = kill(*pid, sig);
+    
+fail:
+    
+    if (fd >= 0) {
+        pa_lock_fd(fd, 0);
+        close(fd);
+    }
+
+    return ret;
+    
+}
+
+#else /* OS_IS_WIN32 */
+
+int pa_pid_file_kill(int sig, pid_t *pid) {
+    return -1;
+}
+
+#endif