kolan
/
CMake
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

ENH: Added KWSYSPE_DEBUG macro to print debugging trace information. Added TODO comment explaining why process execution can still hang when a grandchild keeps the output pipes open.

This commit is contained in:
Brad King 2007-04-12 10:56:20 -04:00
parent 0a0e89ee8a
commit 688ebad20e
1 changed files with 54 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

55
Source/kwsys/ProcessWin32.c
View File

@ -77,6 +77,22 @@ Q190351 and Q150956.
/* The maximum amount to read from a pipe at a time. */
#define KWSYSPE_PIPE_BUFFER_SIZE 1024
/* Debug output macro. */
#if 0
# define KWSYSPE_DEBUG(x) \
( \
(void*)cp == (void*)0x00226DE0? \
( \
fprintf(stderr, "%d/%p/%d ", (int)GetCurrentProcessId(), cp, __LINE__), \
fprintf x, \
fflush(stderr), \
1 \
) : (1) \
)
#else
# define KWSYSPE_DEBUG(x) (void)1
#endif
#define kwsysEncodedWriteArrayProcessFwd9x kwsys_ns(EncodedWriteArrayProcessFwd9x)
typedef LARGE_INTEGER kwsysProcessTime;
@ -1238,6 +1254,7 @@ int kwsysProcess_WaitForData(kwsysProcess* cp, char** data, int* length,
done with the data. */
if(cp->CurrentIndex < KWSYSPE_PIPE_COUNT)
{
KWSYSPE_DEBUG((stderr, "releasing reader %d\n", cp->CurrentIndex));
ReleaseSemaphore(cp->Pipe[cp->CurrentIndex].Reader.Go, 1, 0);
cp->CurrentIndex = KWSYSPE_PIPE_COUNT;
}
@ -1282,6 +1299,7 @@ int kwsysProcess_WaitForData(kwsysProcess* cp, char** data, int* length,
inform the wakeup thread it is done with this process. */
kwsysProcessCleanupHandle(&cp->Pipe[cp->CurrentIndex].Read);
ReleaseSemaphore(cp->Pipe[cp->CurrentIndex].Waker.Go, 1, 0);
KWSYSPE_DEBUG((stderr, "wakeup %d\n", cp->CurrentIndex));
--cp->PipesLeft;
}
else if(data && length)
@ -1337,6 +1355,7 @@ int kwsysProcess_WaitForData(kwsysProcess* cp, char** data, int* length,
else
{
/* The process timeout has expired. Kill the child now. */
KWSYSPE_DEBUG((stderr, "killing child because timeout expired\n"));
kwsysProcess_Kill(cp);
cp->TimeoutExpired = 1;
cp->Killed = 0;
@ -1372,10 +1391,13 @@ int kwsysProcess_WaitForExit(kwsysProcess* cp, double* userTimeout)
}
}
KWSYSPE_DEBUG((stderr, "no more data\n"));
/* When the last pipe closes in WaitForData, the loop terminates
without releasing the pipe's thread. Release it now. */
if(cp->CurrentIndex < KWSYSPE_PIPE_COUNT)
{
KWSYSPE_DEBUG((stderr, "releasing reader %d\n", cp->CurrentIndex));
ReleaseSemaphore(cp->Pipe[cp->CurrentIndex].Reader.Go, 1, 0);
cp->CurrentIndex = KWSYSPE_PIPE_COUNT;
}
@ -1383,7 +1405,9 @@ int kwsysProcess_WaitForExit(kwsysProcess* cp, double* userTimeout)
/* Wait for all pipe threads to reset. */
for(i=0; i < KWSYSPE_PIPE_COUNT; ++i)
{
KWSYSPE_DEBUG((stderr, "waiting reader reset %d\n", i));
WaitForSingleObject(cp->Pipe[i].Reader.Reset, INFINITE);
KWSYSPE_DEBUG((stderr, "waiting waker reset %d\n", i));
WaitForSingleObject(cp->Pipe[i].Waker.Reset, INFINITE);
}
@ -1434,15 +1458,18 @@ void kwsysProcess_Kill(kwsysProcess* cp)
if(!cp || cp->State != kwsysProcess_State_Executing || cp->TimeoutExpired ||
cp->Killed)
{
KWSYSPE_DEBUG((stderr, "kill: child not executing\n"));
return;
}
/* Disable the reading threads. */
KWSYSPE_DEBUG((stderr, "kill: disabling pipe threads\n"));
kwsysProcessDisablePipeThreads(cp);
/* Skip actually killing the child if it has already terminated. */
if(cp->Terminated)
{
KWSYSPE_DEBUG((stderr, "kill: child already terminated\n"));
return;
}
@ -1498,8 +1525,11 @@ DWORD WINAPI kwsysProcessPipeThreadRead(LPVOID ptd)
void kwsysProcessPipeThreadReadPipe(kwsysProcess* cp, kwsysProcessPipeData* td)
{
/* Wait for space in the thread's buffer. */
while((WaitForSingleObject(td->Reader.Go, INFINITE), !td->Closed))
while((KWSYSPE_DEBUG((stderr, "wait for read %d\n", td->Index)),
WaitForSingleObject(td->Reader.Go, INFINITE), !td->Closed))
{
KWSYSPE_DEBUG((stderr, "reading %d\n", td->Index));
/* Read data from the pipe. This may block until data are available. */
if(!ReadFile(td->Read, td->DataBuffer, KWSYSPE_PIPE_BUFFER_SIZE,
&td->DataLength, 0))
@ -1511,11 +1541,16 @@ void kwsysProcessPipeThreadReadPipe(kwsysProcess* cp, kwsysProcessPipeData* td)
/* The pipe closed. There are no more data to read. */
td->Closed = 1;
KWSYSPE_DEBUG((stderr, "read closed %d\n", td->Index));
}
KWSYSPE_DEBUG((stderr, "read %d\n", td->Index));
/* Wait for our turn to be handled by the main thread. */
WaitForSingleObject(cp->SharedIndexMutex, INFINITE);
KWSYSPE_DEBUG((stderr, "reporting read %d\n", td->Index));
/* Tell the main thread we have something to report. */
cp->SharedIndex = td->Index;
ReleaseSemaphore(cp->Full, 1, 0);
@ -1523,6 +1558,7 @@ void kwsysProcessPipeThreadReadPipe(kwsysProcess* cp, kwsysProcessPipeData* td)
/* We were signalled to exit with our buffer empty. Reset the
mutex for a new process. */
KWSYSPE_DEBUG((stderr, "self releasing reader %d\n", td->Index));
ReleaseSemaphore(td->Reader.Go, 1, 0);
}
@ -1560,13 +1596,17 @@ void kwsysProcessPipeThreadWakePipe(kwsysProcess* cp, kwsysProcessPipeData* td)
(void)cp;
/* Wait for a possible wake command. */
KWSYSPE_DEBUG((stderr, "wait for wake %d\n", td->Index));
WaitForSingleObject(td->Waker.Go, INFINITE);
KWSYSPE_DEBUG((stderr, "waking %d\n", td->Index));
/* If the pipe is not closed, we need to wake up the reading thread. */
if(!td->Closed)
{
DWORD dummy;
KWSYSPE_DEBUG((stderr, "waker %d writing byte\n", td->Index));
WriteFile(td->Write, "", 1, &dummy, 0);
KWSYSPE_DEBUG((stderr, "waker %d wrote byte\n", td->Index));
}
}
@ -1910,6 +1950,15 @@ void kwsysProcessDestroy(kwsysProcess* cp, int event)
can detect end-of-data. */
for(i=0; i < KWSYSPE_PIPE_COUNT; ++i)
{
/* TODO: If the child created its own child (our grandchild)
which inherited a copy of the pipe write-end then the pipe
may not close and we will still need the waker write pipe.
However we still want to be able to detect end-of-data in the
normal case. The reader thread will have to switch to using
PeekNamedPipe to read the last bit of data from the pipe
without blocking. This is equivalent to using a non-blocking
read on posix. */
KWSYSPE_DEBUG((stderr, "closing wakeup write %d\n", i));
kwsysProcessCleanupHandle(&cp->Pipe[i].Write);
}
}
@ -2842,6 +2891,7 @@ static void kwsysProcessDisablePipeThreads(kwsysProcess* cp)
/* If data were just reported data, release the pipe's thread. */
if(cp->CurrentIndex < KWSYSPE_PIPE_COUNT)
{
KWSYSPE_DEBUG((stderr, "releasing reader %d\n", cp->CurrentIndex));
ReleaseSemaphore(cp->Pipe[cp->CurrentIndex].Reader.Go, 1, 0);
cp->CurrentIndex = KWSYSPE_PIPE_COUNT;
}
@ -2862,6 +2912,7 @@ static void kwsysProcessDisablePipeThreads(kwsysProcess* cp)
below. */
if(cp->Pipe[i].Read)
{
KWSYSPE_DEBUG((stderr, "releasing waker %d\n", i));
ReleaseSemaphore(cp->Pipe[i].Waker.Go, 1, 0);
}
}
@ -2871,9 +2922,11 @@ static void kwsysProcessDisablePipeThreads(kwsysProcess* cp)
{
/* The waking threads will cause all reading threads to report.
Wait for the next one and save its index. */
KWSYSPE_DEBUG((stderr, "waiting for reader\n"));
WaitForSingleObject(cp->Full, INFINITE);
cp->CurrentIndex = cp->SharedIndex;
ReleaseSemaphore(cp->SharedIndexMutex, 1, 0);
KWSYSPE_DEBUG((stderr, "got reader %d\n", cp->CurrentIndex));
/* We are done reading this pipe. Close its read handle. */
cp->Pipe[cp->CurrentIndex].Closed = 1;