diff options
Diffstat (limited to 'winsup/cygserver/process.cc')
| -rw-r--r-- | winsup/cygserver/process.cc | 389 |
1 files changed, 389 insertions, 0 deletions
diff --git a/winsup/cygserver/process.cc b/winsup/cygserver/process.cc new file mode 100644 index 000000000..a5173afd3 --- /dev/null +++ b/winsup/cygserver/process.cc @@ -0,0 +1,389 @@ +/* cygserver_process.cc + + Copyright 2001 Red Hat Inc. + + Written by Robert Collins <rbtcollins@hotmail.com> + + This file is part of Cygwin. + + This software is a copyrighted work licensed under the terms of the + Cygwin license. Please consult the file "CYGWIN_LICENSE" for + details. */ + +#include <errno.h> +#include <stdio.h> +#include <unistd.h> +#include <stdlib.h> +#include <windows.h> +#include <sys/types.h> +#include <sys/socket.h> +#include <netdb.h> +#include "wincap.h" +#include <pthread.h> +#include <threaded_queue.h> +#include <cygwin/cygserver_process.h> + +#define debug_printf if (DEBUG) printf +#define DEBUG 1 + +/* the cache structures and classes are designed for one cache per server process. + * To make multiple process caches, a redesign will be needed + */ + +/* process cache */ +process_cache::process_cache (unsigned int num_initial_workers): +head (NULL) +{ + /* there can only be one */ + InitializeCriticalSection (&cache_write_access); + if ((cache_add_trigger = CreateEvent (NULL, FALSE, FALSE, NULL)) == NULL) + { + printf ("Failed to create cache add trigger (%lu), terminating\n", + GetLastError ()); + exit (1); + } + initial_workers = num_initial_workers; +} + +process_cache::~process_cache () +{ +} + +class process * +process_cache::process (long pid) +{ + class process *entry = head; + /* TODO: make this more granular, so a search doesn't involve the write lock */ + EnterCriticalSection (&cache_write_access); + if (!entry) + { + entry = new class process (pid); + entry->next = + (class process *) InterlockedExchangePointer (&head, entry); + PulseEvent (cache_add_trigger); + } + else + { + while (entry->winpid != pid && entry->next) + entry = entry->next; + if (entry->winpid != pid) + { + class process *new_entry = new class process (pid); + new_entry->next = + (class process *) InterlockedExchangePointer (&entry->next, + new_entry); + entry = new_entry; + PulseEvent (cache_add_trigger); + } + } + LeaveCriticalSection (&cache_write_access); + return entry; +} + +static DWORD WINAPI +request_loop (LPVOID LpParam) +{ + class process_process_param *params = (process_process_param *) LpParam; + return params->request_loop (); +} + +void +process_cache::process_requests () +{ + class process_process_param *params = new process_process_param; + threaded_queue::process_requests (params, request_loop); +} + +void +process_cache::add_task (class process * theprocess) +{ + /* safe to not "Try" because workers don't hog this, they wait on the event + */ + /* every derived ::add must enter the section! */ + EnterCriticalSection (&queuelock); + queue_request *listrequest = new process_cleanup (theprocess); + threaded_queue::add (listrequest); + LeaveCriticalSection (&queuelock); +} + +/* NOT fully MT SAFE: must be called by only one thread in a program */ +void +process_cache::remove_process (class process *theprocess) +{ + class process *entry = head; + /* unlink */ + EnterCriticalSection (&cache_write_access); + if (entry == theprocess) + { + entry = (class process *) InterlockedExchangePointer (&head, theprocess->next); + if (entry != theprocess) + { + printf ("Bug encountered, process cache corrupted\n"); + exit (1); + } + } + else + { + while (entry->next && entry->next != theprocess) + entry = entry->next; + class process *temp = (class process *) InterlockedExchangePointer (&entry->next, theprocess->next); + if (temp != theprocess) + { + printf ("Bug encountered, process cache corrupted\n"); + exit (1); + } + } + LeaveCriticalSection (&cache_write_access); + /* Process any cleanup tasks */ + add_task (theprocess); +} + + +/* copy <= max_copy HANDLEs to dest[], starting at an offset into _our list_ of + * begin_at. (Ie begin_at = 5, the first copied handle is still written to dest[0] + * NOTE: Thread safe, but not thread guaranteed - a newly added process may be missed. + * Who cares - It'll get caught the next time. + */ +int +process_cache::handle_snapshot (HANDLE * hdest, class process ** edest, + ssize_t max_copy, int begin_at) +{ + /* TODO:? grab a delete-lock, to prevent deletes during this process ? */ + class process *entry = head; + int count = begin_at; + /* skip begin_at entries */ + while (entry && count) + { + if (entry->exit_code () == STILL_ACTIVE) + count--; + entry = entry->next; + } + /* hit the end of the list within begin_at entries */ + if (count) + return 0; + HANDLE *hto = hdest; + class process **eto = edest; + while (entry && count < max_copy) + { + /* hack */ + if (entry->exit_code () == STILL_ACTIVE) + { + *hto = entry->handle (); + *eto = entry; + count++; + hto++; + eto++; + } + entry = entry->next; + } + return count; +} + +/* process's */ +/* global process crit section */ +static CRITICAL_SECTION process_access; +static pthread_once_t process_init; + +void +do_process_init (void) +{ + InitializeCriticalSection (&process_access); + /* we don't have a cache shutdown capability today */ +} + +process::process (long pid): +winpid (pid), next (NULL), cleaning_up (0), head (NULL), _exit_status (STILL_ACTIVE) +{ + pthread_once (&process_init, do_process_init); + EnterCriticalSection (&process_access); + thehandle = OpenProcess (PROCESS_ALL_ACCESS, FALSE, pid); + if (!thehandle) + { + printf ("unable to obtain handle for new cache process %ld\n", pid); + thehandle = INVALID_HANDLE_VALUE; + } + debug_printf ("Got handle %p for new cache process %ld\n", thehandle, pid); + InitializeCriticalSection (&access); + LeaveCriticalSection (&process_access); +} + +process::~process () +{ + DeleteCriticalSection (&access); +} + +HANDLE +process::handle () +{ +// DWORD exitstate = exit_code (); +// if (exitstate == STILL_ACTIVE) + return thehandle; + + /* FIXME: call the cleanup list ? */ + +// CloseHandle (thehandle); +// debug_printf ("Process id %ld has terminated, attempting to open a new handle\n", +// winpid); +// thehandle = OpenProcess (PROCESS_ALL_ACCESS, FALSE, winpid); +// debug_printf ("Got handle %p when refreshing cache process %ld\n", thehandle, winpid); +// /* FIXME: what if OpenProcess fails ? */ +// if (thehandle) +// { +// _exit_status = STILL_ACTIVE; +// exit_code (); +// } +// else +// thehandle = INVALID_HANDLE_VALUE; +// return thehandle; +} + +DWORD process::exit_code () +{ + if (_exit_status != STILL_ACTIVE) + return _exit_status; + bool + err = GetExitCodeProcess (thehandle, &_exit_status); + if (!err) + { + debug_printf ("Failed to retrieve exit code (%ld)\n", GetLastError ()); + thehandle = INVALID_HANDLE_VALUE; + return _exit_status; + } + else if (_exit_status == STILL_ACTIVE) + return _exit_status; + /* add new cleanup task etc etc ? */ + return _exit_status; +} + +/* this is single threaded. It's called after the process is removed from the cache, + * but inserts may be attemped by worker threads that have a pointer to it */ +void +process::cleanup () +{ + /* Serialize this */ + EnterCriticalSection (&access); + InterlockedIncrement (&(long)cleaning_up); + class cleanup_routine *entry = head; + while (entry) + { + class cleanup_routine *temp; + entry->cleanup (winpid); + temp = entry->next; + delete entry; + entry = temp; + } + LeaveCriticalSection (&access); +} + +bool +process::add_cleanup_routine (class cleanup_routine *new_cleanup) +{ + if (cleaning_up) + return false; + EnterCriticalSection (&access); + /* check that we didn't block with ::cleanup () + * This rigmarole is to get around win9x's glaring missing TryEnterCriticalSection call + * which would be a whole lot easier + */ + if (cleaning_up) + { + LeaveCriticalSection (&access); + return false; + } + new_cleanup->next = head; + head = new_cleanup; + LeaveCriticalSection (&access); + return true; +} + +/* process_cleanup */ +void +process_cleanup::process () +{ + theprocess->cleanup (); + delete theprocess; +} + +/* process_process_param */ +DWORD +process_process_param::request_loop () +{ + process_cache *cache = (process_cache *) queue; + /* always malloc one, so there is no special case in the loop */ + ssize_t HandlesSize = 2; + HANDLE *Handles = (HANDLE *) malloc (sizeof (HANDLE) * HandlesSize); + process **Entries = (process **) malloc (sizeof (LPVOID) * HandlesSize); + /* TODO: put [1] at the end as it will also get done if a process dies? */ + Handles[0] = interrupt; + Handles[1] = cache->cache_add_trigger; + while (cache->active && !shutdown) + { + int copied; + copied = -1; + int offset; + offset = 1; + int count; + count = 2; + while ((copied == HandlesSize - 2 - offset) || copied < 0) + { + /* we need more storage to cope with all the HANDLES */ + if (copied == HandlesSize - 2 - offset) + { + HANDLE *temp = (HANDLE *) realloc (Handles, + sizeof (HANDLE) * + HandlesSize + 10); + if (!temp) + { + printf + ("cannot allocate more storage for the handle array!\n"); + exit (1); + } + Handles = temp; + process **ptemp = (process **) realloc (Entries, + sizeof (LPVOID) * + HandlesSize + 10); + if (!ptemp) + { + printf + ("cannot allocate more storage for the handle array!\n"); + exit (1); + } + Entries = ptemp; + HandlesSize += 10; + } + offset += copied; + copied = + cache->handle_snapshot (&Handles[2], &Entries[2], + HandlesSize - 2 - offset, offset); + count += copied; + } + debug_printf ("waiting on %u objects\n", count); + DWORD rc = WaitForMultipleObjects (count, Handles, FALSE, INFINITE); + if (rc == WAIT_FAILED) + { + printf ("Could not wait on the process handles (%ld)!\n", + GetLastError ()); + exit (1); + } + int objindex = rc - WAIT_OBJECT_0; + if (objindex > 1 && objindex < count) + { + debug_printf ("Process %ld has left the building\n", + Entries[objindex]->winpid); + /* fire off the termination routines */ + cache->remove_process (Entries[objindex]); + } + else if (objindex >= 0 && objindex < 2) + { + /* 0 is shutdown - do nothing */ + /* 1 is a cache add event - just rebuild the object list */ + } + else + { + printf + ("unexpected return code from WaitForMultiple objects in process_process_param::request_loop\n"); + } + } + running = false; + return 0; +} |