From 344ced4622ffc9d38ab0388d3ed44fe55ce5e86c Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Thu, 4 Nov 2004 18:57:31 +0000 Subject: add some more comments git-svn-id: file:///home/lennart/svn/public/pulseaudio/trunk@271 fefdeb5f-60dc-0310-8127-8f9354f1896f --- polyp/util.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 66 insertions(+), 8 deletions(-) (limited to 'polyp/util.c') diff --git a/polyp/util.c b/polyp/util.c index b138266b..794ae514 100644 --- a/polyp/util.c +++ b/polyp/util.c @@ -50,16 +50,20 @@ #include "xmalloc.h" #include "log.h" +/** Make a file descriptor nonblock. Doesn't do any error checking */ void pa_make_nonblock_fd(int fd) { int v; + assert(fd >= 0); if ((v = fcntl(fd, F_GETFL)) >= 0) if (!(v & O_NONBLOCK)) fcntl(fd, F_SETFL, v|O_NONBLOCK); } +/** Creates a directory securely */ int pa_make_secure_dir(const char* dir) { struct stat st; + assert(dir); if (mkdir(dir, 0700) < 0) if (errno != EEXIST) @@ -78,6 +82,8 @@ fail: return -1; } +/** Calls read() in a loop. Makes sure that as much as 'size' bytes, + * unless EOF is reached or an error occured */ ssize_t pa_loop_read(int fd, void*data, size_t size) { ssize_t ret = 0; assert(fd >= 0 && data && size); @@ -99,6 +105,7 @@ ssize_t pa_loop_read(int fd, void*data, size_t size) { return ret; } +/** Similar to pa_loop_read(), but wraps write() */ ssize_t pa_loop_write(int fd, const void*data, size_t size) { ssize_t ret = 0; assert(fd >= 0 && data && size); @@ -120,10 +127,16 @@ ssize_t pa_loop_write(int fd, const void*data, size_t size) { return ret; } +/* Print a warning messages in case that the given signal is not + * blocked or trapped */ void pa_check_signal_is_blocked(int sig) { struct sigaction sa; sigset_t set; + /* If POSIX threads are supported use thread-aware + * pthread_sigmask() function, to check if the signal is + * blocked. Otherwise fall back to sigprocmask() */ + #ifdef HAVE_PTHREAD if (pthread_sigmask(SIG_SETMASK, NULL, &set) < 0) { #endif @@ -137,6 +150,8 @@ void pa_check_signal_is_blocked(int sig) { if (sigismember(&set, sig)) return; + + /* Check whether the signal is trapped */ if (sigaction(sig, NULL, &sa) < 0) { pa_log(__FILE__": sigaction() failed: %s\n", strerror(errno)); @@ -149,7 +164,8 @@ void pa_check_signal_is_blocked(int sig) { pa_log(__FILE__": WARNING: %s is not trapped. This might cause malfunction!\n", pa_strsignal(sig)); } -/* The following is based on an example from the GNU libc documentation */ +/* The following function is based on an example from the GNU libc + * documentation. This function is similar to GNU's asprintf(). */ char *pa_sprintf_malloc(const char *format, ...) { int size = 100; char *c = NULL; @@ -176,6 +192,8 @@ char *pa_sprintf_malloc(const char *format, ...) { } } +/* Same as the previous function, but use a va_list instead of an + * ellipsis */ char *pa_vsprintf_malloc(const char *format, va_list ap) { int size = 100; char *c = NULL; @@ -199,11 +217,12 @@ char *pa_vsprintf_malloc(const char *format, va_list ap) { } } - +/* Return the current username in the specified string buffer. */ char *pa_get_user_name(char *s, size_t l) { struct passwd pw, *r; char buf[1024]; char *p; + assert(s && l > 0); if (!(p = getenv("USER"))) if (!(p = getenv("LOGNAME"))) @@ -222,21 +241,50 @@ char *pa_get_user_name(char *s, size_t l) { p = r->pw_name; } - - snprintf(s, l, "%s", p); - return s; + + return pa_strlcpy(s, p, l); } +/* Return the current hostname in the specified buffer. */ char *pa_get_host_name(char *s, size_t l) { + assert(s && l > 0); gethostname(s, l); s[l-1] = 0; return s; } +/* Return the home directory of the current user */ +char *pa_get_home(char *s, size_t l) { + char *e; + char buf[1024]; + struct passwd pw, *r; + assert(s && l); + + if ((e = getenv("HOME"))) + return pa_strlcpy(s, e, l); + + if (getpwuid_r(getuid(), &pw, buf, sizeof(buf), &r) != 0 || !r) + return NULL; + + return pa_strlcpy(s, r->pw_dir, l); +} + +/* Similar to OpenBSD's strlcpy() function */ +char *pa_strlcpy(char *b, const char *s, size_t l) { + assert(b && s && l > 0); + + strncpy(b, s, l); + b[l-1] = 0; + return b; +} + +/* Calculate the difference between the two specfified timeval + * timestamsps. */ pa_usec_t pa_timeval_diff(const struct timeval *a, const struct timeval *b) { pa_usec_t r; assert(a && b); + /* Check which whan is the earlier time and swap the two arguments if reuqired. */ if (pa_timeval_cmp(a, b) < 0) { const struct timeval *c; c = a; @@ -244,8 +292,10 @@ pa_usec_t pa_timeval_diff(const struct timeval *a, const struct timeval *b) { b = c; } + /* Calculate the second difference*/ r = ((pa_usec_t) a->tv_sec - b->tv_sec)* 1000000; + /* Calculate the microsecond difference */ if (a->tv_usec > b->tv_usec) r += ((pa_usec_t) a->tv_usec - b->tv_usec); else if (a->tv_usec < b->tv_usec) @@ -254,6 +304,7 @@ pa_usec_t pa_timeval_diff(const struct timeval *a, const struct timeval *b) { return r; } +/* Compare the two timeval structs and return 0 when equal, negative when a < b, positive otherwse */ int pa_timeval_cmp(const struct timeval *a, const struct timeval *b) { assert(a && b); @@ -272,6 +323,7 @@ int pa_timeval_cmp(const struct timeval *a, const struct timeval *b) { return 0; } +/* Return the time difference between now and the specified timestamp */ pa_usec_t pa_timeval_age(const struct timeval *tv) { struct timeval now; assert(tv); @@ -279,6 +331,7 @@ pa_usec_t pa_timeval_age(const struct timeval *tv) { return pa_timeval_diff(&now, tv); } +/* Add the specified time inmicroseconds to the specified timeval structure */ void pa_timeval_add(struct timeval *tv, pa_usec_t v) { unsigned long secs; assert(tv); @@ -289,6 +342,7 @@ void pa_timeval_add(struct timeval *tv, pa_usec_t v) { tv->tv_usec += v; + /* Normalize */ while (tv->tv_usec >= 1000000) { tv->tv_sec++; tv->tv_usec -= 1000000; @@ -297,12 +351,16 @@ void pa_timeval_add(struct timeval *tv, pa_usec_t v) { #define NICE_LEVEL (-15) +/* Raise the priority of the current process as much as possible and +sensible: set the nice level to -15 and enable realtime scheduling if +supportted.*/ + void pa_raise_priority(void) { + if (setpriority(PRIO_PROCESS, 0, NICE_LEVEL) < 0) pa_log(__FILE__": setpriority() failed: %s\n", strerror(errno)); - else - pa_log(__FILE__": Successfully gained nice level %i.\n", NICE_LEVEL); - + else pa_log(__FILE__": Successfully gained nice level %i.\n", NICE_LEVEL); + #ifdef _POSIX_PRIORITY_SCHEDULING { struct sched_param sp; -- cgit