Change AllocateRWX/DeallocateRWX to not throw an exception.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29058 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2006-07-07 17:32:37 +00:00
parent c1780d2a0a
commit bed22d8902
4 changed files with 85 additions and 45 deletions

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@ -14,6 +14,8 @@
#ifndef LLVM_SYSTEM_MEMORY_H #ifndef LLVM_SYSTEM_MEMORY_H
#define LLVM_SYSTEM_MEMORY_H #define LLVM_SYSTEM_MEMORY_H
#include <string>
namespace llvm { namespace llvm {
namespace sys { namespace sys {
@ -24,10 +26,10 @@ namespace sys {
/// @brief Memory block abstraction. /// @brief Memory block abstraction.
class MemoryBlock { class MemoryBlock {
public: public:
void* base() const { return Address; } void *base() const { return Address; }
unsigned size() const { return Size; } unsigned size() const { return Size; }
private: private:
void * Address; ///< Address of first byte of memory area void *Address; ///< Address of first byte of memory area
unsigned Size; ///< Size, in bytes of the memory area unsigned Size; ///< Size, in bytes of the memory area
friend class Memory; friend class Memory;
}; };
@ -45,21 +47,27 @@ namespace sys {
/// attempt to allocate \p NumBytes bytes of virtual memory is made. /// attempt to allocate \p NumBytes bytes of virtual memory is made.
/// \p NearBlock may point to an existing allocation in which case /// \p NearBlock may point to an existing allocation in which case
/// an attempt is made to allocate more memory near the existing block. /// an attempt is made to allocate more memory near the existing block.
/// @throws std::string if an error occurred. ///
/// On success, this returns a non-null memory block, otherwise it returns
/// a null memory block and fills in *ErrMsg.
///
/// @brief Allocate Read/Write/Execute memory. /// @brief Allocate Read/Write/Execute memory.
static MemoryBlock AllocateRWX(unsigned NumBytes, const MemoryBlock* NearBlock); static MemoryBlock AllocateRWX(unsigned NumBytes,
const MemoryBlock *NearBlock,
std::string *ErrMsg = 0);
/// This method releases a block of Read/Write/Execute memory that was /// This method releases a block of Read/Write/Execute memory that was
/// allocated with the AllocateRWX method. It should not be used to /// allocated with the AllocateRWX method. It should not be used to
/// release any memory block allocated any other way. /// release any memory block allocated any other way.
///
/// On success, this returns false, otherwise it returns true and fills
/// in *ErrMsg.
/// @throws std::string if an error occurred. /// @throws std::string if an error occurred.
/// @brief Release Read/Write/Execute memory. /// @brief Release Read/Write/Execute memory.
static void ReleaseRWX(MemoryBlock& block); static bool ReleaseRWX(MemoryBlock &block, std::string *ErrMsg = 0);
/// @} /// @}
}; };
} }
} }
#endif #endif

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@ -18,14 +18,14 @@
#include <sys/mman.h> #include <sys/mman.h>
#endif #endif
namespace llvm {
/// AllocateRWXMemory - Allocate a slab of memory with read/write/execute /// AllocateRWXMemory - Allocate a slab of memory with read/write/execute
/// permissions. This is typically used for JIT applications where we want /// permissions. This is typically used for JIT applications where we want
/// to emit code to the memory then jump to it. Getting this type of memory /// to emit code to the memory then jump to it. Getting this type of memory
/// is very OS specific. /// is very OS specific.
/// ///
MemoryBlock Memory::AllocateRWX(unsigned NumBytes, const MemoryBlock* NearBlock) { llvm::sys::MemoryBlock
llvm::sys::Memory::AllocateRWX(unsigned NumBytes, const MemoryBlock* NearBlock,
std::string *ErrMsg) {
if (NumBytes == 0) return MemoryBlock(); if (NumBytes == 0) return MemoryBlock();
long pageSize = Process::GetPageSize(); long pageSize = Process::GetPageSize();
@ -35,7 +35,8 @@ MemoryBlock Memory::AllocateRWX(unsigned NumBytes, const MemoryBlock* NearBlock)
#ifdef NEED_DEV_ZERO_FOR_MMAP #ifdef NEED_DEV_ZERO_FOR_MMAP
static int zero_fd = open("/dev/zero", O_RDWR); static int zero_fd = open("/dev/zero", O_RDWR);
if (zero_fd == -1) { if (zero_fd == -1) {
ThrowErrno("Can't open /dev/zero device"); GetErrno("Can't open /dev/zero device", ErrMsg);
return MemoryBlock();
} }
fd = zero_fd; fd = zero_fd;
#endif #endif
@ -48,15 +49,17 @@ MemoryBlock Memory::AllocateRWX(unsigned NumBytes, const MemoryBlock* NearBlock)
#endif #endif
; ;
void* start = NearBlock ? (unsigned char*) NearBlock->base() + NearBlock->size() : 0; void* start = NearBlock ? (unsigned char*)NearBlock->base() +
NearBlock->size() : 0;
void *pa = ::mmap(start, pageSize*NumPages, PROT_READ|PROT_WRITE|PROT_EXEC, void *pa = ::mmap(start, pageSize*NumPages, PROT_READ|PROT_WRITE|PROT_EXEC,
flags, fd, 0); flags, fd, 0);
if (pa == MAP_FAILED) { if (pa == MAP_FAILED) {
if (NearBlock) //Try again without a near hint if (NearBlock) //Try again without a near hint
return AllocateRWX(NumBytes, 0); return AllocateRWX(NumBytes, 0);
else
ThrowErrno("Can't allocate RWX Memory"); GetErrno("Can't allocate RWX Memory", ErrMsg);
return MemoryBlock();
} }
MemoryBlock result; MemoryBlock result;
result.Address = pa; result.Address = pa;
@ -64,12 +67,10 @@ MemoryBlock Memory::AllocateRWX(unsigned NumBytes, const MemoryBlock* NearBlock)
return result; return result;
} }
void Memory::ReleaseRWX(MemoryBlock& M) { bool llvm::sys::Memory::ReleaseRWX(MemoryBlock &M, std::string *ErrMsg) {
if (M.Address == 0 || M.Size == 0) return; if (M.Address == 0 || M.Size == 0) return false;
if (0 != ::munmap(M.Address, M.Size)) { if (0 != ::munmap(M.Address, M.Size))
ThrowErrno("Can't release RWX Memory"); return GetErrno("Can't release RWX Memory", ErrMsg);
} return false;
}
} }

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@ -66,6 +66,35 @@
# define WIFEXITED(stat_val) (((stat_val) & 255) == 0) # define WIFEXITED(stat_val) (((stat_val) & 255) == 0)
#endif #endif
inline bool GetErrno(const std::string &prefix, std::string *ErrDest,
int errnum = -1) {
char buffer[MAXPATHLEN];
if (ErrDest == 0) return true;
buffer[0] = 0;
if (errnum == -1)
errnum = errno;
#ifdef HAVE_STRERROR_R
// strerror_r is thread-safe.
if (errnum)
strerror_r(errnum, buffer, MAXPATHLEN-1);
#elif HAVE_STRERROR
// Copy the thread un-safe result of strerror into
// the buffer as fast as possible to minimize impact
// of collision of strerror in multiple threads.
if (errnum)
strncpy(buffer, strerror(errnum), MAXPATHLEN-1);
buffer[MAXPATHLEN-1] = 0;
#else
// Strange that this system doesn't even have strerror
// but, oh well, just use a generic message
sprintf(buffer, "Error #%d", errnum);
#endif
*ErrDest = prefix + ": " + buffer;
return true;
}
inline void ThrowErrno(const std::string& prefix, int errnum = -1) { inline void ThrowErrno(const std::string& prefix, int errnum = -1) {
char buffer[MAXPATHLEN]; char buffer[MAXPATHLEN];
buffer[0] = 0; buffer[0] = 0;

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@ -23,7 +23,9 @@ using namespace sys;
//=== and must not be UNIX code //=== and must not be UNIX code
//===----------------------------------------------------------------------===// //===----------------------------------------------------------------------===//
MemoryBlock Memory::AllocateRWX(unsigned NumBytes, const MemoryBlock* NearBlock) { MemoryBlock Memory::AllocateRWX(unsigned NumBytes,
const MemoryBlock *NearBlock,
std::string *ErrMsg) {
if (NumBytes == 0) return MemoryBlock(); if (NumBytes == 0) return MemoryBlock();
static const long pageSize = Process::GetPageSize(); static const long pageSize = Process::GetPageSize();
@ -34,7 +36,8 @@ MemoryBlock Memory::AllocateRWX(unsigned NumBytes, const MemoryBlock* NearBlock)
void *pa = VirtualAlloc(NULL, NumPages*pageSize, MEM_COMMIT, void *pa = VirtualAlloc(NULL, NumPages*pageSize, MEM_COMMIT,
PAGE_EXECUTE_READWRITE); PAGE_EXECUTE_READWRITE);
if (pa == NULL) { if (pa == NULL) {
ThrowError("Can't allocate RWX Memory: "); GetError("Can't allocate RWX Memory: ", ErrMsg);
return MemoryBlock();
} }
MemoryBlock result; MemoryBlock result;
@ -43,11 +46,10 @@ MemoryBlock Memory::AllocateRWX(unsigned NumBytes, const MemoryBlock* NearBlock)
return result; return result;
} }
void Memory::ReleaseRWX(MemoryBlock& M) { bool Memory::ReleaseRWX(MemoryBlock &M, std::string *ErrMsg) {
if (M.Address == 0 || M.Size == 0) return; if (M.Address == 0 || M.Size == 0) return;
if (!VirtualFree(M.Address, 0, MEM_RELEASE)) { if (!VirtualFree(M.Address, 0, MEM_RELEASE))
ThrowError("Can't release RWX Memory: "); return GetError("Can't release RWX Memory: ", ErrMsg);
}
} }
} }