]> granicus.if.org Git - postgresql/commitdiff
Code review for recent libpq changes. Be more careful about error
authorTom Lane <tgl@sss.pgh.pa.us>
Thu, 2 Dec 2004 23:20:21 +0000 (23:20 +0000)
committerTom Lane <tgl@sss.pgh.pa.us>
Thu, 2 Dec 2004 23:20:21 +0000 (23:20 +0000)
handling in SIGPIPE processing; avoid unnecessary pollution of application
link-symbol namespace; spell 'pointer to function' in the conventional
way.

src/interfaces/libpq/fe-connect.c
src/interfaces/libpq/fe-print.c
src/interfaces/libpq/fe-secure.c
src/interfaces/libpq/libpq-fe.h
src/interfaces/libpq/libpq-int.h

index 30e56b4b6eb616b98fefe4f4f553766722451814..57d7ee8e6ff3d88407c6081833ee0267a2db5d05 100644 (file)
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/interfaces/libpq/fe-connect.c,v 1.291 2004/12/02 15:32:54 momjian Exp $
+ *       $PostgreSQL: pgsql/src/interfaces/libpq/fe-connect.c,v 1.292 2004/12/02 23:20:19 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -202,6 +202,11 @@ static int parseServiceInfo(PQconninfoOption *options,
 static char *pwdfMatchesString(char *buf, char *token);
 static char *PasswordFromFile(char *hostname, char *port, char *dbname,
                                 char *username);
+static void default_threadlock(int acquire);
+
+
+/* global variable because fe-auth.c needs to access it */
+pgthreadlock_t pg_g_threadlock = default_threadlock;
 
 
 /*
@@ -3276,16 +3281,6 @@ PasswordFromFile(char *hostname, char *port, char *dbname, char *username)
  * if they are not required.
  */
 
-void
-PQinitSSL(int do_init)
-{
-#ifdef USE_SSL
-       pq_initssllib = do_init;
-#endif
-}
-
-static pgthreadlock_t default_threadlock;
-
 static void
 default_threadlock(int acquire)
 {
@@ -3313,17 +3308,15 @@ default_threadlock(int acquire)
 #endif
 }
 
-pgthreadlock_t *g_threadlock = default_threadlock;
-
-pgthreadlock_t *
-PQregisterThreadLock(pgthreadlock_t *newhandler)
+pgthreadlock_t
+PQregisterThreadLock(pgthreadlock_t newhandler)
 {
-       pgthreadlock_t *prev;
+       pgthreadlock_t prev = pg_g_threadlock;
 
-       prev = g_threadlock;
        if (newhandler)
-               g_threadlock = newhandler;
+               pg_g_threadlock = newhandler;
        else
-               g_threadlock = default_threadlock;
+               pg_g_threadlock = default_threadlock;
+
        return prev;
 }
index 9992de533d705f79091c706ca7357bfb3004afea..8c2ce003ac86f96d0d889e187dcced93d50185c5 100644 (file)
@@ -10,7 +10,7 @@
  * didn't really belong there.
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/interfaces/libpq/fe-print.c,v 1.56 2004/12/02 15:32:54 momjian Exp $
+ *       $PostgreSQL: pgsql/src/interfaces/libpq/fe-print.c,v 1.57 2004/12/02 23:20:20 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -193,8 +193,8 @@ PQprint(FILE *fout,
                                {
                                        usePipe = 1;
 #ifdef ENABLE_THREAD_SAFETY
-                                       pq_block_sigpipe(&osigset, &sigpipe_pending);
-                                       sigpipe_masked = true;
+                                       if (pq_block_sigpipe(&osigset, &sigpipe_pending) == 0)
+                                               sigpipe_masked = true;
 #else
 #ifndef WIN32
                                        oldsigpipehandler = pqsignal(SIGPIPE, SIG_IGN);
@@ -316,8 +316,9 @@ PQprint(FILE *fout,
                        pclose(fout);
 #endif
 #ifdef ENABLE_THREAD_SAFETY
+                       /* we can't easily verify if EPIPE occurred, so say it did */
                        if (sigpipe_masked)
-                               pq_reset_sigpipe(&osigset, sigpipe_pending);
+                               pq_reset_sigpipe(&osigset, sigpipe_pending, true);
 #else
 #ifndef WIN32
                        pqsignal(SIGPIPE, oldsigpipehandler);
index 79ea192f99c0c40ff7aa09c8f34bfe35668dc0e1..a40b92065b9983b1d9cbbe79df8dd2e33243632c 100644 (file)
@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/interfaces/libpq/fe-secure.c,v 1.58 2004/12/02 15:32:54 momjian Exp $
+ *       $PostgreSQL: pgsql/src/interfaces/libpq/fe-secure.c,v 1.59 2004/12/02 23:20:21 tgl Exp $
  *
  * NOTES
  *       [ Most of these notes are wrong/obsolete, but perhaps not all ]
@@ -147,7 +147,7 @@ static void SSLerrfree(char *buf);
 #endif
 
 #ifdef USE_SSL
-bool           pq_initssllib = true;
+static bool pq_initssllib = true;
 
 static SSL_CTX *SSL_context = NULL;
 #endif
@@ -212,6 +212,19 @@ KWbuHn491xNO25CQWMtem80uKw+pTnisBRF/454n1Jnhub144YRBoN8CAQI=\n\
 /*                      Procedures common to all secure sessions                       */
 /* ------------------------------------------------------------ */
 
+
+/*
+ * Exported (but as yet undocumented) function to allow application to
+ * tell us it's already initialized OpenSSL.
+ */
+void
+PQinitSSL(int do_init)
+{
+#ifdef USE_SSL
+       pq_initssllib = do_init;
+#endif
+}
+
 /*
  *     Initialize global context
  */
@@ -377,8 +390,10 @@ pqsecure_write(PGconn *conn, const void *ptr, size_t len)
 #ifdef ENABLE_THREAD_SAFETY
        sigset_t        osigmask;
        bool            sigpipe_pending;
+       bool            got_epipe = false;
        
-       pq_block_sigpipe(&osigmask, &sigpipe_pending);
+       if (pq_block_sigpipe(&osigmask, &sigpipe_pending) < 0)
+               return -1;
 #else
 #ifndef WIN32
        pqsigfunc       oldsighandler = pqsignal(SIGPIPE, SIG_IGN);
@@ -413,9 +428,13 @@ pqsecure_write(PGconn *conn, const void *ptr, size_t len)
                                        char            sebuf[256];
 
                                        if (n == -1)
+                                       {
+                                               if (SOCK_ERRNO == EPIPE)
+                                                       got_epipe = true;
                                                printfPQExpBuffer(&conn->errorMessage,
                                                                libpq_gettext("SSL SYSCALL error: %s\n"),
                                                SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
+                                       }
                                        else
                                        {
                                                printfPQExpBuffer(&conn->errorMessage,
@@ -448,15 +467,16 @@ pqsecure_write(PGconn *conn, const void *ptr, size_t len)
        }
        else
 #endif
+       {
                n = send(conn->sock, ptr, len, 0);
-               /*
-                *      Possible optimization:  if sigpending() turns out to be an
-                *      expensive operation, we can set sigpipe_pending = 'true'
-                *      here if errno != EPIPE, avoiding a sigpending call.
-                */
+#ifdef ENABLE_THREAD_SAFETY
+               if (n < 0 && SOCK_ERRNO == EPIPE)
+                       got_epipe = true;
+#endif
+       }
 
 #ifdef ENABLE_THREAD_SAFETY
-       pq_reset_sigpipe(&osigmask, sigpipe_pending);
+       pq_reset_sigpipe(&osigmask, sigpipe_pending, got_epipe);
 #else
 #ifndef WIN32
        pqsignal(SIGPIPE, oldsighandler);
@@ -1228,13 +1248,14 @@ pq_block_sigpipe(sigset_t *osigset, bool *sigpipe_pending)
 {
        sigset_t sigpipe_sigset;
        sigset_t sigset;
-       int              ret;
        
        sigemptyset(&sigpipe_sigset);
        sigaddset(&sigpipe_sigset, SIGPIPE);
 
        /* Block SIGPIPE and save previous mask for later reset */
-       ret = pthread_sigmask(SIG_BLOCK, &sigpipe_sigset, osigset);
+       SOCK_ERRNO_SET(pthread_sigmask(SIG_BLOCK, &sigpipe_sigset, osigset));
+       if (SOCK_ERRNO)
+               return -1;
 
        /* We can have a pending SIGPIPE only if it was blocked before */
        if (sigismember(osigset, SIGPIPE))
@@ -1251,44 +1272,52 @@ pq_block_sigpipe(sigset_t *osigset, bool *sigpipe_pending)
        else
                *sigpipe_pending = false;
        
-       return ret;
+       return 0;
 }
        
 /*
  *     Discard any pending SIGPIPE and reset the signal mask.
- *     We might be discarding a blocked SIGPIPE that we didn't generate,
- *     but we document that you can't keep blocked SIGPIPE calls across
- *     libpq function calls.
+ *
+ * Note: we are effectively assuming here that the C library doesn't queue
+ * up multiple SIGPIPE events.  If it did, then we'd accidentally leave
+ * ours in the queue when an event was already pending and we got another.
+ * As long as it doesn't queue multiple events, we're OK because the caller
+ * can't tell the difference.
+ *
+ * The caller should say got_epipe = FALSE if it is certain that it
+ * didn't get an EPIPE error; in that case we'll skip the clear operation
+ * and things are definitely OK, queuing or no.  If it got one or might have
+ * gotten one, pass got_epipe = TRUE.
+ *
+ * We do not want this to change errno, since if it did that could lose
+ * the error code from a preceding send().  We essentially assume that if
+ * we were able to do pq_block_sigpipe(), this can't fail.
  */
-int
-pq_reset_sigpipe(sigset_t *osigset, bool sigpipe_pending)
+void
+pq_reset_sigpipe(sigset_t *osigset, bool sigpipe_pending, bool got_epipe)
 {
+       int     save_errno = SOCK_ERRNO;
        int     signo;
        sigset_t sigset;
 
        /* Clear SIGPIPE only if none was pending */
-       if (!sigpipe_pending)
+       if (got_epipe && !sigpipe_pending)
        {
-               if (sigpending(&sigset) != 0)
-                       return -1;
-       
-               /*
-                *      Discard pending and blocked SIGPIPE
-                */
-               if (sigismember(&sigset, SIGPIPE))
+               if (sigpending(&sigset) == 0 &&
+                       sigismember(&sigset, SIGPIPE))
                {
                        sigset_t sigpipe_sigset;
                        
                        sigemptyset(&sigpipe_sigset);
                        sigaddset(&sigpipe_sigset, SIGPIPE);
-       
+
                        sigwait(&sigpipe_sigset, &signo);
-                       if (signo != SIGPIPE)
-                               return -1;
                }
        }
        
        /* Restore saved block mask */
-       return pthread_sigmask(SIG_SETMASK, osigset, NULL);
+       pthread_sigmask(SIG_SETMASK, osigset, NULL);
+
+       SOCK_ERRNO_SET(save_errno);
 }
 #endif
index b472a1ae81c37cdb8e20d4c36aba070da135318c..638c27542c3877f7f77dcdd4c1e10b9df679391d 100644 (file)
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2004, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/interfaces/libpq/libpq-fe.h,v 1.114 2004/12/02 15:32:54 momjian Exp $
+ * $PostgreSQL: pgsql/src/interfaces/libpq/libpq-fe.h,v 1.115 2004/12/02 23:20:21 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -279,6 +279,9 @@ extern SSL *PQgetssl(PGconn *conn);
 extern void *PQgetssl(PGconn *conn);
 #endif
 
+/* Tell libpq whether it needs to initialize OpenSSL */
+extern void PQinitSSL(int do_init);
+
 /* Set verbosity for PQerrorMessage and PQresultErrorMessage */
 extern PGVerbosity PQsetErrorVerbosity(PGconn *conn, PGVerbosity verbosity);
 
@@ -301,11 +304,9 @@ extern PQnoticeProcessor PQsetNoticeProcessor(PGconn *conn,
  *        Only required for multithreaded apps that use kerberos
  *        both within their app and for postgresql connections.
  */
-typedef void (pgthreadlock_t) (int acquire);
+typedef void (*pgthreadlock_t) (int acquire);
 
-extern pgthreadlock_t *PQregisterThreadLock(pgthreadlock_t *newhandler);
-
-extern void PQinitSSL(int do_init);
+extern pgthreadlock_t PQregisterThreadLock(pgthreadlock_t newhandler);
 
 /* === in fe-exec.c === */
 
@@ -495,8 +496,6 @@ extern int  PQdsplen(const unsigned char *s, int encoding);
 /* Get encoding id from environment variable PGCLIENTENCODING */
 extern int     PQenv2encoding(void);
 
-/* === in fe-secure.c === */
-
 #ifdef __cplusplus
 }
 #endif
index 13b7e3588ce5aacf8e71a8dae0373a4cf3305133..7657b364a50df30fb81c8e78090a881e77bc59ec 100644 (file)
@@ -12,7 +12,7 @@
  * Portions Copyright (c) 1996-2004, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/interfaces/libpq/libpq-int.h,v 1.97 2004/12/02 15:32:54 momjian Exp $
+ * $PostgreSQL: pgsql/src/interfaces/libpq/libpq-int.h,v 1.98 2004/12/02 23:20:21 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -379,13 +379,13 @@ extern int pqPacketSend(PGconn *conn, char pack_type,
                         const void *buf, size_t buf_len);
 
 #ifdef ENABLE_THREAD_SAFETY
-extern pgthreadlock_t *g_threadlock;
+extern pgthreadlock_t pg_g_threadlock;
 
-#define pglock_thread() g_threadlock(true);
-#define pgunlock_thread() g_threadlock(false);
+#define pglock_thread()                pg_g_threadlock(true)
+#define pgunlock_thread()      pg_g_threadlock(false)
 #else
-#define pglock_thread() ((void)0)
-#define pgunlock_thread() ((void)0)
+#define pglock_thread()                ((void) 0)
+#define pgunlock_thread()      ((void) 0)
 #endif
 
 
@@ -476,13 +476,10 @@ extern void pqsecure_close(PGconn *);
 extern ssize_t pqsecure_read(PGconn *, void *ptr, size_t len);
 extern ssize_t pqsecure_write(PGconn *, const void *ptr, size_t len);
 
-#ifdef USE_SSL
-extern bool pq_initssllib;
-#endif
-
 #ifdef ENABLE_THREAD_SAFETY
-int pq_block_sigpipe(sigset_t *osigset, bool *sigpipe_pending);
-int pq_reset_sigpipe(sigset_t *osigset, bool sigpipe_pending);
+extern int     pq_block_sigpipe(sigset_t *osigset, bool *sigpipe_pending);
+extern void pq_reset_sigpipe(sigset_t *osigset, bool sigpipe_pending,
+                                                        bool got_epipe);
 #endif
 
 /*