diff options
Diffstat (limited to 'psycopg/pqpath.c')
| -rw-r--r-- | psycopg/pqpath.c | 43 |
1 files changed, 32 insertions, 11 deletions
diff --git a/psycopg/pqpath.c b/psycopg/pqpath.c index 0f5beb1..e7bed66 100644 --- a/psycopg/pqpath.c +++ b/psycopg/pqpath.c @@ -19,6 +19,12 @@ * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ +/* IMPORTANT NOTE: no function in this file do its own connection locking + except for pg_execute and pq_fetch (that are somehow high-level. This means + that all the othe functions should be called while holding a lock to the + connection. +*/ + #include <Python.h> #include <string.h> @@ -33,7 +39,9 @@ #include "psycopg/pgtypes.h" #include "psycopg/pgversion.h" -/* pq_raise - raise a python exception of the right kind */ +/* pq_raise - raise a python exception of the right kind + + This function should be called while holding the GIL. */ void pq_raise(connectionObject *conn, cursorObject *curs, PyObject *exc, char *msg) @@ -106,7 +114,8 @@ pq_raise(connectionObject *conn, cursorObject *curs, PyObject *exc, char *msg) critical condition like out of memory or lost connection. it save the error message and mark the connection as 'wanting cleanup'. - both functions do not call any Py_*_ALLOW_THREADS macros. */ + both functions do not call any Py_*_ALLOW_THREADS macros. + pq_resolve_critical should be called while holding the GIL. */ void pq_set_critical(connectionObject *conn, const char *msg) @@ -140,6 +149,7 @@ pq_resolve_critical(connectionObject *conn, int close) note that this function does block because it needs to wait for the full result sets of the previous query to clear them. + this function does not call any Py_*_ALLOW_THREADS macros */ void @@ -149,6 +159,7 @@ pq_clear_async(connectionObject *conn) do { pgres = PQgetResult(conn->pgconn); + Dprintf("pq_clear_async: clearing PGresult at %p", pgres); IFCLEARPGRES(pgres); } while (pgres != NULL); } @@ -291,7 +302,10 @@ pq_abort(connectionObject *conn) a status of 1 means that a call to pq_fetch will block, while a status of 0 means that there is data available to be collected. -1 means an error, the - exception will be set accordingly. */ + exception will be set accordingly. + + this fucntion locks the connection object + this function call Py_*_ALLOW_THREADS macros */ int pq_is_busy(connectionObject *conn) @@ -299,9 +313,15 @@ pq_is_busy(connectionObject *conn) PGnotify *pgn; Dprintf("pq_is_busy: consuming input"); + + Py_BEGIN_ALLOW_THREADS; + pthread_mutex_lock(&(conn->lock)); + if (PQconsumeInput(conn->pgconn) == 0) { Dprintf("pq_is_busy: PQconsumeInput() failed"); PyErr_SetString(OperationalError, PQerrorMessage(conn->pgconn)); + pthread_mutex_unlock(&(conn->lock)); + Py_BLOCK_THREADS; return -1; } @@ -315,11 +335,12 @@ pq_is_busy(connectionObject *conn) notify = PyTuple_New(2); PyTuple_SET_ITEM(notify, 0, PyInt_FromLong((long)pgn->be_pid)); PyTuple_SET_ITEM(notify, 1, PyString_FromString(pgn->relname)); - pthread_mutex_lock(&(conn->lock)); PyList_Append(conn->notifies, notify); - pthread_mutex_unlock(&(conn->lock)); free(pgn); } + + pthread_mutex_unlock(&(conn->lock)); + Py_END_ALLOW_THREADS; return PQisBusy(conn->pgconn); } @@ -656,14 +677,14 @@ pq_fetch(cursorObject *curs) Dprintf("pq_fetch: no data: entering polling loop"); - Py_BEGIN_ALLOW_THREADS; - pthread_mutex_lock(&(curs->conn->lock)); - while (pq_is_busy(curs->conn) > 0) { fd_set rfds; struct timeval tv; int sval, sock; + Py_BEGIN_ALLOW_THREADS; + pthread_mutex_lock(&(curs->conn->lock)); + sock = PQsocket(curs->conn->pgconn); FD_ZERO(&rfds); FD_SET(sock, &rfds); @@ -677,14 +698,14 @@ pq_fetch(cursorObject *curs) Dprintf("pq_fetch: entering PDflush() loop"); while (PQflush(curs->conn->pgconn) != 0); sval = select(sock+1, &rfds, NULL, NULL, &tv); + + pthread_mutex_unlock(&(curs->conn->lock)); + Py_END_ALLOW_THREADS; } Dprintf("pq_fetch: data is probably ready"); IFCLEARPGRES(curs->pgres); curs->pgres = PQgetResult(curs->conn->pgconn); - - pthread_mutex_unlock(&(curs->conn->lock)); - Py_END_ALLOW_THREADS; } /* check for PGRES_FATAL_ERROR result */ |