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authorSverker Eriksson <[email protected]>2010-04-28 20:24:48 +0200
committerRaimo Niskanen <[email protected]>2010-05-24 15:08:41 +0200
commitcb42b3d86e131f6d3ba883055990bb4164e0d6a6 (patch)
tree84f04e25c1355d08ee217ee72b0a5fd0145b7487 /erts/emulator/sys
parent458dcb10f98bffd241a837cbac7c108eb485f706 (diff)
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Fix deadlock in spawn driver on windows
A misbehaving port program that does not read all data written to the port may deadlock the scheduler thread when it calls port_close. The chosen solution was to use the new function CancelIoEx if it exist (Vista) otherwise let the spawn driver wait for a short while (10ms) and then to spawn a thread that will wait for the port program to exit.
Diffstat (limited to 'erts/emulator/sys')
-rw-r--r--erts/emulator/sys/win32/sys.c118
1 files changed, 100 insertions, 18 deletions
diff --git a/erts/emulator/sys/win32/sys.c b/erts/emulator/sys/win32/sys.c
index 46dee826f0..65719a91d6 100644
--- a/erts/emulator/sys/win32/sys.c
+++ b/erts/emulator/sys/win32/sys.c
@@ -33,6 +33,7 @@
#include "../../drivers/win32/win_con.h"
+
void erts_sys_init_float(void);
void erl_start(int, char**);
@@ -95,6 +96,10 @@ static erts_smp_mtx_t sys_driver_data_lock;
static FUNCTION(int, driver_write, (long, HANDLE, byte*, int));
static void common_stop(int);
static int create_file_thread(struct async_io* aio, int mode);
+#ifdef ERTS_SMP
+static void close_active_handles(ErlDrvPort, const HANDLE* handles, int cnt);
+static DWORD WINAPI threaded_handle_closer(LPVOID param);
+#endif
static DWORD WINAPI threaded_reader(LPVOID param);
static DWORD WINAPI threaded_writer(LPVOID param);
static DWORD WINAPI threaded_exiter(LPVOID param);
@@ -132,6 +137,9 @@ static BOOL win_console = FALSE;
static OSVERSIONINFO int_os_version; /* Version information for Win32. */
+#ifdef ERTS_SMP
+static BOOL (WINAPI *fpCancelIoEx)(HANDLE,LPOVERLAPPED);
+#endif
/* This is the system's main function (which may or may not be called "main")
- do general system-dependent initialization
@@ -676,25 +684,50 @@ release_driver_data(DriverData* dp)
erts_smp_mtx_lock(&sys_driver_data_lock);
#ifdef ERTS_SMP
- /* This is a workaround for the fact that CancelIo cant cancel
- requests issued by another thread and that we still cant use
- CancelIoEx as that's only availabele in Vista etc. */
- if(dp->in.async_io_active && dp->in.fd != INVALID_HANDLE_VALUE) {
- CloseHandle(dp->in.fd);
- dp->in.fd = INVALID_HANDLE_VALUE;
- DEBUGF(("Waiting for the in event thingie"));
- WaitForSingleObject(dp->in.ov.hEvent,INFINITE);
- DEBUGF(("...done\n"));
- }
- if(dp->out.async_io_active && dp->out.fd != INVALID_HANDLE_VALUE) {
- CloseHandle(dp->out.fd);
- dp->out.fd = INVALID_HANDLE_VALUE;
- DEBUGF(("Waiting for the out event thingie"));
- WaitForSingleObject(dp->out.ov.hEvent,INFINITE);
- DEBUGF(("...done\n"));
+ if (fpCancelIoEx != NULL) {
+ if (dp->in.thread == (HANDLE) -1 && dp->in.fd != INVALID_HANDLE_VALUE) {
+ (*fpCancelIoEx)(dp->in.fd, NULL);
+ }
+ if (dp->out.thread == (HANDLE) -1 && dp->out.fd != INVALID_HANDLE_VALUE) {
+ (*fpCancelIoEx)(dp->out.fd, NULL);
+ }
+ }
+ else {
+ /* This is a workaround for the fact that CancelIo cant cancel
+ requests issued by another thread and that we cant use
+ CancelIoEx as that's only availabele in Vista etc.
+ R14: Avoid scheduler deadlock by only wait for 10ms, and then spawn
+ a thread that will keep waiting in in order to close handles. */
+ HANDLE handles[2];
+ int i = 0;
+ int timeout = 10;
+ if(dp->in.async_io_active && dp->in.fd != INVALID_HANDLE_VALUE) {
+ CloseHandle(dp->in.fd);
+ dp->in.fd = INVALID_HANDLE_VALUE;
+ DEBUGF(("Waiting for the in event thingie"));
+ if (WaitForSingleObject(dp->in.ov.hEvent,timeout) == WAIT_TIMEOUT) {
+ handles[i++] = dp->in.ov.hEvent;
+ dp->in.ov.hEvent = NULL;
+ timeout = 0;
+ }
+ DEBUGF(("...done\n"));
+ }
+ if(dp->out.async_io_active && dp->out.fd != INVALID_HANDLE_VALUE) {
+ CloseHandle(dp->out.fd);
+ dp->out.fd = INVALID_HANDLE_VALUE;
+ DEBUGF(("Waiting for the out event thingie"));
+ if (WaitForSingleObject(dp->out.ov.hEvent,timeout) == WAIT_TIMEOUT) {
+ handles[i++] = dp->out.ov.hEvent;
+ dp->out.ov.hEvent = NULL;
+ }
+ DEBUGF(("...done\n"));
+ }
+ if (i > 0) {
+ close_active_handles(dp->port_num, handles, i);
+ }
}
#else
- if (dp->out.thread == (HANDLE) -1 && dp->in.fd != INVALID_HANDLE_VALUE) {
+ if (dp->in.thread == (HANDLE) -1 && dp->in.fd != INVALID_HANDLE_VALUE) {
CancelIo(dp->in.fd);
}
if (dp->out.thread == (HANDLE) -1 && dp->out.fd != INVALID_HANDLE_VALUE) {
@@ -737,6 +770,48 @@ release_driver_data(DriverData* dp)
erts_smp_mtx_unlock(&sys_driver_data_lock);
}
+#ifdef ERTS_SMP
+
+struct handles_to_be_closed
+{
+ int cnt;
+ HANDLE handles[2];
+};
+
+static void close_active_handles(ErlDrvPort port_num, const HANDLE* handles, int cnt)
+{
+ DWORD tid;
+ HANDLE thread;
+ int i;
+ struct handles_to_be_closed* htbc = erts_alloc(ERTS_ALC_T_DRV_TAB,
+ sizeof(struct handles_to_be_closed));
+ htbc->cnt = cnt;
+ for (i=0; i < cnt; ++i) {
+ htbc->handles[i] = handles[i];
+ (void) driver_select(port_num, (ErlDrvEvent)handles[i],
+ ERL_DRV_USE_NO_CALLBACK, 0);
+ }
+ thread = (HANDLE *) _beginthreadex(NULL, 0, threaded_handle_closer, htbc, 0, &tid);
+ CloseHandle(thread);
+}
+
+
+static DWORD WINAPI
+threaded_handle_closer(LPVOID param)
+{
+ struct handles_to_be_closed* htbc = (struct handles_to_be_closed*) param;
+ int i;
+ DEBUGF(("threaded_handle_closer waiting for %d handles\r\n",htbc->cnt));
+ WaitForMultipleObjects(htbc->cnt, htbc->handles, TRUE, INFINITE);
+ for (i=0; i < htbc->cnt; ++i) {
+ CloseHandle(htbc->handles[i]);
+ }
+ erts_free(ERTS_ALC_T_DRV_TAB, htbc);
+ DEBUGF(("threaded_handle_closer terminating\r\n"));
+ return 0;
+}
+#endif /* ERTS_SMP */
+
/*
* Stores input and output file descriptors in the DriverData structure,
* and calls driver_select().
@@ -1026,12 +1101,19 @@ static int
spawn_init()
{
int i;
-
+#ifdef ERTS_SMP
+ HMODULE module = GetModuleHandle("kernel32");
+ fpCancelIoEx = (module != NULL) ?
+ (BOOL (WINAPI *)(HANDLE,LPOVERLAPPED))
+ GetProcAddress(module,"CancelIoEx") : NULL;
+ DEBUGF(("fpCancelIoEx = %p\r\n", fpCancelIoEx));
+#endif
driver_data = (struct driver_data *)
erts_alloc(ERTS_ALC_T_DRV_TAB, max_files * sizeof(struct driver_data));
erts_smp_atomic_add(&sys_misc_mem_sz, max_files*sizeof(struct driver_data));
for (i = 0; i < max_files; i++)
driver_data[i].port_num = PORT_FREE;
+
return 0;
}