diff options
Diffstat (limited to 'src/backend/port/unix_latch.c')
| -rw-r--r-- | src/backend/port/unix_latch.c | 80 |
1 files changed, 40 insertions, 40 deletions
diff --git a/src/backend/port/unix_latch.c b/src/backend/port/unix_latch.c index 32d0cb5e3f8..6dae7c94c03 100644 --- a/src/backend/port/unix_latch.c +++ b/src/backend/port/unix_latch.c @@ -37,11 +37,11 @@ * * for (;;) * { - * ResetLatch(); - * if (work to do) - * Do Stuff(); + * ResetLatch(); + * if (work to do) + * Do Stuff(); * - * WaitLatch(); + * WaitLatch(); * } * * It's important to reset the latch *before* checking if there's work to @@ -100,8 +100,8 @@ static volatile sig_atomic_t waiting = false; /* Read and write end of the self-pipe */ -static int selfpipe_readfd = -1; -static int selfpipe_writefd = -1; +static int selfpipe_readfd = -1; +static int selfpipe_writefd = -1; /* private function prototypes */ static void initSelfPipe(void); @@ -205,7 +205,8 @@ int WaitLatchOrSocket(volatile Latch *latch, pgsocket sock, bool forRead, bool forWrite, long timeout) { - struct timeval tv, *tvp = NULL; + struct timeval tv, + *tvp = NULL; fd_set input_mask; fd_set output_mask; int rc; @@ -225,13 +226,13 @@ WaitLatchOrSocket(volatile Latch *latch, pgsocket sock, bool forRead, waiting = true; for (;;) { - int hifd; + int hifd; /* * Clear the pipe, and check if the latch is set already. If someone - * sets the latch between this and the select() below, the setter - * will write a byte to the pipe (or signal us and the signal handler - * will do that), and the select() will return immediately. + * sets the latch between this and the select() below, the setter will + * write a byte to the pipe (or signal us and the signal handler will + * do that), and the select() will return immediately. */ drainSelfPipe(); if (latch->is_set) @@ -278,7 +279,7 @@ WaitLatchOrSocket(volatile Latch *latch, pgsocket sock, bool forRead, (forWrite && FD_ISSET(sock, &output_mask)))) { result = 2; - break; /* data available in socket */ + break; /* data available in socket */ } } waiting = false; @@ -293,7 +294,7 @@ WaitLatchOrSocket(volatile Latch *latch, pgsocket sock, bool forRead, void SetLatch(volatile Latch *latch) { - pid_t owner_pid; + pid_t owner_pid; /* Quick exit if already set */ if (latch->is_set) @@ -302,17 +303,17 @@ SetLatch(volatile Latch *latch) latch->is_set = true; /* - * See if anyone's waiting for the latch. It can be the current process - * if we're in a signal handler. We use the self-pipe to wake up the - * select() in that case. If it's another process, send a signal. + * See if anyone's waiting for the latch. It can be the current process if + * we're in a signal handler. We use the self-pipe to wake up the select() + * in that case. If it's another process, send a signal. * - * Fetch owner_pid only once, in case the owner simultaneously disowns - * the latch and clears owner_pid. XXX: This assumes that pid_t is - * atomic, which isn't guaranteed to be true! In practice, the effective - * range of pid_t fits in a 32 bit integer, and so should be atomic. In - * the worst case, we might end up signaling wrong process if the right - * one disowns the latch just as we fetch owner_pid. Even then, you're - * very unlucky if a process with that bogus pid exists. + * Fetch owner_pid only once, in case the owner simultaneously disowns the + * latch and clears owner_pid. XXX: This assumes that pid_t is atomic, + * which isn't guaranteed to be true! In practice, the effective range of + * pid_t fits in a 32 bit integer, and so should be atomic. In the worst + * case, we might end up signaling wrong process if the right one disowns + * the latch just as we fetch owner_pid. Even then, you're very unlucky if + * a process with that bogus pid exists. */ owner_pid = latch->owner_pid; if (owner_pid == 0) @@ -351,15 +352,14 @@ latch_sigusr1_handler(void) static void initSelfPipe(void) { - int pipefd[2]; + int pipefd[2]; /* * Set up the self-pipe that allows a signal handler to wake up the * select() in WaitLatch. Make the write-end non-blocking, so that * SetLatch won't block if the event has already been set many times - * filling the kernel buffer. Make the read-end non-blocking too, so - * that we can easily clear the pipe by reading until EAGAIN or - * EWOULDBLOCK. + * filling the kernel buffer. Make the read-end non-blocking too, so that + * we can easily clear the pipe by reading until EAGAIN or EWOULDBLOCK. */ if (pipe(pipefd) < 0) elog(FATAL, "pipe() failed: %m"); @@ -376,8 +376,8 @@ initSelfPipe(void) static void sendSelfPipeByte(void) { - int rc; - char dummy = 0; + int rc; + char dummy = 0; retry: rc = write(selfpipe_writefd, &dummy, 1); @@ -388,16 +388,16 @@ retry: goto retry; /* - * If the pipe is full, we don't need to retry, the data that's - * there already is enough to wake up WaitLatch. + * If the pipe is full, we don't need to retry, the data that's there + * already is enough to wake up WaitLatch. */ if (errno == EAGAIN || errno == EWOULDBLOCK) return; /* - * Oops, the write() failed for some other reason. We might be in - * a signal handler, so it's not safe to elog(). We have no choice - * but silently ignore the error. + * Oops, the write() failed for some other reason. We might be in a + * signal handler, so it's not safe to elog(). We have no choice but + * silently ignore the error. */ return; } @@ -408,11 +408,11 @@ static void drainSelfPipe(void) { /* - * There shouldn't normally be more than one byte in the pipe, or maybe - * a few more if multiple processes run SetLatch at the same instant. + * There shouldn't normally be more than one byte in the pipe, or maybe a + * few more if multiple processes run SetLatch at the same instant. */ - char buf[16]; - int rc; + char buf[16]; + int rc; for (;;) { @@ -420,9 +420,9 @@ drainSelfPipe(void) if (rc < 0) { if (errno == EAGAIN || errno == EWOULDBLOCK) - break; /* the pipe is empty */ + break; /* the pipe is empty */ else if (errno == EINTR) - continue; /* retry */ + continue; /* retry */ else elog(ERROR, "read() on self-pipe failed: %m"); } |