Changeset 2787 for trunk

Timestamp:

Aug 27, 2006, 4:28:26 PM (19 years ago)

Author:

bird

Message:

Fixed problems with fork() and module loading/unloading. Fixes #76.
Fixed atexit() and on_exit() problem with callbacks in unloaded DLLs. Fixes #103.

Location:

trunk/libc

Files:

• ChangeLog.LIBC (modified) (1 diff)
• include/InnoTekLIBC/atexit.h (modified) (3 diffs)
• include/InnoTekLIBC/fork.h (modified) (2 diffs)
• src/kNIX/b_termDll.c (added)
• src/kNIX/os2/b_processWait.c (modified) (8 diffs)
• src/kNIX/os2/libcfork.c (modified) (7 diffs)
• src/libc/libc.def (modified) (1 diff)
• src/libc/misc/atexit.c (modified) (6 diffs)
• src/libc/misc/on_exit.c (modified) (2 diffs)
• src/libc/startup/386/dll0.s (modified) (3 diffs)

trunk/libc/ChangeLog.LIBC

@@ -5 +5 @@
 2006-08-27: knut st. osmundsen <bird-gccos2-spam@anduin.net>
     - libc:
+        o Fixed problems with fork() and module loading/unloading. Fixes #76.
+        o Fixed atexit() and on_exit() problem with callbacks in unloaded DLLs. Fixes #103.
         o Added usage counting to _CRT_init and _CRT_term. Fixing #114. (from 0.6)
         o Inlined _um_find_bucket. (from 0.6)

trunk/libc/include/InnoTekLIBC/atexit.h

@@ -37 +37 @@
     __LIBC_ATEXITTYPE_ONEXIT,
     /** State transition state. */
-    __LIBC_ATEXITTYPE_TRANS
+    __LIBC_ATEXITTYPE_TRANS,
+    /** The module containing the callback was unloaded. */
+    __LIBC_ATEXITTYPE_UNLOADED
 } __LIBC_ATEXITTYPE;
 
@@ -47 +49 @@
     /** Entry type. */
     __LIBC_ATEXITTYPE volatile enmType;
+    /** The (native) module handle this callback is connected to.
+     * This will be 0 if no such association. */
+    uintptr_t                  hmod;
     union
     {
@@ -92 +97 @@
  * @returns Pointer to new entry.
  * @returns NULL on failure.
+ *
+ * @param   pvCallback      The callback address.
+ *                          This used to initialize the __LIBC_AT_EXIT::hmod field.
  */
-__LIBC_PATEXIT __libc_atexit_new(void);
+__LIBC_PATEXIT __libc_atexit_new(void *pvCallback);
+
+/**
+ * Invalidate all atexit and on_exit callback for a
+ * module which is being unloaded.
+ *
+ * @param   hmod        The module handle.
+ */
+void __libc_atexit_unload(uintptr_t hmod);
 
 __END_DECLS

trunk/libc/include/InnoTekLIBC/fork.h

@@ -575 +575 @@
 /** Indicates that the module is an executable. */
 #define __LIBC_FORKMODULE_FLAGS_EXECUTABLE      0x00000001
-/** Indicates that the module was dynamically loaded. */
-#define __LIBC_FORKMODULE_FLAGS_DYNAMIC         0x00010000
+/** Indicates that the module already has been deregistered (libc termination). */
+#define __LIBC_FORKMODULE_FLAGS_DEREGISTERED    0x00010000
 /** @} */
 
@@ -606 +606 @@
  */
 int __libc_ForkRegisterModule(__LIBC_PFORKMODULE pModule, int fExecutable);
+
+
+/**
+ * Deregister a forkable module. Called by dll0.
+ *
+ * The call links pModule out of the list of forkable modules
+ * which is maintained in the process block.
+ *
+ * @param   pModule     Pointer to the fork module structure for the
+ *                      module which is to registered.
+ */
+void __libc_ForkDeregisterModule(__LIBC_PFORKMODULE pModule);
 
 

trunk/libc/src/kNIX/os2/b_processWait.c

@@ -49 +49 @@
 #include <InnoTekLIBC/sharedpm.h>
 #include <InnoTekLIBC/backend.h>
-#include <klibc/fib.h>
+#include <InnoTekLIBC/FastInfoBlocks.h>
 #include <InnoTekLIBC/fork.h>
 #define __LIBC_LOG_GROUP __LIBC_LOG_GRP_BACK_PROCESS
@@ -124 +124 @@
 /** Number of known child processes. */
 static volatile unsigned    gcChildren;
-/** Total number of born child processes. */
+/** Total number of born child processes. (For statistical purposes only.) */
 static volatile unsigned    gcBirths;
 /** Total number of died child processes. */
@@ -171 +171 @@
          * Create the fmutex.
          */
-        _fmutex_checked_create(&gmtxWait, 0);
+        _fmutex_checked_create2(&gmtxWait, _FMC_MUST_COMPLETE, "b_processWait.c: gmtxWait");
         int rc = DosCreateEventSemEx(NULL, (PHEV)&ghevWait, 0, TRUE);
         if (rc)
@@ -194 +194 @@
 void __libc_back_processWaitNotifyTerm(void)
 {
+    __atomic_xchg(&gfTerminate, 1);
+
+    /* kill the thread - this is probably a waste of time in the exitlist handler... */
     if (gtidThread)
     {
-        /* kill the thread - this is probably a waste of time in the exitlist handler... */
-        __atomic_xchg(&gfTerminate, 1);
         DosKillThread(gtidThread);
         gtidThread = 0;
@@ -223 +224 @@
      * Kill all known decendants.
      */
+    /** @todo We should really reparent them to the init process, but only the session manager can do that. */
     PWAITCHILD pChild = gpChildrenHead;
     if (pChild)
     {
+        gpChildrenHead = NULL;
+        gcChildren = 0;
+
         /*
          * Kill the process tree so we don't end up having childrens
@@ -268 +273 @@
     int rc = _fmutex_request(&gmtxWait, fNoInterrupts ? _FMR_IGNINT : 0);
     if (!rc)
-    {
-        ULONG cIgnore = 0;
-        DosEnterMustComplete(&cIgnore);
         return 0;
-    }
     LIBC_ASSERTM_FAILED("_fmutex_request -> %d\n", rc);
     return -__libc_native2errno(rc);
@@ -284 +285 @@
     int rc = _fmutex_release(&gmtxWait);
     LIBC_ASSERTM(!rc, "_fmutex_release -> %d\n", rc);
-    ULONG cIgnore = 0;
-    DosExitMustComplete(&cIgnore);
     rc = rc;
 }
@@ -652 +651 @@
     if (!gtidThread)
     {
+        gfTerminate = 0;
+
         /*
          * Create the internal thread for dealing with waiting.

trunk/libc/src/kNIX/os2/libcfork.c

@@ -47 +47 @@
 #include <InnoTekLIBC/fork.h>
 #include <InnoTekLIBC/sharedpm.h>
-#include <klibc/fib.h>
+#include <InnoTekLIBC/FastInfoBlocks.h>
 #define __LIBC_LOG_GROUP    __LIBC_LOG_GRP_FORK
 #include <InnoTekLIBC/logstrict.h>
@@ -314 +314 @@
 
     /*
-     * Install exceptionhandler.
+     * Install an exceptionhandler.
      */
     DosGetInfoBlocks(&pTib, &pPib);
@@ -346 +346 @@
 
     /*
-     * Check if dynamically loaded or not.
-     */
-    /** @todo! */
-
-    /*
      * Register the module.
-     */
+     * (We're hoping for OS/2 to indirectly serialize this... not properly verified yet.)
+     */
+    if (pModule->fFlags & __LIBC_FORKMODULE_FLAGS_DEREGISTERED)
+        LIBCLOG_MSG("__LIBC_FORKMODULE_FLAGS_DEREGISTERED!\n");
+    pModule->fFlags &= ~__LIBC_FORKMODULE_FLAGS_DEREGISTERED;
     pModule->pNext = NULL;
     if (pProcess->pvModuleHead)
@@ -433 +432 @@
     pTib->tib_pexchain = XcptRegRec.prev_structure;
     LIBCLOG_RETURN_INT(1);
+}
+
+
+/**
+ * Deregister a forkable module. Called by dll0.
+ *
+ * The call links pModule out of the list of forkable modules
+ * which is maintained in the process block.
+ *
+ * @param   pModule     Pointer to the fork module structure for the
+ *                      module which is to registered.
+ */
+void __libc_ForkDeregisterModule(__LIBC_PFORKMODULE pModule)
+{
+    LIBCLOG_ENTER("pModule=%p:{.uVersion=%#x, .pfnAtFork=%p, .papParent1=%p, .papChild1=%p, .pvDataSegBase=%p, .pvDataSegEnd=%p, .fFlags=%#x, .pNext=%p}\n",
+                  (void *)pModule, pModule->uVersion, (void *)pModule->pfnAtFork, (void *)pModule->papParent1, (void *)pModule->papChild1,
+                  (void *)pModule->pvDataSegBase, (void *)pModule->pvDataSegEnd, pModule->fFlags, (void *)pModule->pNext);
+
+    /*
+     * Don't deregister modules which has already been deregistered.
+     * Don't deregister if we're in shutting down the process (waste of time and
+     * SPM might already be shut down).
+     */
+    if (pModule->fFlags & __LIBC_FORKMODULE_FLAGS_DEREGISTERED)
+        LIBCLOG_RETURN_MSG_VOID( "ret void (__LIBC_FORKMODULE_FLAGS_DEREGISTERD)\n");
+    if (!__libc_GpFIBLIS)
+        LIBCLOG_RETURN_MSG_VOID( "ret void (__libc_GpFIBLIS)\n");
+    if (fibIsInExit())
+        LIBCLOG_RETURN_MSG_VOID( "ret void (fibIsInExit)\n");
+
+    /*
+     * Find the SPM process.
+     */
+    __LIBC_PSPMPROCESS pProcess = __libc_spmSelf();
+    if (!pProcess)
+    {
+        LIBC_ASSERTM_FAILED("can't find the process! weird!\n");
+        LIBCLOG_RETURN_VOID();
+    }
+
+    /*
+     * Deregister the module.
+     * (We're hoping for OS/2 to indirectly serialize this... not properly verified yet.)
+     */
+    if ((__LIBC_PFORKMODULE)pProcess->pvModuleHead == pModule)
+    {
+        pProcess->pvModuleHead = pModule->pNext;
+        if (!pModule->pNext)
+            pProcess->ppvModuleTail = &pProcess->pvModuleHead;
+    }
+    else
+    {
+        __LIBC_PFORKMODULE pPrev = (__LIBC_PFORKMODULE)pProcess->pvModuleHead;
+        while (pPrev && pPrev->pNext != pModule)
+            pPrev = pPrev->pNext;
+        if (!pPrev)
+        {
+            LIBC_ASSERTM_FAILED("can't find the module! weird!\n");
+            LIBCLOG_RETURN_VOID();
+        }
+
+        pPrev->pNext = pModule->pNext;
+        if (!pModule->pNext)
+            pProcess->ppvModuleTail = (void **)&pPrev->pNext;
+    }
+
+    pModule->pNext = NULL;
+    pModule->fFlags |= __LIBC_FORKMODULE_FLAGS_DEREGISTERED;
+
+    LIBCLOG_RETURN_VOID();
 }
 
@@ -1280 +1349 @@
     /*
      * Open and process the buffer on first call.
+     *
+     * Because of DosLoadModuleEx processing, we can end up here in while
+     * processing the initial fork buffer. This means that if any of those
+     * DLLS tries to talk to the parent at __LIBC_FORK_EXEC_CHILD time the
+     * fork() will fail. Fortunately, this is very unlikely. (Otherwise, we
+     * should've delayed those pfnAtFork() calls.)
      */
     if (pForkHandle->enmStage == __LIBC_FORK_STAGE_EXEC)
@@ -1289 +1364 @@
             LIBCLOG_RETURN_INT(rc);
         }
+        pForkHandle->enmStage = __LIBC_FORK_STAGE_INIT_CHILD;
         rc = forkBthBufferProcess(pForkHandle, __LIBC_FORK_CTX_CHILD, NULL);
         if (rc < 0)
@@ -1295 +1371 @@
             LIBCLOG_RETURN_INT(rc);
         }
-
-        /* next stage */
-        pForkHandle->enmStage = __LIBC_FORK_STAGE_INIT_CHILD;
     }
 

trunk/libc/src/libc/libc.def

@@ -1953 +1953 @@
     "__std_getdirents" @1951
     "___libc_Back_ioFileControlStandard" @1952
+    "___libc_Back_termDll" @1953
+    "___libc_ForkDeregisterModule" @1954

trunk/libc/src/libc/misc/atexit.c

@@ -30 +30 @@
 *******************************************************************************/
 #include "libc-alias.h"
+#ifdef __OS2__
+# define INCL_DOSMODULEMGR
+# define INCL_ERRORS
+# define INCL_FSMACROS
+# include <os2emx.h>
+#endif
 #include <stdlib.h>
 #include <InnoTekLIBC/atexit.h>
-#include <386/builtin.h>
+#include <sys/builtin.h>
 #include <emx/umalloc.h>
 #define __LIBC_LOG_GROUP __LIBC_LOG_GRP_INITTERM
@@ -41 +47 @@
 {
     LIBCLOG_ENTER("pfnCallback=%p\n", (void *)pfnCallback);
-    __LIBC_PATEXIT pCur = __libc_atexit_new();
+    __LIBC_PATEXIT pCur = __libc_atexit_new((void *)pfnCallback);
     if (pCur)
     {
@@ -57 +63 @@
  * @returns Pointer to new entry.
  * @returns NULL on failure.
+ *
+ * @param   pvCallback      The callback address.
+ *                          This used to initialize the __LIBC_AT_EXIT::hmod field.
  */
-__LIBC_PATEXIT __libc_atexit_new(void)
+__LIBC_PATEXIT __libc_atexit_new(void *pvCallback)
 {
+    /*
+     * Try find the module this callback belongs to.
+ */
+    uintptr_t   hmod = 0;
+    /** @todo generalize DosQueryModFromEIP and let the (loader) backend do that kind of job. */
+#ifdef __OS2__
+    HMODULE     hmodOS2;
+    ULONG       iObj, offObj;
+    FS_VAR_SAVE_LOAD();
+    APIRET rc = DosQueryModFromEIP(&hmodOS2, &iObj, 0, NULL, &offObj, (uintptr_t)pvCallback);
+    if (rc == NO_ERROR)
+        hmod = hmodOS2;
+    FS_RESTORE();
+#else
+    /** @todo port to NT and other target platforms. */
+#endif
+
     /*
      * Search existing chunks.
@@ -72 +98 @@
             if (__atomic_cmpxchg32(&pChunk->c, i + 1, i))
             {
+                pChunk->a[i].hmod = hmod;
                 pChunk->a[i].enmType = __LIBC_ATEXITTYPE_TRANS;
                 return &pChunk->a[i];
@@ -84 +111 @@
     if (!pChunk)
         return NULL;
+    /** @todo There is a chance that the exit list order could be screwed up here if two threads get here at the same time. (bird, 2006-08-21) */
     pChunk->c = 1;
+    pChunk->a[0].hmod = hmod;
     pChunk->a[0].enmType = __LIBC_ATEXITTYPE_TRANS;
     do
@@ -94 +123 @@
 }
 
+
+/**
+ * Invalidate all atexit and on_exit callback for a
+ * module which is being unloaded.
+ *
+ * @param   hmod        The module handle.
+ */
+void __libc_atexit_unload(uintptr_t hmod)
+{
+    /*
+     * Search existing chunks.
+     * (This is made simple by us not freeing anything.)
+     */
+    __LIBC_PATEXITCHUNK pChunk;
+    for (pChunk = __libc_gAtExitHead; pChunk; pChunk = pChunk->pNext)
+    {
+        uint32_t i = pChunk->c;
+        while (i-- > 0)
+        {
+            if (    pChunk->a[i].hmod == hmod
+                &&  pChunk->a[i].enmType > __LIBC_ATEXITTYPE_FREE
+                &&  pChunk->a[i].enmType < __LIBC_ATEXITTYPE_TRANS)
+                pChunk->a[i].enmType = __LIBC_ATEXITTYPE_UNLOADED;
+        }
+    }
+}
+

trunk/libc/src/libc/misc/on_exit.c

@@ -4 +4 @@
  * LIBC on_exit().
  *
- * Copyright (c) 2005 knut st. osmundsen <bird@anduin.net>
+ * Copyright (c) 2005-2006 knut st. osmundsen <bird@anduin.net>
  *
  *
@@ -39 +39 @@
 {
     LIBCLOG_ENTER("pfnCallback=%p pvUser=%p\n", (void *)pfnCallback, pvUser);
-    __LIBC_PATEXIT pCur = __libc_atexit_new();
+    __LIBC_PATEXIT pCur = __libc_atexit_new((void *)pfnCallback);
     if (pCur)
     {

trunk/libc/src/libc/startup/386/dll0.s

@@ -50 +50 @@
 #endif
 
+#if defined(NOFORK)
+#define FLAG_NOFORK     4
+#else
+#define FLAG_NOFORK     0
+#endif
+
+    /*
+     * The DLL Entry Point.
+     */
 __text:
     cmpl    $0, 8(%esp)
-    jz      do_common_init
-    jmp     do_initterm
+    je      do_init
+    cmpl    $1, 8(%esp)
+    je      do_term
+    jmp     _DLL_InitTerm
+
 
     /*
-     * Nonstandard: we're doing some early initializations.
+     * DLL Initialization.
      */
-do_common_init:
+do_init:
 #if !defined(NOFORK) && !defined(NOUNIX)
     pushl   $0
@@ -65 +77 @@
     addl    $8, %esp
     cmpl    $0, %eax
-    je      do_init
-    jg      do_fork
-
-    /* return failure (eax < 0). */
+    je      do_init_not_forking
+    jg      do_return_success   /* we're forking; no init. */
+    /* else: eax < 0 - failure. */
+do_return_failure:
     xorl    %eax, %eax
     ret
-
-    /* return success - we're forking; no init. */
-do_fork:
+do_return_success:
     xorl    %eax, %eax
     inc     %al
@@ -79 +89 @@
 
     /* normal dll init. */
-do_init:
+do_init_not_forking:
 #endif
+    /* call __init_dll() */
     pushl   4(%esp)
-    pushl   $(FLAG_HIGHMEM + FLAG_NOUNIX)
+    pushl   $(FLAG_HIGHMEM + FLAG_NOUNIX + FLAG_NOFORK)
     call    ___init_dll
     add     $8, %esp
     orl     %eax, %eax
-    jz      do_initterm
+    jnz     do_return_failure
+
+    /* call _DLL_InitTerm */
+    cld
+    pushl   8(%esp)
+    pushl   8(%esp)
+    call    _DLL_InitTerm
+    add     $8, %esp
+    orl     %eax, %eax
+    jnz     do_return_success
+
+    /* _DLL_InitTerm failed, undo the module registration. */
+#if !defined(NOFORK) && !defined(NOUNIX)
+    pushl   $ForkModule
+    call    ___libc_ForkRegisterModule
+    addl    $4, %esp
+#endif
+    jmp     do_return_failure;
+
+
     /*
-     * __init_dll() failed - fail the dll loading.
+     * DLL Termination.
      */
-    xorl    %eax, %eax
+do_term:
+    /* do init term first */
+    cld
+    pushl   8(%esp)
+    pushl   8(%esp)
+    call    _DLL_InitTerm
+    add     $8, %esp
+    orl     %eax, %eax
+    jnz     do_term_dll
     ret
 
-    /*
-     * Standard initialization.
-     */
-do_initterm:
-    cld
-    jmp     _DLL_InitTerm
+do_term_dll:
+    /* call __libc_Back_termDll() */
+    pushl   4(%esp)
+    pushl   $(FLAG_HIGHMEM + FLAG_NOUNIX + FLAG_NOFORK)
+    call    ___libc_Back_termDll
+    add     $8, %esp
+
+    /* call __libc_ForkDeregisterModule */
+#if !defined(NOFORK) && !defined(NOUNIX)
+    pushl   $ForkModule
+    call    ___libc_ForkDeregisterModule
+    addl    $4, %esp
+#endif
+    jmp     do_return_success